METHODS OF MAKING THE SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 62/655,780 filed April 10, 2018, U.S. Provisional Patent Application No. 62/655,784 filed April 10, 2018, U.S. Provisional Patent Application No. 62/655,790 filed April 10, 2018, European Patent Application No. 18187842.2 filed August 7, 2018, European Patent Application No. 18187846.3 filed August 7, 2018, European Patent Application No. 18190789.0 filed August 24, 2018, U.S. Provisional Patent Application No. 62/744,116 filed October 10, 2018, U.S. Provisional Patent Application No. 62/744, 119 filed October 10, 2018, and U.S. Provisional Patent Application No. 62/744, 121 filed October 10, 2018, all of which are hereby incorporated by reference in their entireties.

FIELD OF INVENTION

[0002] The present invention relates generally to portable electronic devices and more particularly, but without limitation to portable electronic device housings having a composite base and methods of making the same.

BACKGROUND

[0003] Portable electronic devices such as mobile phones, tablets, watches, laptops, and the like typically comprise a housing to contain and protect electronic components thereof. Electronic device housings should have adequate stiffness and impact resistance to sustain impacts during everyday use, such as when the electronic device is dropped. And, at least a portion of the housing generally must be RF transparent to permit transmission of electromagnetic signals through the housing and/or wireless charging. Current housings typically comprise a glass back which can be RF transparent and can provide a suitable stiffness for the housing. However, glass backs are susceptible to cracking when the housing sustains an impact, which can reduce the life of the housing and lead to expensive repair costs. Additionally, there is increasing demand for housings constructed from cost-effective, sustainable materials, e.g., materials that can be produced from recycled products. There accordingly is a need in the art for portable electronic device housings that can provide suitable stiffness, impact resistance, and RF transparency and can be manufactured from cost-effective, sustainable materials. SUMMARY

[0004] The present housings address the need in the art for adequately stiff, impact-resistant, and RF transparent housings with a composite base and a sidewall that projects outwardly from and surrounds at least a majority of a planar portion of the housing defined by the composite base. The composite base can comprise a laminate having one or more laminae, each comprising fibers dispersed in a matrix material, or a mixture of a matrix material and discontinuous fibers. Suitable fibers can include, for example, glass fibers and/or ceramic fibers, and suitable matrix materials can include, for example, a blend of polybutylene terephthalate (PBT) and polycarbonate (PC). The composite material can promote stiffness, impact resistance, and RF transparency, and can be formed from cost-effective, sustainable materials. The sidewall can comprise a composite material and/or a metal.

[0005] The term“coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are“coupled” may be unitary with each other. The terms“a” and“an” are defined as one or more unless this disclosure explicitly requires otherwise. The term“substantially” is defined as largely but not necessarily wholly what is specified - and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel - as understood by a person of ordinary skill in the art. In any disclosed embodiment, the term“substantially” may be substituted with“within [a percentage] of’ what is specified, where the percentage includes 0.1, 1, 5, and 10 percent.

[0006] The terms“comprise” and any form thereof such as“comprises” and“comprising,” “have” and any form thereof such as“has” and“having,” and“include” and any form thereof such as“includes” and“including” are open-ended linking verbs. As a result, an apparatus that “comprises,”“has,” or“includes” one or more elements possesses those one or more elements, but is not limited to possessing only those elements. Likewise, a method that“comprises,” “has,” or“includes” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps.

[0007] Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of - rather than comprise/include/have - any of the described steps, elements, and/or features. Thus, in any of the claims, the term“consisting of’ or“consisting essentially of’ can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open- ended linking verb. [0008] Further, a device or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described.

[0009] The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments.

[0010] Some details associated with the embodiments described above and others are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. Views in the figures are drawn to scale, unless otherwise noted, meaning the sizes of the depicted elements are accurate relative to each other for at least the embodiment in the view.

[0012] FIGs. 1 is a schematic view of a first embodiment of the present portable electronic device housings that has a base defining a planar portion and a sidewall that projects outwardly from and surrounds at least a majority of the planar portion. The sidewall and the base of the housing are unitary.

[0013] FIG. 2 is a schematic exploded view of a second embodiment of the present portable electronic device housings in which the base and the sidewall are non-unitary.

[0014] FIG. 3 is a schematic exploded view of a third embodiment of the present portable electronic devices in which the sidewall comprises a rim and a connecting member that couples the rim to the base. The rim can comprise multiple, non-unitary pieces.

[0015] FIGs. 4A and 4B are schematic sectional views of a mold that can be used to form a connecting member to couple a rim to the base in some of the present housings. The mold can also be used to form a base and/or an entire sidewall.

[0016] FIG. 4C is a schematic sectional view of one of the present housings that has a rim, a connecting member, and a base. FIG. 4C illustrates some of the features defined by the rim and/or the base that facilitate bonding and impact resistance. [0017] FIGs. 5A-6B depict methods for making ones of the present housings, the methods including molding a sidewall template and/or a back template and removing material from those template(s) to produce a sidewall and/or a base.

[0018] FIG. 7A is a schematic top view of the mold of FIGs. 4A and 4B illustrating an arrangement of mold injection ports that can facilitate fiber alignment and appropriate positioning of weldlines when injection molding the connecting member and/or rim.

[0019] FIGs. 7B and 7C are schematic top and bottom views, respectively, of a mold having an arrangement of mold injection ports that can facilitate fiber alignment, appropriate positioning of weldlines, and comparatively high fiber volume fractions when injection molding a base of one of the present housings.

[0020] FIGs. 8A and 8B are schematic sectional views of a mold that can be used to overmold a laminate that defines the base and the rim.

[0021] FIGs. 9A and 9B are graphs illustrating a design space that shows the relationship between housing deflection and the thicknesses of the base and the sidewall. The design space was generated based on a four-point bending simulation.

[0022] FIG. 9C is a graph illustrating a design space that shows the relationship between tensile modulus and the thicknesses of the base and the sidewall when housing deflection is held constant.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0023] Referring to FIG. 1, shown is a first embodiment lOa of the present portable electronic device housings. Housing lOa can comprise a base 14 (sometimes referred to as a back) and a sidewall 18. Base 14 can define a planar portion 22 of housing lOa and sidewall 18 can project outwardly from and surround at least a majority of (e.g., all of) the planar portion. Housing lOa can thereby define a cavity configured to receive electronic components of a portable electronic device, such as, for example, a logic board, processors (e.g., one or more CPUs, microcontrollers, field effect gate arrays, and/or the like), system memory, data storage devices (e.g., solid state or hard drive), speakers, wireless modems, antennas, batteries, and/or the like. Such components can be secured within housing lOa using any suitable means, such as, for example, screws, clips, rivets, and/or adhesive (e.g., a curable polymer adhesive). After the components of the device are received by housing lOa, a cover (e.g., a clear glass or polymeric cover through which an electronic display of the portable electronic device can be viewed) can be attached to the housing to enclose the cavity (e.g., with fasteners such as screws, clips, or rivets, or with an adhesive such as a curable polymer adhesive).

[0024] Housing lOa can have any suitable shape and size to promote ergonomics and to protect electronic components that are received therein. For example, housing lOa can have a maximum length 26 measured in a first direction 34 and a maximum width 30 measured in a second direction 38 that is perpendicular to the first direction, that is less than or equal to, or between any two of, 90%, 80%, 70%, 60%, 50%, 40%, or less of the maximum length. A minimum thickness 42 of base 14 within planar portion 22, measured in a direction perpendicular to a plane defined by the planar portion, can be greater than or equal to, or between any two of, 0.5 mm, 0.75 mm, 1.0 mm, 1.25 mm, 1.5 mm, 1.75 mm, 2.0 mm, 2.25 mm, 2.5 mm, or more (e.g., between 0.5 mm and 2.5 mm or between 0.8 and 2.5 mm). Such a thickness can promote stiffness and impact resistance.

[0025] Components of a housing lOa can be constructed and coupled in various ways. Each of base 14 and sidewall 18 can comprise a unitary structure or two or more separate pieces, and the base can be unitary with or separate from the sidewall or one or more pieces thereof. As shown, base 14 and sidewall 18 are unitary; in other embodiments, however, the base and the sidewall can be non-unitary (FIGs. 2 and 3).

[0026] Base 14 and sidewall 18 can comprise a composite material selected such that housing lOa has a suitable impact resistance, stiffness, and RF transparency (e.g., to permit wireless transmissions and/or wireless charging through the base). For example, each of base 14 and sidewall 18 can comprise a polymeric matrix material, such as, for example, a thermoplastic and/or thermoset material. A suitable thermoplastic material can include polycarbonate (PC), polybutylene terephthalate (PBT), or a combination thereof. Housing lOa can have improved crack resistance and impact resistance when the matrix material comprises a PBT/PC blend, compared to PC or PBT alone. PBT/PC matrix materials can be cost-effective and sustainable, and can provide a suitable fire resistance and color neutrality for portable electronic device applications. For example, a PBT/PC matrix material can satisfy the UL 94 V-2 flammability standard, as described in UL 94 - Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances by UL Standards (6th ed., March 34, 2013), which is hereby incorporated by reference.

[0027] While the matrix material can be a PBT/PC blend, in other embodiments the matrix material can comprise any suitable thermoplastic and/or thermoset composition. Suitable matrix materials (e.g., thermoplastic compositions) can include polycarbonates (e.g., blends of polycarbonate (such as, polycarbonate-polybutadiene blends, copolyester polycarbonates)), polystyrenes (e.g., copolymers of polycarbonate and styrene, polyphenylene ether-polystyrene blends), polyimides (e.g., polyetherimides), acrylonitrile-styrene-butadiene (ABS), polyalkylmethacrylates (e.g., polymethylmethacrylates), polyesters (e.g., copolyesters, polythioesters), polyolefins (e.g., polypropylenes and polyethylenes, high density polyethylenes, low density polyethylenes, linear low density polyethylenes), polyamides (e.g., polyamideimides), polyarylates, polysulfones (e.g., polyarylsulfones, poly sulfonamides), polyphenylene sulfides, polytetrafluoroethylenes, polyethers (e.g., polyether ketones, polyether etherketones, polyethersulfones), polyacrylics, polyacetals, polybenzoxazoles (e.g., polybenzothiazinophenothiazines, polybenzothiazoles), polyoxadiazoles, polypyrazinoquinoxalines, polypyromellitimides, polyquinoxalines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines (e.g., polydioxoisoindolines), polytriazines, polypyridazines, polypiperazines, polypyridines, polypiperidines, polytriazoles, polypyrazoles, polypyrrolidines, polycarboranes, polyoxabicyclononanes, polydibenzofurans, polyphthalides, polyacetals, polyanhydrides, polyvinyls (e.g., polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polyvinylchlorides), polysulfonates, polysulfides, polyureas, polyphosphazenes, polysilazzanes, polysiloxanes, and a combination thereof.

[0028] For further example, the matrix material can include, but is not limited to, polycarbonate resins (e.g., LEXAN™ resins, commercially available from SABIC such as LEXAN™ XHT, LEXAN™ HFD, etc.), polyphenylene ether-polystyrene blends (e.g., NORYL™ resins, commercially available from SABIC), polyetherimide resins (e.g., EILTEM™ resins, commercially available from SABIC), polybutylene terephthalate- polycarbonate blends (e.g., XENOY™ resins, commercially available from SABIC), copolyestercarbonate resins (e.g. LEXAN™ SLX or LEXAN™ FST resins, commercially available from SABIC), acrylonitrile butadiene styrene resins (e.g., CYCOLOY resins, commercially available from SABIC), polyetherimide/siloxane resins (e.g., SILTEM™, commercially available from SABIC), polypropylene resins, for example, long glass fiber filled polypropylene resins (e.g., STAMAX™ resins, commercially available from SABIC), or a combination thereof. In some embodiments, the matrix material can include, but is not limited to, homopolymers and copolymers of a polycarbonate, a polyester, a polyacrylate, a polyamide, a polyetherimide, a polyphenylene ether, or a combination including at least one of the foregoing resins. The polycarbonate can include copolymers of polycarbonate (e.g., polycarbonate-polysiloxane, such as polycarbonate-polysiloxane block copolymer), linear polycarbonate, branched polycarbonate, end-capped polycarbonate (e.g., nitrile end-capped polycarbonate) blends of PC, such as PC/ABS blend, and combinations including at least one of the foregoing, for example a combination of branched and linear polycarbonate.

[0029] The composite of base 14 and sidewall 18 can comprise a plurality of fibers dispersed within the matrix material. The composite can comprise a non-laminated polymer- fiber blend, e.g., in which the fibers are not arranged as consolidated lamina(e). For example, the fibers can be discontinuous or chopped fibers (e.g., fibers having a length that is less than or equal to, or between any two of, 3.0 mm, 2.75 mm, 2.5 mm, 2.25 mm, 2.0 mm, 1.75 mm, 1.5 mm, 1.25 mm, 1.0 mm, 0.75 mm, 0.5 mm, 0.25 mm, or less). The polymer-fiber blend can have a fiber volume fraction that is greater than or equal to, or between any two of, 10%, 20%, 30%, 40%, 50%, 60%, 70% or higher (e.g., between 20% and 50% or between 40% and 50%) and a fiber weight fraction that is greater than or equal to, or between any two of, 10%, 20%, 30%, 40%, 50%, 60%, 70%, or higher (e.g., between 40% and 80% or between 60% and 80%). Increasing the fiber volume fraction and/or fiber weight fraction can increase the tensile modulus and/or tensile strength of the polymer-fiber blend.

[0030] In other embodiments, the composite of base 14 and sidewall 18 can comprise a laminate having one or more laminae that have been consolidated (e.g., using heat and/or pressure) and that each comprise fibers (e.g., continuous fibers) dispersed in the matrix material. The laminate can include any suitable number of laminae, such as, for example, greater than or equal to or between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more laminae. At least one, optionally all, of the lamina(e) can comprise a unidirectional lamina, or a lamina having fibers, substantially all of which are aligned in a single direction. As used herein, “aligned” means within 10 degrees of parallel. For example, at least one of, or each of, the lamina(e) can have fibers aligned with first direction 34 (e.g., a 0-degree unidirectional lamina) or second direction 38 (e.g., a 90-degree unidirectional lamina). In some embodiments, at least one of the lamina(e) can have fibers that are aligned in a direction angularly disposed at an angle of at least 10 degrees relative to each of first direction 34 and second direction 38.

[0031] At least one of the lamina(e) can comprise a fabric in which the fibers define a woven structure (e.g., as in a lamina having a plane, twill, stain, basket, leno, mock leno, or the like weave). For example, for at least one of the lamina(e), the fibers can include a first set of fibers aligned in a first fiber direction and a second set of fibers aligned in a second fiber direction that is angularly disposed relative to the first fiber direction, where the first set of fibers is woven with the second set of fibers. Lamina(e) including fibers can have a pre-consolidation fiber volume fraction that is greater than or equal to or between any two of 10%, 20%, 30%, 40%, 50%, 60%, or more (e.g., between 35% and 60% or between 45% and 60%). In some embodiments, one or more laminae may not include fibers; such lamina(e) can, for example, comprise a sheet of a matrix material. In other embodiments, at least one of the lamina(e) can comprise discontinuous or chopped fibers.

[0032] The fibers of the composite (e.g., the polymer-fiber blend or laminate) can include any suitable fibers, such as fibers that can promote stiffness and RF transparency. At least a portion, optionally all, of housing lOa (e.g., the portion of housing lOa configured for wireless charging or to receive an antenna) can be RF transparent. For example, to facilitate RF transparency, the fibers can be selected such that the composite of base 14 and/or sidewall 18 has a dielectric constant, at 10 GHz, that is greater than or equal to or between any two of 4, 4.5, 5.0, 5.5, or more (e.g., between 4 and 5.5). The fibers can comprise non-conductive fibers, including ceramic fibers and/or glass fibers. Ceramic fibers that can provide a suitable combination of stiffness and RF transparency can include for example, fibers comprising aluminum oxide. Other suitable ceramic fibers can include fibers comprising silicon carbide, silicon oxide, zirconium oxide, calcium oxide, magnesium oxide, aluminum silicate, calcium sulfate hemihydrate, boron oxide, boron carbide, and/or combinations thereof. Glass fibers that can provide a suitable combination of stiffness and RF transparency can include E-glass (e.g., alumino-lime silicate having less than 1%, by weight, alkali oxides) and/or S-glass (e.g., alumino silicate glass substantially free of calcium oxide). Other suitable glass fibers can include A-glass (e.g., alkali-lime glass substantially free of boron oxide), C-glass (e.g., alkali- lime glass with comparatively high boron oxide content), D-glass (e.g., borosilicate glass), R- glass (e.g., alumino silicate glass substantially free of magnesium oxide and calcium oxide), and/or E-glass derivatives that are fluorine-free and/or boron-free. The glass fibers can, but need not, be coated with a sizing composition to facilitate dispersion in the matrix material. The weight of the sizing composition can be greater than or equal to, or between any two of, 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, or more (e.g., between 0.1% and 2%) of the weight of the glass fibers. The glass fibers can have a nominal filament diameter of about 4.0 to about 35.0 micrometers. For example, E-glass fibers can have a nominal filament diameter of about 9.0 to about 30.0 micrometers. The fibers can be made by standard processes, e.g., by steam or air blowing, flame blowing and mechanical pulling. In some embodiments, the cross-section of the fibers can be non-circular.

[0033] Other suitable fibers can include carbon fibers, basalt fibers, quartz fibers, and/or fibers comprising iron, nickel, copper, boron, and/or one or more organic or synthetic polymers. For example, the fibers can comprise polyethylene terephthalate, polybutylene terephthalate and other polyesters, polyarylates, polyethylene, polyvinylalcohol, polytetrafluoroethylene, acrylic resins, high tenacity fibers with high thermal stability including aromatic polyamides, polyaramid fibers, polybenzimidazole, polyimide fibers such as polyimide 2080 and PBZ fiber; and polyphenylene sulfide, polyether ether ketone, polyimide, polybenzoxazole, aromatic polyimides or polyetherimides, and/or the like. The fibers can comprise any suitable form, such as, for example, single crystal fibers or“whiskers,” needles, rods, tubes, strands, elongated platelets, lamellar platelets, ellipsoids, micro fibers, nanofibers and nontubes, elongated fullerenes, and/or the like. In some embodiments, the fibers can comprise conductive fibers. The fibers (e.g., if discontinuous) can be in an aggregate form (e.g., an aggregate having an aspect ratio greater than 1). Examples of fibers are described in“Plastic Additives Handbook, 5 ^th Edition,” Hans Zweifel, Ed., Carl Hanser Verlag Publishers (Munich 2001), which is hereby incorporated by reference.

[0034] The composite of base 14 and sidewall 18 can comprise one or more additives mixed within the matrix material. At least one of the additive(s) can comprise an impact modifier, a flow modifier, a non-fiber filler (e.g., a particulate polytetrafluoroethylene (PTFE), glass, carbon, mineral, or metal), an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet (UV) light stabilizer, a ETV absorbing additive, a plasticizer, a lubricant, a release agent (e.g., a mold release agent), an adhesion promoter, an antistatic agent, an anti-fog agent, an antimicrobial agent, a colorant (e.g., a dye or pigment), a surface effect additive, a radiation stabilizer, a flame retardant, an anti-drip agent (e.g., a PTFE-encapsulated styrene-acrylonitrile copolymer (TSAN)), or a combination thereof. The total weight of the additives in the composite can be greater than or equal to or between any two of 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or more (e.g., between 0.1% and 10%) of the weight of the matrix material. Additive(s) can be selected to achieve desired properties for housings lOa without a significant adverse effect on the mechanical properties of the composite, and can be soluble or non-soluble in the matrix material.

[0035] TABLES 1 and 2 set forth mechanical characteristics of polymer-fiber blends and laminae, respectively, that are suitable for use in some of the present housings. TABLE 1: Mechanical Properties of Illustrative Polymer-Fiber Blends

TABLE 2: Mechanical Properties of Illustrative Laminae

[0036] Referring to FIGs. 2 and 3, shown are housings lOb and lOc, respectively, in which base 14 and sidewall 18 are not unitary. Base 14 and sidewall 18 can comprise the same material or different materials, such as any of the above-described composites. For example, referring particularly to FIG. 2, sidewall 18 can comprise a polymer-fiber blend and base 14 can comprise a laminate. Both the polymer-fiber blend of sidewall 18 and the lamina(e) of the laminate of base 14 can include ceramic fibers (e.g., that comprise aluminum oxide) dispersed within a PBT/PC matrix material. Additionally or alternatively, at least one of base 14 and sidewall 18 can comprise a metal such as aluminum, titanium, stainless steel, or a combination thereof. Referring particularly to FIG. 2, for example, sidewall 18 can have a rim 46 (sometimes referred to as a sidewall member) that comprises aluminum and/or a laminate (e.g., having glass fibers, ceramic fibers, and/or carbon fibers). Without limitation, when rim 46 comprises aluminum and/or a laminate having glass fibers (e.g., S-glass) and/or carbon fibers, base 14 can comprise a laminate having glass fibers (e.g., S-glass). When rim 46 comprises a laminate having ceramic fibers, base 14 can comprise a laminate or a polymer-fiber blend having ceramic fibers as well. [0037] The base (e.g., 14) and sidewall (e.g., 18) of non-unitary housings (e.g., lOb and lOc) can be coupled in any suitable manner, such as with a snap fit, an adhesive, and/or via overmolding. As shown in FIG. 3, sidewall 18 can comprise a rim 46 and a connecting member 50 that couples the rim to planar portion 22 of base 14. Rim 46 can have opposing interior and exterior surfaces 54a and 54b and connecting member 50 can be disposed on the interior surface; in other embodiments, however, the connecting member can be disposed on the exterior surface. Connecting member 50— or two or more connecting members, collectively— can be disposed along at least a majority of (e.g., up to and including all of) one or both lengthwise sections and/or one or both widthwise sections of the periphery of base 14 (e.g., the complete periphery of the base, as shown in FIG. 3). Those connecting member(s) 50 can be so disposed whether they contact base 14’ s periphery on the front face, back face, and/or edge of the base. Such a configuration can enhance coupling between the rim and the base. At least one of (e.g., both of) rim 46 and connecting member 50 can project outwardly from and surround at least a majority of (e.g., all of) planar portion 22. To promote aesthetics, ergonomics, impact resistance, and stiffness, a minimum thickness 58 of rim 46, measured between interior and exterior surfaces 54a and 54b, can be greater than or equal to or between any two of 0.6 mm, 0.8 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 3.7 mm or larger (e.g., between 0.8 mm and 2.2 mm).

[0038] Connecting member 50, which may be one or more connecting members, can comprise any material suitable for transferring loads between rim 46 and planar portion 22 of base 14. For example, connecting member 50 can include, or be characterized as, a polymeric material, such as any of the matrix materials or polymer-fiber blends described above. To promote bonding between connecting member 50 and base 14, the matrix material of the connecting member can be the same as that of the composite base. For example, connecting member 50 can comprise a PBT/PC matrix material, with or without discontinuous fibers dispersed therein. Without limitation, when base 14 comprises glass fibers, connecting member 50 can comprise a PBT/PC matrix material without fibers, and when the base comprises ceramic fibers, the connecting member can comprise a PBT/PC matrix material with ceramic fibers.

[0039] Rim 46 can have two lengthwise linear portions 62, two widthwise linear portions 66, and four comer portions 70. Lengthwise linear portions 62 can extend in a direction aligned with first direction 34, and widthwise linear portions 66 that each extend in a direction aligned with second direction 38. Each of comer portions 70 can connect one of lengthwise linear portions 62 to a respective one of widthwise linear portions 66. Rim 46 can thereby define a rectangular shape (e.g., having rounded corners).

[0040] Rim 46 can comprise a unitary structure or a non-unitary structure in which the rim comprises greater than or equal to or between any two of 2, 3, 4, 5, 6, 7, 8, 9, or more pieces that are coupled together. Each of the pieces of rim 46 can define at least a section of lengthwise linear portions 62, widthwise linear portions 66, and comer portions 70. For example, as shown, rim 46 comprises four pieces: upper and lower pieces 74a and 74b and side pieces 74c and 74d. Upper and lower pieces 74a and 74b can each define a respective one of widthwise linear portions 66, and side pieces 74c and 74d can each define at least a section of a respective one of lengthwise linear portions 62. Additionally, each of upper and lower pieces 74a and 74b can define one or two of comer portions 70 and at least a section of each of one or two of lengthwise linear portions 62 such that, for example, side pieces 74c and 74d are disposed between and coupled to the upper and lower pieces. As arranged, pieces 74a-74d can be joined at locations spaced apart from corner portions 70 to promote rim strength.

[0041] The pieces of rim 46 can comprise the same material or different materials. Each of the pieces can comprise, for example, a metal (e.g., aluminum), a laminate, or a polymer-fiber blend (e.g., any of those described above). As shown, each of pieces 74a-74d comprises a laminate. At least one of the lamina(e) of upper and lower pieces 74a and 74b can be a unidirectional lamina comprising fibers (e.g., glass fibers) that are aligned in second direction 38 within widthwise linear portions 66. At least one of the lamina(e) of side pieces 74c and 74d can comprise a unidirectional lamina comprising fibers (e.g., carbon fibers) that are aligned in first direction 34 within lengthwise linear portions 62. Side pieces 74c and 74d can promote stiffness, and upper and lower pieces 74a and 74b can promote impact resistance at corner portions 70. In other embodiments, the pieces can comprise any suitable combination of materials; for example, two of the pieces (e.g., 74a and 74b) can comprise a metal (e.g., aluminum).

[0042] Additionally or alternatively, each of the pieces can comprise a laminate having multiple types of fibers. For example, rim 46 can comprise two pieces, e.g., upper and lower pieces 74a and 74b (e.g., no separate side pieces 74c and 74d), that are bonded to one another in lengthwise linear portions 62 to define the rim. The two pieces can comprise a first type of fibers (e.g., glass fibers) within widthwise linear portions 66, comer portions 70, and/or along a section of lengthwise linear portions 62. The two pieces can also comprise a second type of fibers (e.g., carbon fibers) within at least a section of lengthwise linear portions 62. Each of the two pieces can be manufactured by forming a linear laminate and bending the laminate such that the pieces define rim 46 when bonded together.

[0043] Referring to FIGs. 4A-4C, some of the present housings (e.g., lOa-lOc) can be manufactured via injection molding. Manufacturing can be performed using a mold (e.g., 78) comprising two or more mold portions (e.g., 82a and 82b) that are movable between an open position and a closed position in which the mold portions cooperate to define a mold cavity (e.g., 86). Molding surfaces of the mold portions can be shaped such that the mold cavity comprises a planar cavity portion (e.g., 90) and a peripheral channel (e.g., 94) that projects outwardly from and surrounds at least a majority of (e.g., all of) the planar cavity portion. The planar cavity portion can be configured to receive a base (e.g., 14) comprising a laminate (e.g., any of those described above), optionally such that the laminate occupies all of a volume defined by the planar cavity portion. The mold cavity can be configured such that a portion of the laminate (e.g., at least the outer edges thereof) can be disposed within the peripheral channel when the laminate is received in the planar cavity portion. The peripheral channel can be configured to receive a rim (e.g., 46), optionally such that an exterior surface (e.g., 54b) of the rim is disposed on a molding surface of at least one of the molding portions.

[0044] The laminate base and the rim can be manufactured prior to the molding. The laminate, for example, can be formed using a variety of techniques, including but not limited to bladder molding of pre-preg sheets, compression molding of pre-preg sheets, autoclave or vacuum bag molding of prepreg sheets, mandrel molding, wet layup molding of neat sheets, filament winding molding in which fiber bundles are pulled through a wet bath resin and wound over a mandrel, pultrusion or extrusion molding in which fibers saturated with wet resin are pulled or extruded through a die, or resin transfer molding and vacuum assisted resin transfer molding in which fabrics are placed into a mold and injected with fluid resin under pressure.

[0045] To couple the rim to the laminate base, some methods comprise a step of placing each of the laminate and the rim (if multi-piece, each of its pieces) on at least one of the mold portions and moving the mold portions to the closed position such that the laminate is disposed in the planar cavity portion (and, optionally, in the peripheral channel) and the rim is disposed in the peripheral channel (FIG. 4A). A moldable material (e.g., 98) comprising a matrix material (e.g., a PBT/PC blend) with or without fibers can be injected into the peripheral channel (FIG. 4B). For example, injecting can be performed such that the moldable material is introduced into a volume (e.g., 80) defined by an interior surface (e.g., 54a) of the rim, a molding surface of at least one of the mold portions, and the laminate. The moldable material can be set to form one or more connecting members (e.g., 50) that couple the rim to the laminate as described above (FIG. 4C). Optionally, the laminate can be heated before the injecting.

[0046] The rim can be treated and/or can define one or more features to facilitate bonding between the rim and the connecting member. For example, for some housings, the interior surface of the rim can define one or more recessed channels (e.g., 104). During the injecting, the moldable material can enter the recessed channel(s) such that, when the matrix material is set, a portion of the connecting member is disposed therein. The recessed channel(s) can increase the bonding area between the moldable material and the rim to improve bonding. Additionally or alternatively, the interior surface of the rim can define one or more protrusions. In some methods, to facilitate bonding, an adhesive can be applied to the interior surface of the rim and/or the interior surface can be etched (e.g., mechanically and/or chemically), laser engraved, plasma treated, and/or the like prior to the injecting.

[0047] The rim and the laminate base can be positioned such that a portion (e.g., 134) of the volume in the peripheral channel is coplanar with the laminate and is defined between the rim and the laminate. The moldable material can enter the coplanar volume during injecting such that the formed connecting member comprises a portion (e.g., 138) that is coplanar with the planar portion of the base and is disposed between the planar portion and the rim. The coplanar portion of the connecting member can promote bonding and absorb loads during an impact to mitigate damage to the rim.

[0048] Inj ection molding can also be used to form housings in which at least one of the base and sidewall (e.g., 18) comprises a polymer-fiber blend. For example, a housing having a unitary, polymer-fiber sidewall can be formed in substantially the same manner described above, the primary exception being that a pre-manufactured rim is not placed into the peripheral channel prior to the injecting. A housing having a polymer-fiber base can be manufactured in substantially the same manner as well, except that a pre-manufactured laminate base is not placed into the mold cavity. And, omitting both a pre-manufactured rim and base from the mold prior to the injecting can yield a unitary housing.

[0049] The moldable material, when comprising fibers and/or additives, can comprise any suitable proportion of the fibers and/or additives, such as any of those described above. The matrix material and fibers can be mixed prior to introduction into the mold cavity. For example, the matrix material can be mixed with the discontinuous fibers when the matrix material is in a powdered form. The mixture can be fed through an extruder to form the moldable material. Optionally, the fibers can be unchopped when mixed; the mixing, extruding, and/or injecting can shorten the fibers to form discontinuous (e.g., chopped) fibers. Alternatively, the fibers can be compounded into a masterbatch with the matrix material and thereafter fed into the extruder. The extruder can be configured to operate at a temperature higher than that necessary to cause the moldable material to flow. The extrudate can be quenched in a water batch and pelletized.

[0050] The present housings (e.g., lOa, lOb, and lOc) may include features that are relatively thin and/or complex. During injection molding, such features may cause uneven pressure within the mold cavity, hinder flow of moldable material, and, if using a fiber-filled moldable material, damage those fibers via shear. The finished housing may, as a result, be suboptimal (e.g., weaker, blemished, warped, and/or the like). To address these issues, some of the present methods include injection molding a housing template, which can include a sidewall template (e.g., 142), a back template (e.g., 146), and/or the like, where a template component is a component from which material is removed to produce a final component. In this way, thicker and/or less complicated template component(s) (e.g., a sidewall template, a back template) can be injection molded (facilitating the same), and subsequently processed to produce thinner and/or more complicated finished component(s) (e.g., a sidewall and a base, respectively).

[0051] FIG. 5 A depicts injection molding a sidewall template 142, and FIG. 5B illustrates a profile l50a along which material can be removed from the sidewall template to produce a sidewall. Such removal of material can be accomplished in any suitable fashion, including by machining (e.g., using a lathe, mill, router, or grinder). As illustrated in FIGs. 5B, 6A, and 6B, this process can be used whether the sidewall will be connected to a base that comprises a laminate (FIG. 5B), the sidewall will comprise a rim (FIGs. 5B and 6A), or neither (FIG. 6B). If the sidewall will be connected to (or include) a rim, laminate, and/or the like, however, molding a sidewall template and processing the sidewall template to produce the sidewall may result in stronger such connection(s) (e.g., via the sidewall template being easier to effectively mold than the sidewall).

[0052] As shown, profile l50a will produce a number of sidewall surfaces that are parallel to, and a number of sidewall surfaces that are perpendicular to, the base (or back template) or a horizontal plane when the housing template is placed with its base (or back template) resting on a horizontal surface. Profile 150a will also produce a curved sidewall surface. Nevertheless, profiles producing any suitable sidewall surfaces, including those that are angularly disposed relative to the base (or back template) or the horizontal plane), can be used.

[0053] When removing material from sidewall template 142, a thickness of the sidewall template can be reduced. That thickness can be measured along any suitable direction, including one that is perpendicular to a direction along which the sidewall template extends (or the sidewall will extend), parallel to the base (or back template from which the base will be produced) (e.g., such a thickness being characterizable, in some instances, as a width) or perpendicular to the base (or back template) (e.g., such a thickness being characterizable as a height), parallel or perpendicular to a horizontal plane (as described above), or the like (e.g., along any direction lying in the plane of FIG. 5B).

[0054] To illustrate, as shown in FIG. 5B, connector member 50 (e.g., polymeric material) of sidewall template 142 can have a profile 144 taken in a plane that is perpendicular to the back template and is aligned with one of the length and the width of the template component (e.g., including the sidewall template and the base template). And removing material from sidewall template 142 can be performed such that a height of profile 144, measured perpendicularly to the back template, is reduced (e.g., to height 148) (e.g., by at least 5, 10, 15, 20, or more %). Such height reduction can occur— but need not be the same in magnitude— across a majority of (e.g., up to and including all of) the entire width 152 of profile 144, measured perpendicularly to the height. Similarly, in some methods, removing material from sidewall template 142 can be performed such that a width (e.g., measured parallel to width 150) of profile 144 is reduced, in some instances, across a majority of the entire height (e.g., measured parallel to height 148) of the profile.

[0055] As labeled in FIG. 6B, thickness 154 of sidewall template 142 can be reduced to thickness 158 to produce the sidewall. Thickness 154 can be, for example, as low as 1.0, 1.3, 1.5, 1.7, or 2.0 mm, and as high as 7 mm (e.g., less than or equal to 7 mm). And, thickness 158 can be as low as 0.4, 0.5, or 0.6 mm, and as high as 6.5 mm. Reductions in thickness of sidewall template 142 can vary along the sidewall template; for example, a sidewall (produced from the sidewall template) can have a thickness (e.g., a maximum thickness) of at least 5.0, 5.5, 5.7, 6.0, 6.3, or 6.6 mm at one location, and, at another location, a thickness (e.g., a maximum thickness) of less than or equal to 0.4, 0.5, or 0.6 mm.

[0056] Also shown in FIG. 6B is back template 146 and profiles 150b and 150c along which material can be removed from the back template to produce a base. Such material removal can be performed in the same fashion described above for sidewall template 142, produce base surfaces having the orientations described above for sidewall surfaces, and result in thickness reductions of back template measured along the directions described above for those of the sidewall template.

[0057] Provided by way of illustration, a thickness 166 of back template 146 can be reduced to a thickness 170 to produce the base. Thickness 166 can be, for example, as low as 1.0, 1.3, 1.5, 1.7, or 2.0 mm, and as high as 4 mm. And, thickness 170 can be as low as 0.4, 0.5, or 0.6 mm, and as high as 3.5 mm. Reductions in thickness of back template 146 can vary along the back template; for example, a base (produced from the back template) can have a thickness (e.g., a maximum thickness) of at least 2.7, 3.0, 3.3, or 3.6 mm at one location, and, at another location, a thickness (e.g., a maximum thickness) of less than or equal to 0.4, 0.5, or 0.6 mm.

[0058] The final thickness of a sidewall template or a back template (and thus of the sidewall or the base produced therefrom) can be expressed as a percentage of its original (pre- processing) thickness. For example, the final thickness can be greater than or approximately equal to any one of, or between any two of: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95% of the original thickness.

[0059] Additional details useful for manufacturing some of the present housings can be found in U.S. Provisional Patent App. No. 62/655,790, filed on April 10, 2018 and entitled “Portable Electronic Device with Injection Molded Back and Method of Manufacture,” which is hereby incorporated by reference in its entirety.

[0060] Referring to FIGs. 7A-7C, injecting can be performed to facilitate alignment of the fibers of the moldable material and to position weldlines away from the corners of the housing, thereby promoting strength. To illustrate, the peripheral channel can comprise two lengthwise linear channel portions (e.g., l02a and l02b) aligned in a first direction (e.g., 34) and two widthwise linear channel portions (e.g., l06a and l06b) aligned in the second direction (e.g., 38) that is perpendicular to the first direction. The peripheral channel can also comprise four channel corner portions (e.g., 1 lOa-l lOd), each of which connects one of the lengthwise linear channel portions to one of the widthwise linear channel portions such that the channel portions are in fluid communication. The mold can comprise one or more injection ports (e.g., H4a- 1 l4d) through which the moldable material can be introduced into mold cavity.

[0061] To facilitate fiber alignment and appropriate weldline positioning when molding the connecting member and/or sidewall, one or more of the injection port(s) can be positioned at and be in fluid communication with one of the lengthwise linear channel portions or one of the widthwise linear channel portions such that, during the injecting, the moldable material is introduced into the lengthwise or widthwise linear channel portion from the injection port (FIG. 7 A). To promote fiber alignment and appropriate positioning of the weldlines, each of the injection port(s) can be spaced apart from the channel comer portions. For example, each of the injection port(s) that is positioned at one of the lengthwise linear channel portions can be spaced apart from one of the widthwise linear channel portions by a distance (e.g., 118), measured in the first direction, that is greater than or equal to or between any two of 10%, 20%, 30%, 40%, 50%, or more (e.g., between 40% and 60%) of a length (e.g., 122) of the lengthwise linear channel portion. Each of the injection port(s) positioned at one of the widthwise linear channel portions can be spaced apart from one of the lengthwise linear channel portions by a distance (e.g., 126), measured in the second direction, that is greater than or equal to or between any two of 10%, 20%, 30%, 40%, 50%, or more (e.g., between 40% and 60%) of a width (e.g., 130) of the widthwise linear channel portion. As shown, the mold comprises four injection ports, each positioned at and in fluid communication with a respective one of the lengthwise and widthwise linear channel portions; in other embodiments, however, the mold can comprise any suitable number of inj ection ports, such as, for example, greater than or equal to or between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more injection ports. Providing additional injection ports can facilitate the manufacture of thinner sidewalls.

[0062] Inj ecting can be performed by introducing the moldable material through each of the injection port(s) (and, e.g., into the lengthwise and widthwise linear channel portions) sequentially. Sequential introduction of the moldable material can mitigate the presence of multiple flow fronts which may produce weak spots where the flow fronts meet. In other embodiments, however, the moldable material can be introduced through each of the injection port(s) concurrently. The arrangement of the injection port(s) (e.g., as shown) can facilitate fiber alignment (e.g., along the first direction in each of the lengthwise linear channel portions and along the second direction in each of the widthwise linear channel portions), which can reduce shrinkage and warpage.

[0063] To facilitate fiber alignment and appropriate arrangement of weldlines when molding the base, each of the injection port(s) can be positioned at the planar cavity portion such that during the injecting the moldable material is introduced into the planar cavity portion from the injection port (FIGs. 7B and 7C). As shown, the mold comprises three injection ports configured such that a first one of the ports is configured to introduce the moldable material into the planar cavity portion at a first location disposed between the second and third injection ports. Injecting can be performed such that the moldable material is introduced into the mold cavity through the first injection port and/or concurrently through the second and third injection ports. Such an arrangement can facilitate injection molding using a moldable material that has a comparatively higher fiber mass fraction (e.g., greater than or equal to 60%).

[0064] In some of the present housings (e.g., lOa-lOc) the base (e.g., 14) can be planar (e.g., can be a plate comprising a laminate). Referring to FIGs. 8A and 8B, however, a portion of the base can define a portion of the sidewall. For example, the base can define and be unitary with at least a portion of the rim. To form such a housing, the laminate can be placed such that at least a portion of the exterior surface of the rim is spaced apart from the molding surfaces of the mold portions that define the peripheral channel. Injecting can be performed such that the moldable material deforms the laminate and the exterior surface of the rim comes into contact with at least one of the molding surfaces of the mold portions that define the peripheral channel. Formation of the connecting member can maintain the laminate, and thus the rim, in this configuration.

EXAMPLES

[0065] The present invention will be described in detail by way of specific examples. The following examples are offered for illustrative purposes only and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of non-critical parameters that can be changed or modified to yield essentially the same results.

EXAMPLE 1

[0066] FIGs. 9A-9C illustrate the design space that was explored to select the thickness and materials for base 14 and sidewall 18 based on a four-point bending simulation. FIGs. 9A and 9B show that, for a given material tensile modulus, increasing the thickness of base 14 and sidewall 18 reduced the deflection of the simulated housing. Increasing sidewall thicknesses tended to result in comparatively larger deflection reductions when the sidewall thickness was comparatively small. The design space illustrated in FIG. 9C was generated by setting deflection to a target value and plotting constant-tensile modulus contours for different base and sidewall thicknesses. Contours representing materials for use in the housing were superimposed on the plot such that the design space included materials selection and the thicknesses of base 14 and sidewall 18. [0067] The above specification and examples provide a complete description of the structure and use of illustrative embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, elements may be omitted or combined as a unitary structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments.

[0068] The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s)“means for” or“step for,” respectively.