TECHNICAL FIELD

The present invention provides a jig for holding a workpiece during one or more process operations, and in particular such a jig that is able to accommodate workpieces with differing shapes, sizes or layouts.

BACKGROUND

It is often necessary to hold printed circuit boards or other similar items in a jig to perform process steps thereon. For example, when surface modifying an item, e.g. by applying a coating to an item by vapour deposition, there is often a need to mask the item such that part of the item's surface is not modified. The application of a mask for this purpose may be carried out by an automated process, e.g. by a robotic arm, and there is a need to hold the item in a known position to facilitate this. As an example, it is sometimes desirable to apply a masking material to one or more regions of a component of a mobile device, such as a printed circuit board, screen, back cover or other item before a vapour deposited coating is applied to, for example, provide liquid repellence to the non-masked regions.

A jig may also be necessary to hold printed circuit boards or other items during other process steps, such as during mounting of electronic components thereon.

SUMMARY OF THE INVENTION

In general terms the present invention proposes a jig for holding a workpiece such as a printed circuit board while one or more process steps are carried out thereon. The jig comprises two jaws separated by a clamping area within which a workpiece can be held. At least one of the jaws carries a plurality of teeth thereon for contacting a workpiece within the clamping area, each tooth being independently moveable relative to the respective jaw.

A first aspect of the invention provides a jig for holding one or more workpieces, the jig comprising: a pair of jaws defining a clamping area therebetween; at least one of the jaws having a plurality of teeth, each tooth being independently movable relative to its respective jaw and each tooth having a gripping surface configured to contact a surface of a workpiece to hold the workpiece in the clamping area.

The independent movement of the teeth enables the jig to hold workpieces of a multitude of different shapes, sizes and configurations. For example, the jig can be used to hold any generally planar member having a relatively small thickness. Thus, the workpiece may have generally two main faces subtended by a relatively thin edge. The workpiece may have any shape in planform. The jig may be able to hold workpieces having a convoluted perimeter shape. The workpiece typically has a length (i.e. a longest dimension across at least one of its main faces) of 150mm or less, and/or a width (i.e. a longest dimension in a direction perpendicular to the length across at least one of its main faces) of 90mm or less.

Each tooth (alternatively referred to as a probe, or finger) may have a body portion that carries the respective gripping surface.

In preferred embodiments the one or more workpieces comprise one or more printed circuit boards. For example, the one or more workpieces may comprise two printed circuit boards connected by a flexible connection. The one or more printed circuit boards may be single- sided, double-sided or multi-layer printed circuit boards. The one or more printed circuit boards may comprise a substrate carrying one or more conductive tracks thereon electrically connecting two or more electronic components.

Each tooth is preferably moveable away from its respective jaw from a retracted

configuration to an extended configuration, and wherein each tooth is biased towards the extended configuration.

Preferably, the jaws are biased towards one another. In this way, a workpiece will be securely held between the jaws. Biasing the jaws towards one another thus minimises a width of the clamping area.

The jaws are preferably movable towards and away from one another along a common linear clamping direction. Thus, the jaws are able to move in alignment with one another, and a clamping force provided by the jaws is directed along the clamping direction only.

In preferred embodiments each tooth is movable along a linear tooth axis relative to its respective jaw, and the tooth axes of the teeth of each jaw are substantially parallel to one another. Thus, the teeth are able to move in alignment with one another, and a force exerted on a workpiece by each of the teeth is directed along their respective tooth axes only.

The tooth axes of the teeth are preferably each substantially parallel to the clamping direction of the jaws. Thus, the forces exerted on a workpiece by both the jaws and the teeth are exerted in a common direction.

Each tooth may have a gripping surface configured to engage an edge of a workpiece. For example, each gripping surface may comprise a generally V-shaped or U-shaped notch within which an edge of a workpiece can be seated in use. Similarly, each tooth may include a recess portion on which the gripping surface is formed. By providing the gripping surface in the form of a notch or recess minor misalignment between neighbouring teeth (e.g.

resulting from manufacturing or assembly tolerances) can be accompodated.

Each tooth may comprise a piston and cylinder assembly configured to provide the movement relative to its respective jaw. For example, each tooth may comprise one or more pistons rigidly connected to its respective gripping surface, the one or more pistons being slideable within one or more corresponding cylinder bores formed in or on the respective jaw. Alternatively, each tooth may comprise a cylinder bore within which a piston rigidly connected to the respective jaw is slideable. In some embodiments each tooth comprises two piston and cylinder assemblies configured to move in tandem to provide the movement of the tooth relative to its respective jaw.

Preferably, one or more of the plurality of teeth have a different shape and/or size than another one or more of the plurality of teeth. By varying the shape and/or size of the teeth it is possible to even further enhance the ability of the jig to accommodate workpieces of any size or shape. For example, one or more of the plurality of teeth may have a different length in a direction of movement of at least one of the jaws than another one or more of the plurality of teeth. Alternatively, or in addition, one or more of the plurality of teeth may have a differently shaped gripping surface than another one or more of the plurality of teeth.

The teeth of each jaw are preferably arranged in series along the jaw. In this way, workpieces which have edges that are relatively linear in one dimension can be held by the jig. For example, relatively flat, thin workpieces can be held by the jig.

The jig preferably comprises an opening mechanism operable to move the jaws apart to allow removal of a workpiece from the jig. The opening mechanism may comprise any manually operated or powered mechanism. For example, the opening mechanism may comprise a mechanical, electro-mechanical, electrical, or hydraulic actuator.

In preferred embodiments the opening mechanism comprises a pair of hinge arms, each connected at one end to a respective one of the jaws and at another end to a hinged joint, wherein the hinged joint is movable to an open configuration in which the hinge arms are pivoted away from one another to thereby move the jaws apart. This arrangement provides a particularly simple mechanism for opening the jaws, particularly when combined with the feature that the jaws are moveable towards and away from one another along a common linear clamping direction. The opening mechanism may be actuated by a key or similar device arranged to move the hinged joint to the open configuration.

Preferably, the jig comprises a mounting sub-assembly and a rotatable sub-assembly including the pair of jaws, wherein the rotatable sub-assembly is mounted on the mounting sub-assembly so as to be rotatable relative thereto. In this way, all sides/faces of one or more workpieces held by the jig can be inspected, or process steps carried out thereon. In embodiments in which process steps are carried out on a workpiece held in the jig by automated production machinery, such as a robotic arm configured to apply a coating (e.g. a masking material layer) to the workpiece, rotation of the workpiece relative to the machinery enables the complexity of the machinery - and therefore its related cost - to be minimised. For example, it may be necessary to provide only a single robotic arm able to carry out a process step on both sides of the workpiece.

The rotatable sub-assembly may be rotatable relative to the mounting sub-assembly about one axis, or alternatively about two axes, optionally two axes that are generally

perpendicular to one another. In some embodiments the rotatable sub-assembly may be rotatable about three axes.

The rotatable sub-assembly preferably includes a jaw mounting plate to which each of the jaws is mounted via a sliding connection so as to be slidable relative thereto to provide relative movement between the jaws.

The jig may comprise one or more bearings interconnecting the mounting sub-assembly and the rotatable sub-assembly.

The jig preferably comprises control means to control a rotational position of the rotatable sub-assembly relative to the mounting sub-assembly.

A second aspect of the invention provides a method of operating a jig according to the first aspect and/or any of the optional features thereof described herein and/or any of the embodiments described herein, including the steps of: arranging the jig in an open configuration; inserting a workpiece in the clamping area between the jaws; and arranging the jig in a clamping configuration by moving the jaws towards one another so that a gripping surface of each of one or more of the plurality of teeth contact a surface of the workpiece to hold the workpiece in the clamping area.

The method may further comprise rotating the jaws relative to a mounting sub-assembly of the jig to thereby rotate the workpiece held in the clamping area. The jaws may be rotatable between a first configuration, optionally in which a first face of the workpiece is accessible for a first process step, and a second configuration, optionally in which a second face of the workpiece is accessible for a second process step. The first configuration may be substantially 180 degrees opposed to the second configuration. The first and second process steps may comprise steps carried out by the same production apparatus, i.e. an apparatus configured to carry out the first and second process steps.

In some embodiments the method further comprises the step of carrying out a process step on the workpiece. For example, the process step may comprise applying a surface layer such as a coating to the workpiece. The surface layer may comprise a masking material. The masking material may be applied to one or more regions of the workpiece prior to exposing the workpiece to surface modification conditions, to thereby prevent surface modification to those one or more regions. Alternatively, or in addition, the surface layer may comprise an adhesive layer.

The method may comprise the steps of carrying out a first process step on a first face of the workpiece and a second process step on a second face of the workpiece. In preferred embodiments the method further includes the steps of, after carrying out the first process step and before carrying out the second process step, rotating the jaws from a first configuration to a second configuration. Preferably, the jaws are rotated through

substantially 180 degrees form the first configuration to the second configuration. The first and second process steps are preferably carried out by the same production apparatus, i.e. an apparatus configured to carry out the first and second process steps.

A third aspect of the invention provides a method of carrying out a process step on one or more workpieces, the method comprising the steps of: securing the one or more workpieces with a jig according to the first aspect and/or any of the optional features thereof described herein and/or any of the embodiments described herein; and carrying out a process step on the one or more workpieces. In some embodiments the process step may comprise applying a surface layer such as a coating to the one or more secured workpieces. For example, the surface layer may comprise a masking material. The masking material may be applied to one or more regions of the workpiece prior to exposing the one or more secured workpieces to surface modification conditions, to thereby prevent surface modification to those one or more regions. Alternatively, or in addition, the surface layer may comprise an adhesive layer.

The method may comprise the steps of carrying out a first process step on a first face of the workpiece and a second process step on a second face of the workpiece. In preferred embodiments the method further includes the steps of, after carrying out the first process step and before carrying out the second process step, rotating the jaws from a first configuration to a second configuration. Preferably, the jaws are rotated through

substantially 180 degrees form the first configuration to the second configuration. The first and second process steps are preferably carried out by the same production apparatus, i.e. an apparatus configured to carry out the first and second process steps.

Examples of masking processes in the context of each of the aspects of the invention include, but are not limited to, the application of a masking material which is removable after the surface modification process.

The masking material may take any desired form, consistent with achieving a desired masking performance or effect.

In various embodiments, the masking material comprises a curable resin. In particular, the masking material may be fluid in an uncured state and solid in a cured state. The method may comprise curing the resin after application.

Advantageously, the resin may be radiation curable, for example UV curable. Such masking materials are known in the art. They may typically comprise a polymerizable monomer or oligomer, a photoinitiator and optionally various other additives, for example such as antioxidants, fillers and thickening agents. Examples of suitable polymerizable monomers include substituted vinyl compounds, in particular such as acrylates.

The UV curable resin used in the present invention may advantageously comprise an acrylated urethane, for example a substituted or unsubstituted urethane methacrylate or urethane acrylate. Such compositions are sold by DymaxRTM under the trade names DymaxRTM 9-20479-B, DymaxRTM 9-20318-F, and DymaxRTM 9-318-F.

However, the method may also make use of other types of masking material.

The masking material may comprise a plurality of units of masking material. For example, the masking material may comprise a plurality of dots or other regions of masking material. The method may comprise applying a plurality of discrete units of masking material.

Examples of surface modification processes in the context of this invention, and in particular the second and third aspects, include, without limitation, deposition processes, in particular particle or vapour deposition processes. The surface modification process may suitably be sub-atmospheric, i.e. involve exposure of the one or more masked items to sub-atmospheric pressures. Suitably, the sub-atmospheric pressure may be in the range of from 0.01 to 999.99 mbar, such as in the range of from 0.1 to 999.99 mbar, e.g. in the range of from 0.5 to 999.99 mbar. In some embodiments of the surface modification process is a sub- atmospheric vapour deposition process, in particular a plasma polymerisation process.

Surface modification conditions may, for example, be vapour deposition conditions. The surface modification conditions may comprise sub-atmospheric pressure. In an embodiment, the vapour deposition conditions are plasma polymerisation conditions.

Surface modification conditions may optionally comprise: an excitation medium; and a monomer that is at least partly activated by the excitation medium to form a liquid repellent coating on the item. The excitation medium may in particular comprise a plasma, optionally a pulsed plasma.

The monomer may be a compound of formula (I):

where R ¹ , R ² and R ³ are independently selected from hydrogen, alkyl, haloalkyl or aryl optionally substituted by halo; and R ⁴ is a group X-R ⁵ where R ⁵ is an alkyl or haloalkyl group and X is a bond; X is a group of formula -C(0)0(CH2) _n Y, where n is an integer of from 1 to 10 and Y is a bond or a sulphonamide group; or X is a group

-(0)pR ⁶ (0)q(CH2)t, where R ⁶ is aryl optionally substituted by halo, p is 0 or 1 , q is 0 or 1 and t is 0 or an integer of from 1 to 10, provided that where q is 1 , t is other than 0.

Suitably, the workpiece may be exposed to a plasma comprising a monomer compound for a period of time sufficient to allow a protective polymeric coating to form on a surface of the workpiece; wherein the monomer compound has the following formula (II):

where Ri , R2 and R ₄ are each independently selected from hydrogen, optionally substituted branched or straight chain C1-C6 alkyl or halo alkyl or aryl optionally substituted by halo, and R3 is selected from:

where each X is independently selected from hydrogen, optionally substituted branched or straight chain C1-C6 alkyl, halo alkyl or aryl optionally substituted by halo; and ni is an integer from 1 to 27.

In some embodiments, the monomer may be as identified in the claims of WO 2007/083122.

Suitably, the monomer may be selected from 1 H, 1 H,2H,2H-perfluorohexyl acrylate (PFAC4), 1 H,1 H,2H,2H-perfluorooctyl acrylate (PFAC6), 1 H, 1 H,2H,2H-perfluorodecyl acrylate

(PFAC8) and 1 H,1 H,2H,2H-perfluorododecyl acrylate (PFAC10).

Suitably, the masked item may be exposed to the monomer compound in combination with a crosslinking agent comprising two or more unsaturated bonds attached by means of one or more linker moieties and has a boiling point at standard pressure of less than 500 °C. The crosslinking reagent may be selected, for example from 1 ,4-butanediol divinyl ether (BDVE), 1 ,4-cyclohexanedimethanol divinyl ether (CDDE), 1 ,7-octadiene (170D), 1 ,2,4 - trivinylcyclohexane (TVCH), divinyl adipate (DVA), 1 ,3-divinyltetramethyldisiloxane

(DVTMDS), diallyl 1 ,4-cyclohexanedicarboxylate (DCHD), 1 ,6-divinylperfluorohexane (DVPFH), 1 H,1 H,6H,6H-perfluorohexanediol diacrylate (PFHDA) and glyoxal bis(diallyl acetal) (GBDA).

The surface modification conditions may lead to a coating that may advantageously be liquid repelling, e.g. water and/or oil repelling.

The one or more workpieces may be of any desired type. In an embodiment, the one or more items comprise one or more printed circuit boards, electronic devices or electronic components.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", mean "including but not limited to", and do not exclude other components, integers or steps. Moreover the singular encompasses the plural unless the context otherwise requires: in particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. Preferred features of each aspect of the invention may be as described in connection with any of the other aspects. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows an isometric view of a jig according to an embodiment of the invention with a rotatable sub-assembly thereof in a first rotational position;

Figure 2 shows an isometric view of the jig of Figure 1 with the rotatable sub-assembly in a second rotational position;

Figure 3 shows an isometric view of the fig of Figures 1 and 2 with a workpiece held therein;

Figure 4 shows an exploded view of a tooth suitable for use with the jig of Figures 1 , 2 and 3;

Figures 5A and 5B show upper and lower views, respectively, of a PCB held in a jig according to an embodiment of the invention;

Figures 6A and 6B show upper and lower views, respectively, of the jig of Figures 5A and 5B with the PCB held therein in a different configuration;

Figure 7 shows a plan view of a jig according to another embodiment of the invention;

Figure 8 shows a plan view of the jig of Figure 7 in an open configuration;

Figure 9 shows an isometric view of the jig of Figures 7 and 8 in a rotating configuration and with a workpiece held thereby;

Figure 10 shows an isometric view of a jig according to another embodiment of the invention, in a clamping configuration;

Figure 1 1 shows an isometric view of the jig of Figure 10 in an opening configuration; and Figure 12 shows an exploded view of a tooth suitable for use with the jig of Figures107 andl 18.

DETAILED DESCRIPTION

Figures 1 , 2, 3 and 4 illustrate a jig 100 according to an embodiment of the present invention. The jig 100 comprises a rotatable sub-assembly 10 that is rotatable relative to a static mounting sub-assembly 12 between a first rotational position shown in Figure 1 and a second rotational position shown in Figure 2, and any rotational position therebetween. The rotatable sub-assembly 10 is configured to hold a workpiece such as a PCB, as described below, and rotation of the sub-assembly 10 enables process steps (e.g. manufacturing or inspection steps) to be carried out on either main surface of the workpiece.

The rotatable sub-assembly comprises a jaw mounting frame 20 having first and second elongate jaw mounting plates 22 rigidly connected to one another at each end thereof via first and second elongate junction plates 24 to form an open four-sided frame 20. First and second axle portions 26 extend in opposite directions from each of the junction plates 24 so that their rotational axes are aligned.

The rotatable sub-assembly 10 is mounted on the static mounting sub-assembly 12 via first and second bearings 30. The static mounting sub-assembly 12 comprises first and second static bearing mounting plates 32, each having an opening within which an outer race of one of the bearings 30 is mounted via an interference fit, mechanical fixings, or other suitable rigid fixing arrangement. The first axle portion 26 of the mounting frame 20 is fitted via an interference fit, mechanical fixings, or other suitable rigid fixing arrangement into an inner race of the first bearing 30. Similarly, the second axle portion 26 of the mounting frame 20 is fitted into an inner face of the second bearing 30. In this way, the first and second axle portions 26 are able to freely rotate relative to the static bearing mounts 32, and thus the rotatable sub-assembly 10 is able to rotate relative to the static mounting sub-assembly 12 about a rotational axis.

The jaw mounting frame 20 carries first and second sliding jaws 40. Each jaw 40 comprises a generally elongate rectangular plate, and the first jaw 40 is mounted on the first mounting plate 22 and the second jaw 40 is mounted on the second mounting plate 22 so that opposing faces of the jaws 40 comprise teeth-mounting faces 42 separated by a clamping area 50 within which one or more printed mounting boards (PCBs; not shown in Figures 1 and 2) are held in use. The first jaw 40 is mounted on the first jaw mounting plate 22 via a sliding block 28 that permits the first jaw 40 to move relative to the first jaw mounting plate 22 via a translational movement in a clamping direction only. Similarly, the second jaw 40 is mounted on the second jaw mounting plate 22 via a sliding block 28 that permits the second jaw 40 to move relative to the second jaw mounting plate 22 via a translational movement in the clamping direction only. The clamping direction is perpendicular to the rotational axis of the rotatable sub-assembly 10 and permits movement of each jaw 40 towards and away from the rotational axis. Thus, relative movement between the first and second jaws 40 results in movement of the teeth-mounting faces 42 towards each other or away from each other, and a resultant narrowing or widening of the clamping area 50.

Each teeth-mounting face 42 of each jaw 40 supports a plurality of teeth 60. Each tooth 60 has a plastic gripping body 62 that has a generally cuboid shape with a V-shaped notch formed therein to define a gripping surface 64. The teeth 60 are arranged in a linear series along the teeth-mounting face 42 so that in a neutral configuration (shown in Figures 1 and 2) the V-shaped notches of their gripping surfaces 64 are aligned to together provide an aligned elongate notch. Each tooth 60 is separated from its neighbour by a small clearance gap to enable relative movement therebetween.

The gripping body 62 of each tooth 60 is rigidly mounted on either a single pin 66 or a pair of pins 66, each pin 66 being slideably mounted in a corresponding bore 46 in the respective jaw 40 so that the pin 66 moves within the bore 46 in the manner of a piston and cylinder assembly. One or more springs 72 (see Figure 4) bias each tooth 60 away from the teeth- mounting face 42 of its respective jaw 40.

Each pin 66 moves within its respective bore 46 along a tooth axis that is aligned with the clamping direction. In this way, each tooth 60 is independently moveable relative to its respective first or second jaw 40, and relative to the other teeth 60, along its respective tooth axis towards or away from the teeth 60 mounted on the other of the first and second jaws 40. Thus, the position of the gripping surface 64 of each tooth 60 relative to its respective jaw (and relative to the neutral configuration) can be varied.

Figure 4 shows an exploded view of an exemplary tooth 60 that illustrates how each pin portion 66 is constructed. A fixed end rod 67 has a threaded portion 68 that engages a corresponding threaded portion in the respective jaw 40, and a hollow cylindrical portion 69. An internal rod 70 is inserted inside the hollow cylindrical portion 69 and held in place by a ring-shaped fixed rod insert 71 that is fitted, optionally via an interference fit, into the hollow cylindrical portion 69 so that it encircles the internal rod 70. A portion of the internal rod 70 protrudes from the hollow cylindrical portion of the fixed end rod 67 so that it engages a base of a cylindrical recess in the gripping body portion 62 of the respective tooth. A spring 72 located between the gripping body portion 62 and the fixed end rod 67 biases the gripping body portion 62 away from the or each fixed end rod 67.

The gripping body 62 of each tooth may be configured in any one of a number of different ways to cater for the shape and dimensions of the printed circuit board to be clamped, as the skilled reader will readily understand. In the illustrated embodiment the teeth 60 each have a gripping body 62 that is one of three different configurations: the long gripping body 62a has the longest length in the tooth axis direction, and the mid gripping body 62b and the short gripping body 62c have a shorter length in the tooth axis direction. The mid gripping body 62b has a gripping surface 64 with a V-shaped notch that is shallower than those of the long 62a and short 62c gripping bodies. The mid gripping body 62b is also narrower (in the direction along the rotational axis, R) than the long 62a and short 62c gripping bodies, and is mounted on only a single pin 66. By providing multiple possible gripping body 62

configurations it is possible to even further enhance the ability of the jig 100 to accommodate PCBs of any size or shape.

The rotatable sub-assembly 10 comprises an opening mechanism 70 that is operable to move the jaws 40 between an open configuration in which the jaws are moved apart from one another to widen the clamping area, and a clamping configuration in which the jaws are moved towards one another to narrow the clamping area and thereby clamp a printed circuit board 90 (shown in Figure 3).

The opening mechanism 70 comprises a pair of hinge arms 72, each of which is connected at one end via a hinged joint to a piston rod 74 and at the other end via a similar hinged joint to a respective one of the jaws 40. The piston rod 74 is slideable within a bore 76 through the first axle portion 26 between an extended position in which the hinge arms 72 are opened through a wide angle and the jaws 40 are urged away from one another to the open configuration, and a retracted position (shown in Figures 1 and 2) in which the hinge arms are opened through a narrower angle and the jaws 40 are urged towards one another in the clamping configuration. The piston rod 74 is urged towards the retracted position by the action of a spring (not shown), whereby the jaws 40 are biased towards the clamping configuration.

In this embodiment the piston rod 74 is moved between the retracted and extended positions by operation of a key (not shown) to engage the piston rod 76 and displace it within the bore 76. The key may be manually operated or electrically operated via an electric motor and appropriate gearing arrangement. In some embodiments it may comprise a linear actuator such as a hydraulic, pneumatic, electric, magnetic, or mechanical actuator.

The rotatable sub-assembly 10 may also be rotated relative to the static mounting subassembly 12 manually or by an electric motor and appropriate gearing arrangement. Each axle portion 26 of the rotatable sub-assembly 10 comprises a pair of circular recesses 27 or through holes with which a corresponding pair of protrusions of a manual handle or a motor interface can mate to enable rotation of the rotatable sub-assembly 10.

As a result of the independent movement of the teeth 60 on each of the jaws 40, a PCB (or other workpiece) with an irregular shape can be readily held in the jig 100. An example is illustrated in Figure 3, in which a PCB 90 having non-straight edges is held in the jig 100.

Figures 5A, 5B, 6A and 6B also illustrate a jig according to the invention in which a workpiece having an irregular shape is held between two or more teeth 60 of the jig. In Figures 5A and 5B a PCB 92 is held in a first orientation, and in Figures 6A and 6B the same PCB 92 is held in a second orientation generally perpendicular to the first orientation. The PCB 92 PCBs has an irregular, non-straight profile which is accommodated by independent movement of the teeth 60.

In use, to insert a workpiece such as a printed circuit board 90, 92 into the clamping area 50 the jig 100 is moved to the open configuration by moving the piston rod 74 of the opening mechanism 70 to the extended position to thereby urge the jaws 40 away from one another. This movement widens the clamping area 50 and enables the workpiece to be located therein. The jig 100 is then moved to the clamping configuration by moving the piston rod 74 of the opening mechanism 70 to the retracted position to thereby urge the jaws 40 towards one another and consequentially narrow the clamping area 50. As the gripping surfaces 64 of the teeth 60 contact the workpiece 90, 92 the gripping bodies 62 of the teeth are each moved independently along their respective tooth axes towards their respective teeth- mounting face 42 against the biasing action of the springs. Each pin 66 moves within its respective bore 46 only so far as is necessary to ensure both that the workpiece is securely held, and that the contours of the workpiece edge profile are accommodated. To remove the workpiece 90, 92 the jig 100 is returned to the open configuration.

A second embodiment of the present invention is illustrated in Figures 7, 8 and 9. The illustrated jig 200 is similar in many respects to the jig 100 illustrated in Figures 1 to 6, and the description below is focused mainly on those features that are different. The jig 200 comprises a rotatable sub-assembly 110 that is able to rotate relative to a static mounting sub-assembly 1 12. The rotatable sub-assembly 1 10 is configured to hold a workpiece such as a PCB, as described below, and rotation of the sub-assembly 1 10 enables process steps (e.g. manufacturing or inspection steps) to be carried out on either main surface of the workpiece.

The rotatable sub-assembly comprises a jaw mounting frame 120 comprising a generally U- shaped rigid member, the two limbs thereof providing first and second jaw mounting plates 122. An axle portion 126 extends from a base of the U-shaped jaw mounting frame 120 in a direction generally opposed to that in which the first and second jaw mounting plates 122 extend.

The rotatable sub-assembly 110 is mounted on the static mounting sub-assembly 1 12 via a bearing 130. The static mounting sub-assembly 112 comprises a bearing mounting plate 132 having an opening within which an outer race of the bearing 130 is mounted via an interference fit, mechanical fixings, or other suitable rigid fixing arrangement. The axle portion 126 of the mounting frame 120 is fitted via an interference fit, mechanical fixings, or other suitable rigid fixing arrangement into an inner race of the first bearing 130. In this way, the axle portion 126 is able to freely rotate relative to the static bearing mount 132, and thus the rotatable sub-assembly 10 is able to rotate relative to the static mounting sub-assembly 12 about a rotational axis, R.

The jaw mounting frame 120 carries first and second sliding jaws 140. Each jaw 140 comprises a generally elongate rectangular plate, and the first jaw 140 is mounted on the first mounting plate 122 and the second jaw 140 is mounted on the second mounting plate 122 so that opposing faces of the jaws 140 comprise teeth-mounting faces 142 separated by a clamping area 150 within which one or more printed mounting boards (for example, PCB 190 shown in Figure 9) are held in use.

The first jaw 140 is mounted on the first jaw mounting plate 122 via a sliding block 128 that permits the first jaw 140 to move relative to the first jaw mounting plate 122 via a

translational movement in a clamping direction, C, only. Similarly, the second jaw 140 is mounted on the second jaw mounting plate 122 via a sliding block 128 that permits the second jaw 140 to move relative to the second jaw mounting plate 122 via a translational movement in the clamping direction, C, only. The clamping direction, C, is perpendicular to the rotational axis, R, of the rotatable sub-assembly 1 10 and permits movement of each jaw 140 towards and away from the rotational axis. Thus, relative movement between the first and second jaws 140 results in movement of the teeth-mounting faces 142 towards each other or away from each other, and a resultant narrowing or widening of the clamping area 150.

The sliding blocks 128 each comprise a first portion 128a that is rigidly fixed to the jaw mounting frame 120 and a second portion 128b that is rigidly fixed to the respective jaw 140. The first 128a and second 128b portions are interconnected to one another by a pair of rails 129 that permit relative sliding therebetween to provide movement in the clamping direction, C, of the jaws 140.

Each teeth-mounting face 142 of each jaw 140 supports a plurality of teeth 160. Each tooth 160 has a plastic gripping body 162 that has a generally cuboid shape with a V-shaped notch formed therein to define a gripping surface 164. The teeth 160 are arranged in a linear series along the teeth-mounting face 142 so that in a neutral configuration (shown in Figure 7) the V-shaped notches of their gripping surfaces 164 are aligned to together provide an aligned elongate notch. Each tooth 160 is separated from its neighbour by a small clearance gap to enable relative movement therebetween.

The gripping body 162 of each tooth 160 is rigidly mounted on a pair of pins 166, each pin 166 being slideably mounted in a corresponding bore 146 in the respective jaw 140 so that the pin 166 moves within the bore 146 in the manner of a piston and cylinder assembly. One or more springs (not shown) bias each tooth 160 away from the teeth-mounting face 142 of its respective jaw 140.

Each pin 166 moves within its respective bore 146 along a tooth axis that is aligned with the clamping direction, C. In this way, each tooth 160 is independently moveable relative to its respective first or second jaw 140, and relative to the other teeth 160, along its respective tooth axis towards or away from the teeth 160 mounted on the other of the first and second jaws 140. Thus, the position of the gripping surface 164 of each tooth 160 relative to its respective jaw (and relative to the neutral configuration) can be varied.

The gripping body 162 of each tooth may be configured in any one of a number of different ways to cater for the shape and dimensions of the printed circuit board to be clamped, as the skilled reader will readily understand. In the embodiment illustrated in Figures 7, 8 and 9 the teeth 160 each have identical gripping bodies 162.

The rotatable sub-assembly 110 comprises an opening mechanism 170 that is operable to move the jaws 140 between an open configuration in which the jaws are moved apart from one another to widen the clamping area 150, and a clamping configuration in which the jaws are moved towards one another to narrow the clamping area 150 and thereby clamp a workpiece such as a printed circuit board.

The opening mechanism 170 comprises a pair of hinge arms 172, each of which is connected at one end via a hinged joint to a piston rod 174 and at the other end via a similar hinged joint to a respective one of the second portions 128b of the sliding blocks 128 that is rigidly connected to a respective one of the jaws 140. The piston rod 174 is slideable within a bore 176 through the axle portion 126 between an extended position in which the hinge arms 172 are opened through a wide angle and the jaws 140 are urged away from one another to the open configuration, and a retracted position in which the hinge arms are opened through a narrower angle and the jaws 40 are urged towards one another in the clamping configuration. The piston rod 174 is urged towards the retracted position by the action of a spring (not shown), whereby the jaws 140 are biased towards the clamping configuration.

The piston rod 174 is moved between the retracted and extended positions by operation of a key 180 (see Figure 8) having a cylindrical portion 182 that is insertable into the bore 176 to move the piston rod 174 towards the extended position against the action of the spring. The key 180 is manually operated in this embodiment, but in other embodiments it may be operated via an electric motor and appropriate gearing arrangement, or via a linear actuator such as a hydraulic, pneumatic, electric, magnetic, or mechanical actuator, or other arrangement that can be remotely controlled. The key disclosed in relation to this embodiment may also be suitable for use with the first embodiment.

The rotatable sub-assembly 10 is rotatable relative to the static mounting sub-assembly 12 by way of an interface connector 186 (see Figure 9) having a pair of protrusions 188 that are arranged to mate with a corresponding pair of circular recesses 127 or through holes in the axle portion 126. The interface connector 186 can be rotated manually via a handle, or via an electric motor and appropriate gearing arrangement, for example, to rotate the rotatable sub-assembly 10 to facilitate process steps to be carried out on either face of the workpiece 190 (see Figure 9) held by the jig 200. The interface connector disclosed in relation to this embodiment may also be suitable for use with the first embodiment.

In use, to insert a workpiece such as a printed circuit board into the clamping area 150 the jig 200 is moved to the open configuration by moving the piston rod 174 of the opening mechanism 170 to the extended position to thereby urge the jaws 140 away from one another. This movement widens the clamping area 150 and enables the workpiece to be located therein. The jig 200 is then moved to the clamping configuration by moving the piston rod 174 of the opening mechanism 170 to the retracted position to thereby urge the jaws 140 towards one another and consequentially narrow the clamping area 150. As the gripping surfaces 164 of the teeth 160 contact the workpiece the gripping bodies 162 of the teeth are each moved independently along their respective tooth axes towards their respective teeth-mounting face 142 against the biasing action of the springs. Each pin 166 moves within its respective bore 146 only so far as is necessary to ensure both that the workpiece is securely held, and that the contours of the workpiece edge profile are accommodated. To remove the workpiece the jig 200 is returned to the open configuration.

Figures 10, 1 1 and 12 illustrate a third embodiment of the present invention. This embodiment provides a jig 300 that is particularly simple to configure. Figure 10 illustrates the jig 300 in a clamping configuration in which it is holding a workpiece, which in this embodiment is a printed circuit board (PCB) 290. Figure 11 illustrates the jig 300 in an opening configuration in which the jig is opened to facilitate removal or insertion of a workpiece.

The jig 300 comprises first and second jaws 240, each of which is moveable relative to a jaw mounting portion 220. Each jaw mounting portion 220 comprises a cylinder block 222 which may be rigidly mounted on a static mounting frame (not shown) or mounted on a rotatable mounting frame, for example. The cylinder blocks 222 each comprise a plurality of (three in this embodiment) bores 224 within which each of which a respective piston 226 is slideable in the manner of a cylinder and piston assembly. The pistons 226 are configured to move in tandem to move the respective jaw 240 towards or away from the respective cylinder block 222 along a clamping direction, C.

Each jaw 240 is thus movable via a translational movement in the clamping direction, C, only. The jaws 240 have opposing faces which provide teeth-mounting faces 242 separated by a clamping area 250 within which one or more printed mounting boards (for example, PCB 290 shown in Figures 10 and 11) are held in use. Thus, relative movement between the first and second jaws 240 results in movement of the teeth-mounting faces 242 towards each other or away from each other, and a resultant narrowing or widening of the clamping area 250.

Each teeth-mounting face 242 of each jaw 240 supports a plurality of (ten in this

embodiment) teeth 260. Each tooth 260 has a gripping body portion 262 which is moveable along a tooth axis relative to a pin portion 266 that is rigidly connected to the respective jaw 240. Each gripping body portion 262 is generally cylindrical, with a V-shaped notch formed in the end face thereof to define a gripping surface 264. The teeth 260 are arranged in a linear series along the teeth-mounting face 242 so that in a neutral configuration (when a workpiece is not held in the jig 300) the V-shaped notches of their gripping surfaces 264 are aligned to together provide an aligned elongate notch. Each tooth 260 is separated from its neighbour by a small clearance gap to enable relative movement therebetween.

Each gripping body portion 262 moves relative to its respective pin portion 266 along a tooth axis that is aligned with the clamping direction, C. In this way, each tooth 260 is

independently moveable relative to its respective first or second jaw 240, and relative to the other teeth 12260, along its respective tooth axis towards or away from the teeth 160 mounted on the other of the first and second jaws 140. Thus, the position of the gripping surface 164 of each tooth 160 relative to its respective jaw (and relative to the neutral configuration) can be varied. The gripping body portion 262 of each of the teeth 260, and thus the gripping surface 264, is biased away from the respective teeth-mounting face 242, and thus towards a workpiece to be clamped in the clamping area 250.

Figure 12 shows an exploded view of an exemplary tooth 260 that illustrates how the pin portion 266 is constructed. A fixed end rod 267 has a threaded portion 268 that engages a corresponding threaded portion in the respective jaw 240, and a hollow cylindrical portion 269. An internal rod 270 is inserted inside the hollow cylindrical portion 269 and held in place by a ring-shaped fixed rod insert 271 that is fitted, optionally via an interference fit, into the hollow cylindrical portion 269 so that it encircles the internal rod 270. A portion of the internal rod 270 protrudes from the hollow cylindrical portion of the fixed end rod 267 so that it engages a base of a cylindrical recess in the gripping body portion 262 of the respective tooth. A spring 272 located between the gripping body portion 262 and the fixed end rod 267 biases the gripping body portion 262 away from the fixed end rod 267.

The gripping body 262 of each tooth may be configured in any one of a number of different ways to cater for the shape and dimensions of the printed circuit board to be clamped, as the skilled reader will readily understand. In the embodiment illustrated in Figures 10, 11 and 12 the teeth 260 each have identical gripping bodies 262.

In use, to insert a workpiece such as a printed circuit board 290 into the clamping area 250 the jig 300 is moved to the opening configuration illustrated in Figure 11 , in which the pistons 266 are all retracted into their respective bores 224 in the cylinder blocks 222 along the clamping direction, C, as indicated by arrows, R. This movement widens the clamping area 250 and enables the workpiece 290 to be located therein. The jig 300 is then moved to the clamping configuration illustrated in Figure 10, in which the pistons 266 are driven out of their respective bores 224 in the clamping direction, C, as indicated by arrows, D, to thereby narrow the clamping area 250. As the gripping surfaces 264 of the teeth 260 contact the workpiece 290 the gripping bodies 262 of the teeth are each moved independently along their respective tooth axes in the direction indicated by arrows, T, against the biasing action of the springs 272. Each gripping body 262 moves relative to its respective pin portion 266 only so far as is necessary to ensure both that the workpiece is securely held, and that the contours of the workpiece edge profile are accommodated. To remove the workpiece the jig 300 is returned to the opening configuration.

In each of the embodiments and aspects described herein the jig is for clamping a workpiece such as a printed circuit board (PCB), or a plurality of workpieces such as a plurality of PCBs or an assembly of a plurality of PCBs. The or each workpiece is typically a generally planar member having a relatively small thickness. Thus, the or each workpiece has generally two main faces subtended by a relatively thin edge. The or each workpiece may have any shape in planform, and typically has a convoluted perimeter shape. The or each workpiece typically has a length (i.e. a longest dimension across at least one of its main faces) of 150mm or less, and/or a width (i.e. a longest dimension in a direction perpendicular to the length across at least one of its main faces) of 90mm or less.

The or each workpiece may be placed into the clamping area of the jig by hand, or by automated means such as a robotic arm. The use of a robotic arm may be advantageous in making the placement of multiple identical workpieces into the jig highly repeatable.

In each of the embodiments the components may be formed from any suitable material. However, it is envisaged that the gripping portions of the teeth will be formed from plastic, and the remaining components will be formed from an appropriate metal or metal alloy.

In all of the embodiments described above one or more regions of masking material may be applied to a face of a workpiece secured in the jig 100, 200, 300 by a robotic arm (not shown). The rotatable sub-assembly 10, 110, 210 may be subsequently rotated about the rotational axis, R, through 180 degrees, and one or more regions of masking material applied to an opposite face of the workpiece by the robotic arm. Thus, a single robotic arm can be used to operate on both faces of the workpiece. The workpiece is then removed from the jig and exposed to surface modification conditions, e.g. vapour deposition conditions by placing it in a plasma polymerisation deposition chamber. The workpiece may in some circumstances be returned to the jig 100, 200, 300 following the surface modification process in order to remove some or all of the regions of masking material. By way of example, a vapour deposition process in accordance with an embodiment of the invention comprises exposing the workpiece to vapour deposition conditions substantially as described in WO 2007/083122, which is incorporated herein by reference.

In another embodiment the vapour deposition conditions further comprise a cross-linker selected from 1 ,4-butanediol divinyl ether (BDVE), 1 ,4-cyclohexanedimethanol divinyl ether (CDDE), 1 ,7-octadiene (170D), 1 ,2,4 -trivinylcyclohexane (TVCH), divinyl adipate (DVA), 1 ,3-divinyltetramethyldisiloxane (DVTMDS), diallyl 1 ,4-cyclohexanedicarboxylate (DCHD), 1 ,6-divinylperfluorohexane (DVPFH), 1 H, 1 H,6H,6H-perfluorohexanediol diacrylate (PFHDA) and glyoxal bis(diallyl acetal) (GBDA).