"Enclosure with integrated thermal management and improved

EMI-SE"

Technical Field

Present application discloses an enclosure for electronic component use, being provided with integrated thermal management and improved electromagnetic interference (EMI) / immunity shielding effectiveness (SE), through the use of unique high-performance thermoplastic compounds with tailored properties.

Background art

Nowadays, the drive for continuous mass reductions in the overall day-by-day products has promoted the use of polymeric materials. Depending on the final product requirements, diverse polymers can be took into account.

The attraction for the use of thermoplastics lies mainly is the fact that its use promotes weight savings in the final products, being nearly 40% lighter than aluminium for example, being also corrosion resistant. Recently, a new generation of thermoplastic composites is addressing the need for cost-effective and high-throughput parts. This new generation of composites is targeted to replace metals in housings and heat sinks.

An enclosure that assumes the function of assuring electrostatic discharge (ESD) immunity is particularly in need of a proper contact between printed circuit board (PCB) and casing (US 4,494,651). The high variability in terms of PCB thickness results in the use of flexible conductive elements with this purpose (US 8,472,203 B2). Summary

Present application describes an enclosure for electronic component use comprising: a bottom plate; at least one overmolding modular plate, physically bonded with said bottom plate through an injection molding process; at least one heat sink; at least one cooling fan, installed on the top of said at least one heat sink; wherein the combination of the heat sink with the cooling fan and the overmolding modular plate with the bottom plate is responsible for assuring the thermal management of the enclosure.

In one particular embodiment of the enclosure, the bottom plate, the at least one overmolding modular plate and the at least one heat sink comprise the use of thermoplastic compounds.

In yet another particular embodiment of the enclosure, the at least one cooling fan assures the at least one heat sink cooling by forced air convection means, said at least one cooling fan being positioned in an inclination between 15° and 35° degree angle with relation to the horizontal plane.

In yet another particular embodiment of the enclosure, the thermoplastic compounds comprise one of polybutylene terephthalate (PBT) and/or polyamide (PA66).

In yet another particular embodiment of the enclosure, the thermoplastic compounds comprise the use conductive fillers, namely, steel and/or carbon and/or graphite and/or alumina. In yet another particular embodiment of the enclosure, the thermoplastic compounds comprise average admissible service temperatures of 85°C, and/or average heat deflection temperatures of 100°C and/or average thermal conductivity of lOW/mK.

In yet another particular embodiment of the enclosure, the thermoplastic compounds comprise shielding effectiveness of 60dB with a 2mm thickness in a 100kHz to 5GHz frequency range, or maximum surface resistivity of lOOQcm, or a maximum volume resistivity of lOQcm.

Present application further describes a process for injection molding of the bottom plate, comprising the steps of: installation of inserts in specific zones in the mold; heat the overmolding modular plate in a convection oven at a temperature of 140°C; insert the plate inside the mold and close the mold for approximately 30 seconds; after the temperature stabilization, the process of overmolding of the polymeric insert with the metal inserts starts, where the hot channel feeds the system though three injection points; after the injection is completed, the overmolded is cooled through the use of 11 individual water circuits, promoting uniform cooling of the part; after the cooling, 18 air extractors are used to extract the part.

The proposed polymeric solution allows to obtain a weight reduction improvement and overcome some shaving issues introduced in the assembly of metal housings, and for that fact, this technology introduces benefits in its development and use. It is disclosed a holistic solution for those type of products, namely enclosures for electronic component use. The total thermoplastic electronic housing here proposed allows to introduce overall benefits in weight reduction, cost reduction and production waste reduction. The proposed solution lays on a solution fully made of high-performance thermoplastic compounds, including thermal dissipation devices. This cost-effective electronic housing design also promotes the use of thermoplastic multifunctional materials to solve EMC and thermal management functions of the system.

General Description

Present application is related to the integrated design and development of an electronic device housing where main improvements are related to the overall design, operational method, thermal performance and EMI-SE insulating properties of the plastic housing, making it lighter, cheaper, cleaner (in the assembly process), and greener than the metallic solution.

Referring to the actual metallic baseline solution competitor, in the polymer-based inventions, the plastic electronic housing is totally made of high-performance thermoplastic compounds with improved electromagnetic interference / immunity shielding effectiveness, with the inclusion of thermal dissipation devices.

The design of the housing components is developed with a comprehensive approach, combining advanced thermal and EMI simulations, aiming to establish a tailored behavior in specific areas of interest, combining geometric features with particular behavior of high-performance thermoplastics. Two thermoplastic resins with improved properties for EMI- SE and thermal dissipation are used and applied. In each particular element of the developed design, a combination of compound resins is used to optimize the combined thermal and shielding behavior. The thermal environment of the complete electronic system is managed with the usage of the thermal passive diffusion associated with the housing design combined with an innovative design with high conductive thermoplastic for a convective heat exchange device.

The used thermoplastic injection molding method, based on overmolding and bi-material techniques, allows the productivity increase through cycle time reduction, final part quality uplift and EMI-SE and improve the thermal dissipation behavior. This processing technology is used for the production of all the parts of the electronic housing and the heat exchange device. The requirements of the manufacture process were included in the components integrated design.

Thermal management is assured by forced air convection, generated by an optimized fan, and heat conduction through effective conductive materials. The fan promotes the cold air intake into the housing and a quick dispersion of hot air out of the housing. This inverted flow direction optimizes the system thermal performance. Furthermore, the developed system is provided with specific locations where the heat conduction is more significant and efficient, such as the heatsink and the housing areas near the most heat generating components. In these locations, the usage of materials with higher thermal conductivity is an accomplished requirement. The developed heat sink made of polymeric materials allows a significant weight reduction, once the design and phenomena of heat dissipation is optimized through geometric features, interface modelling, and heat transfer analysis between the heat sink and air. The proposed optimized heatsink feature fins with an optimized relation between fins density and thickness as height of fins and base. Thermal conductivity values in the range of the tested materials, present significant impact on the heatsink thermal performance. Typical thermal conductivity (TC) values for some polymers are 0.1 to 0.5 and they have been largely explored, 234 for aluminum, 400 for copper and 600 for graphite (all values in W/mK). Thermoplastics and/or thermosets doped with conductive fillers materials have been appointed as the best option for substitute the aluminum in thermal managements.

In general, polymeric matrices feature low capacity for electron conduction and phonon transportation within their chemical structure. For this reason, carbon, mineral and metallic fillers have been incorporated in the disclosed solution. The conductivity of a filled conductive system depends on the relative concentration of filler and matrix, type of polymer, polymer viscosity, polymer crystallinity, dispersion and distribution of the filler and their compatibility with the polymeric matrix. However, these fillers often exhibit anisotropy both in geometry and thermal conductivities. The thermal conductivities in in-plane/line direction are much higher than that of through-plane/line direction.

During the injection molding an insulated layer on the surface is formed, inducing the shear effect and consequently a significant difference between the orientations of the anisotropic filler particles can be found. Several investigations have been focused on enhancing heat spreading in-plane direction, nevertheless, the through-plane heat conduction is very limited. Anisotropic heat transfer through 3D assembled nanofillers might have great potential for many applications (as shown in Hong et al. 2017). Said that, one of the main objectives of developed application is to identify a solution and substitute for the common aluminum heat sinks.

As previously mentioned, non-conventional injection molding techniques were applied to produce a bi-material enclosure for electronic component use, combining shielding and thermal management enhanced properties.

The nature of the requirements and specifications established to support the material selection process required for the entire development process are divided into four relevant areas: mechanical, thermal, EMC (electromagnetic compatibility) and processing.

The targeted components to be developed are the ones that compose the housing (top plate, bottom plate, back plate) and the heat sink. They will share some requirements but in the end they will present some different specifications because the housing's functions are more related to mechanical and electromagnetic protection, whereas the heat sink serves for heat dissipation.

Thermal Requirements

The thermal issues are of extreme importance in the development of this product, since there is a constant generation of heat by the electrical/electronic components installed inside the enclosure resulting in a thermal environment of high temperatures, which should be dissipated by the chassis. This aspect takes on even more significant proportions when the chassis material is being changed from metal (typically heat conductive material) to plastic (typically thermal insulation) as well as the heat sink itself.

These requirements are mainly focused on general specifications such as service temperatures and HDT (heat deflection temperature), but also thermal conductivity, considering that the heat sink component is also to be replaced from metal to plastic.

Another important aspect related to the thermal specifications is related to the service temperature that the material must withstand, which in the case of the polymers is also much smaller than in the metallic case. Regarding the thermal requirements presented in these standards, it is the "Thermal Shocks Endurance Test" which constitutes the critical condition of the material. The conditions predefined aim to maximum temperature of 85°C and a minimum temperature of -40°C, both applied during lh.

Thus, the thermal specifications of the material are:

- Minimum service temperature below -40 ° C;

- Maximum service temperature higher than 85°C.

Considering that the heat sink material (usually aluminum) is also being replaced by plastic, thermal conductivity of this material is also of relevant matter. Some preliminary analysis, in which the thermal conductivity have been made varying, show that above a certain value of thermal conductivity, this property is no longer of major importance in the solution. For the thermal management, the heat sink is provided with a fan that is intended to promote a rapid dispersion of the hot air inside the housing by forcing the air inside through forced air convection means.

Hence, thermal specifications for these materials are:

— Service temperatures: -40°C e 85°C

— HDT (heat deflection temperature) @1.8MPa: 100°C

— Thermal conductivity: > lOW/mK (In-plane)

> 2W/mK (Through-plane)

Electromagnetic Requirements

Electromagnetic requirements are considered to be the most critical ones, as it is important that the chassis is produced in a shielding conducting material which represents a barrier to any electric, magnetic or electromagnetic field. Its function is quantitatively defined by the Shielding Effectiveness (SE), which is the ability of the material in attenuating an electromagnetic wave and is usually expressed in dB (decibels).

The increased requirement of extra functionality of the proposed enclosure leads to an obvious increase in its complexity in electronic usage terms. This implies a serious susceptibility of interference between different systems through radiated and conducted electromagnetic interference. Thus, electromagnetic compatibility (EMC) is an inescapable subject in the development of this type of products.

In terms of shielding specifications, the attenuation (SE) should be at least 60dB for a thickness of 2mm (which should be approximately the chassis thickness, as it is a typical value for this type of product and material). The frequencies stablished for electronics protection thought the use of the proposed enclosure are within the range of 100kHz to 5GHz. The SE is dependent on the electrical conductivity and the magnetic permeability of the material, and the greatest contribution is given by the electrical conductivity of the material.

The electrical conductivity (or surface/volume resistivity, which is more usual in material datasheets) is also of great importance because of the grounding to the Printed Circuit Board (PCB).

Hence, electromagnetic specifications for these materials are:

- Shielding Effectiveness (SE): 60dB @ 2mm (100kHz - 5GHz)

- Surface resistivity < lOOQcm

- Volume resistivity < lOQcm

Mechanical/Dynamic Requirements

The structural validation of the components must be carried out in accordance with the mechanical, dynamic, shock and vibration test requirements.

The mechanical requirements can be ensured by a correct relationship between material properties vs. component geometry. Thermal and EMC requirements are much more challenging considering that the chassis material is being replaced from metal (typically heat and electrical conductive) to plastic (typical thermal and electrical insulation) . In terms of mechanical requirements, the free fall test is considered the critical one. In this specific test, the proposed enclosure is submitted to a fall from a height of lm onto a concrete floor twice in each axis (in normal and reverse direction). The mechanical requirements are always intrinsically linked to thermal ones, since the properties of these materials are strongly thermal-related. Thus, it makes more sense to address them as thermomechanical requirements.

In terms of dynamic requirements, the resonance point detection test and the resonance point oscillation test are both of interest.

The performed tests were more restrictive to the components, especially because of the material change, since metallic materials of the baseline version are much more rigid than polymeric ones).

The resonance point detection test determines that the resonance frequency of the chassis must be above 50Hz. This is strongly dependent on the rigidity of the system, which in turn is dependent on the material rigidity and the geometry .

As mentioned for the mechanical specifications, for the dynamic specifications of these materials, the performed analysis lead to the conclusion that for the preliminary geometry of the system, a material with a rigidity of approximately llGPa (modulus of elasticity) would present reasonable frequencies.

Hence, mechanical specifications for these materials are:

- E (Tensile Modulus) > llGPa

Material Selection Methodology

Material selection is always a critical aspect in product development. This project aims to change from a metallic material to a polymeric. This is as huge challenge due to the difference in intrinsic properties of those type of materials (e.g. thermal, electrical and mechanical). Material selection procedure is being executed based on previous mentioned requirements, but thermal and electrical specifications impose the need to narrow the search to highly filled materials (with varying types of fillers), which brings us to the final area of requirements, that is processing .

Currently, in the market it is possible find thermoplastic materials specifically developed to address similar requirements, however they are not suitable for all metal substitution in terms of their intrinsic characteristics. These materials are typically composed of engineered thermoplastic resin matrices loaded or coated with conductive fillers (steel fibers, carbon fibers, graphite, alumina, etc.). It is necessary, however, to ensure good dispersion and distribution of the fillers in the matrix, since they are responsible for the mechanical strength and for the conductive (thermal or electric) path.

In terms of thermal conductivity, the developed materials for the purpose achieved up to 14W/m°C which is well below the typical 50W/m°C for example of steel.

As far as EM shielding capacity is concerned, the existing thermoplastic compounds are very close to the specifications of the chassis, i.e. they have attenuation values of about 60dB.

As mentioned previously, despite the latest developments in materials engineering, these are not yet at the level of metals, with respect to thermal and shielding issues. Thus, it may be expected that the selected material does not itself meet the requirements, so the solution will also have to encompass geometric (such as thermal issues, for example that can be circumvented by openings in the chassis that force air convection, or mechanical issues that may be complemented by geometric features, ribs, etc.) and technological features to ensure compliance with the

Processing Requirements

In terms of processing, the main requirement for the materials is its adaptability to the injection molding process due to the complexity of the system geometry.

The developed process constrained the processing temperature to a maximum of approximately 300°C, in order to reduce the number of polymer families (such as PEEK, PEI, LCP, etc.) which are normally difficult to process and highly expensive.

Brief description of the drawings

For better understanding of the present application, figures representing preferred embodiments are herein attached which, however, are not intended to limit the technique disclosed herein.

Fig. 1 - illustrates the general overview of the global concept and design of this invention displayed in the frontal view of the enclosure. The main components that constitute the total housing electronics are the top plate (1), cooling fan (2), heat sink (3), main PCB (4), secondary PCB (5) and secondary PCB support plate (6). The development of the proposed enclosure is based on a TPC design (top plate, back plate and bottom plate) with improved properties for EMI-SE and a total plastic heat dissipation system comprising various elements as heat sink and modular plate with high thermal conductivity. Fig. 2 - illustrates the general overview of the global concept and design of this invention displayed in the back view of the enclosure. It is visible the bottom plate (7) and back plate (8) of the enclosure.

Fig. 3 - illustrates the exploded view of the enclosure. Referred components: top plate (1), cooling fan (2), heat sink (3), main PCB (4), secondary PCB (5), secondary PCB support plate (6), bottom plate (7), back plate (8) and overmolding modular plate (9).

Fig. 4 - illustrates a detailed upper view of the bottom plate (7) with the overmolding modular plate (9). An important appointment, the thermoplastic material for thermal insert (modular plate (9) - with high thermal conductivity) should present chemical compatibility with bottom plate (EMI-SE).

Fig. 5 - illustrates a detailed bottom view of the bottom plate (7).

Fig. 6 - illustrates a detailed upper view of the developed cooling fan (2) and heat sink (3), where the eat sink is produced with a thermoplastic resin with improved thermal dissipation properties.

Fig. 7 - illustrates a detailed side view of the developed cooling fan (2) and heat sink (3). Description of Embodiments

With reference to the figures, some embodiments are now described in more detail, which are however not intended to limit the scope of the present application.

One of the goals for the development of this solution approach sets on surpassing traditional/current metal-based solutions by reducing the weight (45%) and lowering the cost (25%). This solution must comply with the applicable standards and requirements of conventional enclosures.

Forming plastic is the process of transforming a specified material into a desired shape. Most plastic forming processes use either thermoplastics (soften and melt when heated) or thermoset plastics (harden when heated), usually in the form of pellets, powder, liquid components, or sheets.

In general, plastics processes have three main phases: heating (to soften or melt the polymer); shaping/forming (under constraint of some kind); and cooling (so that it retains its shape).

There is a wide diversity of technologies that allow the processing of polymers for the production of plastic products. The selection of a process depends on many factors including: quality and production rate; dimensional accuracy and surface finish; form and detail of the product; nature of the material; and dimensions of the final product. Each process has unique benefits and restrictions relating to cost, lead time, effect on performance, perception of quality, and durability. As previously mentioned, and for all the above reasons, the point injection molding was used due to the complexity of the system geometry. In one of the embodiments of the proposed external housing and heat sink, two thermoplastic resin compounds are applied, more specifically polybutylene terephthalate PBT based thermoplastic resins. These PBT based resins feature an improvement in what concerns to mechanical, thermal and electric and EMI-SE insulating properties when compared with its direct metal competitor. The used compounds were polybutylene terephthalate (PBT) and polyamide (PA66) based materials loaded with carbon, mineral and metallic-based fillers, which lead to average thermal conductivity values of lOW/mK. Bi-material and overmolding injection technology is used to perform the part production.

In one of the conceptual solutions designed for the top and bottom plate components, better dynamic behaviors were obtained, with higher resonance frequencies (more distant from the critical frequency) and less complex vibration modes due to the simplicity of the geometry compared to the metal baseline solution. In this solution it was possible to reduce the total mass of the enclosure by approximately 50% (0.264 kg) compared to the base model (simplified) with a total mass of 0.515 kg.

In one of the proposed embodiments, the enclosure, or Total Plastic Chassis (TPC), has a wall thickness of 2 mm and consists of a material that has an attenuation of the electromagnetic field greater than 40dB allowing to improve the immunity of the chassis in relation to the base model.

In one of the proposed embodiments of the enclosure, the ventilation grilles have circular geometry holes, once they provide more stable shielding and are easier to produce. The spacing between holes has no influence on the shielding efficiency and this characteristic can be defined according to the constraints of the chassis manufacturing process.

Other of the proposed solutions to facilitate air convection, the total area of the ventilation grid holes should be maximized up to a 40dB electromagnetic shield (lower limit). In this case, only plastic materials have properties equivalent to materials with conductivity of 600 or 800 S/m and should always have a shielding greater than 40dB.

The base line metallic system has a higher environmental impact, the material production being the main contributor, followed by the usage phase. The TPC enclosure system shows the best environmental performance (in circa of 15%), being, in this case, the use phase the main contributor, followed by the material production. The Fossil depletion, Climate change human health and Climate change ecosystems impact categories are the most significant environmental burdens of all the systems.

The use of thermoplastic with the proposed compounds in the concept design enclosure, enables approximately a 45% weight reduction, when compare with the baseline system, mitigating the GWP (Global Warming Potential) and CED (Cumulative Energy Demand) environmental impacts until the usage phase. This is due to the fact that polymer matrix composites are produced through a more energy intensive process (by unit weight) than steel/aluminum, and the weight reduction doesn't mitigate this energy increase.

The heat sink was optimized regarding several geometric features that were modelled and analyzed in terms of total heat transfer rate at the interface between heat sink and air. Optimized heat sink present fins with an optimized relation between fins density and thickness as height of fins and base.

The fan mass flow rate has been analyzed by testing several types of more effective fans. Significant differences were achieved for small flow rate, but behind 0.00125 kg/s, the thermal performance increasing is not very significant once it is not linearly dependent on the fan mass flow rate.

On one of the embodiments, the fan orientation is installed over the heatsink in an inclination between 15° and 35° degree angle with relation to the horizontal plane. Although the fan mass flow rate doesn't significantly affect the thermal performance, this proposed positioning helps to improve the temperature minimization.

Considering the final achieved results, the polymeric chassis reinforced with carbon fibers and carbon thermal fillers have a high potential to substitute the metallic chassis with the benefit of cost and weight reductions and consequently the contribution for the reduction of gas emissions.

Top plate

For the production of this item, a mold based on hot channels was used, eliminating the existence of superficial marks on the developed piece. The molding zone is produced by the combination of the bushing, cavity and three different moving elements. Since this component consists of a set of metallic inserts, before the part is produced, the inserts are placed in specific areas in the mold. After the mold is closed, the injection of molten material occurs. Here, the metal inserts are overmolded.

The hot channel feeding system present in the production tool is composed of four injection points (valve gates). The location of entry melt was carefully selected in order to promote a filler material balance, ensuring that the melt reaches the ends of the workpiece simultaneously. This balance in the filling of the part is essential to minimize the total warpage and / or deformation, resulting from the thermal expansion and contraction of the material during the injection, pressurization and cooling phases, contributing to the fulfilment of the required dimensional tolerances. The temperature control system selected for the injection mold (11 individual circuits), also promotes uniform cooling of the part, using water as the main coolant. Due to the existence of several fuel fronts, and to minimize the occurrence of air trapped at the top of the injected part, an efficient exhaust gas system was developed, by the use of 20 extractors, contributing to the air extraction, having the particularity of molding a set of geometric details in the piece.

Back plate

The Back Plate is produced by combining the bushing, cavity and a moving element. This part is produced from two types of feeding system - hot channel and cold channel. With regard to the hot channel supply system, it consists of a distributor, which maintains the molten material from the injection nozzle to the cold channel supply system. This type of system, since it is thermally controlled, allows, for each injection cycle, a reduction in the material used. After the melt reaches the cold channel feed system (main feeder), it is divided into three secondary feeders. The entrance of the cast in the impression occurs from three submarine injection attacks. The location of these points ensures that the ends of the part fill simultaneously. Again, this balance is essential to minimize the total warpage and / or deformation, resulting from the thermal expansion and contraction of the material during the injection, pressurization and cooling phases, contributing to the fulfillment of the required dimensional tolerances. Due to the existence of three injection points, it was necessary to eliminate the visibility of joining lines by optimizing the process conditions, that is, high injection speeds with high melt and / or mold temperatures. The temperature control system adopted consists of 5 individual circuits. These circuits promoted uniform cooling, producing parts in accordance with the project specifications. The selected refrigerant was water. Here, 20 extractors were used, and their geometry (the area in contact with the part) was carefully selected.

Overmolding modular plate

For the production of this part, a mold based on hot channels was used being produced by the combination of the bushing and the cavity. The hot channel feeding system present in the production tool consists of only one injection gate (valve gate). The casting inlet location was carefully selected, allowing it to reach the ends of the part simultaneously. The number of pins on the surface of the part was carefully selected, in order not only to facilitate the filling of this component, but also to better trap this part to the Bottom Plate. Since the overmolding modular plate is a overmolded piece to the Bottom Plate, it is essential that there is no mark of the injection point, otherwise the pins will not all be at the same level and, consequently, the connection between the two plates is more difficult. Around this piece, a set of slots was also machined in order to improve the mechanical connection of this piece to the Bottom Plate. Given that this piece features high thermal conductivity, the temperature control system is critical, since if there is a premature cooling of material, there is an effective compression. The adopted system comprises the use of water circuits, to ensure a constant temperature of the distributor, and resistances to control the temperature of the fixed and moving parts of the mold. To extract the overmolding modular plate, the use of 10 extractors is required .

Bottom plate

For the production of this part, a mold based on hot channels was used being produced through the combination of the bushing, cavity and three distinct mobile elements. This component comprises a polymeric insert (the overmolding modular plate piece) and a set of metallic inserts. Before the piece to be produced, the placing of inserts in specific zones in the mold is processed.

As for the polymeric insert, in order to reduce the temperature difference between the overmolding modular plate (room temperature) and the Bottom Plate mold walls, since different cooling rates promote warping, it is essential to heat the polymeric insert in a convection oven (140°C) for a few minutes. After the heating phase, the plate is placed over the mold. The overmolding modular plate piece, being made of a polymeric and ferrous material, is attracted by the magnets present in the mold. This feature allows the part to be fixed to the mold and its position remains defined after closing it. Then, the mold remains closed for approximately 30 seconds. After temperature stabilization, the overmolding of the polymeric insert and the metal inserts processes takes place. Here, there is also a mechanical trap between the two plates. The hot channel feeding system present in the production tool, consisting of three injection points (valve gates), allows the melt to reach the ends of the part simultaneously. This balance in the part filling is essential to minimize the total warpage and / or deformation. This part is cooled through 11 individual water circuits. The respective circuits and the layouts are responsible for promoting a uniform cooling of the part. Due to the existence of several melt fronts, and to eliminate the air trapped at the top of the injected part, an efficient gas exhaust system was implemented. To extract the component, 18 extractors were used, some of which, in addition to contributing to the extraction itself, have the particularity of molding a set of geometric details in the piece. In this piece it was also machined one set of semicircles with the aim of facilitating the assembly process of various components, involved in the final product.

Heat sink

The Heat Sink component is produced by combining the bushing, cavity and a set of molding inserts to reproduce certain geometric details in the piece. This part is produced from two types of feeding system - hot channel and cold channel. With regard to the hot channel supply system, it consists of a distributor, which maintains the molten material from the injection nozzle to the cold channel supply system. After the melt reaches the cold channel feed system, melt enters the part through a slit. It is this type of attack that allows the creation of a uniform flow front, obtaining complete and properly compacted moldings. Once the material in this part features high thermal conductivity, and taking into account the height of the vane assembly in the heat sink, it is crucial to promote melt inlet along the width of the workpiece. Otherwise, the material would not be able to reach the opposite end due to early cooling. As for the temperature control system, resistances were used to control the temperature of the fixed and moving parts of the mold. It is important to note that one of the resistors penetrates the interior of the molding inserts in order to facilitate the flow of molten material in the region of the fins. For the extraction, 22 extractors were necessary and, to prevent the trapping of the piece in the mold, 6 compression springs were used.