Shell component, shell and preparation method thereof

Abstract

The invention relates to a housing component, a housing and an electronic device. The housing part according to the present invention comprises a first layer, which is molded from a first composition, the first composition comprising a1) 50-90 wt% of a first amorphous polymer and b1) 10-50 wt% of a first thermally conductive filler, the first composition having a thermal conductivity (TC1) of 4-40 W / (m*K), a second layer, which is molded from a second composition, the second composition comprising a2) 50-90 wt% of a second amorphous polymer and b2) 10-50 wt% of a second thermally conductive filler, the second composition having a thermal conductivity (TC2) of 0.5-10 W / (m*K), and the second layer is molded on the first layer by not overmolding at least one area of ​​the first layer by the second layer, so that at least one area of ​​the first layer is exposed to at least one heat source, wherein TC1 is at least 2 W / (m*K) greater than TC2, the amounts of a1 and b1 are based on the total weight of the first composition, the amounts of a2 and b2 are based on the total weight of the second composition, and the thermal conductivity is measured in-plane according to ASTM E1461-01. The housing component provided in the present invention has high heat dissipation efficiency and mechanical properties as well as high dimensional stability.

Description

Technical Field

[0001] The present invention relates to a housing component and a housing used in electronic equipment, in particular to a housing component molded from a polycarbonate composition, and a preparation method thereof. Background Art

[0002] In the electronics industry, electronic devices are becoming more and more compact, which means that more and more electronic components are integrated into smaller and smaller housings. Housings are necessary to protect the electronic components integrated into electronic devices. Typically, these electronic components generate a lot of heat when they are working. Therefore, one of the challenges in preparing such housings is to ensure that the heat generated by the electronic components is effectively dissipated to avoid overheating.

[0003] US 20130216799 A1 discloses an assembly of parts comprising a first part comprising a first polymer composition and a second part comprising a second polymer composition, both compositions comprising a semi-crystalline polymer and optionally one or more other components, the first part and the second part being fastened to each other by an interface between the first polymer composition and the second polymer composition, wherein the interface has no mechanical interlocking members, and the thermal conductivity (TC2) of the second polymer composition is higher than the thermal conductivity (TC1) of the first polymer composition by a factor of TC2 / TC1 of at least 1.5.

[0004] US 5114791 A discloses two-component injection molded articles in which polyarylene sulfide (PAS), preferably polyphenylene sulfide (PPS), is present as at least one component and a method for producing the same, and the PAS can be amorphous and (partially) crystalline and used in filled and unfilled forms. Highly filled (partially) crystalline polyarylene sulfide is preferably used for the core. In addition to polyarylene sulfide, (partially) crystalline and amorphous thermoplastics can be used as additional components.

[0005] In WO 2018 / 164666 Al, a two shot injection molding method for preparing thermoplastic parts of two different compositions is disclosed, the second injection composition has a higher thermal conductivity than the first injection composition, and the mold cavity surface temperature is greater than 70° C., preferably 70-100° C. In WO 2018 / 164666 Al, the second polymer comprises at least one semi-crystalline thermoplastic in an amount of 90-30% by weight of the composition of the second polymer.

[0006] US 8,372,495 B2 discloses a housing for an electronic device or other object formed in a layered configuration. The housing / housing may have a first layer and a second layer formed of a first material. The housing may also include a core formed of a second material. The first layer may be bonded to the top surface of the core, and the second layer may be bonded to the bottom surface of the core.

[0007] US 2017 / 0203551 A1 discloses a shell for an electronic device, comprising: a solid core layer comprising a first thermoplastic material; a first surface layer comprising a second thermoplastic material located on a first side of the core layer; a second surface layer comprising a second thermoplastic material located on a second side of the core layer opposite to the first side; wherein the core layer has a through plane thermal conductivity greater than or equal to 0.1 W / mK; and wherein the thickness of the core layer is 30% to 75% of the total thickness of the shell.

[0008] For high power electronic devices, there is an industrial need in the art for new housing components and housings having high mechanical properties, high heat dissipation efficiency and high dimensional stability. Summary of the invention

[0009] It is an object of the present invention to provide a housing component which preferably meets the above-mentioned needs. The housing component according to the present invention comprises a first layer, the first layer being molded from a first composition, the first composition comprising a1) 50-90 wt. % of a first amorphous polymer and b1) 10-50 wt. % of a first thermally conductive filler, the first composition having a thermal conductivity (TC1) of 4-40 W / (m*K), a second layer, the second layer being molded from a second composition, the second composition comprising a2) 50-90 wt. % of a second amorphous polymer and b2) 10-50 wt. % of a second thermally conductive filler, the second composition having a thermal conductivity (TC2) of 0.5-10 W / (m*K), the second layer being molded over the first layer by not overmolding at least one region of the first layer by the second layer so that at least one region of the first layer is exposed to at least one heat source, wherein TC1 is at least 2 W / (m*K) greater than TC2, the amounts of a1 and b1 are based on the total weight of the first composition, the amounts of a2 and b2 are based on the total weight of the second composition, and the thermal conductivity is 100 % by weight according to ASTM D 1475. E1461-01 is measured in-plane.

[0010] Another object of the present invention is to provide a method for producing a housing part according to the present invention which preferably meets the above requirements. The method comprises the steps of: molding a first layer with a first composition in a first mold cavity, and molding a second layer with a second composition over the first layer in a second mold cavity by not overmolding at least one region of the first layer with the second layer, so that at least one region of the first layer is exposed to at least one heat source.

[0011] Another object of the present invention is to provide a housing that preferably meets the above requirements. The housing comprises a housing part according to the present invention. In the housing, the housing part according to the present invention is preferably used as the bottom part of the housing, and accordingly, the housing preferably also comprises a covering part, and the covering part is made of any suitable material, and is preferably made of a thermoplastic polymer, and alternatively, it can be a housing part according to the present invention.

[0012] Another object of the present invention is to provide an electronic device that preferably meets the above requirements. The electronic device comprises a housing, the housing comprises a housing component according to the present invention, and the electronic device further comprises at least one electronic component installed in the housing, the electronic component generating heat when in operation.

[0013] Preferably, the first amorphous polymer comprised in the first composition and the second amorphous polymer comprised in the second composition are the same.Preferably, the first amorphous polymer and / or the second amorphous polymer is a polycarbonate, more preferably an aromatic polycarbonate.

[0014] Preferably, the first composition and the second composition each independently comprise less than 5 wt%, more preferably less than 3 wt%, even more preferably less than 1 wt% of a semi-crystalline polymer or a crystalline polymer, based on the total weight of the first composition and / or the second composition, respectively, and most preferably contain no semi-crystalline polymer or a crystalline polymer.

[0015] The thermally conductive fillers contained in the first composition and the second composition may be the same or different. Preferably, based on the total weight of b1), at least 50 wt% of b1) is selected from silicon nitride, aluminum nitride, boron nitride, graphite, ceramic fillers and any mixture thereof, and more preferably selected from graphite and ceramic fillers.

[0016] Preferably, at least 50 wt. % of b2), based on the total weight of b1), is selected from magnesium hydroxide, talc, boehmite aluminum hydroxide, diaspore aluminum hydroxide, gibbsite aluminum hydroxide, calcium carbonate, mica, barium oxide, barium sulfate, calcium silicate, zirconium oxide, silicon oxide, glass beads, magnesium aluminum oxide, calcium magnesium carbonate, ceramic-coated graphite, clay and any mixtures thereof, and more preferably is talc.

[0017] Preferably, at least one electronic component in the electronic device generates heat as at least one heat source during operation.

[0018] Preferably, the area of ​​the first layer that is not overmolded by the second layer comprises at least one heat sink, and the heat sink is preferably coupled to at least one heat source. Preferably, the heat sink comprises at least one fin. The heat source may be an electronic component, such as an electronic chip. The heat sink is preferably coupled to the heat source via a thermal interface material.

[0019] The housing component according to the present invention comprises two layers molded by different compositions comprising an amorphous polymer and thermal conductivity. The first layer with relatively high thermal conductivity is exposed to a heat source and dissipates heat from the heat source to a second layer with relatively low thermal conductivity with high efficiency, and such a second layer dissipates heat to the environment and also contributes to high dimensional stability and good mechanical properties. The first composition containing the first amorphous polymer is well fastened to the second composition containing the second amorphous polymer at their interface. The solution according to the present invention ensures that the housing component has high heat dissipation efficiency, good dimensional stability and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 An embodiment of a first layer of a housing component produced according to the invention is shown.

[0021] Figure 2 An embodiment of the second layer of a housing component produced according to the invention is shown.

[0022] Figure 3 An embodiment of a housing component produced according to the invention is shown.

[0023] The use of the same reference numbers in different drawings indicates similar or identical items. DETAILED DESCRIPTION

[0024] The present invention will now be described for purposes of illustration and not limitation.

[0025] Housing components

[0026] The housing component according to the present invention comprises a first layer, which is molded from a first composition, the first composition comprising a1) 50-90 wt%, preferably 60-80 wt%, more preferably 60-70 wt% of a first amorphous polymer and b1) 10-50 wt%, preferably 20-40 wt%, more preferably 30-40 wt% of a first thermally conductive filler, the first composition having a thermal conductivity (TC1) of 4-40 W / (m*K), preferably 4.5-30 W / (m*K), more preferably 5-20 W / (m*K), most preferably 6-18 W / (m*K), and a second layer, which is molded from a second composition, the second composition comprising a2) 50-90 wt%, preferably 50-80 wt%, more preferably 55-80 wt% of a second amorphous polymer and b2) 10-50 wt%, preferably 20-50 wt%, more preferably 20-45 wt% of a second thermally conductive filler, the second composition having a thermal conductivity (TC1) of 0.5-10 W / (m*K). The thermal conductivity (TC2) of the present invention is 0.6-8 W / (m*K), preferably 0.6-8 W / (m*K), more preferably 0.8-5 W / (m*K), and most preferably 1-4 W / (m*K), the second layer is molded on the first layer by not overmolding at least one area of ​​the first layer by the second layer so that at least one area of ​​the first layer is exposed to at least one heat source, wherein TC1 is at least 2 W / (m*K) greater than TC2, preferably at least 3 W / (m*K) greater, the amount of a1 and b1 is based on the total weight of the first composition, the amount of a2 and b2 is based on the total weight of the second composition, and the thermal conductivity is measured in-plane according to ASTM E1461-01.

[0027] Both the first composition and the second composition of the housing part according to the invention comprise an amorphous polymer and a thermally conductive filler and preferably further comprise one or more additives.

[0028] The first amorphous polymer and the second amorphous polymer are each independently preferably an amorphous polycarbonate, more preferably an aromatic polycarbonate, and / or an amorphous polyester, as well as copolymers thereof and blends thereof. The term "polycarbonate" is understood to refer to both homopolycarbonates and copolycarbonates.

[0029] The first amorphous polymer and the second amorphous polymer are preferably the same, thereby enhancing the interfacial adhesion between the first layer and the second layer. The first amorphous polymer and the second amorphous polymer may also be different in specific applications due to reasons such as cost, mechanical properties, heat release, electronic effects or magnetic effects. Preferably, the first amorphous polymer and the second amorphous polymer are independently polycarbonates, more preferably aromatic polycarbonates.

[0030] Preferably, the first composition and the second composition each independently comprise less than 5 wt %, more preferably less than 3 wt %, particularly more preferably less than 1 wt % of a semi-crystalline polymer or a crystalline polymer, based on the total weight of the first composition and / or the second composition, respectively, and most preferably contain no semi-crystalline polymer or a crystalline polymer.

[0031] The first thermally conductive filler and the second thermally conductive filler according to the present invention are any materials that can be dispersed in the first composition and the second composition, respectively, to improve the thermal conductivity of the corresponding compositions.

[0032] Preferably, based on the total weight of the first thermally conductive filler, at least 50 wt. %, preferably at least 60 wt. %, more preferably at least 80 wt. % of the first thermally conductive filler is selected from silicon nitride, aluminum nitride, boron nitride, graphite, ceramic fillers and any mixture thereof, and more preferably selected from graphite, in particular expanded graphite, and ceramic fillers.

[0033] The graphite is preferably used in the form of fibers, rods, beads, hollow beads, flakes and / or powder, in each case in aggregated or agglomerated form, preferably in the preparation of the first composition in the form of flakes.

[0034] The flake form of graphite according to the present invention refers to particles with a flat geometry. Such particles may have undergone aggregation or agglomeration to form a structure. Therefore, the height of such particles is less than 500 nm, preferably less than 200 nm, and more preferably less than 100 nm, and is generally much smaller than the width or length of the particles. The shape of such particles can be curved, curvilinear, corrugated or otherwise deformed. The length dimension of the particles can be determined by standard methods, such as by electron microscopy.

[0035] The graphite preferably has a particle size distribution characterized by D (0.9) of at least 1 mm, preferably at least 1.2 mm, more preferably at least 1.4 mm and even more preferably at least 1.5 mm. Likewise preferably, the graphite has a particle size distribution characterized by D (0.5) of at least 400 μm, preferably at least 600 μm, more preferably at least 750 μm and even more preferably at least 850 μm. Also preferably, the graphite preferably has a particle size distribution characterized by D (0.1) of at least 100 μm, preferably at least 150 μm, more preferably at least 200 μm and even more preferably at least 250 μm. The characteristic values ​​D (0.1), D (0.5) and D (0.9) are determined by sieve analysis according to DIN 51938.

[0036] Graphite preferably has a carbon fiber thickness of 2.0 g / cm2 as measured using xylene. 3 Up to 2.4 g / cm 3 , preferably 2.1 g / cm 3 Up to 2.3 g / cm3 , and more preferably 2.2 25 g / cm 3 Up to 2.27 g / cm 3 density.

[0037] Preferably, the graphite before treatment has a thermal conductivity in the range of 250-400 W / (m*K) parallel to the basal plane and in the range of 6-8 W / (m*K) perpendicular to the basal plane, measured according to ASTM E1461-01.

[0038] Preferably, the graphite before treatment has an electrical resistor of about 0.001 Ω*cm parallel to the base plane and less than 0.1 Ω*cm perpendicular to the base plane.

[0039] Commercially available graphites are, in particular, Ecophit® GFG 5, Ecophit® GM 50, Ecophit® GFG 200, Ecophit® GFG 350, Ecophit® GFG 500, Ecophit® GFG900, Ecophit® GFG 1200 from SGL Carbon GmbH, TIM-REX® BNB90, TIMREX® KS5-44, TIMREX® KS6, TIM-REX® KS150, TIMREX® SFG44, TIMREX® SFG150, TIMREX® C-THERM TM 001 and TIMREX® C-THERM TM 011, SC 20 O, SC 4000 O / SM and SC8000 O / SM from Graphit Kropfmühl AG, Mechano-Cond 1, Mechano-Lube 2 and Mechano -Lube 4G from HC Carbon GmbH, Nord-Min 251 and Nord-Min 560T from Nordmann Rassmann GmbH, and ASBURYA99, Asbury 230U and Asbury 3806 from Asbury Carbons.

[0040] The expanded graphite according to the invention has individual basal planes separated by a specific treatment, which leads to an increase in the volume of the graphite, preferably by a factor of 200 to 400. The production of expanded graphite is described in particular in the documents US Pat. No. 1,137,373 A, US Pat. No. 1,191,383 A and US Pat. No. 3,404,061 A. The expanded graphite according to the invention preferably has a relatively high specific surface area determined as BET surface area by nitrogen adsorption according to ASTM D3037, for example a BET surface area of ​​≥5 m 2 / g, preferably ≥10 m 2 / g and more preferably ≥18 m 2 / g.

[0041] The area of ​​the first layer that is not overmolded by the second layer is used to be exposed to at least one heat source. The heat source may be an electronic chip or other electronic components, such as electronic resistors, which generate heat during operation.

[0042] Preferably, the area of ​​the first layer that is not overmolded by the second layer comprises at least one heat sink, and such heat sink further preferably comprises at least one heat sink. Such heat sink and heat sink are located on the side of the first layer opposite to the other side of the first layer that is overmolded by the second layer. Preferably, at least one of such heat sources is coupled to at least one of the heat sinks, for example, by a thermal interface material.

[0043] Preferably, the first layer made of the first composition has a thickness of at least 1.5 mm, more preferably at least 2 mm. When at least one heat sink is preferably present in the area of ​​the first layer not overmoulded by the second layer, the height of such heat sink is calculated separately from the thickness of the first layer.

[0044] The term thermal conductivity (TC) according to the present invention refers to the in-plane thermal conductivity in the direction of maximum in-plane thermal conductivity. In the present invention, the TC of a composition is measured as follows: 1) a composition sample for measurement is 80 mm × 80 mm × 2 mm, prepared using an injection molding machine equipped with a square mold of appropriate size and a film gate of 80 mm width and 1 mm height located on one side of the square mold, and 2) the thermal diffusivity (α), density (ρ) and heat capacity (C p ). Thermal diffusivity in the plane and in the direction parallel to the injection molding direction (α, cm 21) The heat capacity (C 2 ) of the composition sample used for the measurement was determined by comparison with a reference sample (Pyroceram 9606) of known heat capacity using the same Nanoflash LFA 447 xenon flash apparatus (Netzsch Group) and the procedure described by W. Nunes dos Santos, P. Mummery and A. Wallwork, Polymer Testing 14 (2005), 628-634. p ). Density was determined using the water immersion method (ASTM D792). 4) Three values ​​(α, ρ and C p ) gives the thermal conductivity of the through-surface according to the following equation (1):

[0045] TC = α × ρ × C p Formula (1)

[0046] All values ​​of any TC mentioned in the present invention are measured at 20°C and expressed as W / (m*K).

[0047] The second thermally conductive filler has a TC of 0.5-10 W / (m*K). Preferably, based on the total weight of the second thermally conductive filler, at least 50 wt%, preferably 60 wt%, more preferably 80 wt% of the second thermally conductive filler is selected from magnesium hydroxide (Mg(OH)2), talc (H2Mg3(SiO3)4), boehmite aluminum hydroxide (γ-A1O(OH)), diaspore aluminum hydroxide (α-A1O(OH)), gibbsite aluminum hydroxide (Al(OH)3), calcium carbonate (CaCO3), mica, barium oxide (BaO), barium sulfate (BaSO4), calcium silicate (CaSiO3), zirconium oxide (ZrO2), silicon oxide (SiO2), glass beads, magnesium aluminum oxide (MgO·xAl2O3), calcium magnesium carbonate CaMg(CO3)2, ceramic-coated graphite, clay, and any mixture thereof, and more preferably talc.

[0048] The second thermally conductive filler is preferably present in the form of particles or fibers. In the case where the second thermally conductive filler is in the form of particles, the maximum average particle size of the second thermally conductive filler is preferably less than 300 microns (μm), and more preferably less than 200 μm, for example, as measured by AccuSizer Model 780A (Particle Sizing Systems, Santa Barbara, Calif.) according to laser diffraction type particle size distribution using Selas Granulometer "Model 920" or Coulter KK produced laser diffraction scattering method particle size distribution measuring equipment "LS-230". Preferably, the average particle size is 1 μm to 100 μm, and more preferably 5 μm to 60 μm. According to the present invention, a second thermally conductive filler in the form of particles or granules with a multimodal size distribution can also be used.

[0049] The second thermally conductive filler preferably comprises talc having different particle sizes, and more preferably talc having an average particle size of 1 to 500 micrometers (μm), determined by sieve analysis according to DIN 51938. The average particle size referred to here is the average size of talc single crystals or single crystal agglomerates in any dimension thereof.

[0050] The surfaces of the first thermally conductive filler and the second thermally conductive filler can be treated with a coupling agent to improve the interface bonding between them and their corresponding amorphous polymers. Examples of coupling agents include silane series, titanate series, zirconate series, aluminate series and aluminozirconate series coupling agents. Available coupling agents include metal hydroxides and alkoxides, including those of Ma to VIIIa, Ib, IIb, Mb and IVb groups of the periodic table and lanthanides. Specific coupling agents are metal hydroxides and alkoxides of metals selected from Ti, Zr, Mn, Fe, Co, Ni, Cu, Zn, Al and B.

[0051] The first composition and the second composition each preferably comprise one or more additives. The additive according to the present invention can be any additive known to prepare the function of thermoplastic molding compositions in industry except the above-mentioned thermally conductive filler. These include lubricants, release agents, for example pentaerythritol tetrastearate, antistatic agents, antioxidants, heat stabilizers, hydrolysis stabilizers, impact modifiers, reinforcing agents, colorants or pigments, and any one or more of flame retardants, anti-drip agents or flame retardant synergists. According to industrial common sense, additives can be used in effective amounts, preferably in a total amount of 0.01 to 30% by weight relative to the gross weight of the corresponding composition.

[0052] The first and second compositions for producing the housing part according to the invention can be obtained by dispersing the corresponding thermally conductive fillers and other components such as additives in the corresponding amorphous polymers, the thermally conductive fillers being in concentrations that provide the compositions with the desired thermal conductivity.

[0053] case

[0054] The housing comprises a housing part according to the invention. Preferably, the housing part according to the invention is used as a bottom part of the housing, and correspondingly, the housing also comprises a covering part. The covering part can be made of any suitable material, preferably for example polycarbonate, in particular aromatic polycarbonate, ABS or aromatic polycarbonate / ABS blends.

[0055] Electronic devices

[0056] The electronic device according to the present invention comprises a housing according to the present invention and at least one heat source mounted in the housing, that is, an electronic component, such as an electronic chip or an electronic resistor. Such an electronic component generates heat when in operation, and at least a portion of the area of ​​the first layer that is not overmolded by the second layer is exposed to such an electronic component, receives such heat and transfers such heat to the second layer of the housing, which then transfers the heat to the environment.

[0057] Preferably, if the first layer has a heat sink at the area not overmoulded by the second layer, such electronic component is coupled to the heat sink, for example via a thermal interface material. More preferably, if the heat sink comprises at least one fin, it increases the heat dissipation efficiency.

[0058] Preferred electronic devices according to the present invention are network routers, wireless access point devices, power tools, car multimedia displays or players, and the like.

[0059] Electronic components of the electronic device, such as electronic chips, can be mounted in the space formed by (if any, in particular) the cover part and the housing part according to the invention.

[0060] Method for preparing housing component

[0061] The method for preparing a shell component according to the present invention comprises the following steps: molding a first layer with a first composition in a first mold cavity, and molding a second layer with a second composition on top of the first layer in a second mold cavity by not covering at least one area of ​​the first layer with the second layer, so that at least one area of ​​the first layer is exposed to at least one heat source.

[0062] The housing part is preferably produced with an injection molding machine having one injection unit and two molds each having one cavity, or one mold having two cavities, the first cavity being used to mold the first layer and the second cavity being used to mold the second layer. Thus, the housing part is preferably produced according to the steps of molding the first layer with a first composition in a first cavity, transferring the first layer to a second cavity, and overmolding the second layer with a second composition over the first layer in the second cavity by leaving at least one region of the first layer unovermolded by the second layer, so that at least one region of the first layer is exposed to at least one heat source.

[0063] In the method for producing a shell part according to the present invention, the temperature for melting the first composition is 260-330°C, preferably 270-320°C, more preferably 280-310°C, and the temperature for melting the second composition is 260-320°C, preferably 270-310°C, and more preferably 280-300°C.

[0064] In the method for preparing a shell part according to the present invention, the surface temperature of the mold cavity for molding the first layer is 60-90°C, preferably 65-85°C, and more preferably 70-85°C, and the surface temperature of the mold cavity for molding the second layer is 80-130°C, preferably 85-125°C, and more preferably 90-120°C.

[0065] Attached photos

[0066] The present invention will be described in detail with reference to the following examples. These examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0067] Figure 1 An example of a first layer of a housing component produced according to the invention is shown.

[0068] like Figure 1 As shown in FIG. 1 , layer 100 is the first layer of the housing component according to the present invention, which is molded from the first composition. Layer 100 includes a heat sink 110. The heat sink 110 is a protrusion of the first layer 100. The heat sink 100 is used to couple with electronic components that generate heat during operation. The heat sink 110 also includes a heat sink 130. The heat sink 110 and the heat sink 130 are designed and molded to more effectively collect, transfer and dissipate heat.

[0069] Component 120 is a component that is connected to a corresponding component in the second layer of the shell component (e.g., Figure 2 The holes for coupling the pole elements 210 shown in FIG. 1 are used to further fasten the first and second layers of the shell components together.

[0070] Figure 2 An example of a second layer 200 of a shell component produced according to the present invention is shown.

[0071] like Figure 2 As shown in FIG. 1 , the rod structure member 210 is used to connect with the corresponding member in the first layer of the shell component (e.g., Figure 1 The member 120 shown in FIG. 1 is coupled to the first layer and the second layer for fastening together.

[0072] Figure 3 An example of a housing component 300 prepared according to the present invention is shown.

[0073] The housing component 300 is a combination of a first layer 100 and a second layer 200. In the preparation of the housing component 300, the first layer 100 is first molded in a first injection mold cavity, and then the first layer 100 is transferred to a second injection mold cavity, and the second layer 200 is molded in the second injection mold cavity. Figure 3 As shown in FIG. 1 , the second layer 200 is molded on one side of the first layer 100, but the other side of the first layer 100 is not overmolded by the second composition, and the other side has a heat sink and a heat sink. When the second layer 200 is molded, the rod member 210 is molded and coupled with the member 120 of the first layer 100. Example

[0074] Figure 3 The housing parts shown in FIG. 5 were made of different compositions and were tested as examples according to the invention.

[0075] Raw materials used in the examples

[0076] To prepare samples of the examples and comparative examples of the present invention, combinations of different materials were selected from the materials listed below.

[0077]

[0078] Machines for producing housing components:

[0079] The housing component samples were produced using an injection molding machine having one injection unit and two mold cavities, and the first mold cavity was used to mold the first layer, and the second mold cavity was used to mold the second layer.

[0080] The injection molding machine used in the examples is Sumitomo SE 180DU-C450, with a clamping force of 180 tons.

[0081] Preparation of shell components

[0082] The temperature for melting the first composition was 310°C, and the cavity surface temperature was 80°C.

[0083] After the first layer is molded, a second mold is disposed in the injection molding machine and the first layer is repositioned in a second mold cavity of the injection molding machine.

[0084] The temperature for melting the second composition was 300°C, and the second cavity surface temperature was 90°C.

[0085] The second layer is molded over the first layer in a second mold cavity by exposing one side of the first layer to at least one heat source.

[0086] Test method:

[0087] 1. Drop test method (unpackaged drop method).

[0088] The prepared shell component sample is tested by six random drops from a height of 0.75 m. If the first layer and the second layer are separated, the test result is recorded as "Separation", which means that the cohesion between the first layer and the second layer is weak, otherwise it is recorded as "No", which means that the cohesion between the first layer and the second layer is acceptable. If the shell component is broken but not broken into several parts, the test result is recorded as "Broken", if the shell component is broken into several parts, the test result is recorded as "Severely Broken", if the shell component is not broken, the test result is recorded as "No", which means that the mechanical properties of the shell component are acceptable. Both "Broken" and "Severely Broken" mean that the mechanical properties of the shell component are unacceptable.

[0089] 2. Heat dissipation performance test method.

[0090] As the present invention Figure 3 As shown in FIG. 1 , a 5W resistor 400 is used as a heat source, and the resistor 400 is adhered to the top surface of one of the heat sinks 110 of the first layer together with the thermal interface material. Then, the housing component is placed at the center of a chamber (size: 1000 mm long, 700 mm wide, 800 mm high) 580 mm above the ground (heat sink facing downward) at an ambient temperature of 23°C. When the resistor 400 is in operation (the entire electronic circuit is not in operation), the heat sink 110 is placed at a center of 580 mm above the ground (heat sink facing downward). Figure 3 ), the operating temperature of the resistor 400 gradually increases and then reaches a stable maximum temperature.

[0091] In actual industrial applications, the acceptable stable maximum operating temperature is lower than the lowest tolerable temperature of all components integrated in the housing. In the embodiment according to the present invention, the test is to compare the heat dissipation performance of the housing components between the comparative example and the embodiment of the present invention.

[0092] The test results of the embodiments of the present invention and the comparative examples are listed in Table 1.

[0093] Table 1 Examples of the present invention and comparative examples

[0094]

[0095] All the housing component samples prepared in Examples 1, 2, 3 and 4 of the present invention showed good heat dissipation performance as shown in Table 1, wherein the respective stable maximum operating temperatures were below 75° C., and there was good cohesion between the first layer and the second layer, as shown by the test results of no cracking or separation. In addition, the second layer prepared with the second composition had improved mechanical strength and surface quality, such as high dimensional stability.

[0096] In Comparative Example 1, both the first layer and the second layer were prepared with composition C4 having a relatively low thermal conductivity of 1.0 W / (m*K), which means that the difference between TC1 and TC2 is zero. As a result, the housing part in Comparative Example 1 exhibited poor heat dissipation performance, as indicated by the stable maximum operating temperature of 126.2°C in Table 1.

[0097] In Comparative Example 2, both the first layer and the second layer were prepared with the composition C1 having a thermal conductivity of 16.0 W / (m*K), which means that the difference between TC1 and TC2 is zero. As a result, the shell part prepared in Comparative Example 2 showed low mechanical strength, as indicated by "severe cracking" in Table 1. In addition, the surface quality of the shell part in Comparative Example 2 was poor.

[0098] The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the composition and method of the present invention without departing from the scope of the present invention. With reference to the disclosure in this specification, those skilled in the art can also obtain other examples. This specification and embodiments should only be considered as illustrative, and the true scope of the present invention is limited by the appended claims and their equivalents.

Claims

1. A housing component comprising: a first layer, wherein the first layer is molded from a first composition, the first composition comprising a1) 50-90 wt % of a first amorphous polymer and b1) 10-50 wt % of a first thermally conductive filler, the first composition having a thermal conductivity (TC1) of 4-40 W / (m*K), a second layer, the second layer being molded from a second composition, the second composition comprising a2) 50-90 wt% of a second amorphous polymer and b2) 10-50 wt% of a second thermally conductive filler, the second composition having a thermal conductivity (TC2) of 0.5-10 W / (m*K), and the second layer is molded over the first layer by leaving at least one area of ​​the first layer unmolded by the second layer so that at least one area of ​​the first layer is exposed to at least one heat source, in, TC1 is at least 2 W / (m*K) greater than TC2, the amounts of a1 and b1 are based on the total weight of the first composition, the amounts of a2 and b2 are based on the total weight of the second composition, and the thermal conductivity is measured in-plane according to ASTM E1461-01. 2 . The housing component of claim 1 , wherein the first amorphous polymer and / or the second amorphous polymer is an aromatic polycarbonate.

3. The shell part according to claim 1 or 2, wherein the first composition and / or the second composition comprises less than 5 wt. % of a semi-crystalline polymer or a crystalline polymer, based on the total weight of the first composition and / or the second composition, respectively.

4. The housing component according to claim 1, wherein at least 50 wt. % of b1) based on the total weight of b1) is selected from silicon nitride, aluminum nitride, boron nitride, graphite, ceramic fillers and any mixtures thereof.

5. The housing component of claim 1 , wherein at least 50% by weight of b2) is selected from the group consisting of magnesium hydroxide, talc, boehmite aluminum hydroxide, diaspore aluminum hydroxide, gibbsite aluminum hydroxide, calcium carbonate, mica, barium oxide, barium sulfate, calcium silicate, zirconium oxide, silicon oxide, glass beads, magnesium aluminum oxide, calcium magnesium carbonate, ceramic-coated graphite, clay, and any mixtures thereof.

6. The housing component of claim 1, wherein a region of the first layer not overmolded by the second layer comprises at least one heat sink for coupling to at least one heat source.

7. The housing component of claim 6, wherein the heat sink comprises at least one cooling fin.

8. The housing assembly of claim 6, wherein the heat sink is coupled to the heat source via a thermal interface material.

9. A housing comprising the housing component according to any one of claims 1 to 8.

10. The housing of claim 9, wherein the housing further comprises a cover component coupled with the housing component to form the housing, the cover component being made of a thermoplastic polymer.

11. An electronic device comprising the housing according to claim 9 or 10, and further comprising at least one electronic component installed in the housing as a heat source.

12. A method for preparing a housing component according to any one of claims 1 to 8, comprising the following steps: molding a first layer from a first composition in a first mold cavity, and At least one area of ​​the first layer is exposed to at least one heat source by molding the second layer with a second composition over the first layer in a second mold cavity without overmolding the second layer with the second layer.

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