TWI444399B - Heat-conductive dielectric polymer composition and heat dissipation substrate containing the same - Google Patents

Description

Thermal conductive electrically insulating polymer material and heat dissipation substrate containing the same

The present invention relates to a heat-conductive dielectric polymer material and a heat dissipation substrate comprising the thermally conductive electrically insulating polymer material, in particular to a thermally conductive electrically insulating polymer material having fiber support and A heat dissipation substrate comprising the thermally conductive electrically insulating polymer material.

In recent years, white light-emitting diodes (LEDs) have been the most optimistic and most popular products in the world. It has the advantages of small size, low power consumption, long life and good reaction speed, which can solve the problems that past incandescent bulbs can't overcome. LEDs are increasingly gaining attention in markets such as display backlights, mini projectors, lighting and automotive light sources.

However, for high-power LEDs for lighting, the power of the input LED is only about 15-20% converted into light, and the remaining 80-85% is converted into heat. If these heats are not able to escape to the environment in a timely manner, the interface temperature of the LED elements will be too high, which will affect its luminous intensity and service life. Therefore, the thermal management of LED components has received increasing attention.

1 is a schematic view of a heat dissipating substrate 10 that is conventionally applied to an electronic component (eg, an LED component, not shown). The heat dissipation substrate 10 includes an insulating and thermally conductive material layer 12 and two metal foils 11 stacked on the upper and lower surfaces of the insulating and thermally conductive material layer 12. The electronic component is disposed above the upper metal foil 11. The conventional process of the heat dissipating substrate 10 is to first mix a liquid epoxy resin with a heat conductive filler (for example, alumina particles) and then add a curing agent to form a resin slurry. . Next, the resin slurry is vacuum-removed to remove the gas contained therein, and then coated on the lower metal foil 11. Thereafter, the upper metal foil 11 is placed on the surface of the resin syrup to form a metal foil/resin syrup/metal foil composite structure. Subsequently, the composite structure is subjected to hot pressing and curing to form the heat dissipation substrate 10. The insulating and thermally conductive material layer 12 is formed by hot pressing and curing the resin slurry.

However, the conventional process has the following disadvantages due to the nature of the resin slurry: (1) The conventional process must be completed within a certain time, otherwise the resin slurry will be cured and cannot be coated on the metal foil. Causing waste of the resin slurry; and (2) the conventional resin process will overflow the two metal foils 11 when the hot pressing step is performed, and solid and liquid stratification occurs when a hot pressing temperature is reached. The separation causes the conductive filler to be unevenly distributed in the insulating and thermally conductive material layer 12, thereby affecting the heat dissipation efficiency of the heat dissipation substrate 10. Further, the resin syrup has a problem that storage is not easy, and the flexibility of the heat-dissipating substrate process is restricted by the viscous state of the resin syrup (for example, a heat-dissipating substrate having a different shape cannot be efficiently produced).

It is claimed that the thermal conductive circuit substrate of the prior art is coated with a resin slurry obtained by mixing a liquid epoxy resin, a heat conductive filler and a curing agent onto a metal substrate, and then heated to form a colloidal state ( B-stage), finally made into a circuit board by thermocompression; or in the case of FR4 circuit board, epoxy resin is coated on the glass fiber cloth, heated to form a B-stage, and then heated A glass fiber circuit board was fabricated by pressing.

The above-mentioned prior art process requires the use of a resin paste having a lower viscosity. However, the low-viscosity resin slurry may cause delamination of solids and liquids due to sedimentation of the thermally conductive filler, which may cause uneven mixing and thus affect The heat dissipation efficiency, and the resin slurry also has a problem of difficulty in storage. The circuit board made of glass fiber cloth has a poor thermal conductivity due to its low thermal conductivity (about 0.36 W/mK).

In summary, the thermally conductive circuit substrate of the prior art requires the use of a low-viscosity resin slurry, which is liable to cause delamination of solids and liquids. In addition, since the thermal conductivity of the glass fiber cloth is low, the heat conduction effect of the circuit board made of the glass fiber cloth is not good. Therefore, how to develop a thermal insulating material and can be used as a high-efficiency heat transfer medium for a circuit board has become a very important issue.

In one aspect, the present invention provides a thermally conductive electrically insulating polymeric material having a fibrous support material that is rubbery, thereby improving its processibility and having good thermal conductivity.

Another aspect of the present invention provides a heat dissipating substrate comprising the thermally conductive electrically insulating polymer material, which has excellent heat dissipation characteristics and high voltage dielectric insulating properties.

The invention discloses a thermally conductive electrically insulating polymer material having a fiber supporting structure. The thermally conductive electrically insulating polymer material comprises a polymer component, a fiber supporting material, a curing agent, and a heat-conductive filler. The polymer component comprises a thermosetting epoxy. The curing agent is used to cure the thermosetting epoxy resin at a curing temperature. The fiber supporting material and the heat conductive filler are uniformly dispersed in the polymer component. The thermal conductive filler accounts for between 40% and 70% by volume of the thermally conductive electrically insulating polymer material. The fiber support material accounts for 1% to 35% by volume of the thermally conductive electrically insulating polymer material. The thermal conductivity of the thermally conductive electrically insulating polymer material is greater than 0.5 W/mK.

In one embodiment, the thermosetting epoxy resin included in the polymer component is selected from the group consisting of a terminal epoxy functional epoxy resin, a side chain epoxy functional epoxy resin, or a tetrafunctional epoxy resin. Its mixture. The thermosetting epoxy resin accounts for between 4% and 60% by volume of the thermally conductive electrically insulating polymer material.

In one embodiment, the fibrous support material can be selected from the group of inorganic ceramic fibers or organic polymeric fibers or combinations thereof, such as glass fibers, alumina fibers, carbon fibers, polypropylene fibers, polyester fibers, or mixtures thereof. Also, in terms of shape, the fibrous support material can be a segmented chopped strand fiber material.

In one embodiment, the polymer component may further comprise a thermoplastic plastic, that is, the thermosetting epoxy resin may be added with a thermoplastic plastic, and mutually soluble and homogeneous, thereby making the thermally conductive filler Spread evenly to achieve the best thermal conductivity. Due to the combination of thermoplastic plastic and fiber support material, the thermally conductive electrically insulating material can be formed by a thermoplastic plastic process (for example, extrusion, calendaring or injection molding). And because it contains thermosetting plastic, it can be cured and crosslinked at high temperature to form an inter-penetrating network of thermoplastic plastic and thermosetting plastic. This structure can not only have high temperature resistant type. The thermosetting plastic properties have the characteristics of a thermoplastic plastic that is resistant to brittleness and can be strongly bonded to a metal electrode or substrate.

The invention further discloses a heat dissipation substrate comprising a first metal layer, a second metal layer and a layer of thermally conductive electrically insulating polymer material. The layer of the thermally conductive electrically insulating polymer material is stacked between the first metal layer and the second metal layer to form a physical contact, and the metal layer and the thermosetting plastic are formed by hydrogen bonding or van der Waals force. The force can also be a chemically surfaced metal material that forms a more stable chemical bond with the thermoset plastic. And the thickness of the layer of the thermally conductive electrically insulating polymer material is resistant to a voltage greater than 500 volts at 0.1 mm.

The thermally conductive electrically insulating polymer material of the present invention comprises a polymer component, a fiber supporting material, a curing agent and a heat conducting filler. The polymer component comprises a thermosetting epoxy resin. The curing agent is used to cure the thermosetting epoxy resin at a curing temperature. The thermally conductive filler is uniformly dispersed in the polymer component, and the volume percentage of the thermally conductive electrically insulating polymer material is between 40% and 70%. The fiber support material accounts for 1% to 35% by volume of the thermally conductive electrically insulating polymer material, wherein the thermal conductivity of the thermally conductive electrically insulating polymer material is greater than 0.5 W/mK.

2 is a schematic view of a heat dissipation substrate 20 of the present invention, comprising a first metal layer 21, a second metal layer 22, and a thermally conductive electrically insulating polymer material layer 23 having a fiber support material 24. The interface between the first metal layer 21 and the second metal layer 22 and the thermally conductive electrically insulating polymer material layer 23 is in physical contact, and at least one of the interfaces is a micro-rough surface 25, the micro-rough surface 25 A plurality of knob-like protrusions 26 are included, and the diameter of the knob-like protrusions 26 is mainly distributed between 0.1 and 100 micrometers, thereby increasing the tensile strength between each other. The plurality of knob-like protrusions 26 may comprise a metal plating layer such as copper, nickel, zinc or arsenic, or a coating layer such as organic germanium or organic titanium.

The method of manufacturing the thermally conductive electrically insulating polymer material layer 23 and the heat dissipation substrate 20 is as follows. The thermosetting epoxy resin was first heated and mixed with the fibrous support material at 170 ° C for about 30 minutes to form a uniform colloid. The thermally conductive filler is added to the uniform colloid and uniformly mixed to form a uniform rubbery material, and the curing agent and the accelerator are added to the uniform rubbery material at a temperature of 80 ° C, wherein the uniform rubbery material has a fiber supporting material. Then, the uniform rubbery material is placed between the two release films at 100 ° C by a hot press, and is leveled at a pressure of 30 kg/cm ² to form the thermally conductive electrically insulating polymer material layer 23, which is Sheet-shaped thermal conductive electrical insulation composite material. In order to fabricate the heat dissipation substrate 20, the two release film is peeled off from the upper surface of the thermally conductive electrically insulating polymer material layer 23. Thereafter, the thermally conductive electrically insulating polymer material layer 23 is placed between the first metal layer 21 and the second metal layer 22; after being subjected to hot pressing at 160 ° C for 30 minutes (and controlling the thickness thereof, for example, 0.2 mm) That is, a heat-dissipating electrically insulating polymer material layer having a thickness of 0.2 mm is formed. The sheet-shaped thermally conductive and electrically insulating composite material has a fiber supporting material 24, which can effectively improve the rigidity of the material, does not cause the bending of the plate of the conventional substrate after the thermocompression, and has a high viscosity coefficient of the polymer material (about 10 ⁵ to 10 ⁷ poise), no segregation occurs. The material of the first metal layer 21 and the second metal layer 22 may be selected from copper, nickel, or the like, or metal treated by electroplating or other physical coating methods. The sheet-like thermally conductive electrically insulating composite material has a rubbery appearance (non-resin) and thus has the characteristics of convenient storage and processing. In addition, the thermally conductive electrically insulating composite material can also be processed by a processing method generally used for thermoplastic plastics, such as injection molding or injection molding, thereby improving workability.

Table 1 shows a comparison table of the components, the appearance, the thermal conductivity, and the corresponding heat-resistant substrate withstand voltage of the thermally conductive electrically insulating polymer material layer used in the heat dissipation substrate of Examples 1 to 4 of the present invention. The thickness of the layer of the thermally conductive electrically insulating polymer material of each of the examples and the comparative examples in Table 1 was 0.2 mm.

Table I

Table 2 is a comparison table of components, appearance, thermal conductivity, and corresponding heat-resistant substrate withstand voltage of the heat-conductive and electrically insulating polymer material layer used in the heat-dissipating substrate of Embodiments 5 to 9 of the present invention, wherein the heat-conductive electrical insulation is high. The molecular material layer further comprises a thermoplastic plastic to further improve the impact resistance and support of the material. The thickness of the thermally conductive electrically insulating polymer material layer of each of the examples in Table 2 was 0.2 mm.

Table II

The average particle size of the alumina (thermally conductive filler) in Tables 1 and 2 is between 5 and 45 μm, which is produced by Denki Kagaku Kogyo Kabushiki Kaisya; the liquid epoxy resin is from Dow Chemical Company (Dow). DER331 ^{TM of} Chemical Company), which is a thermosetting epoxy resin; curing agent is dicyandiamide (Dyhard 100S ^TM ) of Degussa Fine Chemicals Co., Ltd. and accelerator UR-500; ultra high molecular weight phenoxy resin ^{(ultrahigh molecular weight phenoxy resin PKHH TM} . from phenoxy Associates), having a molecular weight (weight average Mw) greater than 30,000.

As can be seen from Table 1, in the examples 1 to 4 of the present invention, the thermosetting epoxy resin (the liquid epoxy resin in the examples and comparative examples in Table 1) and the fiber supporting material such as glass fiber and polyester fiber were used. After the addition of the curing agent, a fiber-reinforced structure is formed, so that the formed thermally conductive and electrically insulating polymer material layer has a rubber-like appearance, is suitable for the extrusion processing process, and does not delaminate in the hot pressing process at 100 ° C. The phenomenon. In addition, according to the thermal conductivity and the breakdown voltage shown in Table 1, the embodiments 1 to 4 of the present invention can satisfy the requirements for the heat dissipation condition of the electronic component. However, in the comparative example, since the fiber support material was not added, it was in the form of a resin slurry before curing, and the delamination of solid and liquid occurred during thermocompression, and it could not be extruded into a sheet shape, which was unfavorable for processing.

It can be seen from Table 2 that in the embodiments 5 to 9 of the present invention, in addition to the use of the thermosetting epoxy resin and the fiber supporting material, the thermoplastic plastic can be reacted by adding a curing agent to form an interactive penetrating structure, so that The rubber state of the generated thermally conductive and electrically insulating polymer material layer is further strengthened, and is more suitable for the extrusion processing process and does not cause delamination during the thermal compression bonding process. In addition, according to the thermal conductivity and the breakdown voltage shown in Table 2, the embodiments 5 to 9 of the present invention can satisfy the requirements for the heat dissipation condition of the electronic component.

According to the above embodiments, in addition to using the fiber supporting material to greatly enhance the support and rigidity of the material, the thermally conductive and electrically insulating polymer material of the present invention can be introduced into the thermoplastic plastic and the thermosetting epoxy resin. Through the system, the system is substantially mutually soluble. "Substantially mutually soluble" means that a solution of a single glass transition temperature is formed when the thermoplastic plastic and the thermosetting epoxy resin are mixed. Because the thermoplastic plastic and the thermosetting epoxy resin are mutually soluble, when the two are mixed, the thermoplastic plastic will be dissolved into the thermosetting epoxy resin, so that the thermoplastic plastic glass is converted. The temperature is substantially reduced and allows mixing of the two to occur below the normal softening temperature of the thermoplastic. The resulting mixture (i.e., the polymer component) is rubbery (or solid) at room temperature and is easy to weigh and store. For example, even if the thermosetting epoxy resin is a liquid epoxy resin, the mixture formed after mixing with the thermoplastic plastic can be made into a leather-like tough film (tough) although it is not liquid. Leathery film). At 25 ° C, the mixture has a relatively high viscosity coefficient (about 10 ⁵ to 10 ⁷ poise) which is an important factor in avoiding settling or redistribution of the polymer component. In addition, the mixture has a sufficiently low viscosity coefficient (about 10 ⁴ to 10 ⁵ poise at 60 ° C) at a temperature at which mixing is generally carried out (about 40 ° C to 100 ° C), so that the added curing agent and the thermally conductive filler are added. It can be uniformly distributed in the mixture and reacted. Numerous examples of such mixtures can be found in U.S. Patent Application Serial No. 07/609,682, filed on Nov. 6, 1990, which is hereby incorporated by reference, and PCT Patent Publication No. WO 92/08073 (published May 14, 1992). Reference).

Curing temperature T _cure thermally conductive electrically insulating polymer material of the present invention in the curing agent (curing agent) of higher than 80 ℃ or preferably greater than 100 ℃, for curing (i.e., crosslinking (Crosslink) or catalytic polymerization (Catalyze Polymerization)) The thermosetting epoxy resin. The curing agent rapidly cures the thermosetting epoxy resin at a temperature higher than the mixing temperature T _mix , wherein the mixing temperature T _mix refers to the thermoplastic plastic, the thermosetting epoxy resin, and the curing agent when mixed The temperature, and the mixing temperature T _{mix is} generally from about 25 ° C to 100 ° C. When the curing agent is mixed at the mixing temperature T _mix , a substantial curing is not initiated. In the present invention, the amount of the curing agent is such that the thermosetting epoxy resin is cured at a temperature higher than the mixing temperature T _mix . Preferably, the curing agent does not initiate the substantial curing process at less than about 80 or 100 ° C and causes the thermally conductive electrically insulating polymeric material to remain substantially uncured at 25 ° C for at least half a year. Long.

The above thermosetting epoxy resin may comprise an uncured liquid epoxy resin, a polymeric epoxy resin, a phenolphthalein epoxy resin or a phenol methane resin. The thermosetting epoxy resin may also be a mixture of a plurality of epoxy resins, including at least a terminal epoxy functional epoxy resin, a side chain epoxy functional group, or a tetrafunctional epoxy resin or a combination thereof. In one embodiment, the epoxy resin of the side chain type epoxy functional group may be a NAN YA Plastic corporation NPCN series (for example, NPCN-703) or Chang Chun Group BNE-200.

The thermosetting epoxy resin in the thermally conductive electrically insulating polymer material of the present invention may be selected from "Saechtling International plastic Handbook for the Technology, Engineer and User, Second Edition, 1987, in addition to the materials described in Tables 1 and 2. Thermosetting resin as defined on pages 1 and 2 of Hanser Publishers, Munich. In one embodiment, the volume percentage of the thermosetting epoxy resin in the thermally conductive electrically insulating polymer material is generally between 4% and 60%, preferably between 6% and 50%, optimally Between 8% and 40%. The thermosetting resin preferably has a functional group greater than 2. The thermosetting resin exhibits a liquid or solid state at room temperature. If the thermosetting resin is cured without adding a thermoplastic resin, the thermosetting resin will exhibit a rigid or rubbery shape. A preferred thermoset resin is an uncured epoxy resin, particularly an uncured liquid epoxy resin defined in ASTM D 1763. For the liquid epoxy resin, refer to "Volume 2 of Engineered Materials Handbook, Engineering Plastics, published by ASM International", pages 240-241. The term "epoxy resin" means a conventional dimeric epoxy, an oligomeric epoxy or a polymeric epoxy resin comprising at least two epoxy functional groups. Polymeric epoxy). The type of the epoxy resin may be a product of bisphenol A and epichlorohydrin, a product of phenol and formaldehyde, which is a novolac resin. And epichlorohydrin, cycloaliphatic and peracid epoxies, glycidyl esters, epichlorohydrin and p-amino phenol, epichlorohydrin and glyoxal tetraphenol, novolac epoxy Or bisphenol A epoxy. Commercially available epoxidic esters are preferably 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane-ca rboxylate (for example: ERL 4221 from Union Carbide or CY-179 from Ciba Geigy) or bis (3) , 4-epoxycyclohexylmethyl)adipate (eg, ERL 4299 from Union Carbide). Commercially available diglycidic ether of bisphenol-A (DGEBA) may be selected from Aribaite 6010 from Ciba Geigy, DER 331 from The Dow Chemical Company, and Epon 825, 828, 826, 830 from Shell Chemical Company. 834, 836, 1001, 1004 or 1007, etc. Alternatively, the polyepoxidized phenol formaldehyde novolac prepolymer may be selected from DEN 431 or 438 of The Dow Chemical Company and CY-281 of Ciba Geigy Corporation. The polyepoxidized cersol formaldehyde novolac prepolymer may be selected from Ciba Geigy's ENC 1285, 1280 or 1299. The Polyglycidyl ether of polyhydric alcohol may be selected from Aribaite RD-2 of Ciba Geigy Corporation (based on butane-1,4-diol) or Epon 812 (based on glycerin) selected from Shell Chemical Company. A suitable diepoxide of an alkylcycloalkyl hydrocarbon is a vinyl cyclohexane dioxide such as ERL 4206 from Union Carbide. Further, a suitable diepoxide of a cycloalkyl ether is bis(2,3-diepoxycyclopentyl)-ether, for example, ERL 0400 of Union Carbide. In addition, commercially available flexible epoxy resins include polyglycol diepoxy (eg, DER 732 and 736 from The Dow Chemical Company) and diglycidyl ester of linoleic dimer acid (eg, Epon 871 and 872 from Shell Chemical Company). And diglycidyl ester of a bisphenol, wherein the aromatic ring is linked by a long aliphatic chain (for example: Lekutherm X-80 of Mobay Chemical company).

In addition, the above thermosetting resin having a plurality of functional groups may be selected from DEN 4875 of Tow Chemical Co., Ltd. (which is a solid epoxy novolac resin), and Epon 1031 of Shell Chemical Co., Ltd. A tetrafunctional solid epoxy resin and Araldite MY 720 (N, N, N', N'-tetraglycidyl-4, 4'-methylenebisbenzen amine) from Ciba-Geigy. In addition, a difunctional epoxy resin, which is a double epoxide, may be selected from HPT 1071 of Shell Chemical Co., Ltd. (a solid resin, N, N, N', N'-tetraglycidyl-a, a '-bis(4-aminophenyl)p-diisopropylbenzene), HPT 1079 (either a solid diglycidyl ether of bisphenol-9-fluorene) or Ciba-Geigy's Araldite 0500/0510 (triglycidylether of para-aminophenol).

The curing agent used in the present invention may be selected from the group consisting of isophthaloyl dihydrazide, benzophenone tetracarboxylic dianhydride, diethyltoluene diamine, 3,5-dimethylthio-2, 4-toluene diamine, and dicyandiamide. From American Cyanamid's Curazol 2PHZ) or DDS (diaminodiphenyl sulfone, available from Ciba-Geigy's Calcure). The curing agent may also be selected from the group consisting of substituted dicyandiamides (for example, 2,6-xylenyl biguanide), solid polyamide (for example: HT-939 of Ciba-Geigy Co., Ltd. or Ancamine of Pacific Anchor Co., Ltd.). 2014AS), a solid aromatic amine (for example, HPT 1061 and 1062 of Shell Chemical Company), a solid anhydride hardener (for example, pyromellitic dianhydride (PMDA)), A phenolic resin hardener (eg, poly(p-hydroxy styrene), imidazole, 2-phenyl-2,4-dihydroxymethylimidazole, and 2,4-diamino-6 [2'-methylimidazolyl(1)]ethyl-s-triazine isocyanate adduct), boron trifluoride and amine complex (for example: Pacific Anchor's Anchor 1222 and 1907) and trimethylol Trimethylol propane triacrylate.

For the thermosetting epoxy resin, a preferred curing agent is the above-mentioned dicyandiamide, and can be used in combination with a curing accelerator. Commonly used curing accelerators include urea (urea) or urea compound (urea compound). For example: 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethyl urea, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea, 3-(3-chloro -4-methylphenyl)-1,1-dimethyl urea and imidazole (eg 2-heptadecylimidazole, 1-cyanoethyl-2-phenylimidazole-trimellitate or 2-[.beta.-{2'-methylimidazoyl-(1 ')}]-ethyl-4,6-diamino-s-triazine).

If the thermosetting epoxy resin is urethane, the curing agent may use a blocked isocyanate (for example, an alkyl phenol blocked isocyanate). Desmocap 11A) from Mobay Corporation or a phenol blocked polyisocyanate adduct (for example: Mondur S from Mobay Corporation). If the thermosetting epoxy resin is an unsaturated polyester resin, the curing agent may use a peroxide or a free radical catalyst, for example, peroxidation. Dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butyl cumyl peroxide, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne -3. Further, the non-saturated polyester resin may be irradiated (radiation, for example, ultraviolet irradiation, high-energy electron beam irradiation, or gamma irradiation) to cause crosslinking.

Some thermoset epoxy resins cure without the use of a curing agent. For example, if the thermosetting epoxy resin is a double bismaleimide (BMI), the bismaleimide will crosslink at a high temperature and a co-curing agent. For example, O, O'-diallyl bisphenol A, can be added together to make the cured bismaleimide tougher.

The above-mentioned peroxide crosslinking agent, high energy electron beam or gamma radiation may be used to produce a crosslinked resin. Preferably, a non-saturated crosslinking aid may be added, for example, tripropylene. Trilyl cyanurate (TAIC), trimethylol propane triacrylate (TMPTA).

The fiber supporting material may include a ceramic fiber material or an organic polymer fiber material such as glass fiber, alumina fiber, carbon fiber, polypropylene fiber, polyester fiber or the like, which may also be a mixture of a plurality of fiber materials.

In one embodiment, the thermoplastic resin comprises a volume percentage of the thermally conductive electrically insulating polymeric material generally between 1% and 40%, or preferably between 2% and 30%. The thermoplastic plastic may comprise a hydroxy-phenoxyether polymer structure. The hydroxy-phenoxy resin ether is formed by a polymerization of a stoichiometric mixture of a diepoxide and a difunctional species. The diepoxide is an epoxy resin having an epoxy equivalent weight of from about 100 to 10,000. For example: diglycidyl ether of bisphenol A, diglycidyl ether of 4, 4'-sulfonyldiphenol, diglycidyl ether of 4, 4'-oxydiphenol, diglycidyl ether of 4, 4'-dihydroxybenzophenone, p-benzene Diglycidyl ether of hydroquinone and diglycidyl ether of 9,9-(4-hydroxyphenyl)fluorine. The bifunctional species is a dihydric phenol, a dicarboxylic acid, a primary amine, a dithiol, a disulfonamide or a bis-secondary amine. The dihydric phenol may be selected from the group consisting of 4,4'-isopropylidene bisphenol (bisphenol A), 4,4'-sulfonyldiphenol, 4,4'-oxydiphenol, 4,4'-dihydroxybenzophenone or 9,9-bis (4-hydroxyphenyl). Fluorene. The dicarboxylic acid may be selected from the group consisting of isophthalic acid, terephthalic acid, 4,4'-biphenylenedicarboxylic acid or 2,6-naphthalenedicarboxylic acid. The bis-second amine can be selected from the group consisting of piperazine, dimethylpiperazine or 1,2-bis(N-methylamino)ethane. The primary amine may be selected from the group consisting of 4-methoxyaniline or 2-aminoethanol. The dimercapto compound can be 4,4'-dimercaptodiphenyl ether. The disulfonamide may be selected from N,N'-dimethyl-1,3-benzenedisulfonamide or N,N'-bis(2-hydroxyethyl)-4,4-biphenyldisulfonamide. In addition, the bifunctional species may also be a mixture comprising two different functionalities that can react with an epoxide group; for example, salicylic acid and 4-hydroxybenzoic acid (4) -hydroxybenzoic acid).

The thermoplastic plastic in the thermally conductive electrically insulating polymer material of the present invention may also be selected from the group consisting of a liquid epoxy resin and a bisphenol A, a bisphenol F or a bisphenol S. (reaction product), a liquid epoxy resin and a diacid product or a liquid epoxy resin and an amine product.

In one embodiment, the thermoplastic plastic in the thermally conductive electrically insulating polymer material of the present invention may be selected from a substantially amorphous thermoplastic resin, and the definition thereof may be referred to as "Saechtling International plastic Handbook for the Technology". Engineer and User, Second Edition, 1987, Hanser Publishers, Munich", page 1. "Substantially amorphous" means that the "crystallinity" portion of the resin accounts for at most 15%, preferably at most 10%, particularly at most 5%, for example, from 0 to 5% of crystallinity. . The substantially amorphous thermoplastic resin is a high molecular weight polymer which exhibits a rigid or rubbery at room temperature, and is used in an uncured state of the polymer component. To provide properties such as strength and high viscosity. The substantially amorphous thermoplastic resin may be selected from the group consisting of polysulfone, polyethersulfone, polystyrene, polyphenylene oxide, polyphenylene sulfide, and poly Polyamide, phenoxy resin, polyimide, polyetherimide, polyetherimide and anthrone (polyetherimide/silicone) Block copolymer), polyurethane, polyester, polycarbonate, acrylic resin (eg polymethyl methacrylate, styrene) /Acrylonitrile and styrene block copolymers).

In one embodiment, the thermoplastic plastic may be an ultrahigh molecular weight phenoxy resin, wherein the ultrahigh molecular weight phenoxy resin may have a molecular weight of more than 30,000. The thermoplastic plastic may also comprise a monohydroxy-phenoxy resin ether polymer structure in which the hydroxy-phenoxy resin ether polymer structure is polymerized by reacting a diepoxide with a difunctional species. The thermoplastic plastic can also be formed by reacting liquid epoxy resin with bisphenol A, liquid epoxy resin and divalent acid, liquid epoxy resin and amine.

The thermally conductive filler may comprise one or more ceramic powders, and the ceramic powder may be selected from the group consisting of nitrides, oxides or mixtures of the foregoing nitrides with the foregoing oxides. As the nitride, zirconium nitride, boron nitride, aluminum nitride or tantalum nitride can be used. As the oxide, alumina, magnesia, zinc oxide, ceria or titania can be used. In general, the thermal conductivity of the oxide is poor, and the filling amount of the nitride is not high. Therefore, if the oxide and the nitride are mixed at the same time, the complementary effect can be obtained.

For example, the thermally conductive electrically insulating material of the embodiment can be made by the following method: mixing of the material firstly heating and mixing the polymer material including the fiber supporting material, the thermoplastic plastic and the thermosetting epoxy resin at 200 ° C Approximately 30 minutes to create a uniform gel. Then adding a thermally conductive filler to the uniform colloid and uniformly mixing to form a uniform rubbery material, and then adding a curing agent (Dicy) and an accelerator to the uniform rubber-like material at a temperature higher than 80 ° C to form an insulating material, wherein The uniform rubber-like material has an inter-penetrating network, and since the thermoplastic plastic and the thermosetting epoxy resin are mutually soluble and homogeneous, thereby making the thermally conductive filler uniform Scattered in the interpenetrating structure for optimal thermal conductivity.

The thermally conductive insulating material has the characteristics of being tough and not brittle due to the stable structural characteristics of the fiber supporting material. The characteristics of the thermoplastic plastic material enable the thermal conductive electrical insulating material to be formed through a thermoplastic plastic process, and the thermosetting plastic is cured and crosslinked at a high temperature to form a thermoplastic plastic to interact with the thermosetting plastic. Through the structure of the penetration, this structure not only has the thermosetting plastic characteristics of high temperature resistance, but also has strong strength with the metal electrode or substrate.

Table 3 is an example of the composition of the insulating material of the present invention, wherein the fiber supporting material is made of glass fiber, polyester fiber or a mixture thereof, and the volume percentage thereof is between 1% and 35%. The thermosetting epoxy resin comprises a bisphenol A epoxy resin and a polyfunctional epoxy resin. The polyfunctional epoxy resin comprises a side chain type epoxy functional epoxy resin and a tetrafunctional epoxy resin. The thermoplastic plastic is made of phenoxy resin, and its volume percentage is between 1% and 40%. The thermally conductive filler contains alumina or additional boron nitride and aluminum nitride in a total volume percentage of between 40% and 70%. Table 3 shows that each of the examples has good thermal conductivity, the peeling force is above 0.8 kg/cm (except for Example 7, the peeling force is even greater than 1.5 kg/cm), and has good withstand voltage characteristics.

Table 3

Similar to Figure 2, the above thermally conductive electrically insulating polymer material can be used.

The heat dissipation substrate is also formed, and the micro-rough surface may be formed on the interface between the layer of the thermally conductive electrically insulating polymer material and the first and second metal layers, such that the micro-rough surface comprises a plurality of knob-like protrusions. In one embodiment, the thermally conductive, electrically insulating polymeric material layer has a thickness of 0.1 mm and is resistant to voltages greater than 500 volts.

In the above thermal compression bonding process, since the insulating material has an interactive penetrating structure and contains a fiber supporting material, a separation phenomenon does not occur. The material of the metal layer is selected from the group consisting of copper, aluminum, nickel, copper alloy, aluminum alloy, nickel alloy, copper nickel alloy and aluminum copper alloy. The appearance of the insulating material is rubbery (non-resin) and thus has the characteristics of convenient storage and processing. In addition, if a thermoplastic type plastic is additionally added, the insulating material can be processed by a processing method generally used for a thermoplastic type plastic, thereby improving workability.

Table 4 shows the coefficient of thermal expansion (CTE) data of the fiber materials of different thermal volume in the X-axis and Y-axis directions of the thermally conductive electrically insulating polymer material of the present invention. The polyester fiber used therein is PET (polyethylene terephthalate) fiber, and Tg is a glass transition temperature of a polymer component. In Example 1, glass fiber A was simply used. Example 2 used two different sizes of glass fibers A and B. In Examples 3 and 4, different proportions of polyester fibers were added to the glass fiber A. The glass fiber A has a length of 12.7 mm and a diameter of 13 μm, so that its length/diameter has an aspect ratio of about 970. The glass fiber B has a length of 3.2 mm and a diameter of 10 μm, so that its aspect ratio is about 320. In practice, the aspect ratio of the glass fibers is generally from 100 to 1500, preferably from 200 to 1200.

As can be seen from Table 4, the fiber support material is simply glass fiber A (Example 1). When it is larger than Tg, its CTE on the Y axis is about 100×10 ^-6 /°C, and the C-axis ratio of the Y-axis/X-axis is About 2.1, if this CTE or its ratio is exceeded, the sheet is prone to warp, which is not suitable for actual processing. In addition, Example 2 can utilize a fiber of different length/diameter specifications to reduce the CTE when it is greater than Tg to less than 70 x 10 ^-6 / ° C and its ratio is less than 1.6. In addition, when a suitable ratio of polyester fibers is added, the C-axis ratio of the Y-axis/X-axis may be less than 1.6 or even less than 1.3, or further less than 1.2, even in the case of more than Tg. In summary, the thermally conductive electrically insulating polymer material of the present invention has a volumetric CTE ratio of less than 2.1 or less than 1.3 in two mutually perpendicular axial directions, and a CTE of less than 100×10 ^-6 /°C on the X-axis or the Y-axis. , and can greatly improve the shortcomings of bending to improve the workability. In the examples of the simultaneous addition of glass fibers and polyester fibers in Tables 3 and 4, the volume ratio of the glass fibers to the polyester fibers is between 0.3 and 5, or preferably between 0.5 and 4.5.

The fiber support material of the invention can make the insulating material appear rubbery, and by adjusting the proportion or specification of the fiber supporting material, the thermal expansion ratio in different directions can be controlled below an appropriate value, thereby greatly improving the processability (processibility). ).

The technical and technical features of the present invention have been disclosed as above, and those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be construed as being limited by the scope of the appended claims

10. . . Heat sink substrate

11. . . Metal foil

12. . . Insulating thermal conductive material layer

20. . . Heat sink material

twenty one. . . First metal layer

twenty two. . . Second metal layer

twenty three. . . Thermally conductive and electrically insulating polymer material layer

twenty four. . . Fiber support material

25. . . Micro-rough surface

26. . . Nodular protrusion

1 is a schematic view of a heat sink substrate applied to an electronic component;

2 is a schematic view of a heat dissipation substrate of the present invention.

20. . . Heat sink material

twenty one. . . First metal layer

twenty two. . . Second metal layer

twenty three. . . Thermally conductive and electrically insulating polymer material layer

twenty four. . . Fiber support material

25. . . Micro-rough surface

26. . . Nodular protrusion

Claims (21)

A thermally conductive electrically insulating polymer material comprising: a polymer component comprising a thermosetting epoxy resin selected from the group consisting of a terminal epoxy functional epoxy resin and a side chain epoxy functional group a group of epoxy resin or tetrafunctional epoxy resin or a mixture thereof, wherein the thermosetting epoxy resin accounts for between 4% and 60% by volume of the thermally conductive electrically insulating polymer material; a fiber support material , uniformly dispersed in the polymer component, and the volume percentage of the thermally conductive electrically insulating polymer material is between 1% and 35%; a curing agent curing the thermosetting epoxy at a curing temperature a resin; and a thermally conductive filler uniformly dispersed in the polymer component and occupying a volume percentage of the thermally conductive electrically insulating polymer material between 40% and 70%; wherein the thermal conductivity of the thermally conductive electrically insulating polymer material The system is greater than 0.5 W/mK. The thermally conductive electrically insulating polymer material according to claim 1, wherein the fibrous support material is selected from the group consisting of ceramic fiber materials, organic polymer fiber materials, or a mixture thereof. The thermally conductive electrically insulating polymer material according to claim 1, wherein the fibrous support material is selected from the group consisting of glass fibers, alumina fibers, carbon fibers, polypropylene fibers, polyester fibers, or a mixture thereof. A thermally conductive electrically insulating polymeric material according to claim 1, wherein the fibrous support material is a tangential fibrous material. According to claim 1, the thermally conductive electrically insulating polymer material is higher than When the glass transition temperature of the polymer component is such that the ratio of the thermal expansion coefficients in the two axial directions perpendicular to each other is less than 2.1. The thermally conductive electrically insulating polymer material according to claim 1, wherein a ratio of thermal expansion coefficients of the two axial directions perpendicular to each other is less than 1.3 when the glass transition temperature is higher than the polymer component. The thermally conductive electrically insulating polymer material according to claim 1, which has a thermal expansion coefficient of less than 100 × 10 ^-6 /° C. at a glass transition temperature higher than the polymer component. A thermally conductive electrically insulating polymer material according to claim 1, wherein the fibrous support material comprises glass fibers and polyester fibers. The thermally conductive electrically insulating polymer material according to claim 8, wherein the glass fiber and the polyester fiber have a volume ratio of between 0.3 and 5. A thermally conductive electrically insulating polymeric material according to claim 1 wherein the fibrous support material comprises at least two glass fibers of different aspect ratios. A thermally conductive electrically insulating polymer material according to claim 1, wherein the fibrous support material comprises glass fibers having an aspect ratio of from 320 to 970. The thermally conductive electrically insulating polymer material according to claim 1, wherein the thermosetting epoxy resin is a polymerized epoxy resin. The thermally conductive electrically insulating polymeric material of claim 1, wherein the thermoset epoxy resin comprises a monoepoxy functional group, a diepoxy functional group, three or more epoxy functional groups, or a mixture thereof. The thermally conductive electrically insulating polymer material according to claim 1, wherein the thermosetting epoxy resin further comprises a phenolphthalein epoxy resin or a phenol methane resin. The thermally conductive electrically insulating polymer material according to claim 1, wherein the thermosetting epoxy resin further comprises a bisphenol A epoxy resin, a bisphenol F epoxy resin, a bisphenol S epoxy resin or a mixture thereof. The thermally conductive electrically insulating polymer material according to claim 1, wherein the curing temperature of the curing agent is higher than 80 °C. The thermally conductive electrically insulating polymer material according to claim 1, wherein the polymer component further comprises a thermoplastic plastic, the thermoplastic plastic and the thermosetting epoxy resin being mutually soluble and forming an interpenetrating structure. The thermally conductive electrically insulating polymer material according to claim 17, wherein the thermoplastic plastic material comprises between 1% and 40% by volume of the thermally conductive electrically insulating polymer material. A thermally conductive electrically insulating polymer material according to claim 1, wherein the thermally conductive filler is a nitride, an oxide or a mixture of a nitride and an oxide. A heat dissipating substrate comprising: a first metal layer; a second metal layer; and a thermally conductive electrically insulating polymer material layer comprising the thermally conductive electrically insulating polymer material of claim 1, wherein the thermally conductive electrically insulating polymer material layer is laminated And forming a physical contact between the first metal layer and the second metal layer; wherein the thickness of the thermally conductive electrically insulating polymer material layer is resistant to a voltage greater than 500 volts at 0.1 mm. The heat dissipation substrate of claim 20, wherein the interface of the thermally conductive electrically insulating polymer material and the interface between the first and second metal layers comprises at least one micro-rough surface comprising a plurality of knob-like protrusions.