TW201422760A - Semiconductor device - Google Patents

Abstract

An object of the present invention is to provide a highly reliable semiconductor device having heating body with excellent heat dissipation, which solves the following issues: an issue of lowered bonding strength between a heating body and a substrate caused by stress which is generated due to the difference in thermal expansion coefficient between the heating body and the substrate when a high thermal conductivity film is in cooling after heat curing and in a heating process after assembly, and an issue of insufficient heat-resistance of the film. The present invention provides a semiconductor device l having a heating body 2, a heat receiver 3, and a high heat conduction layer 4 provided in-between the heating body 2 and the heat receiver 3 for transmitting heat from the heating body to the heat receiver, wherein the high heat conduction layer 4 contains a thermosetting body of a high heat conduction film containing the following (A) to (D) and has a thickness of 10 to 300 μ m: (A) two or more thermosetting resins containing at least a polyether compound of phenyl group where vinyl group of a particular structure is bonded; (B) a thermoplastic elastic body; (C) a heat conductive inorganic filler; and (D) a curing agent.

Description

Semiconductor device

The present invention relates to a semiconductor device, and more particularly to a semiconductor device which is excellent in heat dissipation and high in reliability.

In recent years, with the high functionality and high density of modules and electronic components, the amount of heat generated by a heating element such as a module or an electronic component has increased. The heat system derived from the heat generating body is conducted to the substrate or the like to dissipate heat. In order for this heat conduction to proceed efficiently, the adhesive between the heat generating body and the substrate uses a high thermal conductivity. Further, from the viewpoint of operability, an adhesive film of a highly thermally conductive layer can be used instead of the adhesive.

Here, if the heat conduction of the adhesive film is not good, heat may accumulate in the semiconductor device in which the module or the electronic component is incorporated, and there is a problem that the semiconductor device is malfunctioning. Therefore, all companies are investing in the development of high thermal conductivity films.

The high thermal conductivity film has been reported to have a large amount of a heat-dissipating die bond film using a highly thermally conductive filler (Patent Document 1), and a thermal conductivity which enhances heat dissipation of a semiconductor device by containing a filler of a specific shape in the film. Sheet (Patent Document 2).

Advanced technical literature

Patent Document 1: Japanese Patent Laid-Open No. 2011-023607

Patent Document 2: Japanese Laid-Open Patent Publication No. 2011-142129

However, a heat-dissipating solid-state film using a large amount of a highly thermally conductive filler is an epoxy resin, a phenol resin, and an acrylic resin (paragraphs 0035 and 0999 of Patent Document 1), and the heat-dissipating solid-state film after heat curing is too high. When the heat-radiating solid crystal film having a high thermal conductivity is cooled after the heat curing, the stress due to the difference in thermal expansion coefficient between the heat generating body and the substrate causes a problem that the bonding strength between the heating element and the substrate is lowered. Further, in the heat-dissipating solid-state film, it is difficult to provide sufficient heat resistance, and it is sometimes impossible to cope with heat generation due to heat increase of a module or an electronic component, and in a semiconductor device using a heat-conductive film having insufficient heat conduction, fear It is detrimental to the reliability of the semiconductor device itself.

Further, a thermosetting resin containing a filler having a specific shape is also used as a thermosetting resin (paragraphs 0029 and 0037 of Patent Document 2), and the adhesion strength between the heat generating body and the substrate is lowered, and the heat resistance of the heat conductive sheet is difficult to be sufficient. However, it is also fearful of damage to the reliability of the semiconductor device itself. Further, if a special shape or a processed filler is used for the thermally conductive sheet, the cost of the semiconductor device is increased. Further, since the unevenness is formed on the surface of the thermally conductive sheet on the member to be bonded to the thermally conductive sheet, there is a problem that the usable semiconductor device is limited.

An object of the present invention is to provide a highly reliable semiconductor device which is excellent in heat dissipation of a heat generating body and which is generated in a heat history after heat hardening of a high thermal conductivity film and in a heat history after assembly, which is caused by a heat generating body and The stress of the difference in thermal expansion coefficient of the substrate causes a problem that the bonding strength between the heating element and the substrate is lowered, and the heat resistance of the film is insufficient.

The present invention relates to solving the above problems by having the following constitution Semiconductor device.

[1] A semiconductor device comprising a heat generating body, a heat receiver, and a highly thermally conductive layer between the heat generating body and the heat sink for conducting heat from the heat generating body to the heat receiver, wherein the high heat conductive layer contains the following (A) to (D) a thermally hardened body of a high heat conductive film having a thickness of 10 to 300 μm, and (A) two or more kinds of thermosetting resins having at least two ends having the following formula (1) a polyether compound having a vinyl group bonded to a vinyl group; (B) a thermoplastic elastomer; (C) a thermally conductive inorganic filler; (D) a hardener;

Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group, -(OXO) Is represented by the formula (2), wherein R ₈ , R ₉ , R ₁₀ , R ₁₄ and R ₁₅ may be the same or different, and are a halogen atom or an alkyl group having 6 or less carbon atoms or benzene. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, or an alkyl group having 6 or less carbon atoms or a phenyl group, and -(YO)- is represented by the structural formula (3). A structure of one type or a structure in which two or more types of structures represented by the structural formula (3) are randomly arranged, wherein R ₁₆ and R ₁₇ may be the same or different, and are a halogen atom or an alkane having 6 or less carbon atoms. Or a phenyl group, R ₁₈ and R ₁₉ may be the same or different, and are a hydrogen atom, a halogen atom, or an alkyl group having 6 or less carbon atoms or a phenyl group, and Z is an organic group having 1 or more carbon atoms, as the case may be. It contains an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom, and at least either of a and b is not 0, and represents an integer of 0 to 300, and c and d represent an integer of 0 or 1.

[2] The semiconductor device according to [1] above, wherein the high thermal conductive layer has a shear adhesion strength at 25 ° C of 13 N/mm or more.

[3] The semiconductor device according to the above [1], wherein the high heat conductive layer has a thickness of 10 μm or more and 100 μm or less.

[4] The semiconductor device according to [1] above, wherein the high thermal conductive layer has a volume resistivity of 1 × 10 ¹⁰ Ω. Above cm and thermal conductivity is 0.8W/m. K or more.

[5] The semiconductor device according to the above [1], wherein the component (C) is one selected from the group consisting of MgO, Al ₂ O ₃ , AlN, BN, diamond filler, ZnO, and SiC. the above.

[6] The semiconductor device according to the above [1], wherein the component (D) is an imidazole-based curing agent.

[7] The semiconductor device according to [1] above, wherein the heat receiver is a substrate on which an electrode is formed, The highly thermally conductive layer is formed between the heating element and the electrode formed on the substrate.

[8] The semiconductor device according to the above [1], wherein the heat generating body has an electrode and the heat receiver is a substrate, and the high heat conductive layer is formed between the electrode of the heat generating body and the substrate.

[9] The semiconductor device according to [1] above, wherein the heating element is an IC wafer, a bare crystal wafer, an LED wafer, a spin wheel diode (FWD; Free Wheeling Diode), or an insulated gate bipolar two Insulated Gate Bipolar Transistor (IGBT).

[10] The semiconductor device according to any one of [7] to [9] wherein the substrate is a substrate using a metal substrate CCL, a substrate using a high thermal conductivity CEM-3, and a substrate using a high thermal conductivity FR-4. A substrate having a low thermal resistance FCCL, a metal substrate, or a ceramic substrate is used.

[11] The semiconductor device according to [1] above, wherein the heating element is a semiconductor module and the heat receiver is a heat dissipation plate.

[12] The semiconductor device according to [11] above, wherein the semiconductor module is a power semiconductor module.

According to the present invention, it is possible to provide a heat generating body which is excellent in heat dissipation and which does not cause a difference in thermal expansion coefficient between the heat generating body and the substrate, so that the bonding strength between the heat generating body and the substrate is lowered, and further, heat resistance can be imparted. Sex semiconductor device.

1‧‧‧Semiconductor device

2‧‧‧heating body

3‧‧‧heater

4‧‧‧High thermal conductivity layer

10, 20, 30, 40‧‧‧ semiconductor devices

12, 22, 32, 42‧‧‧ IC chips

13, 23, 33, 43‧‧‧ substrates

14, 24, 34, 44‧‧‧ high thermal conductivity layer

15, 25, 35, 45‧‧‧ electrodes

16, 36, 46‧‧‧ welding line

27‧‧‧electrodes (bumps)

48‧‧‧electrode (lead frame)

49‧‧‧Molding

50, 60‧‧‧ semiconductor devices

52, 62‧‧‧ semiconductor modules

53, 63‧‧‧ substrate

54, 64‧‧‧High thermal conductivity layer

55, 65‧‧‧ electrodes

56, 66‧‧‧ heat sink

71‧‧‧Cutting tools

72‧‧‧Substrate

73‧‧‧矽 wafer

74‧‧‧High thermal conductivity layer

81‧‧‧heater

82‧‧‧ copper plate

83‧‧‧High thermal conductivity film

84‧‧‧ Heat sink

85‧‧‧ weights

86‧‧‧K type thermocouple

Fig. 1 is a view showing an example of a schematic view of a cross section of a semiconductor device of the present invention.

Fig. 2 is a graph showing the relationship between the thickness of the highly thermally conductive layer and the adhesion strength (shear strength).

Fig. 3 is a view showing a specific example of a cross section of a semiconductor device.

Fig. 4 is a view showing a specific example of a cross section of a semiconductor device.

Fig. 5 is a view showing a specific example of a cross section of a semiconductor device.

Fig. 6 is a view showing a specific example of a cross section of a semiconductor device.

Fig. 7 is a view showing a specific example of a cross section of a semiconductor device.

Fig. 8 is a view showing a specific example of a cross section of a semiconductor device.

Fig. 9 is a schematic view showing the evaluation method of the shear adhesion strength of the highly thermally conductive layer.

Figure 10 is a schematic diagram of a thermal resistance measuring device.

Figure 11 shows the results of the evaluation of the thermal resistance.

The semiconductor device of the present invention has a heat generating body, a heat receiver, and a highly thermally conductive layer between the heat generating body and the heat sink for conducting heat from the heat generating body to the heat receiver, wherein the high heat conductive layer contains the following (A A thermally hardened body of the high heat conductive film of (D) and having a thickness of 10 to 300 μm.

(A) Two or more kinds of thermosetting resins containing at least a polyether compound having a phenyl group having a bonded vinyl group at both terminals represented by the following formula (1); (B) a thermoplastic elastomer; (C) a thermally conductive inorganic filler; (D) a hardener;

Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group, -(OXO) Is represented by the formula (2), wherein R ₈ , R ₉ , R ₁₀ , R ₁₄ and R ₁₅ may be the same or different and are a halogen atom or an alkyl group having 6 or less carbon atoms or a phenyl group; R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, or an alkyl group having 6 or less carbon atoms or a phenyl group, and -(YO)- is represented by the structural formula (3). a structure of one type or a structure in which two or more types of structures represented by the structural formula (3) are randomly arranged, wherein R ₁₆ and R ₁₇ may be the same or different, and are a halogen atom or an alkyl group having 6 or less carbon atoms or Phenyl group, R ₁₈ and R ₁₉ may be the same or different, and are a hydrogen atom, a halogen atom or an alkyl group having 6 or less carbon atoms or a phenyl group, and Z is an organic group having 1 or more carbon atoms, and optionally contains oxygen. The atom, the nitrogen atom, the sulfur atom, and the halogen atom, at least one of a and b is not 0, and represents an integer of 0 to 300, and c and d represent an integer of 0 or 1.

Since this highly thermally conductive layer is excellent in thermal conductivity and heat resistance, it is a semiconductor device which is excellent in heat dissipation of a heat generating body and has high signal reliability. Figure 1 is a cross section showing the semiconductor device of the present invention An example of a schematic diagram. As shown in FIG. 1, the semiconductor device 1 of the present invention has a heat generating body 2, a heat receiver 3, and a high heat conductive layer 4 for transferring heat of the heat generating body to the heat receiver between the heat generating body and the heat sink, and has high heat conductivity. Layer 4 is a thermally hardened body of a highly thermally conductive film. The heating element, the heat receiver, and the high heat conductive layer will be described in order below.

[heating stuff]

The heat generating system is not particularly limited, and various semiconductor or semiconductor modules can be used. However, in order to exert the effects of the present invention, it is preferable to use a heat generating body having a large amount of heat, that is, an IC chip such as a bare crystal wafer, an LED chip, and a FWD (Free Wheeling). Diodes, semiconductors such as IGBTs (Insulated Gate Bipolar Transistors), and semiconductor modules such as power semiconductor modules used in transportation equipment such as automobiles. Further, in order to exert the effects of the present invention, it is more preferable to have a semiconductor or semiconductor module having a high output of 0.5 W to 500 W.

[heater]

The heat sink is a substrate, a heat sink, or the like. Examples of the substrate include a resin substrate using a substrate having a high thermal conductivity CEM-3, a substrate using a high thermal conductivity FR-4, a substrate using a metal substrate CCL, a substrate using a substrate having a low thermal resistance FCCL, and the like; Al ₂ O ₃ , For ceramic substrates such as AlN, SiC, and BN, various substrates can be used in accordance with the design of a semiconductor device. When a resin-based substrate is used as the heat-receiving device, the high thermal conductivity layer having a low modulus of elasticity can alleviate the stress caused by the difference in thermal expansion between the heat-generating body and the heat-receiving device, thereby preventing warpage and further imparting heat resistance to the semiconductor device. When a metal substrate or a ceramic substrate is used as the heat sink, since the heat transfer rate of the heat generating body and the heat receiver is close to each other, the stress due to the difference in thermal expansion between the heat generating body and the heat sink can be alleviated, and the high heat conductive layer has a low modulus of elasticity, so that it can be prevented. Cracks are generated in the high heat conductive layer, and heat resistance can be further imparted to the semiconductor device. In particular, a resin-based substrate is preferably used for the purpose of stress relaxation, and a metal substrate or a ceramic substrate is preferably used from the viewpoint of low thermal resistance. Table 1 shows an example of the thermal expansion coefficient and thermal conductivity of each resin-based substrate for reference. Further, Table 1 also discloses information on materials such as IC chips. In addition, the heat dissipation plate is not particularly limited as long as it can dissipate heat derived from a semiconductor module or the like.

[High thermal conductivity layer]

First, a highly thermally conductive film for forming a thermosetting body constituting a highly thermally conductive layer will be described. The component (A) contained in the high heat conductive film is a thermosetting resin containing two or more kinds of polyether compounds having a phenyl group having a bonded vinyl group at both terminals represented by the general formula (1). Hereinafter referred to as modified OPE). In the present invention, since the modified OPE is used as the thermosetting resin, the Tg is higher (216 ° C) than the conventional epoxy-based product, and the heat resistance is excellent, and the high heat conductive layer is less likely to change with time, and the semiconductor device can be maintained. Long-term reliability. Further, since it has a small number of hydrophilic groups in the resin, it is excellent in hygroscopicity. Therefore, even if the temperature in the vicinity of 150 ° C is used for such a purpose, the highly thermally conductive layer does not peel off from the heat generating body or the heat receiver, and is a highly reliable semiconductor device. Furthermore, by modifying the effect of the OPE and the elastomer, since the highly thermally conductive layer has moderate flexibility to alleviate external stress, the semiconductor device can be alleviated. The stress generated inside. Further, the modified OPE is excellent in insulation properties, and the reliability of the semiconductor device can be maintained even if the thickness of the high heat conductive layer is reduced. This modified OPE is described in JP-A-2004-59644. Further, the composition using an epoxy resin having a high Tg cannot be formed into a film shape, and the composition using an epoxy resin having a low Tg can be formed into a film shape, but the Tg of the obtained film becomes low, so that the heat resistance of the film is poor. .

In the structural formula (2) of the modified OPE-(OXO)- represented by the formula (1), R ₈ , R ₉ , R ₁₀ , R ₁₄ and R _{15 are} preferably an alkyl group having 3 or less carbon atoms. R ₁₁ , R ₁₂ and R _{13 are} preferably a hydrogen atom or an alkyl group having 3 or less carbon atoms. Specifically, the structural formula (4) can be mentioned.

In the structural formula (3) for -(YO)-, R ₁₆ and R _{17 are} preferably an alkyl group having 3 or less carbon atoms, and R ₁₈ and R _{19 are} preferably a hydrogen atom or an alkyl group having 3 or less carbon atoms. Specifically, the structural formula (5) or (6) can be mentioned.

The Z system may, for example, be an alkylene group having 3 or less carbon atoms, and specific examples thereof include a methylene group.

At least one of a, b is not 0, and represents an integer from 0 to 300, preferably representing an integer from 0 to 30.

Preferred is a modified OPE of the formula (1) having a number average molecular weight of 1,000 to 3,000. The number average molecular weight is the value of the standard polystyrene calibration curve by gel permeation chromatography (GPC).

The modified OPE may be used singly or in combination of two or more.

Examples of the thermosetting resin other than the modified OPE of the formula (1) contained in the component (A) include a biphenyl type epoxy resin, a naphthalene type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol. F-type epoxy resin, novolak type epoxy resin, carbodiimide resin, bismaleimide resin, etc., from the viewpoint of moldability of a high heat conductive film, a biphenyl type epoxy is preferable. Resin. Epoxy resin is used to improve the adhesion strength. Further, the carbodiimide resin can improve the adhesion strength compared with the epoxy resin, and therefore, a carbodiimide resin is preferable in applications requiring high adhesion. From the viewpoint of improving the adhesion strength and high Tg (glass transition temperature), a bismaleimide resin is preferred. The thermosetting resin other than the modified OPE contained in the component (A) may be used alone or in combination of two or more.

The component (B) may, for example, be a styrene-butadiene block copolymer (SBS), a styrene-ethylene/butylene-styrene block copolymer (SEBS), or a styrene-isoprene-styrene. Block copolymer (SIS), polybutadiene (PB), styrene-(ethylene-ethylene/propylene)-styrene block copolymer (SEEPS), from the viewpoint of imparting heat resistance to a highly thermally conductive film after hardening, A styrene-ethylene/butylene-styrene block copolymer is preferred. The component (B) may be used alone or in combination of two or more. The component (B) is preferably a weight average molecular weight of 30,000 to 200,000. The weight average molecular weight is the value of the standard polystyrene calibration line by gel permeation chromatography (GPC).

The thermal conductivity inorganic filler of component (C) is a thermal conductivity of 5W/m. K or above. From the viewpoint of maintaining the insulating property, the general inorganic filler can be used as the component (C), and from the viewpoints of thermal conductivity, insulating property and thermal expansion coefficient, it is preferably MgO, Al ₂ O ₃ , AlN, BN, diamond filler, ZnO, And at least one or more inorganic fillers selected from the group consisting of SiC. In addition, ZnO and SiC may be subjected to insulation treatment as needed. One example of the thermal conductivity measurement of each material (unit: W/m.K), MgO is 37, Al ₂ O ₃ is 30, AlN is 200, BN is 30, diamond is 2000, ZnO is 54, SiC is 90. .

The average particle diameter of the component (C) (the average maximum diameter in the case of non-granularity) is not particularly limited, but is preferably 0.05 to 50 μm from the viewpoint of uniformly dispersing the component (C) in the highly thermally conductive film. If it is less than 0.05 μm, the viscosity of the composition for forming a highly thermally conductive film rises, and the formability deteriorates. If it exceeds 50 μm, it may be difficult to uniformly disperse the component (C) in the high heat conductive film. Here, the average particle diameter of the component (C) is measured by a dynamic light scattering type nanometer tracking particle size analyzer. The component (C) may be used alone or in combination of two or more.

Examples of the component (D) include a phenolic curing agent, an amine curing agent, an imidazole curing agent, and an acid anhydride curing agent, and the (D) component has curability and adhesion from a thermosetting resin other than the modified OPE. From the viewpoint, an imidazole-based hardener is preferred.

The component (A) is preferably 5 to 25 parts by mass based on 100 parts by mass of the high heat conductive film from the viewpoint of the thermal conductivity of the highly thermally conductive film after curing. Moreover, the modified OPE is preferably 60 to 95 parts by mass based on 100 parts by mass of the component (A) from the viewpoint of heat resistance of the high heat conductive film after curing.

The component (B) is preferably 5 to 25 parts by mass based on 100 parts by mass of the high heat conductive film from the viewpoint of the moldability of the high heat conductive film and the elastic modulus of the high heat conductive film after curing.

The component (C) is preferably 50 to 90 parts by mass based on 100 parts by mass of the high heat conductive film from the viewpoint of the insulating property, the adhesive property, and the thermal expansion coefficient. When the component (C) exceeds 90 parts by mass, the adhesion of the high heat conductive film is liable to lower. On the other hand, if the component (C) is less than 50 parts by mass, even if the thermal conductivity of the inorganic filler is high, there is a fear that the heat conduction of the high heat conductive layer may be insufficient.

The component (D) is preferably 0.01 to 1 part by mass based on 100 parts by mass of the high heat conductive film from the viewpoint of storage stability of the high heat conductive film and hardenability of the high heat conductive film.

Further, the high heat conductive film may contain additives such as a tackifier, an antifoaming agent, a flow regulating agent, a film forming auxiliary agent, and a dispersing aid, insofar as the effects of the present invention are not impaired.

The composition for forming a high heat conductive film (hereinafter referred to as a composition for a high heat conductive film) is obtained by dissolving or dispersing a raw material containing the components (A) to (D) in an organic solvent, thereby obtaining a highly heat conductive film. Use the composition. The apparatus for dissolving or dispersing the raw materials is not particularly limited, and a crucible equipped with a stirring and heating device, a 3-roll mill, a ball mill, a planetary mixer, a bead mill, or the like can be used. In addition, these devices can be suitably used in combination.

The organic solvent may, for example, be an aromatic solvent such as toluene or xylene, or a ketone solvent such as methyl ethyl ketone or methyl isopropyl ketone. The organic solvent may be used singly or in combination of two or more. Further, the amount of the organic solvent to be used is not particularly limited, but is preferably used in a form of a solid content of 20 to 50% by mass. From the point of view of workability, the composition for the high heat conductive film is preferably from 200 to 3000 mPa. s viscosity range. The viscosity was measured using an E-type viscometer at a number of revolutions of 10 rpm and 25 °C.

The highly thermally conductive film is obtained by applying a composition for a highly thermally conductive film to a desired support and drying it. The support system is not particularly limited, and examples thereof include copper and aluminum. An organic film such as a metal foil, a polyester resin, a polyethylene resin, or a polyethylene terephthalate resin. The support system can be subjected to mold release treatment by a polyoxo compound or the like.

The method of applying the composition for a high heat conductive film to the support is not particularly limited, and from the viewpoint of film formation and film thickness control, a micro gravure method, a slit die method, and a doctor blade method are preferable. A highly thermally conductive film having a thickness of 10 to 300 μm after heat curing can be obtained by a slit die method.

The drying conditions can be appropriately set depending on the type and amount of the organic solvent used in the composition for a high heat conductive film, the coating thickness, and the like, and may be, for example, 50 to 120 ° C for about 1 to 30 minutes. The highly thermally conductive film obtained by such a method has good preservation stability. In addition, the highly thermally conductive film can be peeled off from the support at the desired timing.

The high heat conductive layer can be formed by, for example, disposing a high heat conductive film in an uncured state between a heat generating body and a heat sink, for example, at 130 to 200 ° C for 60 to 180 minutes. In the high heat conductive layer, the heat generating body, the heat receiver, and the electrode of the heat sink are adhered, and the heat from the heat generating body escapes to the heat receiver side, and the heat transfer function of the heat sink on the heat receiver side is exerted. Further, the high heat conductive layer functions to alleviate the stress caused by the difference in thermal expansion coefficient between the heat generating body and the heat receiver, and optionally between the heat generating body or the heat receiver and the electrode.

The thickness of the high heat conductive layer is 10 μm or more and 300 μm or less, preferably 10 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. If it is less than 10 μm, it may be impossible to obtain the desired insulation. If it exceeds 300 μm, the heat radiation of the heating element is insufficient. As the thickness of the highly thermally conductive layer becomes thinner, the distance between the heating element and the heat receiver becomes shorter, so that the thickness of the highly thermally conductive layer is preferably thinner from the viewpoint of efficient heat conduction.

Furthermore, the higher the thermal conductivity layer, the thinner the thickness, the higher the adhesion strength. Characteristics. The relationship between the thickness of the highly thermally conductive layer and the adhesion strength (shear strength) is shown in Table 2 and Figure 2. In Fig. 2, the horizontal axis represents the film thickness, the vertical axis represents the shear strength, and the broken line indicates the tendency of the shear strength and the film thickness. As can be seen from Fig. 2, the thinner the thickness of the highly thermally conductive layer, the higher the adhesion strength. Therefore, when the thickness of the high heat conductive layer is 10 μm or more and 300 μm or less and the shear strength is 10 N/mm or more, it is preferable that the shear strength is 14 N/mm or more when the thickness is 10 μm or more and 100 μm or less. The thickness is preferably 10 μm or more and 50 μm or less, and the shear strength is 15 N/mm or more. The high heat conductive layer has a high shear strength because the high heat conductive layer has moderate flexibility to alleviate stress from the outside. However, if the high heat conductive layer exceeds 300 μm, the high heat conductive layer itself is cracked and easily broken. In the heat dissipation application when the heating element is a semiconductor module and the heat sink is a heat dissipation plate, high adhesion is not often required, but in the case where the heating element is a semiconductor such as an IC chip and the heat receiver is a substrate, high adhesion is required. The high thermal conductivity layer is thicker than 300 μm, which is not preferable. In order to make the thickness of the high heat conductive film into the above preferred range, the high heat conductive layer can be realized in the thickness of the above preferred range.

The shear strength of the highly thermally conductive layer at 25 ° C is preferably 13 N/mm or more. If it is less than 13N, it is difficult to use it in the case where the heat generating body is a semiconductor such as an IC chip and the heat sink is used as a substrate.

The high thermal conductivity layer preferably has a volume resistivity of 1×10 ¹⁰ Ω. Above cm and thermal conductivity is 0.8W/m. K or more. The high thermal conductivity layer has a better volume resistivity of 1 × 10 ¹² Ω. More than cm, and more preferably 1 × 10 ¹³ Ω. More than cm. In addition, the high thermal conductivity layer has a better thermal conductivity of 1.0 W/m. K or more. The volume resistivity of the high thermal conductivity layer is less than 1 × 10 ¹⁰ Ω. At the time of cm, there is a fear that the insulation required for the semiconductor device cannot be satisfied. In addition, the thermal conductivity of the high thermal conductivity layer is less than 0.8W/m. At the time of K, there is a fear that the heat generating body does not sufficiently heat the heat exchanger. The volume resistivity and thermal conductivity of the highly thermally conductive layer can be controlled by the type and content of the component (C).

[semiconductor device]

Hereinafter, each embodiment of the semiconductor device of the present invention will be described, but the present invention is not limited to the embodiments. In the semiconductor device of the present invention, the heat receiver is a substrate on which an electrode is formed, and if a high heat conductive layer is formed between the heat generating body and the electrode formed on the substrate, heat of the heat generating body is dissipated through the electrode formed on the substrate. Therefore, it is better. This structure exists in Fig. 5 which will be described later. Further, in another semiconductor device of the present invention, the heat generating body has an electrode and the heat receiver is a substrate, and if the high heat conductive layer is formed between the electrode of the heat generating body and the substrate, the heat of the heat generating body is passed through the electrode of the heat generating body. It is better to dissipate heat. This structure exists in the fourth and sixth figures which will be described later. Hereinafter, specific examples of the cross section of such a semiconductor device will be described based on the third to eighth embodiments.

The structure of the semiconductor device 10 shown in FIG. 3 is such that a high heat conductive layer 14 is provided between the IC wafer 12 as a heat generating body and the substrate 13 as a heat sink, and is connected to the IC wafer 12 by a bonding wire 16 on the substrate 13. A highly thermally conductive layer 14 is also disposed between the upper electrode 15 and the substrate 13. In this configuration, the heat derived from the IC wafer 12 is radiated to the substrate 13 via the highly thermally conductive layer 14, and further radiated by the passage of the bonding wire 16 and the electrode 15 to the substrate 13 via the highly thermally conductive layer 14 to dissipate heat. In Fig. 3, the highly thermally conductive layer 14 functions as an adhesive layer between the substrate 13 and the IC wafer 12, and between the substrate 13 and the electrode 15. Further, the high heat conductive layer 14 moderates the stress caused by the difference in thermal expansion coefficient between the substrate 13 and the IC wafer 12 and between the substrate 13 and the electrode 15.

The structure of the semiconductor device 20 shown in FIG. 4 is such that an electrode (bump) 27 formed on the IC wafer 22 as a heat generating body is bonded to the electrode 25 formed on the substrate 23 as a heat sink, and is bonded to the substrate 23 and A highly thermally conductive layer 24 is provided between the electrodes 25 for conducting heat from the IC wafer 22 to the substrate 23. In this configuration, heat-transmissive electrodes (bumps) 27 and electrodes 25 derived from the IC wafer 22 are radiated to the substrate 23 via the highly thermally conductive layer 24. In Fig. 4, the highly thermally conductive layer 24 functions as an adhesive layer between the substrate 23 and the electrode 25. Further, the high heat conductive layer 24 moderates the stress caused by the difference in thermal expansion coefficient between the substrate 23 and the electrode 25.

In the semiconductor device 30 shown in FIG. 5, the IC wafer 32 as a heat generating element is adhered to the electrode 35 through the upper high heat conductive layer 34, and the electrode 35 is adhered to the substrate 33 through the lower high heat conductive layer 34. Further, the IC wafer 32 is bonded to the electrode 35 by the bonding wire 36. In this configuration, the heat from the IC wafer 32 is dissipated to the electrode 35 via the upper high thermal conductivity layer 34 and is also dissipated to the electrode 35 via the bonding wire 36. The heat conducted to the electrode 35 is radiated to the substrate 33 via the lower high heat conductive layer 34. In Fig. 5, the highly thermally conductive layer 34 also functions as an adhesive layer between the IC wafer 32 and the electrode 35, and between the electrode 35 and the substrate 33. Further, the high heat conductive layer 34 moderates the stress caused by the difference between the thermal expansion rates of the IC wafer 32 and the electrode 35 and the electrode 35 and the substrate 33.

In the semiconductor device 40 shown in Fig. 6, the IC chip 42 is bonded to the electrode (lead frame) 48 on the left side. Further, the IC chip 42 is bonded to the right electrode (lead frame) 48 by the bonding wire 46. The lead frame 48 is bonded to the electrode 45, and the electrode 45 is adhered to the substrate 43 through the high heat conductive layer 44. Further, a part of the IC wafer 42, the bonding wire 46, and the electrode (lead frame) 48 are packaged by a mold resin 49. In this configuration, the heat from the IC wafer 42 is directly conducted to the left electrode (lead frame) 48, and by soldering The wire 46 is conducted to the right electrode (lead frame) 48, and is further conducted to the left and right electrodes (lead frame) 48 by the mold resin 49. The heat transmitted to the electrode (lead frame) 48 is transmitted through the electrode 45 and the highly thermally conductive layer 44 to the substrate 43. In Fig. 6, the highly thermally conductive layer 44 also functions as an adhesive layer between the electrode 45 and the substrate 43. Further, the high heat conductive layer 44 moderates the stress caused by the difference in thermal expansion coefficient between the electrode 45 and the substrate 43.

In the semiconductor device 50 shown in FIG. 7, the semiconductor module 52 is bonded to the electrode 55. The electrode 55 is adhered to the substrate 53 through the upper high heat conductive layer 54, and the substrate 53 is adhered to the heat sink 56 through the lower high heat conductive layer 54. In this structure, the heat-transmissive electrode 55 of the semiconductor module 52, the upper high heat conductive layer 54, the substrate 53, and the lower high heat conductive layer 54 are radiated to the heat sink 56. In Fig. 7, the high heat conductive layer 54 functions as an adhesive layer between the electrode 55 and the substrate 53, and the substrate 53 and the heat sink 56. Further, the high heat conductive layer 54 moderates the stress caused by the difference in thermal expansion coefficient between the electrode 55 and the substrate 53, and the substrate 53 and the heat sink 56.

In the semiconductor device 60 shown in FIG. 8, the semiconductor module 62 is bonded to the electrode 65. The electrode 65 is adhered to the substrate 63 through the lower high heat conductive layer 64. Further, the semiconductor module 62 is adhered to the heat dissipation plate 66 through the upper high heat conductive layer 64. In this configuration, the heat from the semiconductor module 62 is radiated to the heat dissipation plate 66 through the upper high heat conductive layer 64, and is radiated to the substrate 63 through the electrode 65 and the lower high heat conductive layer 64. In Fig. 8, the high heat conductive layer 64 also functions as an adhesive layer between the electrode 65 and the substrate 63, and the semiconductor module 62 and the heat sink 66. Further, the high heat conductive layer 64 moderates the stress caused by the difference between the thermal expansion coefficients of the electrode 65 and the substrate 63 and the semiconductor module 62 and the heat dissipation plate 66.

Example

The present invention will be described by way of examples, but the invention is not limited thereto. In the following examples, the parts and % represent the parts by mass and the mass% unless otherwise stated.

[Examples 1 to 5, Comparative Examples 1 to 7]

The blending ratios shown in Tables 3 and 4 were measured by blending the components (A) and (B) with an appropriate amount of toluene, and then feeding them into a reaction vessel heated to 80 ° C while rotating. The mixture was rotated at 150 rpm and mixed under normal pressure for 3 hours to prepare a clear liquid. The component (C), the component (D), and other components as the case may be added to the prepared clear liquid, and the composition for a high heat conductive film is dispersed by a planetary mixer. The composition for a high heat conductive film obtained in this manner was applied to one surface of a PET film which has been subjected to release treatment as a support, and dried at 100 ° C to obtain a highly thermally conductive film with a support. Further, in Comparative Example 5 and Comparative Example 7, a film could not be formed.

[Evaluation of high thermal conductivity layer]

In order to evaluate the highly thermally conductive layer, the highly thermally conductive film was thermally hardened in each of the following evaluations. Tables 5 and 6 show the hardening temperature and the hardening time when the high heat conductive film is thermally cured.

"Thermal conductivity"

The uncured high heat conductive film was heat-hardened by a press at 200 ° C for 60 minutes. The thermal conductivity of the hardened high thermal conductive film was measured using a thermal conductivity meter (Xe flash analyzer, model: LFA447 Nanoflash) manufactured by NETZSCH.

Peel Strength

The copper foil was bonded to both sides of the adhesive film so that the roughened surface was inside, and the press was heat-pressed (180 ° C, 60 min, 0.1 MPa). The test piece was cut to a width of 10 mm and The peeling strength was measured by drawing the automatic drawing machine. The average value of each N=5 was calculated for the measurement results.

Glass Transfer Point Temperature (Tg)

Determined by dynamic viscoelasticity measurement (DMA). After the high heat conductive film was thermally hardened at 200 ° C for 60 minutes and peeled off from the support, a test piece (10 ± 0.5 mm × 40 ± 1 mm) was cut out from the thermally hardened body of the high heat conductive film, and the width and thickness of the test piece were measured. Thereafter, the measurement (stretching mode) (3 ° C/min, 10 Hz, 25-220 ° C) was carried out by DMS (model: EXSTAR 6100) manufactured by Seiko Instruments. The peak temperature of tan δ was read as Tg.

Evaluation of Elasticity Rate

The storage modulus at 25 ° C measured by the above dynamic viscoelasticity measurement (DMA) was taken as the modulus of elasticity. Tables 5 and 6 show the results of evaluation of the elastic modulus of the highly thermally conductive film.

Evaluation of Shear Adhesion Strength

The shear adhesion strength of the highly thermally conductive layer was evaluated for Example 1, Comparative Examples 1, and 2. Fig. 9 is a schematic view showing the evaluation method of the shear adhesion strength of the highly thermally conductive layer. An FR-4 substrate as the substrate 72 and a 5 mm square germanium wafer as the germanium wafer 73 were prepared. A high thermal conductive film of Φ 2 mm is placed on the substrate 72 at a position where the high heat conductive layer 74 is to be formed, and the germanium wafer 73 is mounted on the high heat conductive film. Thereafter, the highly thermally conductive film was thermally cured at 200 ° C for 60 minutes to form a highly thermally conductive layer 74. The shear strength (unit: N) at 25 ° C and 150 ° C was measured using a table strength tester (Model: 1605HTP) made of AIKOH ENGINEERING. Table 7 shows the results of evaluation of the shear adhesion strength of the highly thermally conductive layer.

Thermal resistance

A schematic diagram of the thermal resistance measuring device is shown in Fig. 10. A high-heat-conducting film 83 having a width of 20 mm, a length of 20 mm, and a thickness of 20 to 390 μm and hardened at 200 ° C for 60 minutes is provided between the copper plates 82 having a width of 50 mm, a length of 50 mm, and a thickness of 5 mm embedded in the K-type thermocouple 86. The copper plate 82 is pressed against the heat sink 84 and a weight of 660 g. The heater 81 was placed in the lower portion, heated under the following conditions, and the thermal resistance was calculated.

The test conditions were a supply voltage of 40 W (=100 V × 0.4 A) and a measurement range of 20 mm □. The heater side temperature is Ta after the start of the supply of electric power for 5 minutes, the heat sink side temperature is Tb, and the supplied electric power is P, and the thermal resistance (unit: ° C/W) is calculated from the following formula: Rth = (Ta - Tb) / P

Tables 8 and 11 show the results of the evaluation of the thermal resistance.

As is apparent from Table 5, in Examples 1 to 5, the thermal conductivity, the peel strength, and the glass transition temperature were all higher, and the elastic modulus was within the desired range. However, as is clear from Table 6, Comparative Example 1 in which the modified OPE was not used had a low glass transition temperature and an elastic modulus. Further, in Comparative Example 2 in which the modified OPE was not used, the modulus of elasticity was too high. Comparative Example 3 in which the (C) component was replaced with an inorganic filler of cerium oxide (thermal conductivity of about 1 W/m.K) was low in thermal conductivity. In Comparative Example 4 in which the thermosetting resin was only modified OPE, the peel strength was low. In Comparative Example 5 containing no component (B) and Comparative Example 7 containing no component (D), a film could not be formed. Comparative Example 6 containing no (C) component was low in thermal conductivity and modulus.

Further, as is clear from Table 7, Example 1 had high shear adhesion strength at 25 ° C and 150 ° C. However, in Comparative Example 1, the shear adhesion strength at 25 ° C was low, and the shear adhesion strength at 150 ° C was remarkably low. Further, in Comparative Example 2, the same values as in Example 1 were shown.

From the evaluation results of the thermal resistances in Tables 8 and 11, it can be seen that if the thickness of the high heat conductive layer is 300 μm or less and the thermal resistance is less than 0.4 ° C/W, it can be said to have low thermal resistance. It is also known that if the thickness of the highly thermally conductive layer is 100 μm or less and the thermal resistance is less than 0.3 ° C/W, it is considered to have a markedly low thermal resistance.

As described above, the semiconductor device of the present invention is excellent in heat dissipation of the heating element The adhesion between the heating element and the heat sink is not lowered and the heat resistance is high, so that it has high reliability.

1‧‧‧Semiconductor device

2‧‧‧heating body

3‧‧‧heater

4‧‧‧High thermal conductivity layer

Claims (12)

A semiconductor device comprising a heating element, a heat receiver, and a highly thermally conductive layer between the heating element and the heat sink for conducting heat from the heating element to the heat receiver, wherein the high thermal conductivity layer comprises the following (A) (A) a thermosetting resin having a thickness of 10 to 300 μm, and (A) two or more kinds of thermosetting resins containing at least a bond at both ends as shown by the following formula (1) a polyether compound of a vinyl group; (B) a thermoplastic elastomer; (C) a thermally conductive inorganic filler; (D) a hardener; Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group, -(OXO) Is represented by the formula (2), wherein R ₈ , R ₉ , R ₁₀ , R ₁₄ and R ₁₅ may be the same or different and are a halogen atom or an alkyl group having 6 or less carbon atoms or a phenyl group; R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, or an alkyl group having 6 or less carbon atoms or a phenyl group, and -(YO)- is represented by the structural formula (3). One type of structure or a structure in which two or more types of structures represented by the structural formula (3) are randomly arranged, wherein R ₁₆ and R ₁₇ may be the same or different, and are a halogen atom or an alkyl group having 6 or less carbon atoms. Or a phenyl group, R ₁₈ and R ₁₉ may be the same or different, and are a hydrogen atom, a halogen atom, or an alkyl group having 6 or less carbon atoms or a phenyl group, and Z is an organic group having 1 or more carbon atoms, and may be optionally used. The oxygen atom, the nitrogen atom, the sulfur atom, and the halogen atom are contained, and at least one of a and b is not 0, and represents an integer of 0 to 300, and c and d represent an integer of 0 or 1. The semiconductor device according to claim 1, wherein the high thermal conductive layer has a shear adhesion strength at 25 ° C of 13 N/mm or more. The semiconductor device according to claim 1, wherein the high heat conductive layer has a thickness of 10 μm or more and 100 μm or less. The semiconductor device according to claim 1, wherein the high thermal conductivity layer has a volume resistivity of 1×10 ¹⁰ Ω. Above cm and thermal conductivity is 0.8W/m. K or more. The semiconductor device according to the first aspect of the invention, wherein the component (C) is one selected from the group consisting of MgO, Al ₂ O ₃ , AlN, BN, diamond filler, ZnO, and SiC. . The semiconductor device according to claim 1, wherein the component (D) is an imidazole-based curing agent. The semiconductor device according to claim 1, wherein the heat receiver is formed with a substrate of an electrode, and the highly thermally conductive layer is formed between the heat generating body and the electrode formed on the substrate. The semiconductor device according to claim 1, wherein the heat generating body has an electrode and the heat receiver is a substrate, and the high heat conductive layer is formed between the electrode of the heat generating body and the substrate. The semiconductor device according to claim 1, wherein the heating element is an IC wafer, a bare crystal wafer, an LED wafer, a spin wheel diode (FWD; Free Wheeling Diode), or an insulated gate bipolar transistor. (IGBT; Insulated Gate Bipolar Transistor). The semiconductor device according to any one of claims 7 to 9, wherein the substrate is a substrate using a metal substrate CCL, a substrate using a high thermal conductivity CEM-3, a substrate using a high thermal conductivity FR-4, and a low thermal resistance. A substrate, a metal substrate, or a ceramic substrate of FCCL. The semiconductor device according to claim 1, wherein the heating element is a semiconductor module and the heat receiver is a heat dissipation plate. The semiconductor device according to claim 11, wherein the semiconductor module is a power semiconductor module.