Chip bottom filling adhesive for semiconductor packaging and preparation method thereof

Abstract

The invention discloses a chip bottom filling adhesive for semiconductor packaging and a preparation method thereof, and relates to the technical field of semiconductor packaging adhesives. The chip bottom filling adhesive is prepared from the following components in parts by weight: 5-15 parts of multifunctional epoxy resin, 5-15 parts of common epoxy resin, 5-25 parts of a curing agent, 0.1-0.5 part of carbon black, 0.1-1 part of an accelerant, 40-70 parts of heat-conducting filler and 0.5-5 parts of a coupling agent. During preparation, firstly, the multifunctional epoxy resin, the common epoxy resin, the curing agent, the heat-conducting filler and the carbon black are uniformly mixed; and adding the accelerant and the coupling agent, and uniformly mixing under a vacuum condition. Through reasonable matching of the components, the prepared chip underfill adhesive has the advantages of good thermal conductivity, low thermal expansion coefficient and low viscosity, can effectively improve a chip manufacturing process, meets the heat dissipation requirement of a high-power chip during working, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor packaging glue, and particularly relates to a chip bottom filling glue for semiconductor packaging and a preparation method thereof. BACKGROUND

[0002] The chip bottom filling glue is a key material for electronic packaging, and is mainly used for filling the gap between the chip and the substrate to enhance the structural stability, disperse mechanical stress and improve the reliability, and the physical and chemical properties thereof directly determine the reliability and service life of the device. The inherent thermal conductivity coefficient of the traditional epoxy resin base filling glue is generally low, and it is difficult to meet the heat dissipation demand of the local high power density of the chip. Although the thermal conductivity can be improved by adding high thermal conductivity fillers such as alumina and boron nitride, a high filling ratio will cause a sharp increase in viscosity, affect the filling uniformity of the small gap, form filling defects and aggravate the thermal resistance. Moreover, the thermal expansion coefficient of the conventional bottom filling glue is significantly different from that of the silicon chip and the ceramic substrate, and the interface delamination or solder cracking is easily caused by stress concentration in the thermal cycle process. In order to balance the thermal conductivity and the thermal expansion coefficient, the existing technology mostly adopts a composite of multi-particle size spherical silicon oxide and bisphenol type epoxy resin, but the viscosity of the composite material is large, and a long-chain silane coupling agent needs to be used to improve the dispersibility of the filler and the viscosity reduction at high temperature, but there are still problems of flowability deterioration and thermal expansion coefficient mismatch. SUMMARY

[0003] The purpose of the present application is to provide a chip bottom filling glue for semiconductor packaging and a preparation method thereof to solve the problems in the background art.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] A chip bottom filling glue for semiconductor packaging comprises the following components in parts by weight: 5-15 parts of multifunctional epoxy resin, 5-15 parts of ordinary epoxy resin, 5-25 parts of curing agent, 0.1-0.5 parts of carbon black, 0.1-1 part of accelerator, 40-70 parts of thermal conductive filler and 0.5-5 parts of coupling agent.

[0006] The multifunctional epoxy resin is selected from one of N,N-diglycidyl-4-glycidyl aniline, N,N,N,N,-tetraglycidyl-4,4-diaminodiphenyl methane and 1,3-biscyclohexane;

[0007] The ordinary epoxy resin is one or a mixture of several of bisphenol A type epoxy resin, bisphenol F type epoxy resin and naphthalene type epoxy resin;

[0008] The curing agent is selected from one of methyl tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and methyl nadic anhydride;

[0009] The particle size of the carbon black is 10-30 nm;

[0010] The accelerator is a modified amine curing agent;

[0011] The thermally conductive filler is selected from one of silicon dioxide, aluminum oxide and boron nitride;

[0012] The coupling agent is a silane coupling agent.

[0013] Preferably, the particle size of the silicon dioxide, aluminum oxide, and boron nitride is less than 10 μm.

[0014] Preferably, the invention further comprises 0.5-3 parts of a leveling agent, wherein the leveling agent is an organic silicon surface additive.

[0015] A method for preparing chip underfill for semiconductor packaging comprises the following steps:

[0016] The multifunctional epoxy resin, ordinary epoxy resin, curing agent, thermal conductive filler and carbon black are mixed evenly, and then the accelerator and coupling agent are added and mixed evenly under vacuum conditions to obtain the chip bottom filling glue for semiconductor packaging.

[0017] Preferably, the vacuum degree of the vacuum condition is -0.08 to -0.1 MPa.

[0018] Preferably, the stirring rate during mixing is 800-1200 r / min, and the stirring time is 20-40 min.

[0019] Preferably, in an application of chip bottom filling glue for semiconductor packaging, the bottom filling glue is coated on the surface of a substrate, preheated at 70° C., and then heated at 160° C. for 10 minutes to complete curing.

[0020] Preferably, the substrate is an electrical component, metal, glass, ceramic, plastic, wood, masonry or fiber.

[0021] Compared with the prior art, the present invention provides a chip underfill for semiconductor packaging and a preparation method thereof, which has the following beneficial effects:

[0022] 1. The present invention increases the glass transition temperature of the underfill after curing and improves heat resistance by compounding a variety of modified multifunctional epoxy resins. At the same time, it reduces the overall viscosity of the product before curing and increases fluidity, which is conducive to filling small gaps.

[0023] 2. The present invention optimizes the initial conditions of the curing reaction and promotes the reaction rate by adjusting the type, usage, and ratio of the curing agent to the accelerator, thereby realizing a response mechanism of the overall product formula to certain environmental conditions, so that the underfill does not cure at medium temperatures and cures rapidly under certain high temperature conditions.

[0024] 3. The present invention introduces insulating thermally conductive fillers of specific size and shape to enhance the compatibility and dispersibility of the fillers with the epoxy resin matrix, thereby improving thermal conductivity and reducing viscosity, ensuring the filling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a picture of the dielectric performance test sample of the chip bottom filler.

[0026] Figure 2 This is the thermal expansion coefficient test curve of the chip bottom filling glue in the thickness direction.

[0027] Figure 3 This is the thermal resistance-thickness linear fitting curve of the chip bottom filling glue. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] The present invention provides Figure 1-3 shown

[0030] A chip underfill for semiconductor packaging, comprising the following components in parts by weight: 5-15 parts of a multifunctional epoxy resin, 5-15 parts of a common epoxy resin, 5-25 parts of a curing agent, 0.1-0.5 parts of carbon black, 0.1-1 parts of an accelerator, 40-70 parts of a thermally conductive filler, and 0.5-5 parts of a coupling agent;

[0031] The multifunctional epoxy resin is selected from one of N,N-diglycidyl-4-glycidyloxyaniline, N,N,N,N,-tetraglycidyl-4,4-diaminodiphenylmethane, and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane;

[0032] The common epoxy resin is one or a mixture of bisphenol A epoxy resin, bisphenol F epoxy resin, and naphthalene epoxy resin;

[0033] The curing agent is selected from one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and methylnadic anhydride;

[0034] The particle size of the carbon black is 10-30 nm;

[0035] The accelerator is a modified amine curing agent;

[0036] The thermally conductive filler is selected from one of silicon dioxide, aluminum oxide and boron nitride;

[0037] The coupling agent is a silane coupling agent.

[0038] The particle sizes of the silicon dioxide, aluminum oxide and boron nitride are less than 10 μm.

[0039] It also includes 0.5-3 parts of leveling agent, which is an organic silicon surface additive.

[0040] Example 1

[0041] A chip bottom filling glue for semiconductor packaging is composed of the following components in parts by weight: 10 parts of N,N-diglycidyl-4-glycidyloxyaniline, 10 parts of bisphenol A epoxy resin, 20 parts of methylhexahydrophthalic anhydride, 0.3 parts of carbon black, 0.5 parts of modified amine accelerator, 50 parts of silicon dioxide, 2 parts of silane coupling agent, and 1 part of organic silicon surface additive.

[0042] Preparation method: Add N,N-diglycidyl-4-glycidyloxyaniline, bisphenol A epoxy resin, methylhexahydrophthalic anhydride, silica, and carbon black into a stirring kettle, stir at a stirring rate of 1000 r / min for 30 minutes, then add a modified amine accelerator, a silane coupling agent, and an organic silicone surface additive, and stir at a vacuum degree of -0.09 MPa and a stirring rate of 1000 r / min for 30 minutes to obtain a chip bottom filling glue for semiconductor packaging.

[0043] During application, the bottom filling glue is coated on the surface of the ceramic substrate, preheated at 70° C., and then heated at 160° C. for 10 minutes to complete curing.

[0044] Example 2

[0045] A chip bottom filling glue for semiconductor packaging is composed of the following components in parts by weight: 15 parts of N,N,N,N,-tetraglycidyl-4,4-diaminodiphenylmethane, 5 parts of bisphenol F epoxy resin, 15 parts of methyltetrahydrophthalic anhydride, 0.1 part of carbon black, 0.3 part of modified amine accelerator, 60 parts of aluminum oxide, and 3 parts of silane coupling agent.

[0046] Preparation method: Add N,N,N,N,-tetraglycidyl-4,4-diaminodiphenylmethane, bisphenol F epoxy resin, methyltetrahydrophthalic anhydride, alumina, and carbon black into a stirring kettle, stir at a stirring rate of 800 r / min for 40 minutes, then add a modified amine accelerator and a silane coupling agent, and stir at a vacuum degree of -0.08 MPa and a stirring rate of 800 r / min for 40 minutes to obtain a chip bottom filling glue for semiconductor packaging.

[0047] In application, the underfill adhesive is coated on the surface of the metal substrate, preheated at 70 DEG C, heated at 160 DEG C for 10 minutes after application to complete curing.

[0048] Example 3

[0049] An underfill adhesive for semiconductor packaging is composed of the following components by weight: 1,3-bis(N,N-diglycidyl aminomethyl) cyclohexane 5 parts, naphthalene type epoxy resin 15 parts, hexahydrophthalic anhydride 25 parts, carbon black 0.5 parts, modified amine type accelerator 1 part, boron nitride 40 parts, silane coupling agent 1 part, silicone surface additive 3 parts.

[0050] Preparation method: 1,3-bis(N,N-diglycidyl aminomethyl) cyclohexane, naphthalene type epoxy resin, hexahydrophthalic anhydride, boron nitride, carbon black are added to the stirred tank, stirred at a stirring rate of 1200 r / min for 20 min, then modified amine type accelerator, silane coupling agent and silicone surface additive are added, stirred at a vacuum degree of -0.1 MPa and a stirring rate of 1200 r / min for 20 min, to obtain the underfill adhesive for semiconductor packaging.

[0051] In application, the underfill adhesive is coated on the surface of the metal substrate, preheated at 70 DEG C, heated at 160 DEG C for 10 minutes after application to complete curing.

[0052] The underfill adhesive prepared in examples 1-3 is tested for performance, and the results are shown in the following table:

[0053]

[0054]

[0055] As shown in the above table, the underfill adhesive prepared in the application has low viscosity, high thermal conductivity, high glass transition temperature, low thermal expansion coefficient and good tensile shear strength, which can meet the use requirements of semiconductor packaging.

[0056] Finally, it should be noted that: the above only for the preferred embodiments of the application, and not for limiting the application, although the application is described in detail with reference to the foregoing examples, for those skilled in the art, it still can be modified, or equivalent replacement of part of the technical features, which are recorded in the technical solutions of the foregoing embodiments, within the spirit and principles of the application, any modification, equivalent replacement, improvement, etc., should be included in the protection scope of the application.

Claims

1. A chip underfill for semiconductor packaging, characterized in that: The invention comprises the following components in parts by weight: 5-15 parts of multifunctional epoxy resin, 5-15 parts of common epoxy resin, 5-25 parts of curing agent, 0.1-0.5 parts of carbon black, 0.1-1 parts of accelerator, 40-70 parts of thermal conductive filler, and 0.5-5 parts of coupling agent; The multifunctional epoxy resin is selected from one of N,N-diglycidyl-4-glycidyloxyaniline, N,N,N,N,-tetraglycidyl-4,4-diaminodiphenylmethane, and 1,3-dicyclohexane; The common epoxy resin is one or a mixture of bisphenol A epoxy resin, bisphenol F epoxy resin, and naphthalene epoxy resin; The curing agent is selected from one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and methylnadic anhydride; The particle size of the carbon black is 10-30 nm; The accelerator is a modified amine curing agent; The thermally conductive filler is selected from one of silicon dioxide, aluminum oxide and boron nitride; The coupling agent is a silane coupling agent.

2. The chip underfill for semiconductor packaging according to claim 1, characterized in that: The particle sizes of the silicon dioxide, aluminum oxide and boron nitride are less than 10 μm.

3. The chip underfill for semiconductor packaging according to claim 1, characterized in that: The invention also includes 0.5-3 parts of a leveling agent, which is an organic silicon surface additive.

4. A method for preparing a chip underfill for semiconductor packaging according to any one of claims 1 to 3, characterized in that: The following steps are involved: The multifunctional epoxy resin, ordinary epoxy resin, curing agent, thermal conductive filler and carbon black are mixed evenly, and then the accelerator and coupling agent are added and mixed evenly under vacuum conditions to obtain the chip bottom filling glue for semiconductor packaging.

5. The preparation method according to claim 4, characterized in that The vacuum degree of the vacuum condition is -0.08 to -0.1 MPa.

6. The preparation method according to claim 4, characterized in that The stirring rate during mixing is 800-1200 r / min, and the stirring time is 20-40 min.

7. An application of the chip underfill for semiconductor packaging according to any one of claims 1 to 3, characterized in that: The bottom filling glue is coated on the surface of the substrate, preheated at 70° C., and then heated at 160° C. for 10 minutes to complete curing.

8. The use according to claim 7, characterized in that The substrate is electrical components, metal, glass, ceramic, plastic, wood, masonry or fiber.

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