High-resistance resin composition for stacked chip packaging and preparation method therefor

Abstract

A high-resistance resin composition for stacked chip packaging, which is prepared from the following raw materials in parts by weight: 3-10 parts of an epoxy resin, 2-6 parts of a curing agent, 80-90 parts of a filling material and 1-5 parts of an auxiliary agent. In the technical solution, a crystalline epoxy resin having an epoxy equivalent of 180-190 g / eq is used. In combination with a tertiary amine-terminated hyperbranched polymer, the resin compositon exhibits a good fluidity even at a high filling amount, enables the stacking of multiple layers of chips, results in a low product stress and high reliability, and prevents wire sweeping during the stacking of multiple layers of chips. The fluidity of the resin composition can be further improved by using the spherical silicon dioxide of 20 μm and 75 μm in combination, and the stress of the obtained resin composition is small, thereby avoiding the risk of delamination that affects the reliability of the chip packaging.

Description

A high-durability resin composition for multilayer chip packaging and its preparation method Technical Field

[0001] This invention relates to the field of chip packaging, and more specifically to a high-durability resin composition for multilayer chip packaging and its preparation method. Background Technology

[0002] With the development of technology and the trend towards miniaturization and integration of electronic products, these products need to achieve higher information functions within a smaller volume, requiring chip stacking and packaging. As the number of chip layers increases, the chip bonding wire arcs become longer, placing higher demands on the bonding wires. Improving the flowability of the encapsulating resin can improve the effect of multilayer chip packaging, but high-flow encapsulating resins have poor adhesion. Therefore, developing an encapsulating resin for multilayer chips with both high flowability and good adhesion is crucial.

[0003] Chinese invention patent CN101186802B discloses an epoxy resin composition for multi-chip encapsulation and multi-chip encapsulation using this composition. It uses a mixture of spherical fused silica with an average particle size of 5μm to 30μm and spherical fused silica with an average particle size of 1μm as an inorganic filler, exhibiting good moisture resistance, crack resistance, and toughness. However, its encapsulation effect for multi-layer chips is not ideal. Chinese invention patent CN115260963B discloses a low-modulus vertical stacking encapsulant film, its preparation method, and its application. The mixed raw materials are ground into a gel using a bead mill, and the gel is obtained by vacuum degassing. It has low storage modulus, high glass transition temperature, high film tensile strength, low coefficient of thermal expansion, low moisture absorption, and high silicon wafer adhesion. However, it can only achieve two-layer chip stacking encapsulation; as the number of chips increases, the encapsulation effect decreases. Summary of the Invention

[0004] In order to develop a high-flowability and good-adhesion encapsulation resin for multilayer chips, the first aspect of the present invention provides a high-durability resin composition for multilayer chip encapsulation, wherein the raw materials for preparation include 3-10 parts of epoxy resin, 2-6 parts of curing agent, 80-90 parts of filler, and 1-5 parts of additives by weight.

[0005] In a preferred embodiment, the raw materials for preparation include 5-10 parts epoxy resin, 3-5 parts curing agent, 85-90 parts filler, and 1-3 parts additives by weight.

[0006] In a preferred embodiment, the raw materials for preparation include 6 parts epoxy resin, 4 parts curing agent, 88 parts filler, and 2 parts additives by weight.

[0007] In a preferred embodiment, the epoxy resin includes at least epoxy resin I, wherein epoxy resin I is a crystalline reduced resin, and the epoxy equivalent of the crystalline reduced resin is 150-200 g / eq.

[0008] In a preferred embodiment, the epoxy resin further includes epoxy resin II, wherein epoxy resin II is a dicyclopentadiene multifunctional solid epoxy resin.

[0009] In a preferred embodiment, the weight ratio of epoxy resin I to epoxy resin II is (4-6):1; preferably, the weight ratio of epoxy resin I to epoxy resin II is 6:1.

[0010] In a preferred embodiment, the curing agent includes at least curing agent I, which is a terminal tertiary amine hyperbranched polymer.

[0011] In a preferred embodiment, the viscosity of the curing agent I is <10 mPa·s, and the gelation time is 5-15 min at 100°C and 1 g.

[0012] In a preferred embodiment, the curing agent further includes curing agent II, the structural formula of which is:

[0013] In a preferred embodiment, the weight ratio of curing agent I to curing agent II is (2-4):1; preferably, the weight ratio of curing agent I to curing agent II is 3:1.

[0014] During experiments, the inventors discovered that using a crystalline epoxy resin with an epoxy equivalent of 180-190 g / eq, combined with a terminal tertiary amine hyperbranched polymer, can achieve good flowability at high filler contents, enabling multilayer chip stacking. This results in low product stress, high reliability, and reduced risk of gold wire breakage during multilayer chip stacking. The likely reason is that as the number of stacked electronic chips increases, the arc length between chips becomes longer, and the spacing between chip lines becomes smaller. To avoid risks to encapsulation reliability, it is necessary to improve the flowability of the resin composition while maintaining good adhesion. The crystalline epoxy resin in this invention, at a preferred epoxy equivalent, exhibits high flowability with the terminal tertiary amine hyperbranched polymer at a certain temperature, improving the toughness of the resin composition and enabling wetting of multilayer stacked chips, thus achieving good encapsulation results.

[0015] In a preferred embodiment, the filler material is a spherical inorganic filler material with a particle size of 10-100 μm.

[0016] In a preferred embodiment, the particle size of the spherical inorganic filler material includes a combination of 10-50 μm and 50-100 μm.

[0017] In a preferred embodiment, the particle size of the spherical inorganic filler material includes a combination of 20 μm and 75 μm.

[0018] As a preferred embodiment, the weight ratio of the 20μm and 75μm spherical inorganic filler materials is (10-30):(50-80).

[0019] In a preferred embodiment, the weight ratio of the 20μm and 75μm spherical inorganic filler materials is (12-30):(58-76).

[0020] In a preferred embodiment, the spherical inorganic filler material is selected from at least one of silica, alumina, and talc.

[0021] In a preferred embodiment, the spherical inorganic filler material is silicon dioxide.

[0022] The inventors further discovered that using 20μm and 75μm spherical silica in combination can further improve the flowability of the resin composition. Especially when the line spacing is small, the spherical silica with the same particle size can roll, making it easier to flow and encapsulate multilayer chips compared to sheet silica. In addition, the resin composition with the same particle size has low stress, which can avoid the risk of delamination caused by chip packaging reliability issues.

[0023] In a preferred embodiment, the additives include at least one of coupling agents, low-stress agents, release agents, and colorants.

[0024] In a preferred embodiment, the coupling agent is a multifunctional silane coupling agent, and the functional group equivalent of the multifunctional silane coupling agent is 500-700 g / mol. Preferably, the functional group equivalent of the multifunctional silane coupling agent is 600 g / mol.

[0025] In a preferred embodiment, the viscosity of the multifunctional silane coupling agent is 5-10 mm. 2 / s. Preferably, the viscosity of the multifunctional silane coupling agent is 8.6 mm. 2 / s.

[0026] In a preferred embodiment, the low-stress agent is a propylene-based elastomer (POE).

[0027] In a preferred embodiment, the release agent includes, but is not limited to, polyethylene wax; the colorant includes, but is not limited to, carbon black.

[0028] A second aspect of the present invention provides a method for preparing a high-durability resin composition for multilayer chip packaging, comprising the following steps:

[0029] S1 mixes epoxy resin, curing agent, filler and additives evenly according to the weight ratio;

[0030] S2 is transferred to a mixer and mixed at 90-110℃ for 5-10 minutes, then discharged.

[0031] S3 is cooled to room temperature and then pulverized to 1-3mm to obtain pulverized material;

[0032] S4 compacts, shapes, and packages the crushed material before discharging it.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The high-durability resin composition for stacked chip packaging described in this invention uses a crystalline epoxy resin with an epoxy equivalent of 180-190 g / eq. Combined with a terminal tertiary amine hyperbranched polymer, it can have good flowability at a high filling amount, enabling the stacking of multi-layer chips. The product has low stress, high reliability, and the gold wires are not easily broken when stacking multi-layer chips.

[0035] (2) The high-durability resin composition for stacked chip packaging described in this invention uses 20μm and 75μm spherical silica in combination to further improve the fluidity of the resin composition. The resulting resin composition has low stress and can avoid the risk of delamination caused by chip packaging reliability issues.

[0036] (3) The high-durability resin composition for multilayer chip packaging described in this invention has high fluidity, meets the requirements for multilayer chip die bonding, and can also be well bonded to the frame, with excellent bonding performance.

[0037] (4) The high-durability resin composition for multilayer chip packaging described in this invention has low stress and meets the reliability requirements of multilayer chip packaging.

[0038] (5) The high-durability resin composition for stacked chip packaging described in this invention can achieve the packaging of 8-layer chips without wire breakage, with a small coefficient of thermal expansion, small molding shrinkage, and large flexural modulus. Attached Figure Description

[0039] Figure 1 is a schematic diagram of the structure calculated during the leveling performance test.

[0040] Figure 2 shows a physical image of a multilayer stacked chip.

[0041] In the diagram: 1: Gold wire; 2: Chip; 3: Frame. Detailed Implementation

[0042] Example

[0043] A high-durability resin composition for multilayer chip packaging, the raw materials for which are prepared are shown in Table 1 below by weight.

[0044] Table 1

[0045] The epoxy resin I is a crystalline reducing resin with an epoxy equivalent of 180-190 g / eq, purchased from Mitsubishi Chemical, and its grade is YX-4000.

[0046] The epoxy resin II is a dicyclopentadiene multifunctional solid epoxy resin, purchased from DIC, with the grade HP-7200; the curing agent I has a viscosity of <10 mPa·s, and a gelation time of 10 min at 100℃ and 1 g, purchased from Shanghai Wujing Chemical Technology Co., Ltd., with the grade QNP1-4110.

[0047] The structural formula of the curing agent II is: Purchased from Shandong Shengquan, brand name PF-8011;

[0048] The coupling agent is a multifunctional silane coupling agent (γ-glycidoxypropyltrimethoxysilane) with a viscosity of 8.6 mm. 2 / s, with a functional group equivalent of 600 g / mol, purchased from Shin-Etsu Chemical, brand name X-12-972F; the low-stress agent was purchased from ExxonMobil, brand name POE 3588FL.

[0049] The release agent is polyethylene wax, purchased from Hebei Tianyu Chemical Co., Ltd., brand name: TY-113;

[0050] The colorant is carbon black.

[0051] The 20μm silica was spherical in shape and was purchased from Lianrui, with the grade NQ-1240.

[0052] The 75μm silica was spherical in shape and purchased from Lianrui, with the grade NQ-1150.

[0053] A method for preparing a high-durability resin composition for multilayer chip packaging includes the following steps:

[0054] S1 mixes epoxy resin, curing agent, filler and additives evenly according to the weight ratio;

[0055] S2 is transferred to a mixer and mixed at 100℃ for 10 minutes, then discharged.

[0056] S3 is cooled to room temperature and pulverized to 2mm to obtain pulverized material;

[0057] S4 compacts, shapes, and packages the crushed material before discharging it.

[0058] Performance testing

[0059] 1. Curing time: Raise the temperature of the hot plate to 175℃ and maintain it within ±1℃. Place 0.5-1.5g of sample on the hot plate and press it into a 6cm shape using a flat spatula. 2 -10cm 2 For thin slices, when the sample melts and the surface of the melt becomes glossy, press the stopwatch to start timing. Use a flat spatula to continuously scrape the sample and observe, or use a needle-shaped stirring rod to continuously stir the sample and observe. The timer stops when the sample changes from a molten state to a gel state. The time required is the gelation time of the sample.

[0060] 2. Spiral flow length: When the mold temperature is constant at 175℃, weigh 15-25g of powdered sample and pour it into the mold cavity for injection molding. Turn on and start timing; after automatic mold opening, remove the mold and open it to read the length of the longest continuous point.

[0061] 3. Glass Transition Temperature (Tg): The sample is mounted on the TMA stage. The initial temperature is 20℃, the heating rate is 10℃ / min, and the final temperature is 220℃. After scanning, the TMA test curve is obtained. Tangents are plotted at temperatures above and below the transition temperature. The temperature at the intersection of the two tangents is the glass transition temperature (Tg).

[0062] 4. Coefficient of thermal expansion: TMA: The sample is mounted on the TMA sample stage, with a starting temperature of 20℃, a heating rate of 10℃ / min, and a final temperature of 220℃. After scanning, the TMA test curve is obtained, and the coefficient of thermal expansion is obtained from the equipment reading.

[0063] 5. Molding shrinkage: Inject the epoxy molding compound into a 120mm×15mm×10mm sample. After injection molding, measure the difference between the sample and the mold.

[0064] 6. Thermal conductivity: Tested according to GB / T3139-2005 standard.

[0065] 7. Flexural modulus at 25℃: Tested according to GB / T40564-2021 standard.

[0066] 8. Bending strength at 25℃: tested according to GB / T40564-2021 standard.

[0067] The prepared resin composition was injection molded and filled with multilayer chips at 175°C, cured, and the punching level was tested.

[0068] 9. Wire Cutting Level: When the product is placed under X-ray, the gold wire, chip, and frame will be clearly visible. The first connection point between the gold wire and the chip is designated as the first solder point, and the connection point between the gold wire and the frame is designated as the second solder point. The maximum arc value is selected, and the equipment will automatically read the value. During the injection molding process, the prepared resin composition impacts the gold wire, creating an arc. If the arc is greater than the maximum arc value, the gold wire will break. The straight line length L between the first and second solder points is denoted as l, and the maximum distance from the arc to the straight line L is denoted as a. Wire cutting level = a / l × 100%. See Figure 1 for a schematic diagram and Figure 2 for a physical image.

[0069] The test results are shown in Table 2.

[0070] Table 2

Claims

1. A high-durability resin composition for multilayer chip packaging, characterized in that, The raw materials are prepared by weight parts, including epoxy resin 3-10 parts, curing agent 2-6 parts, filling material 80-90 parts, and auxiliary agent 1-5 parts.

2. The high reliability resin composition for a stacked chip package according to claim 1, wherein The epoxy resin at least includes epoxy resin I, the epoxy resin I is crystalline type reduced resin, and the epoxy equivalent weight of the crystalline type reduced resin is 150-200 g / eq.

3. The high reliability resin composition for a stacked chip package according to Claim 1, wherein The curing agent at least includes curing agent I, and the curing agent I is hyperbranched polymer with terminal tertiary amine group.

4. The high reliability resin composition for a stacked chip package according to Claim 3, wherein The viscosity of the curing agent I is <10 mPa·s, and the gelation time of 1 g under the condition of 100℃ is 5-15 min.

5. The high reliability resin composition for a stacked chip package according to Claim 1, wherein The filling material is spherical inorganic filling material, and the particle size of the spherical inorganic filling material is 10-100 μm.

6. The high reliability resin composition for a stacked chip package according to Claim 5, wherein The particle size of the spherical inorganic filling material includes a combination of 10-50 μm and 50-100 μm.

7. The high reliability resin composition for a stacked chip package according to Claim 5, wherein The spherical inorganic filling material is selected from at least one of silica, alumina, and talc powder.

8. The high reliability resin composition for a stacked chip package according to Claim 1, wherein The auxiliary agent includes at least one of coupling agent, low stress agent, release agent, and coloring agent.

9. The high reliability resin composition for a stacked chip package according to Claim 8, wherein The coupling agent is multifunctional silane coupling agent, and the functional group equivalent weight of the multifunctional silane coupling agent is 500-700 g / mol.

10. A method for producing the high reliability resin composition for a stacked chip package according to any one of claims 1 to 9, characterized by, The method includes the following steps: S1, uniformly mixing the epoxy resin, curing agent, filling material, and auxiliary agent according to the weight ratio; S2, transferring into a mixing machine to mix at 90-110℃ for 5-10 min, and discharging; S3, cooling at room temperature, crushing to 1-3 mm, and obtaining crushed material; S4, compacting, shaping, packaging, and discharging the crushed material.

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