Organosilicon modified epoxy composition capable of being used for underfill adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of underfill adhesives, and particularly relates to an organic silicon modified epoxy composition capable of being used for an underfill adhesive and a preparation method thereof.The organic silicon modified epoxy composition capable of being used for the underfill adhesive is prepared from, by weight, 17-26 parts of first organic silicon modified epoxy resin; 27-32 parts of organic silicon modified epoxy resin II; 4.5 to 12 parts of organosilicone modified epoxy resin III; 34-35 parts of organic acid anhydride; and 7-8 parts of a modified imidazole adduct. The organic silicon modified epoxy composition for the underfill adhesive provided by the invention has the advantages of low curing shrinkage, high bonding strength, excellent high and low temperature resistance and good fluidity and flexibility, can significantly improve the reliability and long-term stability of an electronic packaging structure, and is suitable for a harsh application environment of high-performance electronic equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to a silicone-modified epoxy composition for underfill adhesive and a preparation method thereof, and belongs to the technical field of underfill adhesive. BACKGROUND

[0002] With the continuous reduction of electronic component packaging size and the continuous increase of pin number, the solder joint size is increasingly miniaturized, which leads to the decrease of mechanical strength and the difficulty to withstand the stress generated by temperature cycle and mechanical vibration during the operation of the device. The effect of periodic stress can accelerate the fatigue failure of the solder joint, thereby affecting the reliability of the electronic component. To solve this problem, the industry generally adopts the technical solution of injecting underfill adhesive between the ball grid array (BGA) device and the printed circuit board (PCB) substrate. This technology completely covers the pin solder joint with underfill adhesive to isolate the interference of the external environment on the solder joint, effectively alleviates the thermal stress generated by the mismatch of the thermal expansion coefficient (CTE) of the chip and the substrate, prevents the fatigue failure of the solder joint during the thermal cycle, and improves the reliability and stability of the packaging structure, thereby prolonging the service life of the electronic component.

[0003] Underfill adhesive is widely used in the manufacturing of electronic devices in many fields such as smart phones, tablet computers, notebook computers, automotive electronics, etc. However, with the continuous improvement of the performance of electronic devices and the increasing complexity of the use environment, the performance requirements of underfill adhesive are also becoming increasingly stringent. Currently, the existing underfill adhesive usually generates a large volume shrinkage during thermal curing, with a shrinkage rate generally between 3% and 5%. This shrinkage behavior can introduce additional stress between the chip and the substrate, which can cause defects such as chip warping and solder joint cracking, thereby affecting the reliability of the packaging structure. In addition, the existing underfill adhesive is prone to softening at high temperatures and hardening at low temperatures, which leads to a significant decrease in its mechanical properties and adhesive properties, making it difficult to effectively buffer thermal stress. This temperature dependence makes the packaging structure more prone to failure under high and low temperature cycle conditions, limiting the application of underfill adhesive in harsh environments.

[0004] Therefore, it is urgent to develop an underfill adhesive material to solve the series of problems caused by high curing shrinkage and insufficient temperature stability in the prior art, thereby improving the long-term reliability and environmental adaptability of the electronic packaging structure. SUMMARY

[0005] The present application provides a silicone-modified epoxy composition for underfill adhesive and a preparation method thereof to solve the technical problems of high curing shrinkage and insufficient temperature stability of the existing underfill adhesive.

[0006] The technical solution of the present application to solve the above technical problems is as follows: One of the purposes of the present application is to provide a silicone-modified epoxy composition for underfill adhesive, comprising the following components by weight: Silicone-modified epoxy resin one 17-26 parts; Silicone-modified epoxy resin two 27-32 parts; Silicone-modified epoxy resin three 4.5-12 parts; Organic acid anhydride 34-35 parts; Modified imidazole adduct 7-8 parts.

[0007] Based on the above technical solutions, the present application can also be improved as follows: Further, the silicone-modified epoxy resin two has at least one structural feature of a carbon six-membered ring, a siloxysilicon ring structure, and a four-functionality epoxy group.

[0008] Further, the silicone-modified epoxy resin two has the following structure: .

[0009] Among them, the four-functionality epoxy group in the molecular structure has good heat resistance, and the carbon six-membered ring and the siloxysilicon ring structure in the molecular structure make it have good low shrinkage.

[0010] Further, the silicone-modified epoxy resin one is a linear silicone-modified epoxy resin.

[0011] Further, the preparation method of the silicone-modified epoxy resin one is: Under the protection of inert gas, the allyl glycidyl ether and the platinum gold catalyst are mixed, then the phenyl hydrogen-containing silicone oil is added, stirred uniformly, heated to 60-80 DEG C, vacuum incubated for 4-6 h, and the silicone-modified epoxy resin one is obtained after the reaction is completed.

[0012] Further, in the preparation of the silicone-modified epoxy resin one, the amount of platinum gold catalyst is 0.1wt‰-1wt‰, the molar ratio of allyl glycidyl ether to phenyl hydrogen-containing silicone oil is 2:1; the viscosity of the phenyl hydrogen-containing silicone oil is 5000 mPa·s-10000 mPa·s; The preparation process reaction formula is as follows: .

[0013] Under the action of platinum gold catalyst, the double bond in the allyl glycidyl ether reacts with the silicon-hydrogen bond in the phenyl hydrogen-containing silicone oil, so that the both ends of the phenyl hydrogen-containing silicone oil are capped by the allyl glycidyl ether containing epoxy group, forming the silicone-modified epoxy resin one with good heat resistance.

[0014] Further, the organic silicon modified epoxy resin three is a linear organic silicon modified epoxy resin.

[0015] Further, the preparation method of the organic silicon modified epoxy resin three is: Under the protection of inert gas, allyl glycidyl ether and platinum gold catalyst are mixed, then methyl hydrogen silicone oil is added, after uniform stirring, the temperature is raised to 50-70 DEG C, vacuum incubation reaction for 4-6h, after the reaction is completed, the organic silicon modified epoxy resin three is obtained.

[0016] Further, in the preparation of the organic silicon modified epoxy resin three, the amount of platinum gold catalyst is 0.1wt‰-1wt‰, the molar ratio of allyl glycidyl ether to methyl hydrogen silicone oil is 2:1; the viscosity of methyl hydrogen silicone oil is 50-100 mPa·s.

[0017] The reaction formula in the preparation process is as follows: .

[0018] Under the action of platinum gold catalyst, the double bond in allyl glycidyl ether and the silicon hydrogen bond in methyl hydrogen silicone oil are added, so that the two ends of methyl hydrogen silicone oil are capped by allyl glycidyl ether containing epoxy group, forming the organic silicon modified epoxy resin three, the number of repeating units ((CH3)2SiO) is n, n=4-6. The organic silicon modified epoxy resin three has a linear silicon-oxygen-silicon molecular structure, which can improve the temperature resistance and flexibility of the modified epoxy resin; at the same time, it has a lower viscosity, so it can improve the flow filling performance of the composition.

[0019] The second object of the present application is to provide a preparation method of the organic silicon modified epoxy composition for underfill adhesive. The required weight of the organic silicon modified epoxy resin one, the organic silicon modified epoxy resin two, the organic silicon modified epoxy resin three and the modified imidazole adduct are weighed, after sufficient stirring, the required weight of organic acid anhydride is added, under vacuum condition, sufficient stirring, the organic silicon modified epoxy composition for underfill adhesive is obtained.

[0020] The present application has the following advantages: The present application provides a single-component underfill adhesive material suitable for sealing and protecting between silicon chips and substrates. The material takes the tetrafunctional organic silicon modified epoxy resin two as the main resin, which has good compatibility with silicon chip materials, low solidification shrinkage and excellent heat resistance, and can effectively reduce the chip warping and solder cracking problems caused by thermal curing shrinkage.

[0021] The application introduces linear silicone-modified epoxy resin one, introduces phenyl structure in the molecular chain, forms rigid segment, and significantly improves the bond energy of siloxane bond. This structure design not only enhances the bonding performance of the resin to the interface material, but also greatly improves the high and low temperature resistance of the composition, so that the composition can still maintain stable mechanical properties and bonding strength in extreme temperature environment.

[0022] The application introduces linear silicone-modified epoxy resin three, introduces methyl structure in the molecular chain, forms a helical conformation, thereby endowing the material with excellent flexibility. On the one hand, the structure acts as a toughening agent, effectively alleviating the impact of thermal stress on the solder joint; on the other hand, due to the low surface energy, the material shows good wettability to silicon materials, significantly improves the flowability and filling capacity of the composition, and ensures uniform coverage in a fine gap.

[0023] In summary, the silicone-modified epoxy composition for underfill adhesive provided by the application has low curing shrinkage, high bonding strength, excellent high and low temperature resistance, and good flowability and flexibility, can significantly improve the reliability and long-term stability of the electronic packaging structure, and is suitable for harsh application environments of high-performance electronic devices.

[0024] On the basis of the application, the material system can be adaptively adjusted according to actual application requirements. For example, the material can be endowed with fluorescence detection capability by adding a fluorescent agent, which facilitates quality monitoring in the packaging process; the appearance color of the material can be adjusted by introducing pigments such as color paste or carbon black, so as to meet the identification or aesthetic requirements of different application scenarios; the rheological properties of the system can be optimized by adding inorganic fillers such as spherical silica, and the thermal expansion coefficient can be adjusted, thereby further improving the thermal matching with the chip and the substrate. In addition, the heat aging resistance, moisture resistance stability and ultraviolet degradation resistance of the material can be significantly improved by adding functional additives such as antioxidants, anti-hydrolysis agents or ultraviolet absorbers, so as to adapt to more severe environmental conditions and prolong the service life of the packaging structure. The above adjustments can be implemented without departing from the core concept of the application, and are covered within the protection scope of the application. DETAILED DESCRIPTION

[0025] The principles and characteristics of the application are described below, and the examples are only used to explain the application and not to limit the scope of the application.

[0026] Example 1 Preparation of silicone-modified epoxy resin one: Under the protection of inert gas, 228 g of allyl glycidyl ether and 0.35 g of platinum gold catalyst were uniformly mixed, 500 g of phenyl hydrogen-containing silicone oil was added, stirred uniformly, heated to 70℃, and vacuum incubated for 5 h. After the reaction was completed, silicone-modified epoxy resin one was obtained.

[0027] Example 2 Synthesis of silicone-modified epoxy resin three Under the protection of inert gas, 228 g of allyl glycidyl ether and 0.30 g of platinum gold catalyst were uniformly mixed, 658 g of methyl hydrogen-containing silicone oil was added, and after uniform stirring, the temperature was raised to 60°C, and vacuum incubation was performed for 5 h. After the reaction was completed, silicone-modified epoxy resin three was obtained.

[0028] Examples 3-5 According to the addition amount of the formulation ratio in Table 1, the silicone-modified epoxy compositions for the underfill adhesive of Example 3, Example 4 and Example 5 were prepared.

[0029] The preparation method is as follows: the required weights of silicone-modified epoxy resin one (S1E), silicone-modified epoxy resin two (S2E), silicone-modified epoxy resin three (S3E), and modified imidazole adduct were weighed, uniformly stirred, and then the required weight of organic acid anhydride was added. After uniform stirring under vacuum, the silicone-modified epoxy composition was obtained.

[0030] Comparative Examples 1-4 According to the addition amount of the formulation ratio in Table 1, the compositions of Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 were prepared.

[0031] The preparation method is as follows: the required weights of silicone-modified epoxy resin one (S1E), silicone-modified epoxy resin two (S2E), silicone-modified epoxy resin three (S3E), aliphatic epoxy resin, core-shell epoxy toughener, reactive long-chain epoxy diluent or modified imidazole adduct were weighed, uniformly stirred, and then the required weight of organic acid anhydride was added. After uniform stirring under vacuum, the composition was obtained.

[0032] Among them, the core-shell epoxy toughener is MX553 produced by Japan Clock Chemical Co., Ltd.; The aliphatic epoxy resin is CELLOXIDE 2021P of Japan DKS Co., Ltd.; The reactive long-chain epoxy diluent is HELOXY Modifier 8 of HEXION Holdings Corporation, USA; The silicone-modified epoxy resin two is HSL-50 of Shanghai Huayi Resin Co., Ltd.; The organic acid anhydride is MH700G of Shin-Etsu Chemical Co., Ltd., Japan; The modified imidazole adduct is HX3921HP of Asahi Kasei Corporation, Japan.

[0033] The compositions of Examples 3-5 and Comparative Examples 1-4 were tested for the following properties, and the results are shown in Table 1.

[0034] Flowability test, record the filling time of the composition on 10mm*10mm simulation chip.

[0035] Thermal curing shrinkage test, test the liquid density and solid density of the composition respectively by density method, and calculate the shrinkage. Thermal curing condition: 130℃ oven, baking time 15min.

[0036] Adhesion test, use the composition to bond glass on PCB substrate, test the thrust at 25℃ and 80℃.

[0037] High and low temperature resistance test, after the simulation chip filled with the composition is put into-40℃~120℃ temperature cycle equipment for 500 cycles, test the chip function.

[0038] Table 1 Component ratio and performance test results of examples and comparative examples

[0039] As can be seen from the test results in Table 1 above, the organic silicon modified epoxy composition for underfill adhesive of the present application is a heat-curable modified epoxy composition, which has the advantages and characteristics of fast flow filling, low thermal curing volume shrinkage, good high and low temperature performance. Comparative example 1 does not use the organic silicon modified epoxy resin two of the present application, but uses a commercially available alicyclic epoxy resin, the flowability and adhesion are acceptable, but the thermal curing shrinkage is large, and the high and low temperature resistance is poor. Comparative example 2 and comparative example 3 do not use the organic silicon modified epoxy resin one and the organic silicon modified epoxy resin three of the present application, but use commercially available core-shell toughening agent and active epoxy diluent, the flowability and thermal curing shrinkage are acceptable, but the high and low temperature resistance and adhesion are poor. Comparative example 4 does not use the organic silicon modified epoxy resin one, the organic silicon modified epoxy resin two and the organic silicon modified epoxy resin three of the present application, the adhesion is poor, the flowability is poor, the thermal curing shrinkage is large, and the high and low temperature resistance is poor.

[0040] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A silicone-modified epoxy composition useful for underfill adhesive, characterized by, By weight, comprising the following components: Silicone-modified epoxy resin one 17-26 parts; Silicone-modified epoxy resin two 27-32 parts; Silicone-modified epoxy resin three 4.5-12 parts; Organic acid anhydride 34-35 parts; Modified imidazole adduct 7-8 parts.

2. The silicone-modified epoxy composition for underfill adhesive according to claim 1, characterized by, The silicone-modified epoxy resin two has at least one structural feature of a carbon six-membered ring, a siloxysilicon ring structure and a four-functionality epoxy group.

3. The silicone-modified epoxy composition for underfill adhesive according to claim 2, characterized by, The silicone-modified epoxy resin two has the following structure: 。 4. The silicone-modified epoxy composition for underfill adhesive according to claim 1, characterized by, The silicone-modified epoxy resin one is a linear silicone-modified epoxy resin.

5. The silicone-modified epoxy composition for underfill adhesive according to claim 4, characterized by, The preparation method of the silicone-modified epoxy resin one is: Under the protection of inert gas, the allyl glycidyl ether and platinum gold catalyst are mixed, then the phenyl hydrogen-containing silicone oil is added, after stirring uniformly, the temperature is raised to 60-80℃, and vacuum incubation is reacted for 4-6h, after the reaction is completed, the silicone-modified epoxy resin one is obtained.

6. The silicone-modified epoxy composition for underfill adhesive according to claim 5, characterized by, In the preparation of the silicone-modified epoxy resin one, the amount of platinum gold catalyst is 0.1wt‰-1wt‰, the molar ratio of allyl glycidyl ether to phenyl hydrogen-containing silicone oil is 2:1; the viscosity of phenyl hydrogen-containing silicone oil is 5000-10000mPa·s.

7. The silicone-modified epoxy composition for underfill adhesive according to claim 1, characterized by, The silicone-modified epoxy resin three is a linear silicone-modified epoxy resin.

8. The silicone-modified epoxy composition for underfill adhesive according to claim 7, characterized by, The preparation method of the silicone-modified epoxy resin three is: Under the protection of inert gas, the allyl glycidyl ether and platinum gold catalyst are mixed, then the methyl hydrogen-containing silicone oil is added, after stirring uniformly, the temperature is raised to 50-70℃, and vacuum incubation is reacted for 4-6h, after the reaction is completed, the silicone-modified epoxy resin three is obtained.

9. The silicone-modified epoxy composition for underfill adhesive according to claim 8, characterized by, In the preparation of the silicone-modified epoxy resin three, the amount of platinum gold catalyst is 0.1wt‰-1wt‰, the molar ratio of allyl glycidyl ether to methyl hydrogen-containing silicone oil is 2:1; the viscosity of methyl hydrogen-containing silicone oil is 50-100mPa·s.

10. A method for producing the silicone-modified epoxy composition for underfill adhesive according to any one of claims 1 to 9, characterized by, Specifically comprising the following steps: The required weight of the silicone-modified epoxy resin one, the silicone-modified epoxy resin two, the silicone-modified epoxy resin three and the modified imidazole adduct are weighed, after fully stirring, the required weight of the organic acid anhydride is added, under vacuum condition, fully stirring, the silicone-modified epoxy composition for the underfill adhesive is obtained.

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