Small-spacing chip filling adhesive for temperature control crystal oscillator and preparation method of small-spacing chip filling adhesive

Abstract

The invention relates to the technical field of filling adhesive processing, in particular to a temperature control crystal oscillator small-spacing chip filling adhesive and a preparation method thereof. The high-performance epoxy resin composite material is prepared from the following raw materials in parts by weight: bisphenol A type epoxy resin, aliphatic epoxy resin, epoxy modified silicone oil, epoxy polyhedral oligomeric silsesquioxane, core-shell nano rubber, a surfactant, a curing agent, a coupling agent, a defoaming agent, nano silicon micropowder and a diluent, the epoxy modified silicone oil is composed of side chain epoxy polyether silicone oil and side chain epoxy silicone oil, the controlled crystal oscillator small-spacing chip filling adhesive prepared according to the formula is specially adapted to a narrow gap scene with the spacing between a chip and a substrate smaller than or equal to 50 microns, the capillary flow capacity is improved, the narrow gap is completely filled, and cavities are completely eradicated; bubble wrapping is effectively inhibited, meanwhile, the glue viscosity and the curing rate are accurately adjusted, and it is guaranteed that a glue layer is evenly formed; the shear stress caused by the difference of thermal expansion coefficients is relieved, and the structural stability in flexible bending and high-temperature and high-humidity environments is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of filling glue processing, and more particularly to a temperature-controlled crystal oscillator small-pitch chip filling glue and a preparation method thereof. BACKGROUND

[0002] As one of the core parts of a display screen module, a temperature-controlled crystal oscillator chip compensates for temperature frequency deviation in real time, locks accurate clock required for high-definition display, eliminates picture shaking, tearing and color deviation, guarantees high refresh rate, high resolution and long-term stability, and is a metronome for synchronous imaging of the display screen module. With the development of display screens in the direction of ultra-thin and curlable, to adapt to the design of lighter and softer modules, the temperature-controlled crystal oscillator chip must evolve in the direction of miniaturization, low thickness and flexibility. This trend leads to a significant reduction in the packaging gap between the chip and the substrate, and the glue filling, curing and stress control means used in the traditional packaging process gradually reveal many problems, seriously affecting the packaging yield and the long-term reliability of the crystal oscillator.

[0003] Firstly, in the miniaturized packaging structure, the gap between the chip and the substrate is usually less than 50 microns, even reaching below 20 microns. Such a narrow gap severely limits the capillary flow ability of the glue, leading to incomplete filling and forming voids. These voids not only weaken the mechanical strength of the packaging structure, but also easily become stress concentration points, causing solder joint cracking or crystal oscillator frequency drift during thermal cycling or flexible bending, and further affecting the clock stability of the display system.

[0004] Secondly, the narrow-pitch packaging structure increases the risk of air bubble wrapping. During the flow of the glue, due to the limited space, air is more likely to be wrapped inside the glue layer, forming flow-type bubbles. These bubbles will block the heat conduction path, affecting the response speed and compensation accuracy of the temperature-controlled crystal oscillator to temperature changes, leading to frequency drift or even loss of lock, directly damaging the display quality.

[0005] Furthermore, to make up for the lack of filling, it is often inclined to increase the amount of glue, but under the condition of narrow pitch, the glue is prone to overflow to the adjacent pads or functional areas, causing short circuit, signal interference, and even contaminating the temperature control circuit or thermal element inside the crystal oscillator, affecting its frequency stability. In addition, uneven thickness or local thinness of the glue layer may form new stress concentration points in flexible applications, especially in rollable display modules, repeated bending will exacerbate the fatigue of the glue layer, causing delamination or solder joint fracture between the crystal oscillator and the substrate, seriously affecting the mechanical reliability of the module.

[0006] At the same time, there is a difference between the thermal expansion coefficient of the glue layer material and the crystal oscillator chip or the substrate, which will generate shear stress during temperature changes. Under the long-term effect, it may cause the crystal oscillator frequency to deviate or the structure to fail. Especially in high temperature and high humidity environments, this thermal stress effect is more obvious, further increasing the risk of long-term stability of the crystal oscillator.

[0007] In summary, with the rapid development of display screen modules towards ultra-thin, flexible and rollable directions, the packaging technology of temperature-controlled crystal oscillator chips is facing severe challenges. The traditional glue filling and packaging process has been difficult to meet the requirements of narrow pitch, high reliability and flexible adaptability, and it is urgent to develop new packaging materials, processes and structural design schemes to solve the problems of incomplete filling, bubbles, glue overflow and stress concentration, improve the packaging yield and long-term stability of the crystal oscillator, and ensure the reliable operation of high-end display systems. SUMMARY

[0008] In order to solve the problems of incomplete filling, bubbles, glue overflow and stress concentration by using glue, the application provides a temperature-controlled crystal oscillator small-pitch chip filling glue and a preparation method thereof.

[0009] In the first aspect, the application provides a temperature-controlled crystal oscillator small-pitch chip filling glue, which adopts the following technical scheme: A temperature-controlled crystal oscillator small-pitch chip filling glue is prepared from the following raw materials by weight: Bisphenol A type epoxy resin 80-100 parts Aliphatic epoxy resin 30-40 parts Epoxy-modified silicone oil 10-15 parts Epoxy-based cage-type silsesquioxane 1-2 parts Core-shell nano rubber 6-10 parts Surfactant 0.5-1 part Curing agent 1-3 parts Coupling agent 3-5 parts Defoaming agent 1-2 parts Nano-silicon powder 15-25 parts Diluent 300 parts The epoxy-modified silicone oil is composed of side-chain epoxy polyether silicone oil and side-chain epoxy silicone oil.

[0010] By adopting the above technical scheme, the temperature-controlled crystal oscillator small-pitch chip filling glue prepared is specially adapted to the narrow gap scene with a chip-to-substrate pitch of ≤50 microns. The formulation of the application improves the capillary flow ability, realizes complete filling of the narrow gap, and eliminates the generation of voids. It effectively suppresses bubble wrapping, precisely adjusts the viscosity and curing rate of the glue, avoids short circuit, signal interference and component contamination caused by glue overflow, ensures uniform formation of the glue layer, improves the flexibility and interface compatibility of the glue layer, relieves the shear stress caused by the difference in thermal expansion coefficient, improves the structural stability under flexible bending and high temperature and high humidity environments, reduces the risk of solder cracking, delamination and other failures, and finally greatly improves the packaging yield and long-term reliability of the crystal oscillator, adapts to the design requirements of ultra-thin and rollable display screen modules, and ensures the high refresh rate, high resolution and stable operation of high-end display systems.

[0011] Bisphenol A type epoxy resin and aliphatic epoxy resin form a stable adhesive matrix, providing basic bonding strength and stability for the encapsulation structure. Epoxy modified silicone oil and epoxy-based cage-type silsesquioxane work synergistically to enhance the flexibility and interfacial wettability of the matrix, adapting to the repeated bending requirements of rollable modules, while also improving compatibility with chips and substrates and reducing the risk of delamination. The polyether segments of the side-chain epoxy polyether silicone oil optimize the wetting properties and capillary flow capabilities of the adhesive, improving penetration and spreading efficiency in narrow gaps below 50 micrometers, and helping to solve the problem of incomplete filling. The siloxane backbone of the side-chain epoxy silicone oil gives the adhesive layer excellent flexibility and bending resistance, and together with core-shell nano-rubber, it further alleviates adhesive layer fatigue caused by repeated bending of rollable modules. The combination of the two can also balance the hydrophobicity and thermal stability of the adhesive layer, reduce performance degradation under high temperature and high humidity environments, and reduce interfacial stress between the adhesive layer and the chip and substrate, indirectly helping to improve the stability of crystal oscillator frequency, fully adapting to the encapsulation requirements of ultra-thin and flexible display modules.

[0012] Meanwhile, the combination of core-shell nano-rubber and nano-silicon powder, on the one hand, offsets the difference in thermal expansion coefficients between the adhesive layer and the chip / substrate through elastic dispersion, reducing shear stress caused by temperature changes; on the other hand, it improves the mechanical strength of the adhesive layer, avoiding solder joint cracking caused by stress concentration. Surfactants improve the wetting and flow properties of the adhesive in narrow gaps, and together with defoamers, they effectively eliminate air bubbles generated during the flow process, ensuring complete filling. Coupling agents strengthen the interfacial bonding between the adhesive layer and the chip / substrate, while curing agents and diluents precisely control the curing rate and viscosity of the adhesive, preventing overflow caused by excessive adhesive and ensuring uniform adhesive layer thickness. All components work together to form a comprehensive solution for filling, defoaming, overflow prevention, and stress resistance, fully covering the defects of traditional processes.

[0013] Preferably, the diluent is composed of at least one of 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, n-butyl glycidyl ether, diethylhexyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, glycidyl methacrylate ether.

[0014] Preferably, the weight ratio of the side-chain epoxy polyether silicone oil to the side-chain epoxy silicone oil is 3:(0.5-1).

[0015] By adopting the above technical solutions, the dosage of side-chain epoxy polyether silicone oil and side-chain epoxy silicone oil is optimized, further improving the wetting and capillary flow properties of the adhesive, ensuring rapid penetration and complete filling of narrow gaps, helping to solve the problem of incomplete filling, while enhancing the flexibility and bending resistance of the adhesive layer, adapting to the repeated bending scenarios of rollable modules, and alleviating adhesive layer fatigue.

[0016] Preferably, the surfactant is composed of sorbitan fatty acid ester and fatty alcohol phosphate ester in a weight ratio of 1:(3-5).

[0017] By adopting the above technical solution, fatty alcohol phosphate esters dominate, effectively improving the wettability of the adhesive on the chip and substrate surfaces, reducing interfacial tension, and significantly enhancing capillary flow penetration capabilities. This facilitates rapid and complete filling of narrow gaps, reducing voids from the source. Dehydrated sorbitan fatty acid esters synergistically optimize the emulsification and dispersibility of the adhesive system, preventing component aggregation, and simultaneously helping to suppress bubble generation and retention. The synergy of these two components does not interfere with the reaction of other components, and also improves the uniformity of adhesive layer formation, indirectly reducing the risk of adhesive overflow.

[0018] Preferably, the side-chain epoxy polyether silicone oil has an epoxy value of 0.15-0.25 mmol / g and a polyether segment molecular weight of 500-1000. By adopting the above technical solution, the epoxy value of the side-chain epoxy polyether silicone oil is optimized, enabling efficient cross-linking with epoxy matrix, enhancing component compatibility, preventing phase separation, and improving the cohesive strength of the adhesive layer. The moderate molecular weight of the polyether segments ensures both the capillary flow and penetration ability of the adhesive in narrow gaps below 50 micrometers, facilitating complete filling, and also imparts appropriate flexibility to the adhesive layer. These two factors synergistically optimize the wetting, spreading, and bending resistance of the adhesive layer, reducing adhesive layer fatigue caused by repeated bending of the flexible module.

[0019] Preferably, the side-chain epoxy silicone oil has an epoxy value of 0.10-0.20 mmol / g and a viscosity of 100-500 cP at 25°C.

[0020] By adopting the above technical solution, the parameters of the side-chain epoxy silicone oil are optimized to form a synergistic crosslinking effect with epoxy resin and side-chain epoxy polyether silicone oil, ensuring component compatibility, avoiding phase separation, and strengthening the interfacial adhesion of the adhesive layer. The viscosity is within the suitable range, neither hindering capillary flow and penetration within narrow gaps to facilitate complete filling, nor hindering the adhesive layer to impart appropriate flexibility. Both work synergistically to improve the bending resistance of the adhesive layer, alleviate fatigue damage from repeated bending of the rollable module, and reduce interfacial stress under high temperature and high humidity environments.

[0021] Preferably, the bisphenol A type epoxy resin has an epoxy value of 0.1-0.5 and a viscosity of 5000-8000 mPa·s at 25°C.

[0022] By adopting the above technical solution, epoxy values ​​of 0.1-0.5 can efficiently and synergistically crosslink with aliphatic epoxy resins, epoxy-modified silicone oils, and other components to construct a structurally stable adhesive matrix. This ensures compatibility between components, prevents phase separation, and provides basic bonding strength for encapsulation. The viscosity of 5000-8000 mPa·s at 25℃ is within the suitable range, which can meet the capillary flow and penetration requirements of narrow gaps below 50 micrometers, ensuring complete filling and eliminating voids, while also suppressing the problem of glue overflow caused by excessive glue volume.

[0023] Preferably, the average particle size of the nano-silicon powder is 100-150 nm.

[0024] By adopting the above technical solution, the average particle size of the nano-silicon powder is optimized, enabling it to be uniformly dispersed in the adhesive matrix. This does not hinder the capillary flow and narrow-gap penetration of the adhesive, ensuring the integrity of the filling to eliminate voids, and also forming a synergistic effect with the core-shell nano-rubber. Its rigidity can enhance the mechanical strength of the adhesive layer, complementing the elastic rubber core, and efficiently absorbing the shear stress caused by the difference in thermal expansion coefficients, reducing the risk of weld cracking and delamination under flexible bending and high temperature and humidity environments.

[0025] Preferably, the core-shell nano-rubber includes at least one of polybutadiene rubber core, styrene-butadiene rubber core, acrylate rubber core, and polysiloxane rubber core.

[0026] By employing the aforementioned core-shell nano-rubber, dispersed elastic sites can be formed within the adhesive layer, efficiently absorbing and dispersing shear stress caused by differences in thermal expansion coefficients, thus alleviating stress concentration resulting from temperature changes and flexible bending. Simultaneously, it does not interfere with the crosslinking reaction and filling properties of the adhesive matrix, enhancing the impact resistance and fatigue resistance of the adhesive layer while ensuring its mechanical strength, and reducing the risk of failures such as weld cracking and delamination.

[0027] Secondly, this application provides a method for preparing a filler adhesive for a temperature-controlled crystal oscillator small-pitch chip, employing the following technical solution: A method for preparing a filler adhesive for a temperature-controlled crystal oscillator small-pitch chip includes the following preparation steps: Bisphenol A type epoxy resin, aliphatic epoxy resin and diluent are mixed evenly, and then epoxy modified silicone oil, epoxy cage-type silsesquioxane, core-shell nano rubber, surfactant, curing agent, coupling agent, defoamer and nano silicon powder are added and stirred evenly to obtain temperature-controlled crystal oscillator small-pitch chip filling adhesive.

[0028] By adopting the above technical solution, and first mixing the epoxy resin matrix and diluent as a base, followed by adding the remaining functional components and stirring evenly, it is ensured that all raw materials, including bisphenol A epoxy resin, epoxy-modified silicone oil, and core-shell nano-rubber, are fully dispersed and free from agglomeration. This ensures that the adhesive achieves capillary flow and wetting properties suitable for narrow gaps below 50 micrometers, achieving complete filling and suppressing air bubbles and overflow. It also allows the crosslinking reaction to proceed fully, enhancing the mechanical strength, flexibility, and stress resistance of the adhesive layer. At the same time, it simplifies the production process, improves preparation efficiency and batch stability, and ultimately produces a stable high-reliability filler adhesive. This provides process assurance for improving the yield of temperature-controlled crystal oscillator packaging and the stable application of ultra-thin, rollable display modules.

[0029] Preferably, the curing process of the temperature-controlled crystal oscillator small-pitch chip filler adhesive is as follows: first, pre-curing at 80-100℃ for 30-60 minutes, and then post-curing at 120-150℃ for 2-4 hours.

[0030] By adopting the above technical solution, pre-curing at 80-100℃ for 30-60 minutes can slowly release residual air bubbles in the adhesive layer, avoiding air bubble retention in narrow-gap encapsulation, and simultaneously initially fixing the adhesive layer morphology to prevent adhesive overflow from contaminating solder pads and components. Post-curing at 120-150℃ for 2-4 hours can promote full cross-linking of various components, enhancing the mechanical strength, flexibility, and thermal stability of the adhesive layer. This two-step synergy ensures the molding quality of the filler adhesive in narrow gaps below 50 micrometers, improves the adhesive layer's resistance to bending and thermal stress, reduces the risk of delamination and solder joint cracking, stabilizes crystal oscillator frequency accuracy, and simultaneously considers process efficiency and batch consistency, providing curing assurance for high packaging yield and long-term reliable operation of ultra-thin, flexible modules.

[0031] In summary, this application has the following beneficial effects: 1. This application combines bisphenol A with aliphatic epoxy resin, and introduces epoxy-modified silicone oil, epoxy-based cage-type silsesquioxane, core-shell nano-rubber, and nano-silicon powder to achieve rapid and complete filling of narrow gaps ≤50μm, without voids or excess adhesive; it also takes into account high flexibility, low stress, high temperature and humidity resistance, and repeated bending, suppresses solder joint cracking and delamination, improves crystal oscillator frequency stability and packaging yield, and meets the long-term reliable operation requirements of ultra-thin, rollable, high refresh rate display modules. Detailed Implementation Example

[0032] The main chain structure of the side-chain epoxy polyether silicone oil is -[Si(CH3)2-O]- n The side chain structure is -CH2-CH(OH)-CH2-O-(CH2CH2O). m -R, where R is a methyl group.

[0033] The main chain structure of the side-chain epoxy silicone oil is -[Si(CH3)2-O]- n The side chain structure is -(CH2)3-O-CH2-CH(OH)-CH2.

[0034] The polybutadiene rubber core is Galata Blendex 338.

[0035] The styrene-butadiene rubber core is Mitsubishi Rayon METABLEN SX-006.

[0036] The acrylate rubber core is TopWin Silicone CSR-PDMS. Example

[0037] A temperature-controlled crystal oscillator small-pitch chip filler is prepared by the following method: Mix 80g of bisphenol A type epoxy resin, 30g of aliphatic epoxy resin (diglycidyl adipate), and 300g of diluent evenly. Then add 10g of epoxy modified silicone oil, 1g of epoxy cage silsesquioxane (glycidyl ether-isobutyl cage silsesquioxane), 6g of core-shell nano rubber (polybutadiene rubber core), 0.5g of surfactant, 1g of curing agent (hexahydrophthalic anhydride), 3g of coupling agent (γ-glycidoxypropyltrimethoxysilane), 1g of defoamer (BYK-019), and 15g of nano-silicon powder and stir evenly to obtain the temperature-controlled crystal oscillator small-pitch chip filling adhesive.

[0038] The epoxy value of bisphenol A type epoxy resin is 0.1, and the viscosity at 25℃ is 5000 mPa·s.

[0039] The epoxy-modified silicone oil is composed of side-chain epoxy polyether silicone oil and side-chain epoxy silicone oil in a ratio of 3:0.5; The epoxy value of the side-chain epoxy polyether silicone oil is 0.15 mmol / g, and the molecular weight of the polyether segment is 500. The side-chain epoxy silicone oil has an epoxy value of 0.10 mmol / g and a viscosity of 100 cP at 25℃.

[0040] The surfactant is composed of dehydrated sorbitan fatty acid ester and fatty alcohol phosphate ester in a weight ratio of 1:3.

[0041] The average particle size of the nano-silicon powder is 100 nm.

[0042] The difference between Examples 2-3 and Example 1 lies in the types, amounts, and parameters of the raw materials used to prepare the filler adhesive for the temperature-controlled crystal oscillator small-pitch chip. Specific differences are shown in Table 1. Table 1. Raw material types, dosages, and parameters for preparing the filler adhesive for temperature-controlled crystal oscillator small-pitch chips.

[0043] In Example 2, the epoxy value of the side-chain epoxy polyether silicone oil was 0.2 mmol / g, and the molecular weight of the polyether segment was 800. The side-chain epoxy silicone oil has an epoxy value of 0.15 mmol / g and a viscosity of 300 cP at 25℃.

[0044] In Example 3, the epoxy value of the side-chain epoxy polyether silicone oil was 0.25 mmol / g, and the molecular weight of the polyether segment was 1000. The side-chain epoxy silicone oil has an epoxy value of 0.20 mmol / g and a viscosity of 500 cP at 25℃.

[0045] Example 4 A temperature-controlled crystal oscillator small-pitch chip filler, the difference between this embodiment and embodiment 1 is that the weight ratio of the side-chain epoxy polyether silicone oil to the side-chain epoxy silicone oil is 1:1.

[0046] Example 5 A temperature-controlled crystal oscillator small-pitch chip filler is described in this embodiment, which differs from Embodiment 1 in that the epoxy value of the side-chain epoxy polyether silicone oil is 0.15 mmol / g and the molecular weight of the polyether segment is 1500.

[0047] Example 6 A temperature-controlled crystal oscillator small-pitch chip filler is described in this embodiment, which differs from Embodiment 1 in that the epoxy value of the side-chain epoxy silicone oil is 0.10 mmol / g and the viscosity at 25°C is 50 cP.

[0048] Example 7 A temperature-controlled crystal oscillator small-pitch chip filler, the difference between this embodiment and embodiment 1 is that the surfactant is dehydrated sorbitan fatty acid ester.

[0049] Example 8 A temperature-controlled crystal oscillator small-pitch chip filler, the difference between this embodiment and embodiment 1 is that the average particle size of the silicon micro powder is 200nm.

[0050] Comparative Example Comparative Example 1 A temperature-controlled crystal oscillator small-pitch chip filler is described. The difference between this comparative example and Example 1 is that the epoxy-modified silicone oil is a side-chain epoxy polyether silicone oil.

[0051] Comparative Example 2 A temperature-controlled crystal oscillator small-pitch chip filler is described. The difference between this comparative example and Example 1 is that polyether-modified silicone oil is used instead of side-chain epoxy polyether silicone oil.

[0052] The polyether-modified silicone oil was purchased from Shanghai McLean Biochemical Technology Co., Ltd., with a viscosity of 1000 cSt and CAS number 67674-67-3.

[0053] Comparative Example 3 A temperature-controlled crystal oscillator small-pitch chip filler is described. The difference between this comparative example and Example 1 is that polydimethylsiloxane is used instead of side-chain epoxy silicone oil.

[0054] The grade of polydimethylsiloxane is 201-50.

[0055] Comparative Example 4 A temperature-controlled crystal oscillator small-pitch chip filler is described. The difference between this comparative example and Example 1 is that octaisobutyl cage silsesquioxane is used instead of epoxy cage silsesquioxane.

[0056] Comparative Example 5 A temperature-controlled crystal oscillator small-pitch chip filler is described. The difference between this comparative example and Example 1 is that no core-shell nano-rubber is added.

[0057] Comparative Example 6 A temperature-controlled crystal oscillator small-pitch chip filler is described. The difference between this comparative example and Example 1 is that no surfactant is added.

[0058] Application examples Application Example 1 Apply 0.1 mg of the adhesive from Example 1 to FR-4, then attach a 1 mm silicon chip on top. Pre-cure at 80°C for 30 minutes, then post-cure at 120°C for 2 hours to obtain the finished product.

[0059] Application Example 2 Apply 0.1 mg of the adhesive from Example 1 to FR-4, then attach a 1 mm silicon chip on top. Pre-cure at 100°C for 60 minutes, then post-cure at 150°C for 4 hours to obtain the finished product.

[0060] The difference between Application Example 3-9 and Application Example 1 lies in the source of the adhesive, as shown in Table 2:

[0061] Flow time: Using two parallel glass plates with gaps of 50 μm, 20 μm, and 10 μm, the time it took for the filler adhesive in Examples 1-8 and Comparative Examples 1-6 to flow to the 30 mm position was recorded, and it was observed whether voids were generated at 10 μm. Void rating: A = no visible voids; B = ≤ 2 pinpoint voids; C = 3-5 small voids; D = > 5 voids or continuous voids.

[0062] Adhesion strength test: The DAGE4000 was used to test the thrust and the adhesion strength of the products in application example 1-15 was tested.

[0063] The double 85 reliability test was conducted according to the standard (GB / T5170.5-2008) using a damp heat aging tester at a temperature of 85℃ and a humidity of 85%RH for 1000 hours, followed by testing the bonding strength.

[0064] Linear thermal expansion coefficient (CTE) test: Tested according to standard (ASTM D696-79) using a Hitachi TMA7300 instrument. The test temperature range was 25℃-300℃, the heating rate was 5℃ / min, and the sample size was Φ6mm with a length of 3mm. Experimental data are shown in Tables 3 and 4. Table 3. Experimental data of Examples 1-8 and Comparative Examples 1-5

[0065] Table 4 Experimental data from Application Examples 1-15

[0066] The experimental data in Tables 3 and 4 demonstrate that this invention utilizes bisphenol A epoxy resin, epoxy-modified silicone oil, and cage-type silsesquioxane to synergistically construct a flexible matrix. This matrix, combined with core-shell nano-rubber and nano-silica powder, forms a stress-buffering network, significantly alleviating shear stress caused by differences in thermal expansion. Surfactants and defoamers synergistically reduce interfacial tension and eliminate air bubbles, improving the wettability and flowability of the adhesive in extremely narrow gaps, achieving complete filling without voids or overflow. After curing, the adhesive layer exhibits high bonding strength, resistance to damp heat aging, and bending resistance, effectively inhibiting solder joint cracking and delamination. This meets the high-reliability packaging requirements of temperature-controlled crystal oscillators for ultra-thin, rollable display modules, comprehensively improving the long-term stability of the device and the clock accuracy of the display system.

[0067] Comparing Example 1 with Comparative Examples 1-6, Application Example 1, and Application Examples 9-15, it is shown that the filler adhesive using side-chain epoxy polyether silicone oil and side-chain epoxy silicone oil, epoxy cage-type silsesquioxane, core-shell nano rubber, and surfactant flows smoothly and without voids in extremely narrow gaps. After curing, the adhesive has reliable bonding and is resistant to aging. This simultaneously solves the problems of incomplete filling, bubbles, overflow, and stress concentration, achieving high yield and long-term reliability of temperature-controlled crystal oscillator small-pitch packaging.

[0068] By comparing Examples 1 and 4-8, and Application Examples 1 and 3-8, optimizing parameters such as the ratio of side-chain epoxy polyether silicone oil to side-chain epoxy silicone oil, the molecular weight of polyether, the viscosity of silicone oil, the surfactant ratio, and the particle size of nano-silicon powder is necessary to balance capillary penetration, bubble elimination, stress release, and interface adhesion, thereby achieving high reliability of temperature-controlled crystal oscillator small-pitch packaging and long-term stable operation of ultra-thin and rollable modules.

[0069] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A temperature-controlled crystal oscillator small-pitch chip filling adhesive, characterized in that, Prepared from the following raw materials by weight parts: Bisphenol A type epoxy resin 80-100 parts Aliphatic epoxy resin 30-40 parts Epoxy modified silicone oil 10-15 parts Epoxy-based cage silsesquioxane 1-2 parts Core-shell nano rubber 6-10 parts Surfactant 0.5-1 parts Curing agent 1-3 parts Coupling agent 3-5 parts Defoaming agent 1-2 parts Nano silicon powder 15-25 parts Diluent 300 parts The epoxy modified silicone oil is composed of side chain epoxy polyether silicone oil and side chain epoxy silicone oil.

2. The temperature-controlled crystal oscillator small-pitch chip filling adhesive according to claim 1, characterized in that: The weight ratio of the side chain epoxy polyether silicone oil and the side chain epoxy silicone oil is 3: (0.5-1).

3. The temperature controlled crystal oscillator small pitch chip filling adhesive according to claim 2, characterized in that: The epoxy value of the side chain epoxy polyether silicone oil is 0.15-0.25 mmol / g, and the polyether segment molecular weight is 500-1000.

4. The temperature controlled crystal oscillator small pitch chip filling adhesive according to claim 1, characterized in that: The epoxy value of the side chain epoxy silicone oil is 0.10-0.20 mmol / g, and the 25℃ viscosity is 100-500 cP.

5. The temperature controlled crystal oscillator small pitch chip filling adhesive according to claim 1, characterized in that: The surfactant is composed of sorbitan fatty acid ester and fatty alcohol phosphate ester in a weight ratio of 1: (3-5).

6. The temperature controlled crystal oscillator small pitch chip filling adhesive according to claim 1, characterized in that: The epoxy value of the bisphenol A type epoxy resin is 0.1-0.5, and the 25℃ viscosity is 5000-8000 mPa.s.

7. The temperature controlled crystal oscillator small pitch chip filling adhesive according to claim 1, characterized in that: The average particle size of the nano silicon powder is 100-150 nm.

8. The temperature controlled crystal oscillator small pitch chip filling adhesive according to claim 1, characterized in that: The core-shell nano rubber includes at least one of polybutadiene rubber core, styrene butadiene rubber core, acrylate rubber core and polysiloxane rubber core.

9. A method for preparing the temperature-compensated crystal oscillator small-pitch chip filling adhesive according to any one of claims 1-8, characterized in that, Including the following preparation steps: Mix the bisphenol A type epoxy resin, aliphatic epoxy resin and diluent uniformly, then add the epoxy modified silicone oil, epoxy-based cage silsesquioxane, core-shell nano rubber, surfactant, curing agent, coupling agent, defoaming agent and nano silicon powder and stir uniformly to obtain the temperature controlled crystal oscillator small pitch chip filling glue.

10. The preparation method of the temperature-controlled crystal oscillator small-pitch chip filling glue according to claim 9, characterized in that, The curing process of the temperature controlled crystal oscillator small pitch chip filling glue is: first pre-curing at 80-100℃ for 30-60 minutes, and then post-curing at 120-150℃ for 2-4 hours.

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