Ball grid array (BGA) packaging process of memory product

Abstract

The invention discloses a BGA (Ball Grid Array) packaging process of a memory product, which belongs to the field of semiconductor packaging, and comprises a bottom filling process between a chip and a substrate, and the bottom filling process comprises the following steps: S1, preparing bottom filling glue, the underfill adhesive comprises the following components: a ternary epoxy resin blending system, modified nano ZnO, boron nitride nanotubes, a curing agent and other auxiliaries, wherein the modified nano ZnO is of a ZnO (at) PDA-Fe < 3 + >-SiC composite structure; s2, the substrate is preheated, and the preheating temperature ranges from 40 DEG C to 60 DEG C; s3, continuously dispensing along the single side of the chip by using a dispensing machine, and naturally diffusing and filling the bottom filling glue into a gap between the chip and the substrate by using a capillary effect; and S4, after the gap is naturally filled with the bottom filling glue, heating and curing are carried out, and bottom filling between the chip and the substrate is completed. According to the invention, the modified nano zinc oxide can realize high addition amount and high dispersity in the underfill adhesive, and low water absorption and high mechanical property of the underfill adhesive can be realized under the condition of high addition amount.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor packaging and relates to a BGA packaging process for memory products. Background Art

[0002] In the flip-chip of electronic packaging, adding bottom filler between the chip and the substrate can improve its reliability and reduce the interfacial stress caused by the difference in thermal expansion coefficient between the solder joint and the substrate. However, when using bottom filler for bottom filling, there are still the following problems: At present, in order to improve the performance of epoxy resin bottom filler, nanofillers are usually added to reduce the water absorption of the bottom filler and improve its shear resistance, temperature resistance and other properties. During the use of nanofillers, silane coupling agents are often used to disperse and modify nano zinc oxide. A specific analysis is given in the paper "The Effect of Nanofillers on the Performance of Epoxy Resin-Based Bottom Filler" published in 2019. While ensuring low water absorption in the bottom filler, the maximum addition amount of nano zinc oxide can only reach 3%. When the addition amount is greater than 3%, the nano zinc oxide will agglomerate and increase the water absorption. However, the shear strength of the bottom filler cannot reach the maximum at an addition amount of 3%; therefore, silane coupling agent-modified nano zinc oxide currently has the problem of limited dispersion. Summary of the Invention

[0003] The purpose of the present invention is to provide a BGA packaging process for memory products, which solves the problem of limited dispersion of alkyl coupling agent modified nano zinc oxide in the process of nano filler modified epoxy resin base bottom filling glue.

[0004] The technical solution adopted in the present invention is as follows:

[0005] A BGA packaging process for memory products includes an underfill process between a chip and a substrate, the underfill process comprising the following steps:

[0006] S1. Prepare bottom filling glue, which includes the following components: ternary epoxy resin blend system, modified nano ZnO, boron nitride nanotubes, curing agent, and other additives, wherein the modified nano ZnO is ZnO@PDA-Fe 3+ -SiC composite structure;

[0007] S2. Preheat the substrate at a temperature of 40-60°C;

[0008] S3. Use a dispensing machine to continuously dispense glue along one side of the chip, using the capillary effect to allow the underfill glue to naturally diffuse and fill the gap between the chip and the substrate;

[0009] S4. The bottom filling glue naturally fills the gap and then heats and cures to complete the bottom filling between the chip and the substrate.

[0010] Furthermore, the preparation method of the bottom filling glue in step S1 is:

[0011] S1.1, preparation of modified nano ZnO: ZnO was dispersed in Tris buffer with pH 8.5, dopamine was added, and the mixture was shaken at 25℃ for 6h, centrifuged, washed and dried to obtain ZnO@PDA particles; ZnO@PDA particles were then immersed in FeCl3 ethanol solution, stirred at 60℃ for 2h, washed and dried to obtain ZnO@PDA-Fe 3+ Composite structure; ZnO@PDA-Fe 3+ Place it in a tube furnace, introduce SiH4 and CH4 mixed gas, react at 600℃ for 30min, and then treat in ammonia atmosphere for 30min to obtain ZnO@PDA-Fe 3+ -SiC composite structure, the ZnO@PDA-Fe 3+ -SiC composite structure is modified nano-ZnO;

[0012] S1.2. Heat the ternary epoxy resin blend to 80-90°C, add modified nano-ZnO and boron nitride nanotubes at a constant temperature, and sonicate at 40 kHz for 1-1.5 hours to obtain a first intermediate;

[0013] S1.3. At 80°C, apply a 1 T magnetic field to the first intermediate for 5 minutes, then linearly reduce the magnetic field intensity to 0.5 T and maintain for 12 minutes to perform the first magnetic field induction to obtain the second intermediate;

[0014] S1.4. Add curing agent and other additives to the second intermediate, stir and mix evenly, then apply a 0.3T weak magnetic field at room temperature for 2 minutes to perform a second magnetic field induction, vacuum degassing, and obtain the bottom filling glue.

[0015] Furthermore, the amount of modified nano ZnO added is 7-8% of the mass of the ternary epoxy resin blend system, the mass ratio of boron nitride nanotubes to modified nano ZnO is 1.8-2:1, and the amount of curing agent added is 20-25% of the mass of the ternary epoxy resin blend system.

[0016] Furthermore, the mass ratio of ZnO to dopamine is 10:1.

[0017] Furthermore, the volume ratio of SiH to CH in the SiH4 and CH4 mixed gas is 1:4.

[0018] Furthermore, the other additives include aluminum borate whiskers and fumed silica. The amount of aluminum borate whiskers added is 3-5% of the mass of the ternary epoxy resin blend system, and the amount of fumed silica added is 0.3-0.5% of the mass of the ternary epoxy resin blend system.

[0019] Furthermore, the ternary epoxy resin blend system includes the following components: polyurethane modified epoxy resin, bisphenol F epoxy resin, and novolac epoxy resin, and the mass ratio of polyurethane modified epoxy resin, bisphenol F epoxy resin, and novolac epoxy resin is 1:3-5:1.

[0020] Furthermore, the curing agent includes a QNP1 low-temperature latent epoxy resin curing agent and an acid anhydride curing agent, and the mass ratio of the QNP1 low-temperature latent epoxy resin curing agent to the acid anhydride curing agent is 2:1.

[0021] Furthermore, the curing method of step S4 is: first heating to 80-85°C, keeping the temperature constant for 5 minutes, then continuing to heat to 120-130°C and keeping it for 8-10 minutes.

[0022] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0023] 1. The present invention improves the bottom filling method of a BGA packaging process for memory products by using a new modified nano-zinc oxide combined with magnetic field induction technology, replacing the existing technical solution of modifying nano-zinc oxide with a silane coupling agent to improve the dispersion of nano-zinc oxide in an epoxy resin matrix. The modified nano-zinc oxide of the present invention has a four-layer composite structure, in which the hydroxyl groups on the ZnO surface and the catechol groups of dopamine are hydrogen-bonded. The dopamine layer inhibits ZnO agglomeration through steric hindrance, achieving the first dispersion step; Fe 3+ Forming coordination bonds with the phenolic hydroxyl groups of PDA, the particle surface carries a positive charge and is further dispersed by electrostatic repulsion; in magnetic field induction, Fe 3+ The paramagnetism of the modified ZnO causes it to align along the magnetic field lines in a magnetic field, reducing the probability of agglomeration. The boron nitride nanotubes are magnetic and align along the magnetic field direction under the magnetic field, interweaving with the ZnO to form a three-dimensional network under the magnetic field, thereby anchoring the nanoparticles and further improving the dispersibility. The chemical inertness of SiC reduces the surface energy and reduces the water adsorption sites. The modified nano-zinc oxide in the present invention can achieve high addition amount and high dispersibility in the bottom filler, and even at a high addition amount, the bottom filler can achieve low water absorption and high mechanical properties.

[0024] 2. The SiC in the modified nano-zinc oxide of the present invention is deposited. On the one hand, the obtained SiC layer is thin and not dense, which reduces the water absorption rate of the nano-zinc oxide without affecting the dispersion of electrostatic repulsion. The SiC outer layer acts as a physical barrier to prevent water molecules from penetrating into the interior. The PDA layer acts as a chemical barrier to further hinder water diffusion through its hydrophobic structure and interfacial cross-linking.

[0025] 3. The present invention uses a ternary epoxy resin blend system instead of the existing single-component epoxy resin. This is because, when a high amount of nanofiller is added to a traditional single-component epoxy resin, the filler particles disrupt the continuity of the resin molecular chain, thereby weakening its ability to reduce the interfacial stress caused by the difference in thermal expansion coefficient between the solder joint and the substrate. To remedy this problem, the present invention used a mixture of polyurethane-modified epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin to replace a single epoxy resin. Through flexible polyurethane bridging, bisphenol F wetting, and high cross-linking of phenolic resin, the disruptive effect of the high filler content is offset.

[0026] 4. Compared with a single epoxy resin, the ternary epoxy resin blend system of the present invention also provides a gradient distribution of thermal expansion coefficient. Compared with a single epoxy resin with a fixed thermal expansion coefficient, it reduces the degree of thermal expansion mismatch, achieves a gradual CTE transition, and avoids sudden stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort, among which:

[0028] Figure 1 This is a block diagram of the underfill process in the BGA packaging process of a memory product. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0031] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0032] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0033] Example 1

[0034] like Figure 1 As shown, a preferred embodiment of the present invention provides a BGA packaging process for a memory product, including a bottom filling process between the chip and the substrate, the bottom filling process comprising the following steps:

[0035] S1. Prepare bottom filling glue, which includes the following components: ternary epoxy resin blend system, modified nano ZnO, boron nitride nanotubes, curing agent, and other additives, wherein the modified nano ZnO is ZnO@PDA-Fe 3+ -SiC composite structure;

[0036] S2. Preheat the substrate at a temperature of 40-60°C;

[0037] S3. Use a dispensing machine to continuously dispense glue along one side of the chip, using the capillary effect to allow the underfill glue to naturally diffuse and fill the gap between the chip and the substrate;

[0038] S4. The bottom filling glue naturally fills the gap and then heats and cures to complete the bottom filling between the chip and the substrate.

[0039] The preparation method of the bottom filling glue in step S1 is:

[0040] S1.1, preparation of modified nano ZnO: ZnO was dispersed in Tris buffer with pH 8.5, dopamine was added, and the mixture was shaken at 25℃ for 6h, centrifuged, washed and dried to obtain ZnO@PDA particles; ZnO@PDA particles were then immersed in FeCl3-ethanol solution, stirred at 60℃ for 2h, washed and dried to obtain ZnO@PDA-Fe 3+ Composite structure; ZnO@PDA-Fe 3+Place it in a tube furnace, introduce SiH4 and CH4 mixed gas, react at 600℃ for 30min, and then treat in ammonia atmosphere for 30min to obtain ZnO@PDA-Fe 3+ -SiC composite structure, the ZnO@PDA-Fe 3+ -SiC composite structure is modified nano-ZnO;

[0041] S1.2. Heat the ternary epoxy resin blend to 80-90°C, add modified nano-ZnO and boron nitride nanotubes at a constant temperature, and sonicate at 40 kHz for 1-1.5 hours to obtain a first intermediate;

[0042] S1.3. At 80°C, apply a 1 T magnetic field to the first intermediate for 5 minutes, then linearly reduce the magnetic field intensity to 0.5 T and maintain for 12 minutes to perform the first magnetic field induction to obtain the second intermediate;

[0043] S1.4. Add curing agent and other additives to the second intermediate, stir and mix evenly, apply a 0.3T weak magnetic field at room temperature for 2 minutes, and vacuum degas to obtain the bottom filling glue.

[0044] The amount of modified nano ZnO added is 7% of the mass of the ternary epoxy resin blend system, the mass ratio of boron nitride nanotubes to modified nano ZnO is 1.8:1, and the amount of curing agent added is 20% of the mass of the ternary epoxy resin blend system.

[0045] The mass ratio of ZnO to dopamine is 10:1.

[0046] The volume ratio of SiH to CH in the SiH 4 and CH 4 mixed gas is 1:4.

[0047] The other additives include aluminum borate whiskers and fumed silica. The amount of aluminum borate whiskers added is 3-5% of the mass of the ternary epoxy resin blending system, and the amount of fumed silica added is 0.3-0.5% of the mass of the ternary epoxy resin blending system.

[0048] The ternary epoxy resin blend system includes the following components: polyurethane modified epoxy resin, bisphenol F epoxy resin, and novolac epoxy resin, and the mass ratio of the polyurethane modified epoxy resin, bisphenol F epoxy resin, and novolac epoxy resin is 1:3:1.

[0049] The curing agent includes a QNP1 low-temperature latent epoxy resin curing agent and an acid anhydride curing agent, and the mass ratio of the QNP1 low-temperature latent epoxy resin curing agent to the acid anhydride curing agent is 2:1.

[0050] The curing method of step S4 is: first heat to 80-85°C, keep constant temperature for 5 minutes, then continue to heat to 120-130°C and keep it for 8-10 minutes.

[0051] Example 2

[0052] This embodiment is based on Example 1, but differs from Example 1 in that the amount of modified nano-ZnO added is 7.5% of the mass of the ternary epoxy resin blend system, the mass ratio of boron nitride nanotubes to modified nano-ZnO is 1.9:1, and the amount of curing agent added is 22.5% of the mass of the ternary epoxy resin blend system.

[0053] Example 3

[0054] This embodiment is based on Example 1, but differs from Example 1 in that the amount of modified nano-ZnO added is 8% of the mass of the ternary epoxy resin blend system, the mass ratio of boron nitride nanotubes to modified nano-ZnO is 2:1, and the amount of curing agent added is 25% of the mass of the ternary epoxy resin blend system.

[0055] Example 4

[0056] This embodiment is based on Example 2, but differs from Example 1 in that the ternary epoxy resin blend system includes the following components: polyurethane-modified epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin, and the mass ratio of polyurethane-modified epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin is 1:4:1.

[0057] Example 5

[0058] This embodiment is based on Example 2, but differs from Example 1 in that the ternary epoxy resin blend system includes the following components: polyurethane-modified epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin, and the mass ratio of polyurethane-modified epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin is 1:5:1.

[0059] Comparative Example 1

[0060] This comparative example is based on Example 1, but differs from Example 1 in that the bottom filling glue and its preparation method in this comparative example are the components and preparation methods given in "The Effect of Nanofillers on the Performance of Epoxy Resin-Based Underfill Glues" by Zhang Xin, Guo Wenli, and Liang Tongxiang, wherein the modified zinc oxide is a nanofiller modified by a silane coupling agent, and the added amount is 0.3% of the mass of the epoxy resin. The filling process steps of the bottom filling glue are the same, except that the components and preparation methods of the bottom filling glue are different.

[0061] Comparative Example 2

[0062] This comparative example is based on Example 1, and differs from Example 1 in that: the modified nano ZnO in the bottom filling glue of this comparative example does not include an outer SiC layer;

[0063] Comparative Example 3

[0064] This comparative example is based on Example 1 and differs from Example 1 in that the modified nano ZnO in the bottom filling glue of this comparative example does not include the intermediate Fe 3+ layer.

[0065] Comparative Example 4

[0066] This comparative example is based on Example 1, but differs from Example 1 in that the modified nano ZnO in the underfill of this comparative example does not include a PDA layer, and thus cannot form a stable multilayer structure.

[0067] Comparative Example 5

[0068] This comparative example is based on Example 1 and differs from Example 1 in that the modified nano ZnO in the bottom filling glue of this comparative example does not include SiC layer and Fe 3+ layer.

[0069] Comparative Example 6

[0070] This comparative example is based on Example 1, but differs from Example 1 in that the bottom filling glue in this comparative example does not include boron nitride nanotubes.

[0071] Comparative Example 7

[0072] This comparative example is based on Example 1, but differs from Example 1 in that the first magnetic field induction is not performed in the preparation process of the underfill glue in this comparative example.

[0073] Comparative Example 8

[0074] This comparative example is based on Example 1, but differs from Example 1 in that the second magnetic field induction is not performed in the preparation process of the underfill glue in this comparative example.

[0075] Comparative Example 9

[0076] This comparative example is based on Example 1, but differs from Example 1 in that the first magnetic field induction and the second magnetic field induction are not performed in the preparation process of the underfill glue in this comparative example.

[0077] Comparative Example 10

[0078] This comparative example is based on Example 1, differing from Example 1 in that a single bisphenol F epoxy resin is used in the underfill instead of a ternary epoxy resin blend. During testing, it was found that underfills prepared using a single polyurethane-modified epoxy resin or a novolac epoxy resin exhibited poor fluidity and were unable to achieve uniform filling, making them unsuitable for the underfill process of the present invention.

[0079] Comparative Example 11

[0080] This comparative example is based on Example 1, but differs from Example 1 in that the ternary epoxy resin blend system in the underfill glue of this comparative example does not include bisphenol F epoxy resin. Therefore, uniform filling cannot be achieved, and the underfill process of the present invention is not applicable.

[0081] Comparative Example 12

[0082] This comparative example is based on Example 1, but differs from Example 1 in that the ternary epoxy resin blend system in the underfill glue of this comparative example does not include polyurethane-modified epoxy resin.

[0083] Comparative Example 13

[0084] This comparative example is based on Example 1, but differs from Example 1 in that the ternary epoxy resin blend system in the underfill glue of this comparative example does not include phenolic epoxy resin.

[0085] Test Example 1

[0086] The shear strength, water absorption (water absorption rate), and heat resistance (decomposition temperature) of the underfills prepared in Examples 1-5 and Comparative Examples 1-13 were tested. The testing method was based on the test method given in "Effect of Nanofillers on the Performance of Epoxy Resin-Based Underfills" by Zhang Xin, Guo Wenli, and Liang Tongxiang. The results are shown in Table 1.

[0087] Table 1 Performance test of bottom filler

[0088]

[0089]

[0090] Compared with the prior art, the present invention can improve shear strength and heat resistance while maintaining low water absorption while adding a filler in an amount higher than the optimal amount of the prior art.

[0091] Test Example 2

[0092] The curing time at 130° C. and the viscosity at 25° C. + 55% relative humidity of Examples 1-5 were tested. The test results are shown in Table 2.

[0093] Table 2 Performance of bottom filling glue of Examples 1-5

[0094] Curing time Viscosity Example 1 ≤15 minutes 800-1000mPa.s Example 2 ≤15 minutes 800-1000mPa.s Example 3 ≤15 minutes 800-1000mPa.s Example 4 ≤15 minutes 800-1000mPa.s Example 5 ≤15 minutes 800-1000mPa.s

[0095] Test Example 3

[0096] Stress failure verification: The CBGA devices packaged using the bottom filling process of Examples 1-5 and Comparative Examples 10-13 were subjected to a temperature cycle test of 0°C to 125°C to detect the number of cycles of stress failure. The detection method is the existing technology. The test results are shown in Table 3.

[0097] Table 3 Stress failure test results

[0098]

[0099] The ternary epoxy resin blend system of the present invention can effectively alleviate the situation where filler particles will cut the continuity of the resin molecular chain, thereby weakening its ability to reduce the interfacial stress caused by the difference in thermal expansion coefficient between the welding point and the substrate.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A BGA packaging process for memory products, including an underfill process between the chip and the substrate, characterized by: The bottom filling process includes the following steps: S1. Prepare bottom filling glue, which includes the following components: ternary epoxy resin blend system, modified nano ZnO, boron nitride nanotubes, curing agent, and other additives, wherein the modified nano ZnO is ZnO@PDA-Fe 3+ -SiC composite structure; S2. Preheat the substrate at a temperature of 40-60°C; S3. Use a dispensing machine to continuously dispense glue along one side of the chip, using the capillary effect to allow the underfill glue to naturally diffuse and fill the gap between the chip and the substrate; S4. The bottom filling glue naturally fills the gap and then heats and cures to complete the bottom filling between the chip and the substrate.

2. The BGA packaging process for a memory product according to claim 1, characterized in that: The preparation method of the bottom filling glue in step S1 is: S1.1, preparation of modified nano ZnO: ZnO was dispersed in Tris buffer with pH 8.5, dopamine was added, and the mixture was shaken at 25℃ for 6h, centrifuged, washed and dried to obtain ZnO@PDA particles; ZnO@PDA particles were then immersed in FeCl3 ethanol solution, stirred at 60℃ for 2h, washed and dried to obtain ZnO@PDA-Fe 3+ Composite structure; ZnO@PDA-Fe 3+ Place it in a tube furnace, introduce SiH4 and CH4 mixed gas, react at 600℃ for 30min, and then treat in ammonia atmosphere for 30min to obtain ZnO@PDA-Fe 3+ -SiC composite structure, the ZnO@PDA-Fe 3+ -SiC composite structure is modified nano-ZnO; S1.

2. Heat the ternary epoxy resin blend to 80-90°C, add modified nano-ZnO and boron nitride nanotubes at a constant temperature, and sonicate at 40 kHz for 1-1.5 hours to obtain a first intermediate; S1.

3. At 80°C, apply a 1 T magnetic field to the first intermediate for 5 minutes, then linearly reduce the magnetic field intensity to 0.5 T and maintain for 12 minutes to perform the first magnetic field induction to obtain the second intermediate; S1.

4. Add curing agent and other additives to the second intermediate, stir and mix evenly, apply a 0.3T weak magnetic field at room temperature for 2 minutes, and vacuum degas to obtain the bottom filling glue.

3. The BGA packaging process for a memory product according to claim 2, wherein: The amount of modified nano ZnO added is 7-8% of the mass of the ternary epoxy resin blend system, the mass ratio of boron nitride nanotubes to modified nano ZnO is 1.8-2:1, and the amount of curing agent added is 20-25% of the mass of the ternary epoxy resin blend system.

4. The BGA packaging process for a memory product according to claim 2, wherein: The mass ratio of ZnO to dopamine is 10:

1.

5. The BGA packaging process for a memory product according to claim 2, wherein: The volume ratio of SiH to CH in the SiH 4 and CH 4 mixed gas is 1:

4.

6. The BGA packaging process for a memory product according to claim 1, wherein: The other additives include aluminum borate whiskers and fumed silica. The amount of aluminum borate whiskers added is 3-5% of the mass of the ternary epoxy resin blending system, and the amount of fumed silica added is 0.3-0.5% of the mass of the ternary epoxy resin blending system.

7. The BGA packaging process for a memory product according to claim 1, wherein: The ternary epoxy resin blend system comprises the following components: polyurethane modified epoxy resin, bisphenol F epoxy resin, and novolac epoxy resin, wherein the mass ratio of the polyurethane modified epoxy resin, the bisphenol F epoxy resin, and the novolac epoxy resin is 1:3-5:

1.

8. The BGA packaging process for a memory product according to claim 7, characterized in that: The curing agent includes a QNP1 low-temperature latent epoxy resin curing agent and an acid anhydride curing agent, and the mass ratio of the QNP1 low-temperature latent epoxy resin curing agent to the acid anhydride curing agent is 2:

1.

9. The BGA packaging process for a memory product according to claim 8, characterized in that: The curing method of step S4 is: first heat to 80-85°C, keep constant temperature for 5 minutes, then continue to heat to 120-130°C and keep it for 8-10 minutes.

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