A resin composition for semiconductor encapsulation

Abstract

The application discloses a semiconductor packaging composition, which comprises a resin containing an imide group, wherein the Tg of the resin is greater than or equal to 200 DEG C, and the CTE of the resin is less than or equal to 250 ppm / DEG C. By using the resin containing the imide group as a matrix, controlling the Tg of the resin to be greater than or equal to 200 DEG C, the overall heat resistance of the semiconductor packaging resin composition is improved, meanwhile, by using the resin with low CTE, the delamination of the device caused by the too large thermal expansion coefficient is avoided, and the reliability of the semiconductor packaging is ensured. Meanwhile, by introducing the polyether modified silicon containing a specific proportion of methyl and phenyl, and controlling the content of each component, the composition has extremely high heat resistance and stability after curing under the synergistic effect, and is not prone to produce bubbles and phase separation defects, the electrical insulation of the composition is greatly improved, and the reliability of the semiconductor packaging is ensured.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, and in particular to a resin composition for semiconductor packaging. Background Technology

[0002] Power semiconductor devices are widely used in consumer electronics, industrial electronics, and automotive electronics. Currently, the electrification of transportation and the energy infrastructure of data and computing centers are placing higher demands on the power density and reliability of power semiconductors.

[0003] Power semiconductor devices are packaged from materials such as chips and substrates. Traditional devices use silicon-based chips, but with the application of wide-bandgap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN), packaging has become a key factor in unlocking chip potential and determining system performance.

[0004] In these types of power devices, polymers are often used as encapsulation materials to buffer against the impact of harsh external environments, improve reliability, and extend device lifespan. However, the application of chips such as SiC and GaN places more stringent demands on the electrical performance, thermal stability, and mechanical strength of encapsulation materials.

[0005] Traditional encapsulation materials such as silicone and epoxy resin can no longer meet the new requirements in terms of temperature resistance, insulation and bonding strength. They are prone to problems such as interface delamination, chip cracking, and loosening, detachment and breakage of bonding points, which in turn lead to decreased device reliability and shortened life.

[0006] Therefore, there is an urgent need to develop a resin composition suitable for semiconductor packaging, which can be used as a packaging adhesive layer to enhance the bonding strength of different packaging materials at high temperatures, thereby effectively addressing the above challenges. Summary of the Invention

[0007] Therefore, the main objective of this application is to provide a resin composition for semiconductor packaging to enhance the bonding force between packaging materials at high temperatures, thereby improving the reliability of semiconductor packaging.

[0008] To achieve the above objectives, the present invention provides a resin composition for semiconductor packaging, comprising a resin containing imide groups, wherein the resin has a Tg ≥ 200°C and a CTE ≤ 250 ppm / °C.

[0009] As a preferred embodiment, the resin composition for semiconductor packaging comprises the following components:

[0010] Matrix resin: 100 parts by weight of a resin containing imide groups;

[0011] Curing agent: 3-10 parts by weight of curing agent;

[0012] Additives: 0.1-1 parts by weight of polyether-modified silicone;

[0013] The polyether-modified silicon has a polysiloxane main chain and polyether segments as side chains. The side chains or end groups of the polysiloxane contain methyl and phenyl groups, and the ratio of methyl to phenyl groups is 3:1 to 5:1.

[0014] As a preferred embodiment, the molecular weight of the matrix resin is 15,000-38,000.

[0015] As a preferred embodiment, the core of the polyether-modified silicon is a Si-O-Si-O-Si structure, and polyether segments are provided at both ends and / or in the middle of the polyether-modified silicon.

[0016] As a preferred embodiment, the polyether-modified silicon comprises fumed silica.

[0017] As a preferred embodiment, the semiconductor packaging composition includes 2-6 parts by weight of a curing initiator, wherein the curing initiator includes a first curing initiator and a second curing initiator having different activation conditions.

[0018] As a preferred embodiment, the curing initiation temperature of the first curing initiator is 80-100℃, and the curing initiation temperature of the second curing initiator is 120-150℃.

[0019] As a preferred embodiment, the photon yield of the first curing initiator is 0.4-0.6, and the photon yield of the second curing initiator is 0.2-0.35.

[0020] As a preferred embodiment, the volume loss rate of the semiconductor packaging resin composition after curing is 0.3%–3%; and / or,

[0021] The viscosity of the resin composition for semiconductor packaging is 50-20000 cP.

[0022] As a preferred embodiment, the resin composition for semiconductor packaging further includes a first solvent and a second solvent, wherein the boiling point of the first solvent is greater than that of the second solvent.

[0023] As a preferred embodiment, the weight ratio of the first solvent to the second solvent is 1-5.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: It provides a resin composition for semiconductor packaging. By using a resin containing imide groups as the matrix and controlling the Tg of the resin to be ≥200℃, it is beneficial to improve the overall heat resistance of the resin composition for semiconductor packaging. At the same time, by using a resin with low CTE, it is avoided that the resin delaminates from the device due to the large coefficient of thermal expansion, thereby ensuring the reliability of semiconductor packaging.

[0025] Furthermore, by introducing polyether-modified silicon containing a specific proportion of methyl and phenyl groups, and by controlling the content of each component, the composition exhibits extremely high heat resistance stability after curing under synergistic effects, and is less prone to generating bubbles and phase separation defects, thereby significantly improving the electrical insulation of the composition and ensuring the reliability of semiconductor packaging. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Furthermore, the terms "first," "second," etc., used in the specification and claims are used only to distinguish the description of the same technical features and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated, nor necessarily the order of description or chronological sequence. Where appropriate, the terms are interchangeable. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0028] The semiconductor packaging resin composition of this invention includes a resin containing imide groups, wherein the resin has a heat resistance (Tg) ≥ 200°C and a thermal expansion coefficient (CTE) ≤ 250 ppm / °C. By using an imide-containing resin as the matrix and controlling the Tg of the resin to ≥ 200°C, the overall heat resistance of the semiconductor packaging resin composition is improved. Simultaneously, using a resin with a low CTE avoids delamination from the device due to a high coefficient of thermal expansion, thereby ensuring the reliability of the semiconductor packaging.

[0029] Furthermore, in an embodiment of the present invention, a resin composition for semiconductor packaging comprises the following components:

[0030] Matrix resin: 100 parts by weight of a resin containing imide groups;

[0031] Curing agent: 3-10 parts by weight of curing agent;

[0032] Additives: 0.1-1 parts by weight of polyether-modified silicone;

[0033] The polyether-modified silicone has a polysiloxane backbone and polyether segments as side chains. The side chains or end groups of the polysiloxane contain methyl and phenyl groups, with a methyl to phenyl ratio of 3:1 to 5:1. By using an imide-containing resin as the matrix, introducing polyether-modified silicone containing a specific proportion of methyl and phenyl groups, and controlling the content of each component, the composition exhibits extremely high heat resistance after curing due to synergistic effects. It is also less prone to bubble formation and phase separation defects, significantly improving the electrical insulation of the composition and thus ensuring the reliability of semiconductor packaging.

[0034] Specifically, resins containing imide groups, as the matrix, possess a rigid structure and a long-term operating temperature far exceeding that of traditional epoxy materials, resulting in extremely high thermal stability after curing. Under the thermal shock generated by repeated switching of power devices, the package maintains structural integrity without softening, deformation, or interface delamination, significantly improving the packaging reliability of power semiconductor modules. While resins containing imide groups exhibit excellent heat resistance, their high molecular chain rigidity makes them prone to generating significant residual internal stress during curing, leading to problems such as substrate warping and chip cracking. By introducing polyether-modified silicon containing a certain proportion of methyl and phenyl groups, compliant chain segments migrate to the interface region within the resin crosslinking network, forming a nanoscale stress buffer layer. When subjected to thermal shock, energy is dissipated through chain segment movement, preventing package warping and deformation. Simultaneously, the phenyl groups adjust the compatibility between the polyether-modified silicon and the matrix resin, preventing polyether-modified silicon precipitation due to poor compatibility, which could lead to interface defects. This affects the reliability of the packaging. Simultaneously, by introducing polyether-modified silicon containing a certain proportion of methyl and phenyl groups, the low surface energy siloxane backbone is enriched on the surface of the semiconductor packaging composition, and the polyether side chains ensure compatibility with the resin. They are oriented at the interface, significantly weakening the intermolecular forces and thus significantly reducing the surface tension of the resin composition. This promotes the coalescence, rise, and rupture of microbubbles during curing, ensuring the material's density and preventing bubble defects, thus avoiding stress concentration points or conductive pathways within the package. Furthermore, by controlling the content of each component in the composition, the composition exhibits extremely high heat resistance stability after curing due to the synergistic effect of each component, and is less prone to bubble and phase separation defects, significantly improving the electrical insulation of the composition and thus ensuring the reliability of the semiconductor packaging.

[0035] In this embodiment of the invention, the resin containing imide groups refers to a polymer whose main molecular chain and / or side chains contain at least one imide ring structure. This type of resin, with its rigid groups, endows the cured product with extremely high heat resistance, excellent mechanical strength, and stable dielectric properties, thereby ensuring the reliability of power semiconductor packaging. The resin containing imide groups can be a thermoplastic resin or a thermosetting resin, preferably a resin capable of undergoing crosslinking or chain growth reactions under the curing conditions commonly used in semiconductor packaging to form a three-dimensional network structure.

[0036] Preferably, the resin containing imide groups in the embodiments of the present invention includes at least one of polyimides, polyamide-imides, bismaleimides, etherimides, and copolymers containing imide structures.

[0037] It is worth noting that in the embodiments of the present invention, polyether-modified silicon is an additive. The low surface energy siloxane backbone is enriched on the surface of the semiconductor packaging composition, and the polyether side chains ensure compatibility with the resin and are oriented at the interface, which greatly weakens the intermolecular forces on the surface, thereby significantly reducing the surface tension of the resin composition. This promotes the merging, floating and rupture of microbubbles during curing and use, ensuring the compactness of the material and making it less prone to bubble defects, thus avoiding stress concentration points or conductive paths in the package. At the same time, in the resin crosslinking network, the compliant segments of polyether-modified silicon migrate to the interface region to form a nanoscale stress buffer layer. When subjected to thermal shock, energy is dissipated through the movement of chain segments, which can prevent the package from warping and deforming.

[0038] It is worth noting that in this embodiment of the invention, the ratio of methyl to phenyl groups is limited to 3:1-5:1. By limiting the ratio of methyl to phenyl groups to 3:1-5:1, the heat resistance of the resin composition and the compatibility between the additive and the matrix resin can be effectively improved, thereby ensuring the reliability of power semiconductor packaging. On the one hand, a high ratio of methyl to phenyl groups will not result in too many flexible segments, leading to a decrease in the heat resistance of the resin composition; conversely, a low number of phenyl groups will result in poor compatibility between polyether-modified silicon and the resin matrix containing imide groups, leading to easy precipitation, interface defects, and affecting packaging reliability. On the other hand, a low ratio of methyl to phenyl groups will not result in too few flexible segments, preventing sufficient compliant segments from migrating to the interface region in the resin crosslinking network, thus failing to form a nanoscale stress buffer layer. When subjected to thermal shock, energy cannot be dissipated through segment movement, easily leading to warping and deformation of the package. Therefore, limiting the ratio of methyl to phenyl groups to 3:1-5:1 not only promotes the migration of compliant segments to the interfacial region, forming a nanoscale stress buffer layer, which dissipates energy through segment movement during thermal shock and, combined with the rigid phenyl group, improves the heat resistance of the encapsulation; it also ensures good compatibility between polyether-modified silicone and imide-containing resin matrices, preventing additive precipitation and avoiding interfacial defects that could affect encapsulation reliability. Optionally, the ratio of methyl to phenyl groups can be any value or a range of any two values ​​from 3:1, 3.2:1, 3.8:1, 4:1, 4.3:1, 4.7:1, and 5:1.

[0039] Preferably, in this embodiment of the invention, the main chain of the polyether-modified silicone is polysiloxane, and the side chains are polyether segments. In aqueous or polar resin systems, the lipophilic polysiloxane main chain is coiled inside, while the hydrophilic polyether side chains extend outward, forming micelles. When the micelles come into contact with the liquid film (gas-liquid interface) of the bubble, due to the strong hydrophobicity of the polysiloxane main chain, it spontaneously migrates from the liquid interior and adsorbs onto the bubble surface, replacing the surfactant that originally stabilized the bubble. Simultaneously, this causes a sudden drop in the local surface tension of the liquid film, leading to a rapid pull of liquid onto areas of high tension, causing the liquid film in the area where the defoamer has been adsorbed to thin rapidly. Ultimately, this weak "bridging point" cannot withstand the pressure difference and breaks, and the bubble is instantly punctured. Meanwhile, because the polyether side chains have similar polarity to the matrix resin or can form hydrogen bonds, they physically entangle with the resin matrix or weakly chemically interact with it, anchoring the entire molecule within the resin network. The long Si-O bonds and large bond angles of the polysiloxane backbone allow for free rotation, giving it extremely high flexibility. When the encapsulated body experiences thermal stress due to temperature changes, this stress is transferred to the internal siloxane microdomains. The siloxane segments act like tiny "springs" or "dampers," dissipating macroscopic thermal stress energy through their microscopic thermal motion, thereby preventing crack initiation and propagation. This achieves encapsulation with high heat resistance and high reliability.

[0040] Furthermore, in this embodiment of the invention, the core of the polyether-modified silicon is a Si-O-Si-O-Si structure, with polyether segments disposed at both ends and / or in the middle. Under the traction of the two ends, the polysiloxane segments have a more regular molecular structure, resulting in a denser and more stable adsorption film formed at the interface, which is less susceptible to replacement by new foam and provides long-lasting foam suppression. It also tends to form more uniformly sized and regularly distributed nanospheres, much like a built-in "nanospring array." These regular spherical micro-regions, acting as "stress dissipation points," can uniformly absorb and buffer thermal stress from all directions, effectively suppressing overall warpage and enabling high reliability in semiconductor packaging.

[0041] In this embodiment of the invention, the polyether-modified silicon comprises fumed silica. The surface of fumed silica contains a large number of silanol groups, which can form hydrogen bonds with the polyether segments or siloxane backbone in the polyether-modified silicon molecules to form a composite dispersion system. Silica particles adsorb onto the surface of the bubble liquid film, increasing the local rigidity of the liquid film and making it easier to break. Furthermore, the adsorption layer formed by silica particles at the gas-liquid interface has a high desorption energy barrier, making it difficult to be replaced by newly formed surfactant molecules, thereby significantly prolonging the defoaming time and effectively reducing the bubble defect rate after the composition is cured. In the cured solid package, the composite micro-region formed by fumed silica and polyether-modified silicon further optimizes the stress buffering effect. Silica acts as a rigid core, and polyether-modified silicon acts as a flexible shell, forming a "core-shell" type composite micro-region that combines rigidity and toughness, more effectively absorbing and dispersing thermal stress. Moreover, the low thermal expansion characteristics of silica help to control the thermal expansion behavior of the composite micro-region, making it more compatible with the thermal expansion coefficients of silicon chips, substrates, and other materials, thus improving the overall reliability of semiconductor packaging.

[0042] Furthermore, in this embodiment of the invention, by controlling the molecular weight of the matrix resin to be 15,000-38,000, sufficient entanglement strength of the resin in the uncured state can be ensured, enabling the formation of a uniform, defect-free film. At this molecular weight, the resin backbone has appropriate segment lengths, allowing the polyether-modified silicon polyether flexible segments with a methyl to phenyl ratio of 3:1-5:1 to more effectively penetrate and anchor in the entanglement network of the matrix resin molecular chains. After curing, the inherent heat-resistant framework of the matrix resin is maintained, and the polyether flexible segments entangle with the matrix resin. When subjected to thermal shock, energy is dissipated through segment movement, effectively releasing internal stress and achieving high heat resistance and low stress in the composition, ensuring the reliability of semiconductor packaging. On the other hand, the low molecular weight of the matrix resin prevents the formation of a self-supporting film before curing, avoids flow control issues, and prevents resin run-out before curing, which can lead to uneven composition on the device surface and accumulation of most of the composition in the device gaps, severely affecting the final semiconductor packaging effect. Simultaneously, due to the low molecular weight and excessively short molecular chain segments between crosslinking points, the cured product exhibits poor toughness and high brittleness, making it difficult to effectively buffer thermal stress and prone to cracking of the encapsulation. On the other hand, excessively high molecular weight of the base resin leads to a sharp decrease in its solubility in organic solvents, which is detrimental to the preparation of a uniform coating. Furthermore, it affects the penetration of the flexible polyether segments of the polyether-modified silicone resin (methyl to phenyl ratio of 3:1-5:1) into the base resin network. Therefore, controlling the molecular weight of the base resin within the range of 15,000-38,000 ensures both the overall heat resistance and strength of the composition, as well as uniformity in application. Optionally, the molecular weight of the base resin can be any value or a range of any two values ​​from 15,000, 16,000, 18,000, 20,000, 23,000, 25,000, 28,000, 30,000, 35,000, and 38,000. Preferably, the molecular weight of the matrix resin is 20,000 to 30,000.

[0043] It is worth noting that in the embodiments of the present invention, the curing method can be thermosetting, photocuring, or a combination of both. Thermosetting curing agents include at least one curing agent selected from end-capped isocyanates, polyamines, polyanhydrides, imidazoles, or quaternary ammonium salts; photocuring curing agents include at least one curing agent selected from acrylates and vinyl reactive diluents. Alternatively, rapid shaping can be achieved first through photocuring, followed by deep and complete curing through thermosetting, effectively improving the heat resistance and electrical insulation of semiconductor packaging.

[0044] Furthermore, in this embodiment of the invention, the amount of curing agent is limited to 3-10 parts by weight, ensuring complete curing of the composition and a defect-free crosslinking network, thereby improving the heat resistance and electrical insulation of the semiconductor package. On the one hand, insufficient curing agent will prevent the formation of enough crosslinking points between the resin molecular chains containing imide groups, leading to low crosslinking density, loose network structure, and a significant decrease in glass transition temperature and thermal decomposition temperature. Simultaneously, polyether-modified silicon additives may easily migrate excessively or even precipitate, failing to form a stable nano-stress buffer layer and thus failing to meet the heat resistance requirements of semiconductor packaging. On the other hand, excessive curing agent will also prevent increased curing shrinkage, resulting in significant residual internal stress at the resin / chip and resin / substrate interfaces, causing problems such as package warping, chip cracking, and interface delamination. Furthermore, even with complete curing, excess curing agent or its decomposition products may remain in the composition in small molecule form, potentially migrating to the interface or volatilizing during high-temperature or long-term use, causing device contamination, decreased electrical performance, or reliability issues. Therefore, limiting the amount of curing agent to 3-10 parts by weight ensures complete curing of the composition, a defect-free cross-linked network, and thus improves the heat resistance and electrical insulation of the semiconductor package. Optionally, the amount of curing agent can be any value or a range of any two values ​​from 3, 3.6, 3.8, 4.2, 4.7, 5, 5.2, 5.5, 6, 6.5, 7.2, 8, 8.8, 9, 9.5, and 10.

[0045] Furthermore, in this embodiment of the invention, the resin composition for semiconductor packaging includes 2-6 parts by mass of a curing initiator, which is a composite initiator comprising a first curing initiator and a second curing initiator. By selecting initiator combinations with different activation temperatures or reactivity, a gradient reaction can be achieved during the curing process, allowing the crosslinking reaction to proceed in stages and in an orderly manner. First, the first curing initiator reacts preferentially, and the system undergoes moderate crosslinking, but the viscosity remains at a relatively low level. At this point, the curing reaction begins, and the generated moisture or gas, due to the low viscosity of the system and the relatively free molecular movement, can slowly and uniformly diffuse to the surface or interface and gradually escape from the system. Finally, the second curing initiator begins to react, further increasing the crosslinking density of the system and ultimately forming a dense network structure. At this point, most of the moisture or gas has been discharged in the first stage, leaving very little moisture or gas remaining in the system, and significantly reducing bubble defects. This gradient reaction process decouples the discharge of moisture or gas in time, completing the release of most of the moisture or gas within the window period when the system viscosity is still low and bubbles are easy to escape, thereby more effectively avoiding bubble encapsulation and residue, and improving the electrical insulation performance and long-term reliability of semiconductor packaging.

[0046] It is worth noting that, in the embodiments of the present invention, the resin composition for semiconductor packaging includes 2-6 parts by weight of a curing initiator. Limiting the amount of curing initiator to 2-6 parts by weight ensures that the composition of the present invention achieves comprehensive performance of high heat resistance, low stress, and easy processing. On the one hand, it avoids the problem of insufficient curing initiator dosage leading to insufficient crosslinking reaction within a reasonable curing process window, resulting in low crosslinking density, loose network structure, and a significant decrease in glass transition temperature and thermal decomposition temperature. Simultaneously, polyether-modified silicon additives are prone to excessive migration or even precipitation, failing to form a stable nano-stress buffer layer and thus failing to meet the heat resistance requirements of semiconductor packaging. On the other hand, it avoids the problem of excessive curing initiator dosage, which could lead to increased curing shrinkage, generating significant residual internal stress at the resin / chip and resin / substrate interfaces, causing problems such as package warping and interface delamination. Furthermore, excessive initiator may remain in small molecule form, migrating and volatilizing during high temperatures or long-term use, causing device contamination or decreased reliability. Therefore, by limiting the amount of curing initiator to 2-6 parts by weight, the composition can achieve comprehensive properties such as high heat resistance, low stress, and easy processing. Optionally, the amount of curing initiator can be any value or a range of any two values ​​from 2, 2.5, 3, 3.5, 4, 4.8, 5.2, 5.5, and 6.

[0047] Furthermore, in this embodiment of the invention, the curing initiation temperature of the first curing initiator is 80-100℃, and the curing initiation temperature of the second curing initiator is 120-150℃. By selecting two curing initiators with different thermal decomposition temperatures, during the curing process, the low-temperature initiator decomposes first, initiating the first stage of cross-linking reaction, causing the system to initially gel, but the viscosity remains at a relatively low level. The generated moisture or gas, due to the low viscosity and free molecular movement of the system, can slowly and uniformly diffuse to the surface or interface, gradually escaping from the system. As the temperature increases, the high-temperature initiator gradually decomposes, initiating the second stage of deep cross-linking reaction, further increasing the cross-linking density of the system, ultimately forming a dense network structure. At this point, most of the moisture or gas has been discharged in the first stage, leaving very little moisture or gas remaining in the system, significantly reducing bubble defects, achieving a gradient reaction, and enabling the cross-linking reaction to proceed in stages and in an orderly manner. This more effectively avoids the sealing and residue of bubbles, improving the electrical insulation performance and long-term reliability of semiconductor packaging. For example, the first curing initiator is a combination of azobisisobutyronitrile (AIBN, Td≈50-70℃) and the second curing initiator is dicumyl peroxide (DCP, Td≈120-140℃).

[0048] Furthermore, in this embodiment of the invention, the photoquantum yield of the first curing initiator is 0.4-0.6, and the photoquantum yield of the second curing initiator is 0.2-0.35. It should be noted that the "photoquantum yield" refers to the quantum efficiency by which a photoinitiator, under illumination of a specific wavelength, absorbs a single photon and generates an active species capable of initiating a polymerization reaction; it is defined as the ratio of the number of active species generated to the number of photons absorbed. The first curing initiator, with a photoluminescence quantum yield of 0.4-0.6, can efficiently generate a large number of active species upon light exposure, rapidly initiating cross-linking polymerization of the surface resin, quickly setting the resin, and preventing oxygen-induced polymerization inhibition. The second curing initiator, with a photoluminescence quantum yield of 0.2-0.35, has a slower photolysis rate, allowing light to reach deeper regions after passing through the partially cured surface layer, where free radicals continue to be generated to initiate polymerization. The synergistic gradient curing of the surface and deep layers allows moisture or gas more time to diffuse and escape at a stage where the system viscosity is appropriate. Furthermore, the microporous channels formed by the rapid curing of the surface layer facilitate the outward diffusion of internal moisture, rather than forming a closed, dense layer that traps moisture inside. This effectively reduces the rate of bubble defects, suppresses shrinkage stress, optimizes the network structure, and improves encapsulation reliability.

[0049] It is worth noting that, in this embodiment of the invention, by limiting the photon yield of the first curing initiator to 0.4-0.6 and the photon yield of the second curing initiator to 0.2-0.35, the technical effect of gradient curing can be achieved, effectively reducing the bubble defect rate, suppressing shrinkage stress, optimizing the network structure, and improving packaging reliability. On the one hand, the surface curing speed will not be too slow due to the quantum yield of the first curing initiator being lower than 0.4, which may easily lead to surface stickiness and incomplete curing due to oxygen inhibition; nor will the surface curing be too fast due to the quantum yield of the first curing initiator being higher than 0.6, which may hinder the penetration of deep light and the expulsion of moisture due to premature densification of the surface, thus affecting the overall curing uniformity and packaging reliability. On the other hand, the initiation efficiency will not be too low due to the quantum yield of the second curing initiator being lower than 0.2, making it difficult to achieve complete curing even with sufficient light; nor will the behavior of the second curing initiator being similar to that of the first curing initiator, which makes it impossible to achieve the technical effect of gradient curing, due to the quantum yield of the second curing initiator being higher than 0.35. Therefore, by limiting the photon yield of the first curing initiator to 0.4-0.6 and the photon yield of the second curing initiator to 0.2-0.35, the technical effect of gradient curing can be achieved, effectively reducing the bubble defect generation rate, suppressing shrinkage stress, optimizing the network structure, and improving the packaging reliability.

[0050] In this embodiment of the invention, the volume loss rate of the cured resin composition for semiconductor packaging is 0.3%–3%. By limiting the volume loss rate of the cured composition to 0.3%–3%, the occurrence rate of bubble defects can be controlled, thereby improving the heat resistance and electrical insulation of the semiconductor package. On the one hand, an excessively small volume loss rate will prevent incomplete curing and ensure proper packaging; on the other hand, an excessively large volume loss rate will prevent drastic changes in internal pressure, which could "squeeze" and aggregate gases or volatile small molecules that have not yet escaped, accelerating bubble formation and growth. As the crosslinking reaction proceeds, the viscosity of the system increases rapidly, and bubbles will be "sealed" inside the cured material, forming permanent bubble defects that seriously affect the reliability of the semiconductor package. Therefore, by limiting the volume loss rate of the cured composition to 0.3%–3%, the compression effect of the matrix on the bubble nucleus is weak. Even if a small number of bubble nuclei form, the bubbles are unlikely to grow into visible defects, effectively improving the reliability of the package. Optionally, the volume loss rate of the composition after curing can be any one of 0.3%, 0.8%, 1%, 1.5%, 2%, 2.7% and 3% or a range of any two values.

[0051] In this embodiment of the invention, the viscosity of the composition is 50-20000 cP. By limiting the viscosity of the composition to 50-20000 cP, the composition possesses both good flowability and controllability, making it suitable for various coating processes such as spin coating, spray coating, slot coating, and screen printing. It can obtain a coating film with moderate thickness and good uniformity in one pass. Moreover, within this viscosity range, bubbles generated during the curing process can escape slowly and uniformly, avoiding being trapped and forming internal bubbles or causing surface defects due to excessively rapid evacuation. On the one hand, if the viscosity is too low, the composition will not experience edge sagging or flow into non-target areas after coating, affecting pattern accuracy and packaging size control; nor will it cause excessively fast and violent bubble evacuation, resulting in surface defects in the coating film due to localized impact when bubbles burst. On the other hand, if the viscosity is too high, the composition will not have poor flowability after coating, leading to incomplete gap filling, leaving voids, or even causing bubbles generated during curing to be unable to overcome the viscous resistance of the system and rise to the surface, easily becoming trapped inside the cured material and forming bubble defects. Meanwhile, excessively high viscosity of the composition reduces its wettability to the substrate, potentially leading to poor interfacial bonding and affecting encapsulation reliability. Therefore, this invention limits the viscosity of the composition to 50-20000 cP. The composition exhibits both good flowability and controllability, making it suitable for various coating processes such as spin coating, spray coating, slot coating, and screen printing, enabling the production of a coating with moderate thickness and good uniformity in a single pass. Optionally, the viscosity of the composition can be any value or a range of any two values ​​from 50 cP, 200 cP, 500 cP, 1000 cP, 2000 cP, 4500 cP, 6000 cP, 8000 cP, 10000 cP, 13000 cP, 15000 cP, and 20000 cP. Preferably, the viscosity of the composition is 50-2000 cP.

[0052] Furthermore, in this embodiment of the invention, the composition includes a first solvent and a second solvent, wherein the boiling point of the first solvent is greater than that of the second solvent. By combining a high-boiling-point solvent with a low-boiling-point solvent, a mixed solvent system with a specific evaporation gradient is formed. During coating, the low-boiling-point solvent evaporates first, causing slight surface drying of the composition. This prevents the composition from flowing extensively into the device gaps, leading to uneven surface encapsulation and encapsulation failure. The high-boiling-point solvent prevents excessively rapid evaporation, which could cause curing defects such as bubbles after the composition has cured, affecting encapsulation quality and reliability. Preferably, the first solvent is N-methylpyrrolidone, and the second solvent is ethylene glycol butyl ether acetate.

[0053] It is worth noting that in this embodiment of the invention, the weight ratio of the first solvent to the second solvent is 1-5. By limiting the weight ratio of the first solvent to the second solvent to 1-5, curing defects can be further reduced, the bubble defect rate can be lowered, and the encapsulation effect can be improved. On the one hand, excessive low-boiling-point solvent content will not lead to excessively fast surface drying, resulting in premature densification of the surface layer, preventing the internal solvent and reaction byproducts from escaping and thus forming defects such as pinholes and dark bubbles. On the other hand, excessively high-boiling-point solvent content will not lead to excessively long actual drying time, affecting production efficiency and potentially causing solvent residue, ultimately affecting the electrical reliability of the encapsulation. Therefore, limiting the weight ratio of the first solvent to the second solvent to 1-5 can ensure gradient evaporation, reduce curing defects, lower the bubble defect rate, and improve the encapsulation effect. Optionally, the weight ratio of the first solvent to the second solvent can be any value or a range of any two values ​​from 1, 1.6, 2.8, 3, 4.2, and 5.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows: It provides a resin composition for semiconductor packaging. By using a resin containing imide groups as the matrix and controlling the Tg of the resin to be ≥200℃, it is beneficial to improve the overall heat resistance of the resin composition for semiconductor packaging. At the same time, by using a resin with low CTE, it is avoided that the resin delaminates from the device due to the large coefficient of thermal expansion, thereby ensuring the reliability of semiconductor packaging.

[0055] Furthermore, by introducing polyether-modified silicon containing a specific proportion of methyl and phenyl groups, and by controlling the content of each component, the composition exhibits extremely high heat resistance stability after curing under synergistic effects, and is less prone to generating bubbles and phase separation defects, thereby significantly improving the electrical insulation of the composition and ensuring the reliability of semiconductor packaging.

[0056] The present invention will be further described in detail below with reference to embodiments and comparative examples. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0057] Example 1:

[0058] A resin composition for semiconductor packaging comprises the following components: 100 parts by weight of a polyimide resin with a molecular weight of 15,000, 3 parts by weight of a capped isocyanate, 0.2 parts by weight of a polyether-modified silicone, wherein the side chains or end groups of the polyether-modified silicone contain methyl and phenyl groups, the ratio of methyl to phenyl groups being 3:1, the solvent being N-methylpyrrolidone, and the viscosity being 50 cP.

[0059] Example 2:

[0060] The semiconductor packaging resin composition in this embodiment differs from that in Example 1 in that the mass fraction of the end-capped isocyanate is 5.

[0061] Example 3:

[0062] The semiconductor packaging resin composition of this embodiment differs from that of Example 1 in that the mass fraction of the end-capped isocyanate is 10.

[0063] Example 4:

[0064] The semiconductor packaging resin composition of this embodiment differs from that of Example 1 in that the mass fraction of the polyether-modified silicon is 0.5, and the ratio of the methyl group to the phenyl group is 4:1.

[0065] Example 5:

[0066] The semiconductor packaging resin composition of this embodiment differs from that of Example 1 in that the mass fraction of the polyether-modified silicon is 0.5, and the ratio of the methyl group to the phenyl group is 5:1.

[0067] Example 6:

[0068] The semiconductor packaging resin composition of this embodiment differs from that of Example 1 in that the mass fraction of the polyether-modified silicon is 1, and the ratio of the methyl group to the phenyl group is 4:1.

[0069] Example 7:

[0070] The semiconductor packaging resin composition of this embodiment differs from that of Example 1 in that the molecular weight of the polyimide resin is 38,000.

[0071] Example 8:

[0072] The difference between the semiconductor packaging resin composition in this embodiment and that in Example 1 is that the viscosity of the semiconductor packaging resin composition is 20000 cP.

[0073] Example 9:

[0074] The difference between the semiconductor packaging resin composition of this embodiment and that of Embodiment 1 is that the solvent of the semiconductor packaging resin composition is a composite solvent, including a first solvent and a second solvent. The first solvent is N-methylpyrrolidone, and the second solvent is ethyl acetate. The weight ratio of the N-methylpyrrolidone to the ethyl acetate is 3.

[0075] Comparative Example 1:

[0076] A resin composition for semiconductor packaging comprises the following components: 100 parts by weight of a polyimide resin with a molecular weight of 15,000, 3 parts by weight of a capped isocyanate, 0.2 parts by weight of a polyether-modified silicone, wherein the side chain or end group of the polyether-modified silicone contains methyl and phenyl groups, the ratio of methyl to phenyl groups is 1:8, the solvent is N-methylpyrrolidone, and the viscosity of the resin composition for semiconductor packaging is 50 cP.

[0077] Comparative Example 2:

[0078] The semiconductor packaging resin composition of this comparative example differs from that of Comparative Example 1 in that the ratio of the methyl group to the phenyl group is 10:1.

[0079] Comparative Example 3:

[0080] The semiconductor packaging resin composition of this comparative example differs from that of Comparative Example 1 in that the mass fraction of the end-capped isocyanate is 20, and the ratio of the methyl group to the phenyl group is 3:1.

[0081] Comparative Example 4:

[0082] The semiconductor packaging resin composition of this comparative example differs from that of Comparative Example 1 in that the molecular weight of the polyimide resin is 55,000, and the ratio of the methyl group to the phenyl group is 3:1.

[0083] The number of air bubbles in the semiconductor packaging resin compositions of Examples 1-9 and Comparative Examples 1-4 after curing was evaluated by microscopic observation, and their heat resistance was evaluated by treating them at 300°C for 60 seconds. The evaluation results are shown in Table 1.

[0084] Table 1. Appearance and properties of the semiconductor packaging resin compositions of Examples 1-9 and Comparative Examples 1-4 after curing

[0085]

[0086] As shown in Table 1, by using a resin containing imide groups as the matrix, introducing polyether-modified silicon containing a specific proportion of methyl and phenyl groups, and controlling the content of each component, the composition exhibits extremely high heat resistance stability after curing under synergistic effects, and is less prone to generating bubbles and phase separation defects, which greatly improves the electrical insulation of the composition and thus ensures the reliability of semiconductor packaging.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A resin composition for semiconductor packaging, characterized in that, The resin includes resins containing imide groups, wherein the resin has a Tg ≥ 200 °C and a CTE ≤ 250 ppm / °C.

2. The resin composition for semiconductor packaging according to claim 1, characterized in that, Includes the following components: Matrix resin: 100 parts by weight of a resin containing imide groups; Curing agent: 3-10 parts by weight of curing agent; Additives: 0.1-1 parts by weight of polyether-modified silicone; The polyether-modified silicon has a polysiloxane main chain and polyether segments as side chains. The side chains or end groups of the polysiloxane contain methyl and phenyl groups, and the ratio of methyl to phenyl groups is 3:1 to 5:

1.

3. The resin composition for semiconductor packaging according to claim 1, characterized in that, The molecular weight of the matrix resin is 15,000-38,000.

4. The resin composition for semiconductor packaging according to claim 2, characterized in that, The core of the polyether-modified silicon is a Si-O-Si-O-Si structure, and polyether segments are provided at both ends and / or in the middle of the polyether-modified silicon.

5. The resin composition for semiconductor packaging according to claim 2, characterized in that, The polyether-modified silicon contains fumed silica.

6. The resin composition for semiconductor packaging according to claim 2, characterized in that, It includes 2-6 parts by weight of a curing initiator, wherein the curing initiator includes a first curing initiator and a second curing initiator with different activation conditions.

7. The resin composition for semiconductor packaging according to claim 6, characterized in that, The curing initiation temperature of the first curing initiator is 80-100℃, and the curing initiation temperature of the second curing initiator is 120-150℃.

8. The resin composition for semiconductor packaging according to claim 6, characterized in that, The photon yield of the first curing initiator is 0.4-0.6, and the photon yield of the second curing initiator is 0.2-0.

35.

9. The resin composition for semiconductor packaging according to claim 2, characterized in that, The volume loss rate of the semiconductor packaging resin composition after curing is 0.3%–3%; and / or, The viscosity of the resin composition for semiconductor packaging is 50-20000 cP.

10. The resin composition for semiconductor packaging according to claim 2, characterized in that, The resin composition for semiconductor packaging further includes a first solvent and a second solvent, wherein the boiling point of the first solvent is greater than that of the second solvent.

11. The resin composition for semiconductor packaging according to claim 10, characterized in that, The weight ratio of the first solvent to the second solvent is 1-5.

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