Polyamide-imide resins, resin compositions and semiconductor devices

Abstract

A polyamide-imide resin comprises a structural unit (Ia) represented by the following formula and at least one selected from the group consisting of structural units (IIa), (IIb), and (IIc) represented by the following formula. In structural unit (Ia), X independently represents a hydrogen atom or a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a hydroxyalkyl group. In structural units (IIa), (IIb), and (IIc), S independently represents an alkyl group having 1 to 3 carbon atoms, a represents an integer from 0 to 4, b represents an integer from 0 to 3, and c represents an integer from 0 to 4.

Description

Technical Field

[0001] This embodiment relates to a polyamide-imide resin containing a caloric structure framework. Additionally, this embodiment relates to a resin composition comprising the polyamide-imide resin and a semiconductor device using the resin composition. Prior Technology

[0002] One of the main causes of global warming is carbon dioxide (CO2) emissions from various industrial equipment. Therefore, addressing global warming requires building a low-carbon society. One method to achieve this is the application of power semiconductors in industrial equipment to reduce power loss. Power semiconductors are also suitable for various applications, including automobiles, and demand is increasing. Examples of power semiconductors used in automobiles include power cards, as well as transistor outline (TO) packages, small outline packages (SOPs), quad flat packages (QFPs), ball grid array (BGA) packages, and chip scale packages (CSPs).

[0003] In recent years, especially with the electrification of automobiles (EVs), the power density of power semiconductors has increased, leading to a rise in the operating temperature (Tj) of the devices. Consequently, the required temperature for thermal cycling tests has also increased. However, in existing power semiconductors, during high-temperature (high Tj) thermal cycling tests assuming a driving temperature, delamination sometimes occurs between components such as the resin sealant layer and the interface between the substrate or semiconductor element. In semiconductor devices, delamination between components can lead to malfunctions, thus significantly reducing the reliability of the semiconductor device.

[0004] To address the increasing heat transfer temperature (Tj) of power semiconductor devices, various studies have been conducted on resin sealing materials that constitute the resin sealing layer. For example, efforts are being made to develop resin sealing materials with excellent heat resistance; these materials exhibit excellent heat resistance even in high-temperature regions exceeding 200°C, despite glass transition temperatures exceeding 230°C. However, on the other hand, as the resin hardens, the adhesion to components decreases, potentially reducing the reliability of the semiconductor device. Furthermore, delamination between components can sometimes occur during the reflow process when mounting the device. Therefore, from the viewpoint of improving the reliability of semiconductor devices, in order to suppress the peeling between components during high-temperature thermal cycling tests and reflow processes, a method to improve the tightness between components in semiconductor devices is desired.

[0005] In contrast, a method is known to improve the adhesion between components of a semiconductor device by forming an undercoat made of a resin material between the components, thereby preventing peeling. For example, a method is being investigated to suppress peeling by providing an undercoat made of polyamide-imide resin between a metal lead frame and a sealing material (Patent Document 1). [Existing Technical Documents] [Patent Literature]

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-135061 Summary of the Invention

[0007] [The problem that the invention aims to solve]

[0008] However, with the increasing Tj of power semiconductor devices, the conditions required for reliability testing of semiconductor devices have become more stringent, and existing resin materials are insufficient to fully meet these requirements. Therefore, from the perspective of providing highly reliable power semiconductors, there is a continued expectation to develop a resin material with excellent heat resistance, such as one that can prevent delamination between components even in high-temperature regions exceeding 250°C.

[0009] Therefore, in view of the above situation, the present invention provides a resin material with excellent heat resistance, which can improve the adhesion between components and suppress the occurrence of peeling, and is particularly suitable as a base coating forming material disposed between components of a semiconductor device. [Methods for solving problems]

[0010] From the perspective of improving delamination between components during thermal cycling tests in high-temperature regions, the resin material forming the undercoat preferably has a glass transition temperature (Tg) that is higher than the upper limit of the driving temperature (Tj) of the power semiconductor. Generally, it is known that resins soften at temperatures exceeding their Tg, resulting in reduced adhesion. Therefore, when the resin's Tg is lower than the driving temperature of the power semiconductor, the heat resistance becomes insufficient, making it difficult to ensure adhesion between components. As a result, for example, delamination may occur between the resin sealant and the substrate or semiconductor element.

[0011] The inventors have conducted extensive research on polyamide-imide resins and their resin compositions as resin materials, and have found that polyamide-imide resins with a caloric structure backbone have high Tg. Furthermore, they have discovered that when the polyamide-imide resin with the specific structural unit or a resin composition containing the resin is used to form an undercoat between components, such as between a resin sealing layer and a substrate or semiconductor element, excellent adhesion between components can be obtained, thus completing the present invention.

[0012] That is, the embodiments of the present invention relate to the following. However, the present invention is not limited to the following embodiments, and various modifications can be made.

[0013] One embodiment relates to a polyamide imide resin comprising a structural unit (Ia) represented by the following formula and at least one selected from the group consisting of structural units (IIa), (IIb) and (IIc) represented by the following formula. [Chemistry 1] [Chemistry 2]

[0014] In the above formula (Ia), X independently represents a hydrogen atom, or a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a hydroxyalkyl group. In formulas (IIa), (IIb) and (IIc) above, S independently represents an alkyl group having 1 to 3 carbon atoms, a represents an integer from 0 to 4, b represents an integer from 0 to 3, and c represents an integer from 0 to 4.

[0015] The polyamide-imide resin preferably further comprises the structural unit (IIIa) represented by the following formula. [Chemistry 3]

[0016] In formula (IIIa) above, R independently represents a hydrogen atom, or a substituent selected from the group consisting of alkyl groups with 1 to 9 carbon atoms, alkoxy groups with 1 to 9 carbon atoms, and halogen atoms, and n represents an integer from 1 to 6.

[0017] The polyamide-imide resin preferably has a linear expansion coefficient of 40 ppm / ℃ to 70 ppm / ℃.

[0018] In the polyamide imide resin, based on the total amount of the structural unit (Ia) and at least one selected from the group consisting of the structural units (IIa), (IIb) and (IIc), the proportion of the structural unit (Ia) is 20 mol% or more.

[0019] The polyamide-imide resin preferably has a glass transition temperature of 250°C or higher. More preferably, the polyamide-imide resin has a glass transition temperature of 300°C or higher.

[0020] Another embodiment relates to a polyamide-imide resin composition comprising the polyamide-imide resin of the embodiment and a solvent. The polyamide-imide resin composition preferably further comprises a coupling agent.

[0021] Another embodiment relates to a semiconductor device, including a substrate and a film formed using the polyamide-imide resin composition of the embodiment. The semiconductor device preferably further includes a resin sealing layer. The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2021-34526, filed on March 4, 2021, the contents of which are incorporated herein by reference. [The effects of the invention]

[0022] According to the present invention, a resin material with excellent heat resistance, which can improve the adhesion between components to suppress delamination at high temperatures, and which can be preferably used as an undercoating material between components in semiconductor devices can be provided. Simple Explanation of the Diagram

[0023] Figure 1 is a schematic cross-sectional view showing an example of a semiconductor device as one embodiment. Implementation

[0024] The preferred embodiments of the present invention will now be described in detail. However, the present invention is not limited to these embodiments.

[0025] <Polyamide-imide resin> In one embodiment, the polyamide-imide resin comprises the structural unit (Ia) described later and at least one selected from the group consisting of structural units (IIa), (IIb), and (IIc). Details of each structural unit are described below.

[0026] The structural unit (Ia) is represented by the following formula. [Chemistry 4]

[0027] In the structural unit (Ia), X may be the same or different from each other. X independently represents a hydrogen atom, or a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a hydroxyalkyl group. The halogen atom may be a fluorine atom, a chlorine atom, or a bromine atom. The alkyl group and the alkoxy group may be any of a straight-chain structure, a branched structure, and a cyclic structure.

[0028] In one embodiment, X is preferably a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, or a halogen atom. The alkyl group is more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms. In one embodiment, X is preferably a hydrogen atom.

[0029] Structural unit (IIa), structural unit (IIb), and structural unit (IIc) are represented by the following formulas. [Chemistry 5]

[0030] In the structural units (IIa), (IIb), and (IIc), S independently represents an alkyl group having 1 to 3 carbon atoms, a represents an integer from 0 to 4, b represents an integer from 0 to 3, and c represents an integer from 0 to 4. The alkyl group can be either a straight-chain structure or a branched structure, preferably a straight-chain structure. The alkyl group preferably has 1 or 2 carbon atoms. When the alkyl group is a straight-chain structure, especially when it is an alkyl group with 1 or 2 carbon atoms, there is a tendency to easily obtain a resin with a rigid structure. By using a resin with a rigid structure to form a film, there is a tendency to easily suppress the coefficient of thermal expansion (CTE). By suppressing the CTE of the film to a low level, for example in the operating environment of a semiconductor device, it is easy to minimize the difference in CTE between the film and other components. As a result, for example in a semiconductor device, there is a tendency to reduce thermal stress and easily improve the reliability of the semiconductor device.

[0031] In one embodiment, the structural unit (IIa), structural unit (IIb), or structural unit (IIc) may be derived using a diamine compound or a diisocyanate compound having the corresponding structures. While not particularly limited, the following compounds are specific examples of diamine compounds capable of deriving the structural units (IIa), (IIb), and (IIc). The amino groups shown in the following compounds may also be substituted with isocyanate groups. [Chemistry 6]

[0032] [Chemistry 7]

[0033] [Chemistry 8]

[0034] In one embodiment, the value of 'a' in structural unit (IIa) is preferably 0 to 3, more preferably 0 to 2, further preferably 0 or 1, and most preferably 0. The value of 'b' in structural unit (IIb) is preferably 0 to 2, more preferably 0 or 1, and most preferably 0. The value of 'c' in structural unit (IIc) is preferably 0 to 3, more preferably 0 to 2, further preferably 0 or 1, and most preferably 0. When the number of substituents in the structural unit (IIa), structural unit (IIb), or structural unit (IIc) is less, especially when there is no substitution (i.e., when a, b, or c is 0), there is a tendency to easily obtain a resin with a rigid structure. By using a resin with a rigid structure to form a film, there is a tendency to easily suppress the coefficient of linear expansion (CTE). By suppressing the CTE of the film to a low level, for example in the use environment of a semiconductor device, it is easy to minimize the difference in CTE with other components. As a result, for example in a semiconductor device, there is a tendency to reduce thermal stress and easily improve the reliability of the semiconductor device.

[0035] In accordance with the aforementioned viewpoint, in one embodiment, the polyamide-imide resin is preferably comprised of at least one of the group consisting of the structural unit (Ia) and structural units (IIa-1), (IIb-1), and (IIc-1) represented by the following formulas. While not particularly limited, it is more preferably a structure in which two bonding sites (indicated by "*") of other structural parts are in a para-position relationship.

[0036] [Chemistry 9]

[0037] Polyamide-imide resins are resins having amide and amide bonds within their molecular backbone, obtained, for example, by reacting a diamine component or a diisocyanate component with an acid component such as a tricarboxylic anhydride. From this perspective, in one embodiment, a polyamide-imide resin comprising at least one of the structural units (Ia), (IIa), (IIb), and (IIc) can be derived using a compound represented by formula (I), and at least one compound represented by formulas (IIA), (IIB), and (IIC). Structural unit (Ia), structural units (IIa), (IIb), and (IIc) are respectively equivalent to the residues after removing the substituent Y (amine or isocyanate group) from the compounds represented by formulas (I), (IIA), (IIB), and (IIC). In the structure of the resin, they can be directly bonded to amide or amide-imine bond sites.

[0038] [Chemistry 10]

[0039] In formula (I), Y is an amino group (-NH₂) or an isocyanate group (-NCO). Additionally, X is as previously described in item (Ia).

[0040] [Chemistry 11]

[0041] In formulas (IIA), (IIB), and (IIC), Y is an amino group (-NH₂) or an isocyanate group (-NCO). Additionally, S, a, b, and c are as previously described.

[0042] Specific examples of compounds represented by formula (I) include: 9,9-bis(4-aminophenyl)furan, 9,9-bis(4-amino-3-methylphenyl)furan, 9,9-bis(4-amino-3-chlorophenyl)furan, and 9,9-bis(4-amino-3-fluorophenyl)furan. These are preferably used as diamine compounds capable of deriving structural unit (Ia).

[0043] Specific examples of compounds represented by formula (IIA) include 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, and 3,3'-diaminodiphenylmethane. These are preferably used as diamine compounds capable of deriving the structural unit (IIa-1).

[0044] Specific examples of compounds represented by formula (IIB) include 1,5-naphthyldiamine and 1,8-naphthyldiamine. These are preferably used as diamine compounds capable of deriving the structural unit (IIb-1).

[0045] Specific examples of compounds represented by the formula (IIC) include 1,3-phenylenediamine and 1,4-phenylenediamine. These are preferably used as diamine compounds capable of deriving the structural unit (IIc-1).

[0046] For example, from the viewpoint of suppressing delamination between components at the drive temperature (Tj) or reflow temperature of power semiconductors, polyamide-imide resin preferably has a glass transition temperature that is higher than the upper limit of Tj or reflow temperature. In this specification, "glass transition temperature (Tg)" refers to the value obtained using a thermomechanical analysis apparatus after coating and heating a film obtained by dissolving a resin in a solvent.

[0047] In one embodiment, it is assumed that the thermal cycling test for increasing the driving temperature (high Tg) of the power semiconductor is performed at a temperature of 175°C or higher. Furthermore, the test is performed at a high temperature of approximately 260°C during semiconductor mounting and reflow. Therefore, in one embodiment, the Tg of the polyamide-imide resin is preferably 250°C or higher. More preferably, the Tg of the polyamide-imide resin is 270°C or higher, further preferably 290°C or higher, and even more preferably 300°C or higher.

[0048] During the reflow process of the installation device, the peeling between components is caused by the stress generated by the rapid vaporization of moisture contained in the device and the stress caused by the difference in linear expansion between the components, which exceeds the bonding force between the components. In one embodiment, from the viewpoint of suppressing peeling during the reflow process, the Tg of the polyamide-imide resin is preferably 300°C or higher, and more preferably 320°C or higher.

[0049] According to the polyamide-imide resin of the embodiment described above, a temperature Tg of 250°C or higher can be easily obtained. In the polyamide-imide resin of the embodiment described above, it is believed that the presence of a skeleton known as a caloric structure in the structural unit (Ia) contributes to the increase in Tg. Furthermore, it is speculated that the presence of structural units (IIa), (IIb), and (IIc) in the resin can further increase the Tg. In addition, when using polyamide-imide resin to form a film, there is a tendency to easily adjust the film's physical properties such as CTE, elastic modulus, and adhesion to the substrate. For example, by adjusting the mixing ratio of structural unit (Ia) to structural units (IIa), (IIb), and (IIc), the desired film physical properties such as Tg, CTE, elastic modulus, and adhesion can be easily obtained. As a result, when the polyamide-imide resin of the aforementioned embodiment is used as a constituent material of the semiconductor device, the reliability of the semiconductor device can be easily improved.

[0050] Generally, films made of resins with high Tg tend to have reduced flexibility. When the film has low flexibility, it cannot mitigate stress generated within the semiconductor device and is prone to peeling. From this perspective, in one embodiment, the polyamide-imide resin preferably includes the structural unit (IIIa) represented by the following formula. It can be considered that by using the polyamide-imide resin of the aforementioned embodiment, which has more structural unit (IIIa), a film with improved flexibility and excellent suppleness can be easily obtained.

[0051] [Chemistry 12]

[0052] In structural unit (IIIa), R independently represents a hydrogen atom, or a substituent selected from the group consisting of an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a halogen atom. The halogen atom may be a fluorine atom, a chlorine atom, or a bromine atom. The alkyl group and the alkoxy group may be any of a straight-chain structure, a branched structure, or a cyclic structure. In one embodiment, R is preferably an alkyl group having 1 to 9 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms. n represents an integer from 1 to 6. Ideally, n should be an integer from 2 to 4, and even better, 3 or 4.

[0053] In one embodiment, the structural unit (IIIa) can be derived using a compound represented by formula (III). The structural unit (IIIa) is equivalent to the residue after removing the substituent Y (amino or isocyanate group) from the compound represented by formula (III), and can be directly bonded to the amide or amide bond site in the structure of the resin. [Chemistry 13]

[0054] In formula (III) above, Y is an amino group (-NH 2) or an isocyanate group (-NCO), and R and n are as previously explained.

[0055] Specific examples of compounds represented by formula (III) above include: 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(2-aminoethyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(aminomethyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(4-aminobutyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(5-aminopentyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(6-aminohexyl)-1,1,3,3-tetramethyldisiloxane, etc.

[0056] As described above, the polyamide-imide resin of the aforementioned embodiment can be considered to have a structural unit (IIIa) further comprising a structural unit (Ia) in combination with at least one of the group consisting of structural units (IIa), (IIb), and (IIc). This allows for a good balance between a high glass transition temperature (Tg) and resin flexibility. Therefore, for example, when the undercoating layer disposed between the components of a semiconductor device comprises the polyamide-imide resin of the aforementioned embodiment, excellent adhesion can be easily obtained even in tests conducted in high-temperature regions above 250°C. Furthermore, when the constituent material of the power semiconductor device includes the polyamide-imide resin of the embodiment described above, it is possible to suppress the softening of the resin and the reduction of its adhesion due to heat generated during operation. Therefore, high reliability can be obtained in power semiconductor devices using the polyamide-imide resin of the embodiment described above.

[0057] In polyamide-imide resins, the proportion of structural units (Ia) relative to the total amount of structural units derived from diamine and / or diisocyanate components can be 10 mol% or more, 15 mol% or more, 18 mol% or more, 30 mol% or more, 40 mol% or more, 45 mol% or more, 55 mol% or more, 65 mol% or more, or 70 mol% or more. The proportion of structural units (Ia) can be 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, or 75 mol% or less. In one embodiment, the proportion of the structural unit (Ia) can be 10 mol% to 95 mol%, preferably 15 mol% to 95 mol%, more preferably 45 mol% to 90 mol%, even more preferably 55 mol% to 85 mol%, and even more preferably 65 mol% to 80 mol%.

[0058] In one embodiment, the total proportion of structural unit (Ia) and the proportion of at least one of structural units (IIa), (IIb), and (IIc), which are derived from diamine and / or diisocyanate components, can be 70 mol% or more, 80 mol% or more, 85 mol% or more, 90 mol% or more, or 100 mol%. In another embodiment, the total proportion can be 95 mol% or less. In one embodiment, based on the total amount of the structural unit (Ia) and at least one selected from the group consisting of the structural units (IIa), (IIb), and (IIc), the proportion of the structural unit (Ia) may be 20 mol% or more. The proportion of the structural unit (Ia) may preferably be 45 mol% or more, more preferably 50 mol% or more, even more preferably 80 mol% or more, and even more preferably 85 mol% or more.

[0059] On the other hand, relative to the total amount of structural units derived from diamine and / or diisocyanate components, the proportion of at least one of structural units (IIa), (IIb), and (IIc) is preferably 10 mol% or more. In one embodiment, the proportion is preferably 10 mol% to 80 mol%, more preferably 12 mol% to 65 mol%, and even more preferably 15 mol% to 50 mol%. Furthermore, the aforementioned proportion, when the polyamide imide resin contains two or more structural units (IIa), (IIb), and (IIc), refers to the total proportion of these.

[0060] In polyamide-imide resin, based on the total amount of all structural units constituting the resin, the sum of the proportion of the structural unit (Ia) and the proportion of at least one of (IIa), (IIb), and (IIc) is preferably 35 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Here, the proportion (mol%) of each structural unit can be calculated based on the number of mol of the monomer compound corresponding to each structural unit.

[0061] In another embodiment, the polyamide-imide resin preferably further comprises structural unit (IIIa). In one embodiment, the proportion of structural unit (IIIa) relative to the total amount of structural units derived from the diamine component and / or diisocyanate component may be 20 mol% or less, 15 mol% or less, or 10 mol% or less. The proportion of said structural unit (IIIa) may be 2.5 mol% or more, 5.0 mol% or more, or 7.5 mol% or more. In the aforementioned embodiment, the proportion of structural unit (Ia), the proportion of at least one of structural unit (IIa), structural unit (IIb), and structural unit (IIc), and the proportion of structural unit (IIIa) can be 75 mol% or more, 80 mol% or more, 85 mol% or more, 90 mol% or more, 95 mol% or more, or 100 mol% as structural units derived from diamine and / or diisocyanate components. In the described embodiment, the proportion of the structural unit (IIIa) is preferably 2.5 mol% to 20 mol%, more preferably 5 mol% to 15 mol%, and even more preferably 7.5 mol% to 10 mol%. By adjusting the proportion of the structural unit (IIIa) to the range described above, the characteristics produced by the structural unit (Ia) and at least one of the structural units (IIa), (IIb), and (IIc) can be readily expressed.

[0062] In another embodiment, the polyamide imide resin may further include, in addition to the structural unit (Ia), at least one selected from the group consisting of the structural unit (IIa), structural unit (IIb) and structural unit (IIc), and the structural unit (IIIa) as needed, additional structural units beyond these structural units. The additional structural unit may be a structural unit derived from an aromatic diamine or aromatic diisocyanate, an aliphatic diamine or aliphatic diisocyanate, or an alicyclic diamine or alicyclic diisocyanate, having a structure different from that of the structural units (Ia), (IIa), (IIb), (IIc), and (IIIa). The proportion of this additional structural unit relative to the total amount of structural units derived from diamine and / or diisocyanate components is preferably 20 mol% or less. More preferably, the proportion of the additional structural unit is 10 mol% or less, and even more preferably 5 mol% or less.

[0063] As an example of aromatic diamines (diisocyanates) capable of deriving additional structural units, the following can be cited: 2,7-Diaminophen, 9,9-Bis[4-(4-aminophenoxy)phenyl]-9H-fu, 2,2'-Di-trifluoromethyl-4,4'-diaminobiphenyl, 4,4'-Diaminodiphenylamine 3,3'-Diaminodiphenyl sulfonium, 4,4'-Diamino-2,2'-Biphenyldisulfonic acid, 3,4'-Diaminodiphenyl ether, Bis[4-(4-aminophenoxy)phenyl] ion, Bis[4-(3-aminophenoxy)phenyl] ion, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,4-Bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 2,2-Bis(4-aminophenyl)hexafluoropropane, 1,4-Phenylenediamine, 2-Chloro-1,4-phenylenediamine, 1,3-phenylenediamine, 4,4'-Diaminobenzophenone 3,3'-Diaminobenzophenone 3,4'-Diaminodiphenylmethane, 4,4'-Diaminobenzoniline, 3,6-Diaminocarbazole, 4,4'-bis(4-aminophenoxy)biphenyl, 2-Trifluoromethyl-1,4-diaminobenzene, 2,2-Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-Bis(4-aminophenyl)hexafluoropropane, 2,2'-Bis(trifluoromethyl)benzidine, 2,2'-Di-trifluoromethyl-4,4'-diaminodiphenyl ether, 4-Aminophenyl sulfide, 4,4'-Diamino-3,3'-Dimethylbiphenyl, Naphthyldiamine, Naphthalene diisocyanate.

[0064] Examples of aliphatic diamines (diisocyanates) capable of deriving additional structural units include: 1,4-Cyclohexanediamine, 1,3-Cyclohexanediamine, 1,4-Di(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, Bis(aminomethyl)norbornene, 4,4'-Methylenebis(cyclohexylamine), Hexamethylenediamine Hexamethylene diisocyanate.

[0065] In one embodiment, when a diamine is used in the manufacture of polyamide-imide resin, an aliphatic or aromatic tricarboxylic acid anhydride can be used. From the viewpoint of heat resistance, it is preferable to use an aromatic tricarboxylic acid anhydride. In one embodiment, for example, as the acid component, an acidic halide of trimellitic anhydride is preferred. Particularly preferred is the use of trimellitic anhydride chloride represented by formula (IV). [Chemistry 14]

[0066] In view of the aforementioned viewpoint, in one embodiment, the polyamide imide resin preferably comprises a structural unit represented by the following formula (IVa), which can be derived from the reaction of an acidic halide of trimellitic anhydride with a diamine component. [Chemistry 15] In one embodiment, based on the total amount of structural units derived from the acid component, the proportion of structural units derived from formula (IV) above is preferably 50 mol% or more, more preferably 75 mol% or more, and even more preferably 90 mol% or more. That is, in one embodiment, based on the total mass of the acid component, the content of acidic halides of trimellitic anhydride is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 90% by mass or more. In one embodiment, the proportion of structural units derived from formula (IV) above can be 100 moles relative to the total amount of acid components. That is, in one embodiment, the content of acidic halides of trimellitic anhydride can be 100 by mass based on the total mass of acid components.

[0067] In one embodiment, the polyamide-imide resin may be a resin obtained by using a compound represented by formula (I) above and a compound selected from the group consisting of formulas (IIA), (IIB) and (IIC) above as a diamine component or a diisocyanate component, and using the compound represented by (IV) above as an acid component. In another embodiment, it may also be a resin obtained by further adding a compound represented by formula (III) as a diamine component or a diisocyanate component. In yet another embodiment, the polyamide-imide resin may also be a resin obtained by further using an acid component other than the compound represented by formula (IV) above as an acid component.

[0068] The acid components that can be used may include, for example, the tricarboxylic anhydrides or their acidic halides other than those represented by formula (IV) above, and tricarboxylic acids such as trimellitic acid. Additionally, as acid components, tetracarboxylic anhydrides such as pyromellitic dianhydride and biphenyltetracarboxylic dianhydride, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid may be used.

[0069] The weight-average molecular weight (Mw) of the polyamide-imide resin is preferably in the range of 30,000 to 120,000. Polyamide-imide resins with Mw within this range readily form coatings of the preferred film thickness described later during coating operations. The Mw of the polyamide-imide resin is more preferably in the range of 35,000 to 110,000, and even more preferably in the range of 38,000 to 100,000. The "Mw" used in this specification is a value determined using gel permeation chromatography and converted to standard polystyrene.

[0070] From the viewpoint of workability during film formation, the polyamide-imide resin is preferably soluble in an organic solvent at room temperature. In this specification, "soluble in an organic solvent at room temperature" means that when an organic solvent is added to the resin at room temperature and stirred, the resulting solution, visually confirmed, is free of precipitates, turbidity, and is entirely transparent. Here, "room temperature" can be approximately in the range of 10°C to 40°C, preferably in the range of 20°C to 30°C. In one embodiment, the "solution" refers, for example, to a solution obtained by adding 1 g to 30 g of the resin powder to 100 mL of organic solvent. The organic solvent will be described later.

[0071] (Manufacturing method of polyamide-imide resin) Polyamide-imide resins can be manufactured using known methods, and there are no particular limitations. For example, polyamide-imide resins can be manufactured by reacting a diamine component and / or a diisocyanate component with an acid component. The diamine component, diisocyanate component, and acid component are as previously described. The reaction can be carried out under solvent-free conditions or in the presence of an organic solvent. The reaction temperature is preferably in the range of 25°C to 250°C. The reaction time can be appropriately adjusted according to the batch size, the reaction conditions used, etc.

[0072] There are no particular restrictions on the organic solvents (reaction solvents) used in the manufacture of polyamide-imide resins. Examples of usable organic solvents include: ether-based solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether; sulfur-based solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfoxide, and cyclobutane sulfoxide; cyclic ester-based (lactone-based) solvents such as γ-butyrolactone; non-cyclic ester-based solvents such as acetic acid cellosol; ketone-based solvents such as cyclohexanone and methyl ethyl ketone; nitrogen-based solvents such as N-methyl-2-pyrrolidone, dimethyl acetamide, and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone; and aromatic hydrocarbon-based solvents such as toluene and xylene. One of these organic solvents may be used alone, or two or more may be used in combination. In one embodiment, it is preferable to use an organic solvent capable of dissolving the generated resin, and more preferably a polar solvent. Polar solvents will be described later; for example, nitrogen-containing solvents are preferred.

[0073] In one embodiment, polyamide-imide resin can be manufactured by the following method: first, a precursor of polyamide-imide resin is prepared by reacting an acid component with a diamine component; then, the precursor is dehydrated and ring-closed to obtain the polyamide-imide resin. However, the ring-opening method of the precursor is not particularly limited, and methods well known in the art can be used. For example, a thermal ring-closure method can be used, in which dehydration and ring-closure are performed by heating under normal or reduced pressure; a chemical ring-closure method can be used, in the presence or absence of a catalyst, using a dehydrating agent such as acetic anhydride, etc.

[0074] In the case of the thermal closed-loop method, it is preferable to remove the water produced in the dehydration reaction to the outside of the system while simultaneously carrying out the dehydration reaction. During the dehydration reaction, the reaction solution can be heated to 80°C~400°C, preferably 100°C~250°C. Alternatively, organic solvents such as benzene, toluene, and xylene, which can azeotropically react with water, can be used to remove the water through azeotropic reaction.

[0075] In the case of a chemical cyclization method, the reaction can be carried out in the presence of a chemical dehydrating agent at a temperature of 0°C to 120°C, preferably 10°C to 80°C. As a chemical dehydrating agent, preferably, acid anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, and benzoic anhydride; or carbodiimide compounds such as dicyclohexylcarbodiimide. Preferably, it is a substance that promotes the cyclization reaction of pyridine, isoquinoline, trimethylamine, triethylamine, aminopyridine, imidazole, etc., during the reaction.

[0076] Relative to the total amount of diamine, chemical dehydrating agents can be used at a ratio of 90 mol% to 600 mol%, while substances that promote cyclization reactions can be used at a ratio of 40 mol% to 300 mol%. Additionally, dehydrating catalysts such as triphenyl phosphite, tricyclohexyl phosphite, triphenyl phosphate, phosphoric acid, phosphorus pentoxide, and boron compounds such as boric acid and boric anhydride can also be used.

[0077] In the manufacture of polyamide-imide resin, the ratio (molar ratio) of acid component to diamine component (diisocyanate component) is not particularly limited and can be adjusted precisely according to the reaction method. In one embodiment, from the viewpoint of the molecular weight and degree of crosslinking of the resulting polyamide-imide resin, relative to the total amount of acid component (1.00 moles), it is preferable to set the total amount of diamine component to 0.90 moles to 1.10 moles, more preferably to 0.95 moles to 1.05 moles, and even more preferably to 0.97 moles to 1.03 moles.

[0078] <Polyamide-imide resin composition> In one embodiment, the polyamide-imide resin composition (hereinafter, sometimes simply referred to as the resin composition) comprises the polyamide-imide resin of the embodiment and a solvent. In this specification, the resin composition is sometimes also referred to as a varnish. (solvent) The solvent can be any solvent capable of dissolving polyamide-imide resin, and there are no particular limitations. A "solvent capable of dissolving polyamide-imide resin" refers to a solvent in which, under conditions where the temperature of the solvent is not particularly limited, polyamide-imide resin powder is added to the solvent and stirred; when the resulting solution is visually observed, no precipitation or turbidity is observed, and the solution becomes completely transparent. In one embodiment, the solvent constituting the resin composition can be the same as the reaction solvent used in manufacturing the resin. A polar solvent is particularly preferred.

[0079] Examples of polar solvents include: nitrogen-containing compounds such as N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and 1,3-dimethyltetrahydro-2(1H)-pyrimidinone; sulfur-containing compounds such as cyclobutane and dimethyl sulfoxide; lactones such as γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-heptyllactone, α-acetyl-γ-butyrolactone, and ε-caprolactone; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetophenone; non-cyclic esters such as acetic acid cellosol; ethylene glycol; glycerol; and compounds including diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethyl sulfadiazine. Diethylene glycol dialkyl ethers such as ethylene glycol dipropyl ether and diethylene glycol dibutyl ether; triethylene glycol dialkyl ethers such as triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dipropyl ether and triethylene glycol dibutyl ether; tetraethylene glycol dialkyl ethers such as tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dipropyl ether and tetraethylene glycol dibutyl ether; diethylene glycol monomethyl ether and diethylene glycol monoethyl ether; triethylene glycol monoalkyl ethers such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether; and ethers of tetraethylene glycol monoalkyl ethers such as tetraethylene glycol monomethyl ether and tetraethylene glycol monoethyl ether.

[0080] In one embodiment, the solvent is preferably selected from at least one group consisting of diethylene glycol dimethyl ether, triethylene glycol, triethylene glycol dimethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, cyclopentanone, cyclohexanone, tetrahydrofuran, 1,4-dioxane, dibutyl ether, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolinone, dimethyl acetamide, N,N-dimethylformamide, ethyl carbonate, propyl carbonate, and propylene glycol methyl acetate. When two or more solvents are used in combination, they can be mixed in any proportion.

[0081] From the viewpoint of film-forming properties, solvents with relatively low boiling points are preferred. For example, diethylene glycol dimethyl ether, triethylene glycol, and triethylene glycol dimethyl ether are preferred.

[0082] The amount of solvent in the resin composition can be adjusted appropriately considering viscosity. While not particularly limited, in one embodiment, the amount of solvent is preferably prepared at a ratio of 500 to 3,500 parts by mass relative to 100 parts by mass of the total resin in the resin composition. More preferably, the solvent is prepared at a ratio of 500 to 2,000 parts by mass relative to 100 parts by mass of the total resin.

[0083] (additive) Compared to the polyamide-imide resin composition (varnish), additional components such as colorants, coupling agents, and resin modifiers may be added as needed. When the polyamide-imide resin composition includes additional components, the amount of the additional component is preferably 50 parts by weight or less, relative to 100 parts by weight of the total amount of polyamide-imide resin (solid component) in the polyamide-imide resin composition. By setting the amount of the additional component to 50 parts by weight or less, it is easier to suppress the reduction of the physical properties of the obtained coating film.

[0084] In one embodiment, the polyamide-imide resin composition may also include a coupling agent. Examples of usable additional components are given below. (Coupling agent) There are no particular limitations on the coupling agents that can be used; they can be any of the silane-based, titanium-based, or aluminum-based systems, but silane-based coupling agents are preferred. As for silane-based coupling agents, there are no particular limitations; examples include: vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β-(aminoethyl)γ-aminopropyltrimethoxysilane. Alkane, N-β-(aminoethyl)γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureopropyltriethoxysilane, 3-ureopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl-tris[2-(2-methoxyethoxy)ethoxy]silane, N-methyl-3-aminopropyltrimethoxysilane, triaminopropyl-trimethoxysilane, 3-4,5- Dihydroimidazol-1-yl-propyltrimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-mercaptopropyl-methyldimethoxysilane, 3-chloropropyl-methyldimethoxysilane, 3-chloropropyl-dimethoxysilane, 3-cyanopropyl-triethoxysilane, hexamethyldisilazane, N,O-bis(trimethylsilyl)acetamide, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, pentyltrichlorosilane, octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane (methacryloxyethoxy)silane, methyltris(glycidoxy)silane, N-β(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate, methylsilyl triisocyanate, vinylsilyl triisocyanate, phenylsilyl triisocyanate, tetraisocyanate silane, ethoxysilane isocyanate, etc. One of these can be used alone, or two or more can be used in combination.

[0085] There are no particular limitations on its use as a titanium-based coupling agent. Examples include: isopropyl trioctyl titanate, isopropyl dimethacrylate isostearyl titanate, isopropyl tri-dodecylbenzenesulfonyl titanate, isopropyl isostearyl diacrylate titanate, isopropyl tris(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, isopropyl tris(n-aminoethyl) titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(di-tetranyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(di-tetranyl) phosphite titanate, dicumylphenyloxyacetate titanate, bis(dioctyl pyrophosphate) titanate, and bis(dioctyl phosphite) titanate. Phosphate ester (P-O-acetate) titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, acetyl acetone titanium, polyacetyl acetone titanium, octyl glycol titanium, titanium ammonium lactate, titanium lactate, titanium ethyl lactate, triethanolamine titanium, polyhydroxystearate titanium, tetramethyl orthotitanate, tetraethyl orthotitanate, tetrapropyl orthotitanate, tetraisobutyl orthotitanate, stearyl titanate, toluene titanate monomer, toluene titanate polymer, diisopropoxy-bis(2,4-pentanedione)titanium(IV), diisopropyl-bis-triethanolamine titanate, octyl glycol titanate, tetra-n-butoxytitanate polymer, tri-n-butoxytitanate monostearate polymer, tri-n-butoxytitanate monostearate, etc. One of these can be used alone, or two or more can be used in combination.

[0086] There are no particular limitations on aluminum-based coupling agents. Examples include: aluminum ethyl acetate diisopropoxide, aluminum tri(ethyl acetate), aluminum alkyl acetate diisopropoxide, aluminum monoacetate bis(ethyl acetate), aluminum tri(acetone), aluminum aluminum-monoisopropoxy-monooleoxy-ethyl acetate, aluminum-di-n-butoxy-monoethyl acetate, aluminum-diisopropoxy-monoethyl acetate, etc.; aluminum alkoxides such as aluminum isopropoxide, aluminum mono-butoxy-diisopropoxide, aluminum dibutoxide, and aluminum ethoxide. One of these can be used alone, or two or more can be used in combination.

[0087] In one embodiment, the viscosity of the polyamide-imide resin composition is preferably in the range of 10 mPa·s to 400 mPa·s, more preferably in the range of 10 mPa·s to 300 mPa·s. Here, the viscosity is defined as the value obtained using an E-type viscometer at 25°C and 10 rpm for a varnish prepared by dissolving the non-volatile component (solid component) in a solvent at a concentration of 1% to 20% by mass. If the viscosity measured at 10 rpm is 10 mPa·s or higher, sufficient film thickness is easily ensured during coating. Furthermore, if the viscosity is 400 mPa·s or lower, uniform film thickness is easily ensured during coating. Therefore, by adjusting the viscosity to the aforementioned range, excellent printability is easily obtained.

[0088] In one embodiment, from the viewpoint of obtaining excellent coatability, the viscosity is preferably greater than 50 mPa·s, and more preferably greater than 100 mPa·s. If the viscosity is too low, the wetting and spreading properties exceed the specified range, and therefore it can sometimes be difficult to handle. Furthermore, the viscosity can be measured, for example, using a viscometer (RE type) manufactured by Toki Industries, Ltd. The viscosity is measured as follows: during measurement, the measurement temperature is set to 25℃±0.5℃, and then 1 mL to 1.5 mL of resin composition (varnish) is added to the viscometer, and the viscosity is recorded 10 minutes after the start of the measurement.

[0089] In one embodiment, the film thickness when forming the resin composition is not particularly limited and can be in the range of 0.5 μm to 50 μm. Having a thickness within this range tends to easily ensure sufficient adhesion. From this perspective, the film thickness is preferably in the range of 1 μm to 15 μm, and more preferably in the range of 3 μm to 15 μm.

[0090] In one embodiment, a 10 μm thick film obtained by coating and heating a resin composition (varnish) preferably has an elastic modulus in the range of 0.5 GPa to 8.0 GPa at 35°C, more preferably in the range of 1.0 GPa to 5.0 GPa, and even more preferably in the range of 2.0 GPa to 4.5 GPa. The heating and drying process for forming the film can be carried out, for example, by heating at 50°C for 10 minutes followed by drying at 260°C for 1 hour. The elastic modulus is a value measured using a dynamic viscoelasticity measuring device. From the viewpoint of further improving the reliability of power semiconductor devices, the film preferably has appropriate flexibility. Therefore, in one embodiment, the elastic modulus of the film is preferably in the range of 3.0 GPa to 4.5 GPa.

[0091] The modulus of elasticity can be measured, for example, using a dynamic viscoelasticity measuring device, the "Rheogel-E4000," manufactured by UBM Corporation. The modulus of elasticity is, for example, measured using a film obtained by coating and drying a resin composition (varnish), at a measurement frequency of 10 MHz and a measurement temperature of 35°C.

[0092] The resin composition of the described embodiment is preferably used as a constituent material of semiconductor devices due to its excellent heat resistance and flexibility. For example, the resin composition can be used to form insulating layers, bonding layers, protective layers, etc., in semiconductor devices, resulting in semiconductor devices with excellent adhesion and reliability between components. In one embodiment, the resin composition is preferably used to form an undercoat in a semiconductor device, such as between a sealing material and a substrate, or between a sealing material and a semiconductor element. The adhesion between the components can be evaluated by shear strength.

[0093] In one embodiment, the shear strength between components having a base coating comprising the resin composition at 260°C is preferably 11 MPa or more, more preferably 15 MPa or more, and even more preferably 17 MPa or more. If the shear strength at 260°C is 11 MPa or more, excellent adhesion can be easily obtained even when the resin composition is used in a power semiconductor device.

[0094] In one embodiment, in a laminate having a base coating comprising the resin composition and a resin sealing layer sequentially on a substrate, the shear strength of the substrate and the resin sealing layer at 260°C can be 11 MPa or higher. The laminate can be obtained by forming a film by coating and drying the resin composition (varnish) on the substrate, and then forming the resin sealing layer on the film.

[0095] Shear strength can be measured, for example, using a shear strength testing apparatus (Nordson Advanced Technology Inc. 4000 series). During the measurement, a sample can be used, for example, formed by coating and drying a resin composition onto a Ni substrate to create a film, and then applying an epoxy sealing resin to the film to form a resin sealing layer with a diameter of ϕ5 mm. Typical measurement conditions include a thermal plateau temperature of 260°C and a probe speed of 3 mm / min. The substrate material and the sealing material constituting the resin sealing layer can also be appropriately modified. During measurement, a Cu substrate can be used instead of a Ni substrate, or an Ag-plated substrate can be used on a Cu substrate.

[0096] When the resin composition is used in a semiconductor device, as described above, to form an undercoating layer between the sealing material and the substrate, or between the sealing material and the semiconductor element, from the viewpoint of suppressing stress caused by thermal expansion and contraction and improving adhesion, it is preferable that the difference in the coefficient of linear expansion (CTE) between each component and the film containing the resin composition is small. From this viewpoint, in one embodiment, the CTE of the polyamide-imide resin is preferably in the range of 40 ppm / ℃ to 90 ppm / ℃, more preferably in the range of 50 ppm / ℃ to 70 ppm / ℃, and even more preferably in the range of 55 ppm / ℃ to 65 ppm / ℃. Furthermore, the CTE of the resin composition containing the polyamide-imide resin is also preferably within the aforementioned range.

[0097] The CTE is a value obtained by measuring a film obtained by coating and drying a varnish of a resin or resin composition. For example, a thermomechanical analyzer (TMA, Hitachi High-Tech Science "SS7100") can be used for measurement. Regarding the measurement conditions, the chuck distance can be set to 10 mm, the load to 10 g, and the heating rate to 10 °C / min. The CTE specified in this specification is the value calculated by connecting the values ​​at 70 °C and 140 °C with a straight line and taking into account its slope.

[0098] Semiconductor Devices One embodiment relates to a semiconductor device having a substrate and a dry film made using the resin composition of the embodiment. The constituent components of a semiconductor device generally include semiconductor elements mounted on a substrate and sealing components (sealing layers). Representative semiconductor elements include inorganic materials such as semiconductor wafers (Si, SiC, GaN), Cu, Ni plating, Ag plating, Au plating, Au / Pd / Ni plating, solder, sintered silver, sintered copper, Al wires, Au wires, and ceramic substrates (alumina, zirconium alumina, aluminum nitride, silicon nitride). Additionally, sealing layers typically contain organic materials such as resins. Hereinafter, sealing layers containing resins will be referred to as resin sealing layers.

[0099] In the semiconductor device, by forming a dry film using the resin composition of the embodiment between the constituent components as a base coating, the adhesion between the constituent components can be easily improved. More specifically, for example, by forming a dry film of the resin composition between the resin sealing layer and the substrate, or between the resin sealing layer and the semiconductor element, the adhesion between the components can be ensured, and peeling during cyclic testing can be prevented. From this viewpoint, in one embodiment, the semiconductor device preferably has a substrate, a semiconductor element mounted on the substrate, a base coating disposed on at least the semiconductor element mounting surface of the substrate, and a resin sealing layer disposed on the base coating, wherein the base coating includes a dry film formed using the resin composition for the semiconductor device of the embodiment. The substrate may be a lead frame including a die pad for mounting the semiconductor element and leads, wherein the electrode pads of the semiconductor element and the leads of the lead frame are electrically connected via wires.

[0100] In one embodiment, the resin composition can also be preferably used as a constituent material for power semiconductor devices using the silicon carbide (SiC) substrate or gallium nitride (GaN) substrate. When the power semiconductor device is constructed using the resin composition, the reduction in the tightness between components during thermal cycling tests can be easily suppressed.

[0101] Hereinafter, a representative structure of the semiconductor device according to the embodiment will be specifically described with reference to the drawings. FIG1 is a schematic cross-sectional view showing an embodiment of the semiconductor device. The semiconductor device shown in FIG1 includes a chip pad 1a, a semiconductor element 2, a base coating 3, a lead 1b, a wire 4, and a resin sealing layer 5. The base coating 3 is formed of the resin composition of the embodiment. As shown in FIG1, since the semiconductor element mounting surface of the substrate 1 (the surface of the lead 1b and the chip pad 1a on which the semiconductor element 2 is mounted) is provided with the base coating 3 formed of the resin composition, which is in contact with the resin sealing layer 5, the adhesion between the components can be easily improved.

[0102] In one embodiment, the method for manufacturing a semiconductor device includes at least the steps of coating the resin composition of the embodiment onto the surface of a substrate on which a semiconductor element is mounted and drying it to form a base coating layer; and the step of forming a resin sealing layer on the base coating layer.

[0103] In the described embodiment, the base coat is formed using the resin composition of the embodiment. From a workability point of view, it is preferable to use a resin composition (varnish) containing polyamide-imide resin as a resin component. The base coat can be obtained by applying the resin composition to a specified area and drying the coating.

[0104] The materials used for the die pads and lead frames, including those for mounting semiconductor elements, are not particularly limited and can be selected from materials well known in the art. From the viewpoint of suitability for power semiconductor devices, the die pad material is preferably at least one selected from the group consisting of Ni or Cu. Additionally, one material selected from the group consisting of Ni or Cu may also have an Ag plating layer on its surface. The lead material of the lead frame is preferably selected from the group consisting of Ni or Cu. There are no particular limitations on the materials used in semiconductor devices; for example, they can be silicon wafers, silicon carbide wafers, etc.

[0105] The resin sealing layer can be formed using sealing materials well known in the art. For example, the resin sealing material can be a liquid or solid epoxy resin composition. The resin sealing layer can be formed, for example, using a resin sealing material and by transfer molding. In another embodiment, the method for manufacturing a semiconductor device includes, for example, the steps of coating and drying the resin composition of the embodiment onto a semiconductor substrate having multiple identical wirings to form a resin layer; and, if necessary, forming rewiring on the resin layer that is electrically connected to electrodes on the semiconductor substrate. In addition to the steps described above, the method may also include, if necessary, the following step: forming a protective layer (resin layer) on the rewiring or the resin layer using the resin composition of the embodiment. Furthermore, in addition to the steps described above, the method may also include, if necessary, the step of forming external electrode terminals on the resin layer, and subsequently, if necessary, the step of cutting.

[0106] The coating method for the resin layer (base coat) is not particularly limited, but spin coating, spray coating, or dispensing coating are preferred. The drying method for the resin layer can be performed using methods known in the art. The resin composition of the embodiment also exhibits excellent sputtering resistance, plating resistance, and alkali resistance, which are required in the rewiring step. Therefore, the resin composition of the embodiment is not limited to the structure of the semiconductor device described above and is preferably used as a material for all semiconductor devices. [Example]

[0107] The present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments, but includes various implementation forms.

[0108] <1> Synthesis of polyamide imide resin (Synthesis example 1) Under a nitrogen gas flow, 25.1 g of 9,9-bis(4-aminophenyl)furan, 3.6 g of 4,4'-diaminodiphenylmethane, and 2.5 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added to a 1-liter four-necked flask equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe with an oil-water separator. Then, 284 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) was added and dissolved to obtain a solution. Next, while cooling the solution at a temperature not exceeding 20°C, 21.1 g of trimellitic anhydride chloride (hereinafter referred to as TAC) was added. After stirring at room temperature for 2 hours, 12.1 g of triethylamine (hereinafter referred to as TEA) was added, and the reaction was carried out at room temperature for at least 12 hours to obtain a polyacrylic acid solution. The obtained polyamide solution was further subjected to dehydration condensation at 180°C for 8 hours to obtain a polyamide-imide resin solution. The polyamide-imide resin solution was then injected into water, and the resulting precipitate was separated, pulverized, and dried to obtain powdered polyamide-imide resin (PAI-1). The obtained polyamide-imide resin powder (PAI-1) is soluble in a polar solvent (NMP) at room temperature (25°C). The weight-average molecular weight (Mw) of the obtained polyamide-imide resin (PAI-1) was determined by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene conversion, and the results showed that Mw was 57,000 to 68,000.

[0109] Furthermore, the determination conditions for GPC are as follows. Liquid delivery pump: LC-20AD manufactured by Shimadzu Corporation UV-Vis detector: SPD-20A, manufactured by Shimadzu Corporation, UV 270 nm Dissolution solution: Tetrahydrofuran / Dimethylformamide = 1 / 1 (volume ratio) + 0.06 M phosphoric acid + 0.06 M lithium bromide Column: 2 x GL-S300M DT-5 gel packs manufactured by Hitachi High-technologies, Inc. String dimensions: 8 mm lD × 300 mm Sample concentration: 5 mg / 1 mL Flow rate: 1 mL / min; Column temperature: 40℃ Molecular weight standard material: Standard polystyrene

[0110] (Synthesis example 2) In the preparation of the polyamide-imide resin (PAI-1) described in Synthesis Example 1, 9,9-bis(4-aminophenyl) benzo[a]ene was changed to 15.7 g and 4,4'-diaminodiphenylmethane was changed to 8.9 g. Otherwise, the same method as in Synthesis Example 1 was followed to obtain the powdered polyamide-imide resin (PAI-2). The polyamide-imide resin powder (PAI-2) is soluble in a polar solvent (NMP) at room temperature (25°C). The weight-average molecular weight (Mw) of the obtained polyamide-imide resin (PAI-2) was determined by conversion to standard polystyrene, and the result was Mw was 72,000. The determination of Mw was performed in the same manner as described in Synthesis Example 1.

[0111] (Synthesis example 3) In the preparation of the polyamide-imide resin (PAI-1) described in Synthesis Example 1, 9,9-bis(4-aminophenyl) benzo[a]ene was changed to 6.3 g and 4,4'-diaminodiphenylmethane was changed to 14.3 g. Otherwise, the same method as in Synthesis Example 1 was followed to obtain powdered polyamide-imide resin (PAI-3). The polyamide-imide resin powder (PAI-3) is soluble in a polar solvent (NMP) at room temperature (25°C). The weight-average molecular weight (Mw) of the obtained polyamide-imide resin (PAI-3) was determined by conversion to standard polystyrene, and the result was Mw was 100,000. The determination of Mw was performed in the same manner as described in Synthesis Example 1.

[0112] (Synthesis Example 4) Under a nitrogen gas flow, 15.7 g of 9,9-bis(4-amino-3-methylphenyl)furan, 7.1 g of 1,5'-diaminonaphthalene, and 2.5 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added to a 1-liter four-necked flask equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe with an oil-water separator. Then, 250 g of NMP was added and dissolved to obtain a solution. Next, while cooling the solution at a temperature not exceeding 20°C, 21.1 g of TAC was added. After stirring at room temperature for 2 hours, 12.1 g of TEA was added, and the reaction was carried out at room temperature for at least 12 hours to prepare a polyacrylic acid solution. The obtained polyamide solution was further subjected to dehydration condensation at 180°C for 8 hours to obtain a polyamide-imide resin solution. The polyamide-imide resin solution was then injected into water, and the resulting precipitate was separated, pulverized, and dried to obtain powdered polyamide-imide resin (PAI-5). The polyamide-imide resin powder (PAI-5) is soluble in a polar solvent (NMP) at room temperature (25°C). The weight-average molecular weight (Mw) of the obtained polyamide-imide resin (PAI-5) was determined using GPC, converted to standard polystyrene, and the result was Mw was 65,000. The determination of Mw was performed in the same manner as described in Synthesis Example 1.

[0113] (Synthesis Example 5) Under a nitrogen gas flow, 15.7 g of 9,9-bis(4-amino-3-methylphenyl)pyroxene, 4.9 g of 1,4-phenylenediamine, and 2.5 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added to a 1-liter four-necked flask equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe with an oil-water separator. Then, 238 g of NMP was added and dissolved to obtain a solution. Next, while cooling the solution at a temperature not exceeding 20°C, 21.1 g of TAC was added. After stirring at room temperature for 2 hours, 12.1 g of TEA was added, and the reaction was carried out at room temperature for at least 12 hours to prepare a polyacrylic acid solution. The obtained polyamide solution was further subjected to dehydration condensation at 180°C for 8 hours to obtain a polyamide-imide resin solution. The polyamide-imide resin solution was then injected into water, and the resulting precipitate was separated, pulverized, and dried to obtain powdered polyamide-imide resin (PAI-5). The polyamide-imide resin powder (PAI-5) is soluble in a polar solvent (NMP) at room temperature (25°C). The weight-average molecular weight (Mw) of the obtained polyamide-imide resin (PAI-5) was determined using GPC, converted to standard polystyrene, and the result was Mw was 42,000. The determination of Mw was performed in the same manner as described in Synthesis Example 1.

[0114] (Synthesis Example 6) Under a nitrogen gas flow, 102.4 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 6.9 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added to a 1-liter four-necked flask equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe with an oil-water separator. Then, 700 g of NMP was added and dissolved to obtain a solution. Next, while cooling the solution to a temperature not exceeding 20°C, 59.0 g of TAC was added. After stirring at room temperature for 1 hour, while cooling the solution to a temperature not exceeding 20°C, 34.0 g of TEA was added, and the mixture was reacted at room temperature for 3 hours to produce a polyacrylic acid solution. The obtained polyamide solution was further subjected to dehydration condensation at 190°C for 6 hours to produce a polyamide imide resin solution. The varnish of the polyamide-imide resin was injected into water, and the resulting precipitate was separated, pulverized, and dried to obtain powdered polyamide-imide resin (PAI-6). The weight-average molecular weight (Mw) of the obtained polyamide-imide resin (PAI-6) was determined by gel permeation chromatography (GPC) with conversion to standard polystyrene, and the result was Mw was 75,000. The determination of Mw was performed in the same manner as described in Synthesis Example 1.

[0115] <2> Preparation of polyamide-imide resin composition In the examples and comparative examples shown below, polyamide-imide resin powders (PAI-1) to (PAI-6) prepared in the previous synthesis examples 1 to 6 were used to prepare polyamide-imide resin compositions (primer varnish for semiconductor devices).

[0116] (Example 1) Under a nitrogen stream, 12 g of polyamide-imide resin powder (PAI-1) obtained in Synthesis Example 1, 60.9 g of N-methyl-2-pyrrolidone, 26.1 g of butyl cellosolve acetate, and 1.2 g of silane coupling agent (product name KBM-402 (3-glycidoxypropylmethyldimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd.) were added to a 0.5 L four-necked flask and stirred for 12 hours to obtain a yellow reaction mixture. The obtained yellow reaction mixture was filled into a KST-47 filter (manufactured by Advantec Co., Ltd.) and pressure filtered at 0.3 MPa to obtain a primer varnish for semiconductor devices (P-1).

[0117] (Example 2) The polyamide imide resin powder (PAI-1) used in Example 1 was replaced with (PAI-2) obtained in Synthesis Example 2. Otherwise, the primer varnish for semiconductor devices (P-2) was prepared in the same manner as in Example 1.

[0118] (Example 3) The polyamide imide resin powder (PAI-1) used in Example 1 was replaced with (PAI-3) obtained in Synthesis Example 3. Otherwise, the primer varnish for semiconductor devices (P-3) was prepared in the same manner as in Example 1.

[0119] (Example 4) The polyamide imide resin powder (PAI-1) used in Example 1 was replaced with (PAI-4) obtained in Synthesis Example 4. Otherwise, the primer varnish for semiconductor devices (P-4) was prepared in the same manner as in Example 1.

[0120] (Example 5) The polyamide imide resin powder (PAI-1) used in Example 1 was replaced with (PAI-5) obtained in Synthesis Example 5. Otherwise, the primer varnish for semiconductor devices (P-5) was prepared in the same manner as in Example 1.

[0121] (Comparative Example 1) The polyamide imide resin powder (PAI-1) used in Example 1 was changed to (PAI-6) obtained in Synthesis Example 6, and the solvent was changed to 35 g of N-methyl-2-pyrrolidone and 52 g of butyl cellosolve acetate. Otherwise, the primer varnish for semiconductor devices (P-6) was prepared in the same manner as in Example 1.

[0122] <3> Evaluation of polyamide-imide resin composition (primer varnish for semiconductor devices) Evaluate the various characteristics according to the following. (Modulus of elasticity) Using a rod coater, the semiconductor device primer varnishes (P-1) to (P-6) obtained in Examples 1 to 5 and Comparative Example 1 were coated and heated to dry on a substrate to obtain a dry film with a thickness of 10 μm. The heating and drying process for forming the dry film was carried out under the conditions of heating at 50°C for 10 minutes and then drying at 260°C for 1 hour. The dried film obtained in the manner described was used as a sample for the following measurements. The elastic modulus of polyamide-imide resin was determined by setting the sample on a dynamic viscoelasticity measuring apparatus (Rheogel-E4000) manufactured by UBM Corporation. The elastic modulus was determined using values ​​obtained under conditions of a chuck distance of 20 mm, a temperature of 35°C, and a measurement frequency of 10 MHz. The measured values ​​are shown in Table 1.

[0123] (Glass transfer temperature) Using a rod coater, the semiconductor device primer varnishes (P-1) to (P-6) obtained in Examples 1 to 5 and Comparative Example 1 were coated and heated to dry on a substrate to obtain a dry film with a thickness of 10 μm. The heating and drying process for forming the dry film was carried out under the conditions of heating at 50°C for 10 minutes and then drying at 260°C for 1 hour. The dried film obtained in the manner described was used as a sample for the following measurements. The measurements were performed using a thermomechanical analysis apparatus (TMA, Hitachi High-Tech Science SS7100) under conditions of a chuck distance of 10 mm, a load of 10 g, and a heating rate of 10 °C / min. The inflection point of the linear expansion coefficient from α1 to α2 obtained from the TMA measurement was taken as the glass transition temperature.

[0124] (Coefficient of linear expansion) Using a rod coater, the semiconductor device primer varnishes (P-1) to (P-6) obtained in Examples 1 to 5 and Comparative Example 1 were coated and heated to dry on a substrate to obtain a dry film with a thickness of 10 μm. To form the dry film, heating was performed at 50°C for 10 minutes, followed by drying at 260°C for 1 hour. The dried film obtained in the manner described was used as a sample for measurement, and the coefficient of linear expansion (CTE) was determined. The measurement was performed using a thermomechanical analysis apparatus (TMA, Hitachi High-Tech Science SS7100) under conditions of a chuck distance of 10 mm, a load of 10 g, and a heating rate of 10 °C / min. The displacements at 70 °C and 140 °C were connected by a straight line, and the value calculated based on its inclination was taken as the CTE value.

[0125] (Adhesion (shear strength)) For the semiconductor device primers (P-1) to (P-6) obtained in Examples 1 to 5 and Comparative Example 1, the adhesion was evaluated using a 4000 series shear strength tester manufactured by ARCTEC Corporation. Specifically, firstly, the primer varnish is applied to a Ni substrate using a spray coating apparatus (model: SV91) manufactured by SAN-EI TECH Co., Ltd., and then heated and dried to obtain a dried film. The thickness of the dried film is 10 μm. Next, a resin sealing layer with a diameter of ϕ5 mm is formed on the dried film to obtain a sample for testing. An epoxy-based sealing resin (CEL-420HFC) manufactured by Showa Denko Materials Co., Ltd. is used as the sealing material. The obtained test samples were placed on the heated platform of an ARCTEC 4000 series shear strength measuring apparatus to determine their shear strength. The measurement was performed at 260°C with a probe speed of 3 mm / min. The results are shown in Table 1.

[0126] Based on the shear strength test results at 260℃, the adhesion in the high-temperature region was evaluated according to the following criteria. The evaluation results are shown in Table 1. <Standards for Sealing Performance in High-Temperature Areas> A: The shear strength at 260℃ is above 18.0 MPa. B: The shear strength at 260℃ is above 11 MPa and less than 18.0 MPa. C: The shear strength at 260℃ is less than 11 MPa.

[0127] (Reliability Evaluation (Moisture Absorption and Reflow Test)) For the semiconductor device primers (P-1) to (P-6) obtained in Examples 1 to 5 and Comparative Example 1, a moisture absorption reflow test was performed. Specifically, firstly, after assembling the package containing the Si wafer on the Cu lead frame, the primer varnish is applied and dried using a spray coating apparatus (model: SV91) manufactured by SAN-EI TECH Co., Ltd., to obtain a dried film. The drying conditions are implemented at a temperature of 260°C for a drying time of 1 hour. Next, a resin sealing layer was formed on the dried film using "CEL-8240" manufactured by Showa Denko Materials Co., Ltd. as a sealing material, and an evaluation sample was obtained. Next, using the obtained evaluation samples, a moisture absorption reflow test was conducted under the following conditions. Moisture absorption conditions: Joint Electron Device Engineering Council (JEDEC) Moisture Sensitivity Level (MSL) 1 (85℃ / 85%RH × 168 hours). Reflow conditions: 260℃ / 10 seconds × 3 times

[0128] Next, in the semiconductor device before and after the reliability test (moisture absorption reflow test), high-precision ultrasonic microscopy (C-SAM) was used to observe whether delamination occurred between the resin sealant, the resin drying film (base coat), and the lead frame. The results are shown in Table 1. The reliability test evaluation results shown in Table 1 are presented as the number of samples (numerator) where peeling was confirmed to have occurred relative to the total number of samples evaluated (denominator). The conditions under which the observations were made are as follows. Apparatus: High-precision ultrasonic microscope (C-SAM), Sonoscan D9600, vibration frequency 30 MHz Conditions: Room temperature (25℃±5℃), using pure water.

[0129] The results of the evaluation of each characteristic in Examples 1 to 5 and Comparative Example 1 are summarized in Table 1. [Table 1] Table 1 Structure of PA1 resin characteristic Reliability testing Structural units derived from diamines Mw Tg (°C) elastic modulus (GPa) CTE (ppm / ℃) Close contact Before the experiment After the test Ia IIa IIb IIc IIIa I'-II' (MPa) evaluate Example 1 72% 18% - - 10% 57,000 -68,000 329 3.4 62 18.0 A 0 / 16 0 / 16 Example 2 45% 45% - - 10% 72,000 294 3.7 62 19.5 A 0 / 16 15 / 16 Example 3 18% 72% - - 10% 100,000 276 3.9 55 17.0 B 0 / 16 14 / 16 Example 4 45% - 45% - 10% 65,000 327 3.4 47 17.4 B 0 / 16 7 / 16 Example 5 45% - - 45% 10% 42,000 328 3.4 56 17.4 B 0 / 16 4 / 16 Comparative Example 1 - - - - 10% 90% 75,000 220 2.8 65 10.0 C 0 / 16 16 / 16

[0130] In Table 1, the structural units I'-II' derived from diamine are structural units derived from 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

[0131] As described above, the resin compositions of the present invention (Examples 1 to 5) exhibit excellent adhesion even at a high temperature of 260°C. On the other hand, the resin composition of Comparative Example 1 has a lower Tg than that of Examples 1 to 5, resulting in significantly poor adhesion in the adhesion test at 260°C. The resin composition of Comparative Example 1 uses a polyamide-imide resin that does not have a caloric structure-type backbone. Furthermore, based on the reliability test results of the moisture absorption reflow test in Examples 1 to 3, it can be seen that Tg can be easily increased by adjusting the ratio of structural unit (Ia) to structural unit (IIa). Moreover, as seen in Examples 1, 4, and 5, it is evident that the adhesion is excellent under high-temperature conditions when Tg exceeds 300°C, and good results can be obtained even in the moisture absorption reflow test, easily improving reliability. As can be seen from the above, according to the present invention, a resin and resin composition can be provided that, by means of a polyamide imide resin comprising a combination of structural units having a caloric structure-type framework and specific structural units, exhibits excellent adhesion in high-temperature regions and can improve the reliability of semiconductor devices.

[0132] 1: Lead frame, Cu substrate 1a: Crystal pad 1b: Lead wire 2: Semiconductor components 3: Primer coating (film of resin composition) 4: Wire 5: Resin sealing layer

Claims

1. A polyamide-imide resin, which is a polyamide-imide resin obtained by using a diamine component and / or a diisocyanate component and an acid component, wherein the polyamide-imide resin comprises, relative to the total amount of structural units derived from the diamine component and / or the diisocyanate component, 10 mol% to 75 mol% of structural units (Ia) represented by the following formula, 10 mol% to 80 mol% of at least one selected from the group consisting of structural units (IIa), (IIb) and (IIc) represented by the following formula, and 7.5 mol% to 10 mol% of structural units (IIIa) represented by the following formula, and further comprises structural units (IVa) represented by the following formula, wherein in formula (Ia), X independently represents a hydrogen atom or a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a hydroxyalkyl group; In formulas (IIa), (IIb), and (IIc), S independently represents an alkyl group having 1 to 3 carbon atoms, a represents an integer from 0 to 4, b represents an integer from 0 to 3, and c represents an integer from 0 to 4. In formula (IIIa), R independently represents a hydrogen atom, or a substituent selected from the group consisting of an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a halogen atom, and n represents an integer from 1 to 6.

2. The polyamide-imide resin as claimed in claim 1, wherein, The coefficient of linear expansion is 40 ppm / ℃~70 ppm / ℃.

3. The polyamide-imide resin as claimed in claim 1, wherein, Based on the total amount of the structural unit (Ia) and at least one selected from the group consisting of the structural units (IIa), (IIb) and (IIc), the proportion of the structural unit (Ia) is 20 mol% or more.

4. The polyamide-imide resin as claimed in claim 1, wherein, The glass transfer temperature is above 250℃.

5. The polyamide-imide resin as claimed in claim 1, wherein, The glass transfer temperature is above 300℃.

6. A polyamide-imide resin composition comprising the polyamide-imide resin as described in claim 1 and a solvent.

7. A semiconductor device comprising a substrate and a film formed using a polyamide imide resin composition as described in claim 6.

8. The semiconductor device as claimed in claim 7 further comprises a resin sealing layer.

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