Polyamic acid, polyamic acid compositions, polyamic acid films, polyimide, polyimide films, wiring circuit boards, semiconductor packages, and electronic devices.

Abstract

Polyamic acid is a precursor to polyimide, used as an insulating layer in wiring circuit boards. Polyamic acid is a reaction product of 3,4'-oxophthalic dianhydride and a diamine containing an ether diamine.

Description

Technical Field

[0001] This invention relates to polyamic acid, polyamic acid compositions, polyamic acid films, polyimide, polyimide films, wiring circuit boards, semiconductor packages, and electronic devices. Background Technology

[0002] Previously, polyamic acid, which is obtained by reacting pyromellitic dianhydride with diamine components (2,2'-bis(trifluoromethyl)benzidine and 3,5-diaminobenzamide), is known as a precursor for polyimide films that can be used as interlayer insulating films (for example, see Patent Document 1 below).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-127503 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, for polyamic acid varnishes as described in Patent Document 1, when the polyamic acid varnish is applied to a substrate with an uneven surface, unevenness sometimes occurs on the surface of the dried film of the polyamic acid varnish corresponding to the unevenness of the coated surface.

[0008] If the drying film is thermally cured while its surface is uneven, unevenness will remain on the surface of the insulating layer that is the cured material, making it difficult to form a conductor pattern on the insulating layer.

[0009] The present invention provides polyamic acid, polyamic acid composition and polyamic acid film capable of improving the flatness of insulating layer, polyimide and polyimide film made of polyamic acid, wiring circuit board having insulating layer made of polyamic acid, and semiconductor package and electronic device having wiring circuit board.

[0010] Problem Solving Methods

[0011] The present invention [1] contains a polyamic acid, which is a precursor of polyimide used as an insulating layer for wiring circuit boards. The polyamic acid is a reaction product of 3,4'-oxophthalic dianhydride and a diamine component containing ether diamine.

[0012] The present invention [2] comprises the polyamic acid of [1] above, wherein the proportion of the above-mentioned ether diamine in the above-mentioned diamine component is 0.5 moles or more relative to 1 mole of 3,4'-oxobisphthalic dianhydride.

[0013] The present invention [3] contains the polyamic acid of [1] or [2] above, and the diamine component contains only the above-mentioned ether diamine.

[0014] The present invention [4] includes any one of the polyamic acids [1] to [3] above, wherein the ether diamine is 1,3-bis(4-aminophenoxy)benzene.

[0015] The present invention [5] comprises a polyamic acid composition containing:

[0016] Any of the polyamic acids mentioned in [1] to [4] above, and

[0017] Solvent.

[0018] The present invention [6] comprises a polyamic acid film, which is the dried product of the polyamic acid composition of the above [5].

[0019] The present invention [7] contains a polyimide, which is an imide of any of the polyamic acids [1] to [4] above.

[0020] The present invention [8] includes a polyimide film formed from the polyimide described above [7].

[0021] The present invention [9] includes a wiring circuit board, which comprises:

[0022] The insulating layer formed from the polyimide described above [7], and

[0023] Conductor pattern.

[0024] The present invention

[10] includes a semiconductor package comprising:

[0025] The wiring circuit board described above [9], and

[0026] Semiconductor chips mounted on the aforementioned wiring circuit board.

[0027] The present invention

[11] includes an electronic device having the semiconductor package described above

[10] .

[0028] The effects of the invention

[0029] The polyamic acid of the present invention is a reaction product of 3,4'-oxobisphthalic dianhydride and a diamine containing an ether diamine. 3,4'-oxobisphthalic dianhydride is an asymmetric tetracarboxylic dianhydride having a molecular structure in which two phthalic anhydrides are bonded by ether bonds.

[0030] Therefore, the dried film (polyamic acid film) made from this polyamic acid can be easily formed by hot pressing.

[0031] Therefore, in the process of forming the insulating layer, the surface of the dried film made of polyamic acid can be easily and flatly formed by hot pressing.

[0032] As a result, the flatness of the insulation layer can be improved. Attached Figure Description

[0033] [ Figure 1 ] Figure 1 This is a perspective view illustrating one embodiment of the semiconductor package of the present invention.

[0034] [ Figure 2 ] Figure 2 yes Figure 1 The diagram shows a cross-sectional view of the semiconductor package substrate.

[0035] [ Figure 3 ] Figure 3 A~ Figure 3 C shows Figure 1 The manufacturing process of the semiconductor package substrate shown is as follows: Figure 3 A illustrates the process of forming a dried film of a polyamic acid composition. Figure 3 B illustrates the process of hot-pressing a dried film of a polyamic acid composition. Figure 3 C illustrates the process of forming a conductor pattern on an insulating layer.

[0036] Symbol Explanation

[0037] 1 Semiconductor package

[0038] 2. Semiconductor package substrate (an example of a wiring circuit substrate)

[0039] 3 Semiconductor chips

[0040] 22 Insulation layer

[0041] 23 Conductor Patterns Detailed Implementation

[0042] 1. Polyamic acid

[0043] The polyamic acid of the present invention can be used in the manufacture of wiring circuit boards. Specifically, the polyamic acid of the present invention is a precursor to polyimide used as an insulating layer of a wiring circuit board. Preferably, the polyamic acid of the present invention is used as a semiconductor package substrate 2 (see reference 2). Figure 1 Interlayer insulation layer 22 (refer to) Figure 2 The precursor used is polyimide. The semiconductor package substrate 2 will be described later.

[0044] Polyamic acid is the product of the reaction between 3,4'-oxobisphthalic dianhydride (α-ODPA) and a diamine component.

[0045] α-ODPA has a molecular structure consisting of two phthalic anhydrides bonded together by an ether bond. The ether bond connects the carbon at position 3 of one phthalic anhydride to the carbon at position 4 of the other. Therefore, with the oxygen atom of the ether bond as the center of symmetry, the molecular structure of α-ODPA is asymmetric. That is, α-ODPA is an asymmetric tetracarboxylic dianhydride.

[0046] It should be noted that, with the oxygen atom of the ether bond as the center of symmetry, 4,4'-oxophthalic dianhydride (s-ODPA), as a structural isomer of α-ODPA, is symmetrical. That is, s-ODPA is a symmetrical tetracarboxylic dianhydride.

[0047] The diamine component contains at least one diamine. The diamine component contains only diamine. The diamine component may contain, for example, ether diamine. Ether diamine is a diamine having an ether bond.

[0048] Examples of ether diamines include aromatic diamines having an ether bond (aromatic ether diamines) and aliphatic diamines having an ether bond (aliphatic ether diamines).

[0049] Examples of aromatic ether diamines include: 1,3-bis(4-aminophenoxy)benzene (1,3,4-APB), 1,3-bis(3-aminophenoxy)benzene (1,3,3-APB), 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 3,3'-oxadiphenylamine, and 3,4'-diaminodiphenyl ether.

[0050] Examples of aliphatic ether diamines include: poly(propylene glycol) diamine, 1,4-butanediol bis(3-aminopropyl) ether, 1,2-bis(2-aminoethoxy) ethane, diethylene glycol bis(3-aminopropyl) ether, 2,2'-oxobis(ethylamine), 1,14-diamino-3,6,9,12-tetraoxatetradecane, polyethylene glycol bis(3-aminopropyl) ether, and polyethylene glycol diamine.

[0051] As an ether diamine, aromatic ether diamines are preferred, and 1,3,4-APB is more preferred.

[0052] When the diamine is 1,3,4-APB, it can improve the heat resistance of the insulating layer.

[0053] The proportion of ether diamine in the diamine component relative to 1 mole of α-ODPA is, for example, 0.5 moles or more, preferably 0.7 moles or more.

[0054] When the proportion of ether diamine in the diamine component is above the lower limit mentioned above, the flatness of the insulation layer can be improved.

[0055] There is no upper limit to the proportion of ether diamine in the diamine component. The proportion of ether diamine in the diamine component relative to α-ODPA can be equimolar. The diamine component may contain only ether diamine.

[0056] Besides ether diamines, diamine components can also contain diamines that do not have ether bonds.

[0057] Examples of diamines that do not have ether bonds include aromatic diamines and aliphatic diamines.

[0058] Examples of aromatic diamines that do not have ether bonds include: p-phenylenediamine, 4,4'-diaminophenylmethane, 4,4'-diaminodiphenyl sulfone, 1,4-diaminobenzene, 2,5-diaminotoluene, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 1,5-diaminonaphthalene, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, m-phenylenediamine, p-phenylenediamine, 3-aminobenzylamine, 4-aminobenzylamine, bis(3-aminophenyl)sulfone, 2,2-bis(4-aminophenyl)hexafluoropropane, 1,3-bis[2-(4-aminophenyl)-3-propyl]benzene, 1,8-diaminonaphthalene, and 3,3'-diaminodiphenyl. Methane, 3,4'-diaminodiphenylmethane, 4,4'-diamino-p-terphenyl, 4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2-ethyl-6-methylaniline), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2,6-dimethylaniline), 1,4-phenylenediamine, 1,3-phenylenediamine, 1,3-phenylenediamine, o-toluidine, bis(4-aminophenyl) sulfide, 3,3',5,5'-tetramethylbenzidine, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-ethylenyldiphenylamine, and 4,4'-diamino-2,2'-dimethylbibenzyl.

[0059] Examples of aliphatic diamines without ether bonds include: 1,12-dodecanediamine, 1,6-diaminohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,2-cyclohexanediamine, ethylenediamine, 3,3'-diamino-N-methyldipropylamine, N,N'-bis(3-aminopropyl)ethylenediamine, 1,10-diaminosilane, 1,12-diaminododecane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,5-diaminopentane, 1,3-diaminopropane, 1,4-diaminobutane, 1,11-diaminoundecane, 2-methyl-1,5-diaminopentane, 2,2'-diamino-N-methyldiethylamine, 2-methyl-1,3-propanediamine, 4,4'-methylenebis(cyclohexylamine), and 1,3-diaminopentane.

[0060] Relative to 1 mole of α-ODPA, the proportion of "diamines without ether bonds" in the diamine component is, for example, less than 0.5 moles, preferably less than 0.3 moles.

[0061] 2. Polyamic acid composition

[0062] The polyamic acid composition is in liquid form (varnish). The polyamic acid composition contains the aforementioned polyamic acid and solvent.

[0063] The solvent can be any solvent that can dissolve polyamic acid; there are no limitations. Examples of solvents include aprotic polar solvents.

[0064] Examples of nonprotic polar solvents include N-methyl-2-pyrrolidone, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, and hexamethylphosphoramide.

[0065] The proportion of polyamic acid in the polyamic acid composition is, for example, 5% by mass or more, preferably 7.5% by mass or more, and more preferably 10% by mass or more.

[0066] The proportion of polyamic acid in the polyamic acid composition is, for example, 20% by mass or less, preferably 16% by mass or less, and more preferably 14% by mass or less.

[0067] The proportion of polyamic acid in the polyamic acid composition can be 5% to 20% by mass, 7.5% to 16% by mass, or 10% to 14% by mass.

[0068] The viscosity of the polyamic acid composition at 25°C is, for example, 5 Pa·s or more, preferably 8 Pa·s or more.

[0069] The viscosity of the polyamic acid composition at 25°C is, for example, 15 Pa·s or less, preferably 14 Pa·s or less.

[0070] The viscosity of the polyamic acid composition at 25°C can be 5 Pa·s to 15 Pa·s or 8 Pa·s to 14 Pa·s.

[0071] Polyamic acid compositions can be obtained, for example, by reacting α-ODPA with a diamine component in a solvent.

[0072] In the case of patterning the insulating layer of a wiring circuit board by photolithography, the polyamic acid composition may contain photosensitizers and development accelerators in addition to polyamic acid and solvents.

[0073] The photosensitizer promotes the imidization of polyamic acid in the exposed portion during the photolithography exposure process. The exposed portion refers to the part of the dried film of the polyamic acid composition that is exposed.

[0074] Developers promote the dissolution of unexposed portions during the development process in photolithography. Unexposed portions refer to the areas in the dried film of the polyamic acid composition that were not exposed during the exposure process.

[0075] 3. Polyamic acid film, polyimide and polyimide film

[0076] The polyamic acid film of the present invention is a dried product of the above-described polyamic acid composition. The polyamic acid film can be obtained, for example, by coating a substrate with the polyamic acid composition and drying it. The polyamic acid film contains the above-described polyamic acid and, if necessary, contains a photosensitizer and a development accelerator.

[0077] The glass transition temperature (Tg) of the polyamic acid film is, for example, below 135°C, preferably below 120°C. The glass transition temperature (Tg) of the polyamic acid film is, for example, above 60°C. The glass transition temperature (Tg) of the polyamic acid film can be 60°C to 135°C or 60°C to 120°C.

[0078] The glass transition temperature (Tg) is the temperature at which the loss tangent (tanδ) reaches its maximum when dynamic viscoelasticity is measured using a dynamic viscoelasticity measuring device (trade name: RSA-G2, manufactured by TA Instruments) under the following measurement conditions.

[0079] <Measurement Conditions>

[0080] Sample dimensions: 10mm width, 20mm length

[0081] Measurement mode: Tensile mode

[0082] Measurement temperature range: 0℃~200℃

[0083] Heating rate: 5℃ / minute

[0084] Frequency: 1Hz

[0085] Load (axial): 0.01N

[0086] The polyimide of the present invention is an imide of the aforementioned polyamic acid. The polyimide film of the present invention is a film made of polyimide. The polyimide film can be obtained, for example, by heating the aforementioned polyamic acid film to imide the polyamic acid.

[0087] The glass transition temperature (Tg) of polyimide films is, for example, above 140°C. There is no upper limit to the glass transition temperature (Tg) of polyimide films.

[0088] The heat resistance temperature of the polyimide film is, for example, 130°C or higher, preferably 200°C or higher, more preferably 300°C or higher, and even more preferably 400°C or higher. There is no upper limit to the heat resistance temperature of the polyimide film.

[0089] The heat resistance temperature of the polyimide film can be determined by the method described in the examples below.

[0090] The dielectric constant of the polyimide film at 10 GHz is, for example, 3.0 to 4.0, preferably 3.2 to 3.5.

[0091] The dielectric loss tangent of the polyimide film at 10 GHz is, for example, 0.00500~0.00800, preferably 0.00550~0.00700.

[0092] The dielectric constant and dielectric loss tangent can be determined by the methods described in the examples below.

[0093] 4. Semiconductor packages and wiring circuit boards

[0094] Semiconductor package 1 is a component of the circuit board of an electronic device. That is, the electronic device has semiconductor package 1.

[0095] like Figure 1 As shown, the semiconductor package 1 includes a semiconductor package substrate 2, a semiconductor chip 3, and a sealing resin 4, which serves as an example of a wiring circuit substrate.

[0096] (1) Semiconductor packaging substrate

[0097] like Figure 2 As shown, the semiconductor package substrate 2 has a core layer 21, multiple insulating layers 22A, 22B, 22C, and multiple conductor patterns 23A, 23B, 23C.

[0098] The core layer 21 can be made of metal, for example. Examples of metals include aluminum, stainless steel, and copper. The core layer 21 is preferably made of stainless steel. The thickness of the core layer 21 is not limited.

[0099] Multiple insulating layers 22A, 22B, and 22C are stacked on one side of the core layer 21 in the thickness direction of the semiconductor package substrate 2. Each of the multiple insulating layers 22A, 22B, and 22C is made of polyimide. That is, each of the multiple insulating layers 22A, 22B, and 22C is an example of the aforementioned polyimide film. Insulating layer 22A is disposed between the conductor pattern 23A and the core layer 21 in the thickness direction. Insulating layer 22B is disposed between the conductor pattern 23B and the conductor pattern 23A in the thickness direction. Insulating layer 22C is disposed between the conductor pattern 23C and the conductor pattern 23B in the thickness direction.

[0100] The thickness of each of the multiple insulating layers 22A, 22B, and 22C is, for example, 5μm to 20μm, preferably 5μm to 15μm.

[0101] Conductor pattern 23A is disposed on one side of insulating layer 22A in the thickness direction. It should be noted that the semiconductor package substrate 2 also has multiple insulating layers 24 on the other side of core layer 21 in the thickness direction (see reference). Figure 1 The figure shows a conductor pattern 23A and multiple conductor patterns. Conductor pattern 23A is connected to a conductor pattern on the other side in the thickness direction via a via (not shown) penetrating the insulating layer 22A and the core layer 21. Conductor pattern 23B is disposed on one side of the insulating layer 22B in the thickness direction. Conductor pattern 23B is connected to conductor pattern 23A via via 25A. Conductor pattern 23C is disposed on one side of the insulating layer 22C in the thickness direction. Conductor pattern 23C is connected to conductor pattern 23B via via 25B. Copper can be cited as an example as the material for each conductor pattern.

[0102] The thicknesses of conductor patterns 23A, 23B, and 23C are, for example, 5μm to 40μm.

[0103] (2) Semiconductor chips

[0104] like Figure 1 As shown, the semiconductor chip 3 is mounted on the semiconductor package substrate 2. The semiconductor chip 3 is disposed on one side of the semiconductor package substrate 2 in the thickness direction. In this embodiment, the semiconductor chip 3 is electrically connected to the terminal 231 of the conductor pattern 23C, for example, via a wire 5.

[0105] (3) Sealing resin

[0106] Sealing resin 4 is disposed on one side of semiconductor package substrate 2 in the thickness direction. Sealing resin 4 seals semiconductor chip 3.

[0107] 5. Manufacturing of semiconductor packaging substrates

[0108] In the manufacturing of the semiconductor package substrate 2 described above, for example, an insulating layer 22 and a conductor pattern 23 are alternately formed using a core layer 21 as the starting material. That is, the manufacturing method of the semiconductor package substrate 2 includes: a process for forming the insulating layer 22 (see...). Figure 3 A and Figure 3 B), and the process of forming conductor pattern 23 (see reference). Figure 3 C).

[0109] In detail, such as Figure 3 As shown in A, in the process of forming the insulating layer 22, firstly, the above-mentioned polyamic acid composition is coated on the surface of the core layer 21 or the insulating layer 22.

[0110] Next, the coating of the polyamic acid composition is dried by heating. The drying temperature is not limited as long as it allows the solvent to evaporate. When the solvent is N-methyl-2-pyrrolidone, the drying temperature is, for example, 120°C to 140°C, preferably 125°C to 135°C. By drying the coating of the polyamic acid composition, a dried film F of the polyamic acid composition is formed. The dried film F is an example of the polyamic acid film described above.

[0111] At this time, due to the evaporation of the solvent and the shrinkage caused by heating during drying (shrinkage of the polyamic acid film due to the imidization of polyamic acid), unevenness may sometimes occur on the surface of the dried film F, corresponding to the unevenness of the surface on which the polyamic acid composition is coated. If the dried film F is thermally cured while the surface of the dried film F is uneven, unevenness will remain on the surface of the insulating layer 22, which may make it difficult to form the conductor pattern 23.

[0112] In this regard, the polyamic acid mentioned above is a reaction product of α-ODPA and a diamine component containing ether diamine.

[0113] Therefore, as Figure 3 As shown in B, the surface of the dried film F can be easily and flatly formed by hot pressing.

[0114] The heating temperature during hot pressing is, for example, 140°C to 200°C, preferably 180°C to 190°C.

[0115] The pressure during hot pressing is, for example, 0.1 MPa to 3 MPa, preferably 1 MPa to 2 MPa.

[0116] After hot pressing, an insulating layer 22 can be formed by curing as needed.

[0117] Next, as Figure 3 As shown in C, for example, a through hole 221 for the passage of the via 25 is formed in the insulating layer 22 by laser processing.

[0118] Next, for example, the conductor pattern 23 and the via 25 are formed by electroplating.

[0119] In this way, by alternately forming insulating layers 22 and conductor patterns 23 with core layer 21 as the starting material, a conductor pattern 23 with the desired number of layers is formed, thereby completing the semiconductor package substrate 2.

[0120] 6. Effects

[0121] The polyamic acid of this invention is a reaction product of α-ODPA and a diamine containing an ether diamine. α-ODPA is an asymmetric tetracarboxylic dianhydride with a molecular structure consisting of two phthalic anhydrides bonded together by ether bonds.

[0122] Therefore, the dry film F (polyamic acid film) made from this polyamic acid can be easily formed by hot pressing.

[0123] Therefore, as Figure 3 A and Figure 3 As shown in B, in the process of forming the insulating layer 22, the surface of the dried film F can be easily and flatly formed by hot pressing.

[0124] As a result, the flatness of the insulation layer 22 can be improved.

[0125] Example

[0126] The present invention will be described in more detail below with reference to embodiments and comparative examples. It should be noted that the present invention is not limited to any embodiments and comparative examples. In addition, the specific numerical values ​​of mixing ratios (including ratios), physical property values, parameters, etc. used in the following description can be replaced with the corresponding upper limits (values ​​defined as "less than" or "less than") or lower limits (values ​​defined as "above" or "greater than") of the mixing ratios (including ratios), physical property values, parameters, etc., described in the "Specific Embodiments" above.

[0127] 1. Preparation of polyamic acid compositions

[0128] (1) Example 1

[0129] 3,4'-O-diphthalic dianhydride (α-ODPA) and 1,3-bis(4-aminophenoxy)benzene (1,3,4-APB) were dissolved in N-methylpyrrolidone (solvent) at a molar ratio of α-ODPA:1,3,4-APB 1:1. The resulting solution was stirred at 25°C to prepare a polyamic acid composition.

[0130] The solid composition and viscosity of the obtained polyamic acid composition are shown in Table 1.

[0131] It should be noted that the viscosity of the polyamic acid composition (at 25°C) was measured using an E-type viscometer (RE-85U, manufactured by Toki Sangyo Co., Ltd.), after preheating at 25°C for 1 minute, and then at 25°C for 5 minutes and a rotation speed of 2.5 rpm.

[0132] (2) Example 2

[0133] As the diamine, 1,3-bis(3-aminophenoxy)benzene (1,3,3-APB) was used instead of 1,3,4-APB. Otherwise, the polyamic acid composition was prepared in the same manner as in Example 1.

[0134] The solid composition and viscosity of the obtained polyamic acid composition are shown in Table 1.

[0135] (3) Example 3

[0136] As a diamine, in addition to 1,3,4-APB, 1,12-dodecanediamine was also used, and α-ODPA, 1,3,4-APB and 1,12-dodecanediamine were combined in a molar ratio (α-ODPA:1,3,4-APB:1,12-dodecanediamine) of 1:7:3. Otherwise, a polyamic acid composition was prepared in the same manner as in Example 1.

[0137] The solid composition and viscosity of the obtained polyamic acid composition are shown in Table 1.

[0138] (4) Comparison Example 1

[0139] As the tetracarboxylic dianhydride, 4,4'-oxobisphthalic dianhydride (s-ODPA) was used instead of α-ODPA. Otherwise, the polyamic acid composition was prepared in the same manner as in Example 1.

[0140] It should be noted that in Comparative Example 1, since the viscosity (at 25°C) was above 15 Pa·s after stirring for 15 hours, N-methylpyrrolidone was added to adjust the viscosity (at 25°C) to 8 Pa·s~14 Pa·s.

[0141] The solid composition and viscosity of the obtained polyamic acid composition are shown in Table 1.

[0142] (5) Comparison Example 2

[0143] As the tetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidene diphenoxy) phthalic anhydride (BPADA) was used instead of α-ODPA. Otherwise, the polyamic acid composition was prepared in the same manner as in Example 1.

[0144] It should be noted that in Comparative Example 2, since the viscosity (at 25°C) was above 15 Pa·s after stirring for 15 hours, N-methylpyrrolidone was added to adjust the viscosity (at 25°C) to 8 Pa·s~14 Pa·s.

[0145] The solid composition and viscosity of the obtained polyamic acid composition are shown in Table 1.

[0146] (6) Comparative Example 3

[0147] As the tetracarboxylic dianhydride, pyromellitic dianhydride (PMDA) was used instead of α-ODPA, and as the diamine, 4,4'-bis(3-aminophenoxy)biphenyl (4,3-BAPOBP) was used instead of 1,3,4-APB. Otherwise, the polyamic acid composition was prepared in the same manner as in Example 1.

[0148] It should be noted that in Comparative Example 1, since the viscosity (at 25°C) was above 15 Pa·s after stirring for 15 hours, N-methylpyrrolidone was added to adjust the viscosity (at 25°C) to 8 Pa·s~14 Pa·s.

[0149] The solid composition and viscosity of the obtained polyamic acid composition are shown in Table 1.

[0150] 2. Evaluation

[0151] (1) Flatness of polyimide film

[0152] A two-layer substrate consisting of a polyimide layer (thickness: 10 μm) and a stainless steel layer (thickness: 25 μm) was prepared, with an opening of 100 μm in diameter formed in the stainless steel layer.

[0153] Next, the polyamic acid compositions of each example and each comparative example were coated onto a stainless steel layer using a coater (coating gap: 150 μm) and dried at 130°C for 5 minutes.

[0154] Thus, a laminate consisting of a polyimide layer (thickness: 10 μm), a stainless steel layer (thickness: 25 μm), and a polyamic acid film (thickness: 5 μm) was fabricated.

[0155] Next, the obtained laminate was hot-pressed at 185°C for 15 minutes and 2 MPa using a vacuum hot pressurization apparatus (VS20-3430, manufactured by Mikado Technos).

[0156] Next, the depth of the depressions on the surface of the hot-pressed polyamic acid film (i.e., polyimide film) was measured using a laser microscope (VK-X1000-300, manufactured by Keyence).

[0157] The maximum values ​​of the measured depths are shown in Table 1. The smaller the value, the better the flatness.

[0158] (2) Electrical properties of polyimide film

[0159] The polyamic acid compositions of each example and each comparative example were applied to a stainless steel substrate (thickness: 20 μm) using a coater (coating gap: 150 μm), dried at 130°C for 5 minutes, and then dried at 185°C for 5 minutes.

[0160] Next, a polyimide film was fabricated on the substrate by heat treatment at 200°C to 400°C under an environment where the pressure was reduced to below 10 Pa.

[0161] Next, the substrate was removed with ferric chloride solution to obtain a polyimide film.

[0162] The dielectric constant and dielectric loss tangent of the obtained polyimide film at 10 GHz were determined using an electrical characteristic device (10 GHz SPDR resonator, manufactured by QWED).

[0163] The results are shown in Table 1.

[0164] (3) Heat resistance temperature of polyimide film

[0165] The polyamic acid compositions of each example and each comparative example were applied to the release film using a coater (coating gap: 200 μm) and dried at 130°C for 5 minutes.

[0166] Next, the obtained polyamic acid film was peeled off from the release film and placed in the heating chamber of a high-temperature observation device (SK-5000, manufactured by Sanyo Seiko Co., Ltd.). The film's shape change was observed while the temperature was increased to 400°C at a rate of 12°C / minute.

[0167] The melting temperature of the film was taken as the heat resistance temperature. The results are shown in Table 1.

[0168] (4) The flexibility of polyimide film

[0169] The polyamic acid compositions of each example and each comparative example were applied to the release film using a coater (coating gap: 200 μm), dried at 130°C for 5 minutes, and then dried at 185°C for 5 minutes.

[0170] Next, the obtained polyamic acid film was peeled off from the release film, and the loss modulus at 185°C was measured using a dynamic viscoelasticity measuring device (RSA-G2, manufactured by TA Instruments Japan). The results are shown in Table 1.

[0171]

[0172] It should be noted that although the above-described invention is provided as an example of an embodiment of the present invention, it is merely an example and not intended to be limiting. Modifications of the invention that are apparent to those skilled in the art are also included within the scope of the claims.

[0173] Industrial applicability

[0174] The polyamic acid, polyamic acid composition, polyamic acid film, polyimide, and polyimide film of the present invention can be used in the manufacture of wiring circuit boards. The wiring circuit boards of the present invention can be used, for example, in semiconductor packages and electronic devices.

Claims

1. A polyamic acid, which is a precursor of polyimide used as an insulating layer for wiring circuit boards, The polyamic acid is a reaction product of 3,4'-oxophthalic dianhydride and a diamine containing an ether diamine.

2. The polyamic acid according to claim 1, wherein, The proportion of the ether diamine in the diamine component is 0.5 moles or more, relative to 1 mole of 3,4'-oxophthalic dianhydride.

3. The polyamic acid according to claim 1, wherein, The diamine component contains only the ether diamine.

4. The polyamic acid according to claim 1, wherein, The ether diamine is 1,3-bis(4-aminophenoxy)benzene.

5. A polyamic acid composition comprising: The polyamic acid according to claim 1, and Solvent.

6. A polyamic acid film, which is the dried product of the polyamic acid composition of claim 5.

7. A polyimide, which is an imide of the polyamic acid of claim 1.

8. A polyimide film formed from the polyimide of claim 7.

9. A wiring circuit board, comprising: An insulating layer formed from the polyimide of claim 7, and Conductor pattern.

10. A semiconductor package comprising: The wiring circuit board according to claim 9, and Semiconductor chips mounted on the wiring circuit board.

11. An electronic device comprising the semiconductor package of claim 10.

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