Polyamic acid, polyamic acid composition, polyamic acid film, polyimide, polyimide film, wiring circuit board, semiconductor package, and electronic device

Abstract

This polyamic acid is a precursor of a polyimide used as an insulation layer of a wiring circuit board. The polyamic acid is a reaction product of 3,4'-oxydiphthalic dianhydride and an ether diamine-containing diamine component.

Description

Polyamic acid, polyamic acid composition, polyamic acid film, polyimide, polyimide film, wiring circuit board, semiconductor package, and electronic device

[0001] The present invention relates to a polyamic acid, a polyamic acid composition, a polyamic acid film, a polyimide, a polyimide film, a printed circuit board, a semiconductor package, and an electronic device.

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

[0003] Japanese Patent Application Laid-Open No. 2019-127503

[0004] However, when the polyamic acid varnish described in Patent Document 1 is applied to a substrate having an uneven surface, unevenness may occur on the surface of the dried film of the polyamic acid varnish in accordance with the unevenness of the applied surface.

[0005] If the dry film is thermally cured while the surface thereof is uneven, the unevenness will remain on the surface of the cured insulating layer, which may make it difficult to form a conductive pattern on the insulating layer.

[0006] The present invention provides a polyamic acid, a polyamic acid composition, and a polyamic acid film that can improve the flatness of an insulating layer; a polyimide and a polyimide film made from the polyamic acid; a wiring circuit board having an insulating layer made from the polyamic acid; and a semiconductor package and an electronic device that include the wiring circuit board.

[0007] The present invention [1] is a precursor of a polyimide used as an insulating layer of a printed circuit board, and contains a polyamic acid which is a reaction product of 3,4'-oxydiphthalic dianhydride and a diamine component containing an etherdiamine.

[0008] The present invention [2] includes the polyamic acid according to the above [1], wherein the ratio of the ether diamine in the diamine component is 0.5 mol or more per 1 mol of 3,4'-oxydiphthalic dianhydride.

[0009] The present invention [3] includes the polyamic acid according to the above [1] or [2], wherein the diamine component contains only the ether diamine.

[0010] The present invention [4] includes the polyamic acid according to any one of the above [1] to [3], wherein the ether diamine is 1,3-bis(4-aminophenoxy)benzene.

[0011] The present invention [5] is a polyamic acid composition containing the polyamic acid according to any one of the above [1] to [4] and a solvent.

[0012] The present invention [6] includes a polyamic acid film, which is a dried product of the polyamic acid composition of the above [5].

[0013] The present invention [7] includes a polyimide which is an imidized product of the polyamic acid according to any one of the above [1] to [4].

[0014] The present invention [8] includes a polyimide film, which is a film made of the polyimide of the above [7].

[0015] The present invention [9] includes a printed circuit board comprising an insulating layer made of the polyimide of the above [7] and a conductor pattern.

[0016] The present invention

[10] includes a semiconductor package comprising the wired circuit board of the above [9] and a semiconductor chip mounted on the wired circuit board.

[0017] The present invention

[11] includes an electronic device comprising the semiconductor package of the above

[10] .

[0018] The polyamic acid of the present invention is a reaction product of 3,4'-oxydiphthalic dianhydride and a diamine component containing an ether diamine. 3,4'-oxydiphthalic dianhydride is an asymmetric tetracarboxylic acid dianhydride having a molecular structure in which two phthalic anhydrides are bonded via an ether bond.

[0019] Therefore, a dry film (polyamic acid film) made from the polyamic acid can be easily molded by heat pressing.

[0020] Therefore, in the step of forming the insulating layer, the surface of the dry film made from polyamic acid can be easily formed flat by heat pressing.

[0021] As a result, the flatness of the insulating layer can be improved.

[0022] Fig. 1 is a perspective view showing one embodiment of a semiconductor package of the present invention. Fig. 2 is a cross-sectional view of the semiconductor package substrate shown in Fig. 1. Figs. 3A to 3C show manufacturing steps for the semiconductor package substrate shown in Fig. 1, with Fig. 3A showing a step of forming a dry film of a polyamic acid composition, Fig. 3B showing a step of heat-pressing the dry film of the polyamic acid composition, and Fig. 3C showing a step of forming a conductor pattern on an insulating layer.

[0023] 1. Polyamic Acid The polyamic acid of the present invention is used in the production of a wired circuit board. Specifically, the polyamic acid of the present invention is a precursor of a polyimide used as an insulating layer of a wired circuit board. Preferably, the polyamic acid of the present invention is a precursor of a polyimide used as an interlayer insulating layer 22 (see FIG. 2) of a semiconductor package substrate 2 (see FIG. 1). The semiconductor package substrate 2 will be described later.

[0024] Polyamic acid is the reaction product of 3,4'-oxydiphthalic dianhydride (α-ODPA) and a diamine component.

[0025] α-ODPA has a molecular structure in which two phthalic anhydrides are bonded via an ether bond. The ether bond connects the carbon atom at position 3 of one phthalic anhydride with the carbon atom at position 4 of the other phthalic anhydride. Therefore, the molecular structure of α-ODPA is asymmetric when the oxygen atom of the ether bond is taken as the center of symmetry. In other words, α-ODPA is an asymmetric tetracarboxylic dianhydride.

[0026] Note that 4,4'-oxydiphthalic dianhydride (s-ODPA), which is a structural isomer of α-ODPA, is symmetrical when the oxygen atom of the ether bond is taken as the center of symmetry. In other words, s-ODPA is a symmetrical tetracarboxylic dianhydride.

[0027] The diamine component contains at least one diamine. The diamine component contains only diamine. The diamine component contains, for example, an ether diamine. An ether diamine is a diamine having an ether bond.

[0028] Examples of the ether diamine include aromatic diamines having an ether bond (aromatic ether diamines) and aliphatic diamines having an ether bond (aliphatic ether diamines).

[0029] 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, and 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'-oxydianiline, and 3,4'-diaminodiphenyl ether.

[0030] 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′-oxybis(ethylamine), 1,14-diamino-3,6,9,12-tetraoxatetradecane, polyethylene glycol bis(3-aminopropyl) ether, and polyethylene glycol diamine.

[0031] As the ether diamine, preferably, an aromatic ether diamine, more preferably, 1,3,4-APB is used.

[0032] When the ether diamine is 1,3,4-APB, the heat resistance of the insulating layer can be improved.

[0033] The proportion of the etherdiamine in the diamine component is, for example, 0.5 mol or more, or preferably 0.7 mol or more, per 1 mol of α-ODPA.

[0034] When the proportion of etherdiamine in the diamine component is equal to or greater than the above lower limit, the flatness of the insulating layer can be improved.

[0035] The upper limit of the proportion of etherdiamine in the diamine component is not limited. The proportion of etherdiamine in the diamine component may be equimolar to α-ODPA. The diamine component may contain only etherdiamine.

[0036] The diamine component may contain a diamine having no ether bond in addition to the ether diamine.

[0037] Examples of diamines having no ether bond include aromatic diamines having no ether bond and aliphatic diamines having no ether bond.

[0038] Examples of aromatic diamines having no ether bond include p-phenylenediamine, 4,4'-diaminophenylmethane, 4,4'-diaminodiphenyl sulfone, 1,4-diaminobenzene, 2,5-diaminotoluene, and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 1,5-diaminonaphthalene, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, m-xylylenediamine, p-xylylenediamine, 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, ... Examples of the phthalene, 3,3'-diaminodiphenylmethane, 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-tolidine, bis(4-aminophenyl)sulfide, 3,3',5,5'-tetramethylbenzidine, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-ethylenedianiline, and 4,4'-diamino-2,2'-dimethylbibenzyl.

[0039] Examples of aliphatic diamines having no ether bond 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-diaminodecane, 1,12 ... amine, 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.

[0040] The proportion of the "diamine having no ether bond" in the diamine component is, for example, less than 0.5 mol, preferably 0.3 mol or less, per 1 mol of α-ODPA.

[0041] 2. Polyamic Acid Composition The polyamic acid composition is a liquid (varnish) and contains the above-described polyamic acid and a solvent.

[0042] The solvent is not limited as long as it can dissolve the polyamic acid, and examples of the solvent include aprotic polar solvents.

[0043] Aprotic polar solvents include, for example, N-methyl-2-pyrrolidone, dimethylacetamide, dimethylsulfoxide, dimethylformamide, and hexamethylphosphoramide.

[0044] The proportion of polyamic acid in the polyamic acid composition is, for example, 5 mass % or more, preferably 7.5 mass % or more, or more preferably 10 mass % or more.

[0045] The proportion of polyamic acid in the polyamic acid composition is, for example, 20 mass % or less, preferably 16 mass % or less, and more preferably 14 mass % or less.

[0046] The proportion of polyamic acid in the polyamic acid composition may be 5% by mass to 20% by mass, 7.5% by mass to 16% by mass, or 10% by mass to 14% by mass.

[0047] The viscosity of the polyamic acid composition at 25°C is, for example, 5 Pa·s or more, or preferably 8 Pa·s or more.

[0048] The viscosity of the polyamic acid composition at 25°C is, for example, 15 Pa·s or less, or preferably 14 Pa·s or less.

[0049] The viscosity of the polyamic acid composition at 25° C. may be 5 Pa·s to 15 Pa·s, or 8 Pa·s to 14 Pa·s.

[0050] The polyamic acid composition can be obtained, for example, by reacting α-ODPA with a diamine component in a solvent.

[0051] When the insulating layer of the wiring circuit board is patterned by photolithography, the polyamic acid composition may contain a photosensitizer and a development accelerator in addition to the polyamic acid and the solvent.

[0052] The photosensitizer promotes imidization of the polyamic acid in the exposed area during the exposure step of the photolithography method, where the exposed area is the area of ​​the dried film of the polyamic acid composition that has been exposed to light.

[0053] The development accelerator promotes dissolution of the unexposed areas during the development step of the photolithography process. The unexposed areas are the areas of the dried film of the polyamic acid composition that are not exposed during the exposure step.

[0054] 3. Polyamic Acid Film, Polyimide, and Polyimide Film The polyamic acid film of the present invention is a dried product of the polyamic acid composition described above. The polyamic acid film can be obtained, for example, by applying the polyamic acid composition to a substrate and drying it. The polyamic acid film contains the polyamic acid described above and, if necessary, a photosensitizer and a development accelerator.

[0055] The polyamic acid film has a glass transition temperature (Tg) of, for example, 135° C. or lower, preferably 120° C. or lower. The polyamic acid film has a glass transition temperature (Tg) of, for example, 60° C. or higher. The polyamic acid film may have a glass transition temperature (Tg) of 60° C. to 135° C. or 60° C. to 120° C.

[0056] The glass transition temperature (Tg) is the temperature at which the loss tangent (tan δ) becomes maximum when dynamic viscoelasticity is measured using a dynamic viscoelasticity measuring device (trade name: RSA-G2, manufactured by TA Instruments Japan) under the following measurement conditions:

[0057] <Measurement conditions> Sample size: width 10 mm, length 20 mm Measurement mode: tension mode Measurement temperature range: 0°C to 200°C Heating rate: 5°C / min Frequency: 1 Hz Load (axial direction): 0.01 N The polyimide of the present invention is an imidized product of the above-mentioned polyamic acid. The polyimide film of the present invention is a film made from polyimide. The polyimide film can be obtained, for example, by heating the above-mentioned polyamic acid film to imidize the polyamic acid.

[0058] The glass transition temperature (Tg) of the polyimide film is, for example, 140° C. or higher. The upper limit of the glass transition temperature (Tg) of the polyimide film is not limited.

[0059] 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 more preferably 400° C. or higher. The upper limit of the heat resistance temperature of the polyimide film is not limited.

[0060] The heat resistance temperature of the polyimide film is measured by the method described in the examples below.

[0061] The dielectric constant of the polyimide film at 10 GHz is, for example, 3.0 to 4.0, or preferably 3.2 to 3.5.

[0062] The polyimide film has a dielectric loss tangent at 10 GHz of, for example, 0.00500 to 0.00800, or preferably 0.00550 to 0.00700.

[0063] The dielectric constant and dielectric loss tangent are measured by the method described in the examples below.

[0064] 4. Semiconductor Package and Wired Circuit Board The semiconductor package 1 is one component that constitutes a circuit board of an electronic device. In other words, the electronic device includes the semiconductor package 1.

[0065] As shown in FIG. 1 , a semiconductor package 1 includes a semiconductor package substrate 2 as an example of a wired circuit board, a semiconductor chip 3 , and a sealing resin 4 .

[0066] (1) Semiconductor Package Substrate As shown in FIG. 2, the semiconductor package substrate 2 includes a core layer 21, a plurality of insulating layers 22A, 22B, and 22C, and a plurality of conductor patterns 23A, 23B, and 23C.

[0067] The core layer 21 is made of, for example, a metal. 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.

[0068] The plurality of insulating layers 22A, 22B, and 22C are laminated on one side of the core layer 21 in the thickness direction of the semiconductor package substrate 2. Each of the plurality of insulating layers 22A, 22B, and 22C is made of polyimide. That is, each of the plurality of insulating layers 22A, 22B, and 22C is an example of the polyimide film described above. The insulating layer 22A is disposed between the conductor pattern 23A and the core layer 21 in the thickness direction. The insulating layer 22B is disposed between the conductor pattern 23B and the conductor pattern 23A in the thickness direction. The insulating layer 22C is disposed between the conductor pattern 23C and the conductor pattern 23B in the thickness direction.

[0069] The thickness of each of the insulating layers 22A, 22B, and 22C is, for example, 5 μm to 20 μm, or preferably 5 μm to 15 μm.

[0070] The conductor pattern 23A is disposed on one surface of the insulating layer 22A in the thickness direction. The semiconductor package substrate 2 also has a plurality of insulating layers 24 (see FIG. 1 ) and a plurality of conductor patterns on the other side of the core layer 21 in the thickness direction. The conductor pattern 23A is connected to the conductor pattern on the other side in the thickness direction via vias (not shown) that penetrate the insulating layer 22A and the core layer 21. The conductor pattern 23B is disposed on one surface of the insulating layer 22B in the thickness direction. The conductor pattern 23B is connected to the conductor pattern 23A via via 25A. The conductor pattern 23C is disposed on one surface of the insulating layer 22C in the thickness direction. The conductor pattern 23C is connected to the conductor pattern 23B via via 25B. An example of the material of each of the conductor patterns is copper.

[0071] The thickness of each of the conductor patterns 23A, 23B, and 23C is, for example, 5 μm to 40 μm.

[0072] 1, the semiconductor chip 3 is mounted on the semiconductor package substrate 2. The semiconductor chip 3 is disposed on one surface 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 via, for example, a wire 5.

[0073] (3) Sealing Resin The sealing resin 4 is disposed on one surface of the semiconductor package substrate 2 in the thickness direction. The sealing resin 4 seals the semiconductor chip 3.

[0074] 5. Manufacturing of Semiconductor Package Substrate In manufacturing the semiconductor package substrate 2 described above, for example, the core layer 21 is used as a starting material, and insulating layers 22 and conductor patterns 23 are alternately formed. That is, the manufacturing method of the semiconductor package substrate 2 includes a step of forming the insulating layers 22 (see FIGS. 3A and 3B ) and a step of forming the conductor patterns 23 (see FIG. 3C ).

[0075] More specifically, as shown in FIG. 3A, in the step of forming the insulating layer 22, first, the above-described polyamic acid composition is applied to the surface of the core layer 21 or the insulating layer 22.

[0076] Next, the coating film of the polyamic acid composition is dried by heating. The drying temperature is not limited as long as it can volatilize the solvent. 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 film of the polyamic acid composition, a dry film F of the polyamic acid composition is formed. The dry film F is an example of the polyamic acid film described above.

[0077] At this time, due to evaporation of the solvent and shrinkage due to heating during drying (shrinkage of the polyamic acid film caused by imidization of the polyamic acid), unevenness may occur on the surface of the dried film F according to the unevenness of the surface on which the polyamic acid composition is applied. If the dried film F is thermally cured while the surface of the dried film F is uneven, the unevenness will remain on the surface of the insulating layer 22, which may make it difficult to form the conductive pattern 23.

[0078] In this regard, the above-mentioned polyamic acid is a reaction product of α-ODPA and a diamine component containing an ether diamine.

[0079] Therefore, as shown in FIG. 3B, the surface of the dry film F can be easily formed flat by heat pressing.

[0080] The heating temperature in the heat press is, for example, 140°C to 200°C, or preferably 180°C to 190°C.

[0081] The pressure in the heat press is, for example, 0.1 MPa to 3 MPa, or preferably 1 MPa to 2 MPa.

[0082] After the heat pressing, the insulating layer 22 is formed by curing as required.

[0083] Next, as shown in FIG. 3C, through-holes 221 for passing vias 25 are formed in the insulating layer 22 by, for example, laser processing.

[0084] Next, the conductive pattern 23 and the vias 25 are formed by, for example, electrolytic plating.

[0085] In this way, the semiconductor package substrate 2 is completed by alternately forming the insulating layers 22 and the conductor patterns 23 using the core layer 21 as a starting material to form a desired number of layers of conductor patterns 23 .

[0086] The polyamic acid of the present invention is a reaction product of α-ODPA and a diamine component containing an ether diamine. α-ODPA is an asymmetric tetracarboxylic dianhydride having a molecular structure in which two phthalic anhydrides are bonded via an ether bond.

[0087] Therefore, the dry film F (polyamic acid film) made from the polyamic acid can be easily molded by heat pressing.

[0088] Therefore, as shown in FIGS. 3A and 3B, in the step of forming the insulating layer 22, the surface of the dry film F can be easily formed flat by heat pressing.

[0089] As a result, the flatness of the insulating layer 22 can be improved.

[0090] The present invention will be described in more detail below with reference to examples and comparative examples. It should be noted that the present invention is in no way limited to these examples and comparative examples. The specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of the Invention" above.

[0091] 1. Production of Polyamic Acid Composition (1) Example 1 3,4'-oxydiphthalic dianhydride (α-ODPA) and 1,3-bis(4-aminophenoxy)benzene (1,3,4-APB) were dissolved in N-methylpyrrolidone (solvent) at a molar ratio (α-ODPA:1,3,4-APB) of 1:1. The resulting solution was stirred at 25°C to prepare a polyamic acid composition.

[0092] The solid content and viscosity of the resulting polyamic acid composition are shown in Table 1.

[0093] The viscosity (at 25°C) of the polyamic acid composition was measured using an E-type viscometer (RE-85U, manufactured by Toki Sangyo Co., Ltd.) at 25°C for 5 minutes at a rotation speed of 2.5 rpm after preheating at 25°C for 1 minute.

[0094] (2) Example 2 A polyamic acid composition was prepared in the same manner as in Example 1, except that 1,3-bis(3-aminophenoxy)benzene (1,3,3-APB) was used as the diamine instead of 1,3,4-APB.

[0095] The solid content and viscosity of the resulting polyamic acid composition are shown in Table 1.

[0096] (3) Example 3 A polyamic acid composition was prepared in the same manner as in Example 1, except that 1,12-dodecanediamine was used in addition to 1,3,4-APB as the diamine, and α-ODPA, 1,3,4-APB, and 1,12-dodecanediamine were blended in a molar ratio (α-ODPA:1,3,4-APB:1,12-dodecanediamine) of 1:7:3.

[0097] The solid content and viscosity of the resulting polyamic acid composition are shown in Table 1.

[0098] (4) Comparative Example 1 A polyamic acid composition was prepared in the same manner as in Example 1, except that 4,4'-oxydiphthalic dianhydride (s-ODPA) was used as the tetracarboxylic dianhydride instead of α-ODPA.

[0099] In Comparative Example 1, since the viscosity (at 25°C) after stirring for 15 hours was 15 Pa s or more, N-methylpyrrolidone was added to adjust the viscosity (at 25°C) from 8 Pa s to 14 Pa s.

[0100] The solid content and viscosity of the resulting polyamic acid composition are shown in Table 1.

[0101] (5) Comparative Example 2 A polyamic acid composition was prepared in the same manner as in Example 1, except that 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA) was used instead of α-ODPA as the tetracarboxylic dianhydride.

[0102] In Comparative Example 2, since the viscosity (at 25°C) after stirring for 15 hours was 15 Pa s or more, N-methylpyrrolidone was added to adjust the viscosity (at 25°C) from 8 Pa s to 14 Pa s.

[0103] The solid content and viscosity of the resulting polyamic acid composition are shown in Table 1.

[0104] (6) Comparative Example 3 A polyamic acid composition was prepared in the same manner as in Example 1, except that pyromellitic dianhydride (PMDA) was used instead of α-ODPA as the tetracarboxylic dianhydride, and 4,4′-bis(3-aminophenoxy)biphenyl (4,3-BAPOBP) was used instead of 1,3,4-APB as the diamine.

[0105] In Comparative Example 1, since the viscosity (at 25°C) after stirring for 15 hours was 15 Pa s or more, N-methylpyrrolidone was added to adjust the viscosity (at 25°C) from 8 Pa s to 14 Pa s.

[0106] The solid content and viscosity of the resulting polyamic acid composition are shown in Table 1.

[0107] 2. Evaluation (1) Flatness of Polyimide Film A two-layer substrate consisting of a polyimide layer (thickness: 10 μm) and a stainless steel layer (thickness: 25 μm) was prepared, and an opening having a diameter of 100 μm was formed in the stainless steel layer.

[0108] Next, the polyamic acid composition of each Example and Comparative Example was applied to the stainless steel layer using an applicator (coating gap: 150 μm) and dried at 130° C. for 5 minutes.

[0109] This produced a laminate of polyimide layer (thickness: 10 μm) / stainless steel layer (thickness: 25 μm) / polyamic acid film (thickness: 5 μm).

[0110] Next, the resulting laminate was heat-pressed at 185° C. for 15 minutes at 2 MPa using a vacuum heat pressurizing device (VS20-3430, manufactured by Mikado Technos Co., Ltd.).

[0111] Next, the depth of the depressions on the surface of the polyamic acid film (ie, polyimide film) after heat pressing was measured using a laser microscope (VK-X1000-300, manufactured by Keyence Corporation).

[0112] The maximum measured depth values ​​are shown in Table 1. The smaller the value, the better the flatness.

[0113] (2) Electrical Properties of Polyimide Film The polyamic acid composition of each Example and Comparative Example was applied to a stainless steel substrate (thickness: 20 μm) using an applicator (coating gap: 150 μm), and dried at 130° C. for 5 minutes and then at 185° C. for 5 minutes.

[0114] Next, the substrate was heated at 200° C. to 400° C. in an environment reduced to 10 Pa or less to produce a polyimide film on the substrate.

[0115] Next, the substrate was removed with a ferric chloride solution to obtain a polyimide film.

[0116] The dielectric constant and dielectric loss tangent of the resulting polyimide film at 10 GHz were measured using an electrical property measurement device (10 GHz SPDR resonator, manufactured by QWED).

[0117] The results are shown in Table 1.

[0118] (3) Heat Resistance Temperature of Polyimide Film The polyamic acid composition of each Example and Comparative Example was applied to a release film using an applicator (coating gap: 200 μm) and dried at 130° C. for 5 minutes.

[0119] Next, the obtained polyamic acid film was peeled off from the release film and placed in a heating chamber of a high-temperature observation device (SK-5000, manufactured by Sanyo Seiko Co., Ltd.). The temperature was raised to 400°C at a rate of 12°C / min, and the change in the shape of the film was observed.

[0120] The temperature at which the film melted was taken as the heat resistance temperature. The results are shown in Table 1.

[0121] (4) Flexibility of Polyimide Film The polyamic acid composition of each Example and Comparative Example was applied to a release film using an applicator (coating gap: 200 μm), and dried at 130° C. for 5 minutes and then at 185° C. for 5 minutes.

[0122] 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 Co., Ltd.) The results are shown in Table 1.

[0123] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the following claims.

[0124] The polyamic acid, polyamic acid composition, polyamic acid film, polyimide, and polyimide film of the present invention can be used to produce a wiring circuit board. The wiring circuit board of the present invention can be used, for example, in semiconductor packages and electronic devices.

[0125] REFERENCE SIGNS LIST 1 Semiconductor package 2 Semiconductor package substrate (an example of a wiring circuit board) 3 Semiconductor chip 22 Insulating layer 23 Conductive pattern

Claims

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

2. The polyamic acid according to claim 1, wherein the ratio of the ether diamine in the diamine component is 0.5 mol or more with respect to 1 mol of 3,4'-oxydiphthalic 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 containing the polyamic acid according to claim 1 and a solvent.

6. A polyamic acid film which is a dried product of the polyamic acid composition according to claim 5.

7. A polyimide which is an imidized product of the polyamic acid according to claim 1.

8. A polyimide film which is a film made of the polyimide according to claim 7.

9. A wiring circuit board comprising an insulating layer made of the polyimide according to claim 7 and a conductor pattern.

10. A semiconductor package comprising the wiring circuit board according to claim 9 and a semiconductor chip mounted on the wiring circuit board.

11. An electronic device comprising the semiconductor package according to claim 10.

Images