JPH0730212A - Conductor/insulating resin composit body, single layer circuit board formed of the composit body and multilayer interconnecting board using the single layer circuit board - Google Patents

Abstract

PURPOSE:To allow reliable electrical connection to a conducting path and bump-shaped conductive protruding part by forming a plurality of penetrating conductive paths and the bump- shaped conductive protruding parts on the insulating resin layer on a base material whereupon a conductive layer is formed on one side. CONSTITUTION:A conductive layer 1 is formed on one side of a low linear expansion insulating resin layer 2, and a thermoplastic insulating resin layer 3 is formed on the other side so as to form a three-layer base material. The insulating resin layers 10 of the base material is provided with a plurality of through holes with a diameter of 10mum or more at intervals of 30mum or more, and the holes are filled with metal materials so as to form conductive paths 7. The 400 to 110,000 conductive paths 7 are formed per 1cm<2> and bump-shaped conductive protruding parts 5 extending from the conductive paths 7 are formed on the top surface of the insulating resin layers 10 (2 and 3). Therefore, the circuit of a single layer circuit board is electrically connected reliably through the bump-shaped conductive protruding parts only by bonding the insulating resin layer side of the single layer circuit board to the conductive circuit side of other single layer circuit board by thermocompression.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor-insulating resin composite mainly used for a multilayer wiring board and a multilayer wiring board formed by laminating the same.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become lighter, thinner, and smaller, so-called two-layer flexible wiring boards, in which wiring boards have higher performance and metal is directly laminated with an insulating resin, have been put on the market. It has become. Further, in the market, there is a demand for the development of multilayer wiring boards for higher density and higher performance, and various multilayer wiring board structures and manufacturing methods thereof have been proposed. Generally, a multilayer wiring board is manufactured by, for example, the following method. First, a plurality of single-layer circuit boards on which a circuit pattern is formed are prepared, and through holes are formed in desired portions of the circuit boards with a drill or the like. Then, the through hole is filled with a metal material by an appropriate method to form a conductive path and a bump-shaped conductive protrusion. Then, by thermocompression bonding using an insulating resin (adhesive), a multilayer wiring board in which the circuit boards are electrically connected via the bump-shaped conductive protrusions is manufactured.

[0003]

However, in the production of the above-mentioned multilayer wiring board, precision is required for the conductive paths formed in the single-layer circuit boards to be laminated, and complicated steps such as alignment during the lamination are required. Therefore, there is a problem that a multilayer wiring board cannot be efficiently manufactured. An object of the present invention is to solve the above-mentioned problems and to provide a conductor-insulating resin composite which can easily produce a single-layer circuit board. Another object of the present invention is to provide a single-layer circuit board having a large number of conductive paths, which can easily produce a multilayer wiring board. Another object of the present invention is to provide a multi-layer wiring board which is formed by stacking a plurality of the single-layer circuit boards described above and is excellent in reliability of conduction between circuit conductors of the single-layer circuit board.

[0004]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the inventors of the present invention have found that the insulating resin layer of a conductor-insulating resin composite has the above-mentioned insulating property with a specific gap. Form a plurality of through holes that penetrate the resin layer in the thickness direction,
A conductive layer is filled in the through hole to form a conductive path and a bump-shaped conductive protrusion extending from the conductive path on the surface of the insulating resin layer, and the conductive layer is subjected to circuit processing to form a single-layer circuit. The inventors have found that a multilayer wiring board can be easily manufactured by manufacturing a board and laminating a plurality of single-layer circuit boards by thermocompression bonding, and have completed the present invention. That is, the conductor-insulating resin composite of the present invention has a hole diameter of 10 μ that penetrates the insulating resin layer in the thickness direction at intervals of 30 μm or more in the insulating resin layer of the base material having the conductor layer formed on one surface.
A plurality of conductive paths of m or more and bump-like conductive protrusions extending from the conductive paths are formed.

Further, the single-layer circuit board of the present invention is one in which the conductor layer of the conductor-insulating resin composite is subjected to circuit processing. Further, the multilayer wiring board of the present invention is formed by laminating at least two of the single-layer circuit boards directly or with an insulating synthetic resin interposed between the circuits of each of the single-layer boards to provide a conductive path and a bump-like conductive structure. It is electrically connected through the prominent protrusion.

[0006]

According to the structure of the conductor-insulating resin composite of the present invention, a conductive path penetrating the insulating resin layer in the thickness direction and communicating with the conductor layer is 30 μm or more in the insulating resin layer of the composite. Since a large number are formed at intervals, no matter what circuit pattern is formed on the conductor layer to manufacture the single-layer circuit board, the conductor circuit is surely electrically connected to the conductive path and the bump-shaped conductive protrusion. In addition, since a large number of bump-like conductive protrusions are formed at intervals of 30 μm or more on the upper surface of the single-layer circuit board on which the circuit pattern is formed, it is possible to reduce the number of bump-like conductive protrusions to the insulating resin layer side The circuit between the boards can be surely conducted through the bump-shaped conductive protrusions only by facing the single-layer circuit board with the conductor circuit pattern side and thermocompression bonding. In addition, since a low linear expansion resin is used for forming the insulating resin layer and the conductor layer is formed on one surface of the low linear expansion resin layer, the difference between the linear expansion coefficient of the insulating resin and the linear expansion coefficient of the conductive layer is small. As a result, the size of the circuit pattern can be reduced, and the circuit pattern can be prevented from being displaced due to thermal contraction or curling after the conductor layer is etched. Further, the insulating resin layer is formed of the low linear expansion resin and the thermoplastic resin, and the respective insulating resins are mixed at the bonding interface, so that the insulating resin layer has excellent adhesiveness.

Further, according to the structure of the multilayer wiring board of the present invention, since a large number of bump-like conductive protrusions extending from the conductive path are formed on the surface, at least two single-layer circuit boards are precisely positioned. There is no need for alignment, the insulating resin layer side of the single-layer circuit board and the circuit pattern side are made to face each other and simply thermocompression bonded, and the conduction between the board circuits is performed through the conductive path and the bump-shaped conductive protrusions. Will be ensured.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more specifically below with reference to the drawings showing the embodiments. The present invention is not limited to these examples. FIG. 1 is a sectional view showing an example of a conductor-insulating resin composite of the present invention. In the figure, reference numeral 2 denotes a low linear expansion insulating resin layer, which forms a three-layer base material having a conductor layer 1 on one surface and a thermoplastic insulating resin layer 3 on the other surface. The insulating resin layer 10 of the three-layer substrate has a gap of 30 μm or more, preferably 40 μm or more.
The diameter of a plurality of holes penetrating in the thickness direction is 10 μm to 500 μm
A through hole of m or more, preferably 15 to 250 μm is formed, and a metal substance is filled in the through hole to form the conduction path 7. If the distance is 30 μm or less, the risk of short-circuiting between the adjacent bump-like conductive protrusions increases, while if the hole diameter is 10 μm or less, it is difficult to fill the conductive metal. Therefore, in the present invention, the conductive paths 7, 400 per complex 1 cm ²
˜110,000, preferably 1,600 to 60,000. Bump-shaped conductive protrusions 5 extending from the conductive paths 7 are formed on the upper surfaces of the insulating resin layers 10 (2, 3).

As the insulating resin used in the conductor-insulating resin composite of the present invention, various synthetic resins having excellent electrical insulation properties can be used. In the present invention, the use of a polyimide resin is preferable, and a conductor layer (copper layer) is particularly preferable. The linear expansion coefficient is 2.0 × 10 ⁻⁵ cm / cm / ° C., which is small in difference from the linear expansion coefficient of (4) and can suppress the deviation of the circuit pattern due to thermal contraction and the curl after etching the conductor layer. A low linear expansion polyimide resin having the following values is preferable. Further, in the present invention,
In order to improve the coating workability and the adhesiveness between the resin layers, it is preferable that the polyimide resin is subjected to a coating step as a polyimide precursor solution, and then heated and dehydrated for ring closure to imidize.

According to this structure, since a large number of conductive paths communicating with the conductor layer are formed in the insulating resin layer, no matter what circuit pattern is formed in the conductor layer, the conductive circuit pattern and the conductive path are not separated from each other. It will be surely conducted. Also, since the composite uses a low linear expansion insulating resin,
The difference from the linear expansion coefficient of the conductor layer is small, and it becomes possible to suppress the deviation of the circuit pattern due to thermal contraction or the like and the curl after the conductor layer is etched. In addition, in the composite in which the insulating resin layer is formed of the low linear expansion insulating resin layer and the thermoplastic insulating resin layer, the respective resins are mixed at the bonding interface, so that the insulating resin layer The adhesion between layers will be excellent.

As the above-mentioned thermoplastic polyimide resin, one having a glass transition temperature of 180 ° C. or higher and a melt viscosity at 390 ° C. of 10 ⁹ poise or less can be preferably used. Similar to the low linear expansion polyimide resin, this polyimide resin is also subjected to a coating step as a polyimide resin precursor solution in order to improve the coating workability and the adhesiveness between the resin layers, followed by heating and dehydration ring closure. And imidization is preferable.

The low linear expansion polyimide resin and the thermoplastic polyimide resin are not particularly limited as long as they meet the above definition, but the low linear expansion polyimide resin is 3,3 ', 4 as a tetracarboxylic acid component. , 4'-
At least one of biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, and 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride is used, and p-phenylenediamine, 4,4 is used as a diamine component. '-Diaminodiphenyl ether, m-phenylenediamine, 3,
It is preferable to use a polymerized product of at least one of 4'-diaminodiphenyl ether and 4,4'-diaminobiphenyl.

On the other hand, as the thermoplastic polyimide resin, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride and bis (3,3) are used as tetracarboxylic acid components. 4-dicarboxyphenyl) hexafluoropropane dianhydride,
3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) difluoromethane dianhydride At least one of the anhydrides is used, and bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane, 3,3′-diaminodiphenyl sulfone, 3,4 ′
-Diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-amino Phenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] propane, 3,3′-diaminodiphenylpropane, 3,3′-diaminobenzophenone used for polymerization reaction Is preferred. Polymerization is carried out by using N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide or the like as an organic solvent and mixing the above components in approximately equimolar amounts.

The conductor-insulating resin composite of the present invention is manufactured by processing, for example, according to the steps shown in the schematic sectional view of FIG. In this example, the insulating resin is polyimide and the conductor is copper foil. First, a low linear expansion polyimide precursor is applied onto a conductor such as a copper foil by means of a roll coater, a comma coater, a knife coater, a doctor blade, etc. and dried, and as shown in FIG. 1 / The structure of the low linear expansion polyimide precursor layer 2'is formed. Then, a thermoplastic polyimide precursor solution is further applied and dried on the low linear expansion polyimide precursor layer 2 ', and as shown in FIG. 2 (b), copper foil 1 / low linear expansion polyimide precursor layer 2 '/
The thermoplastic polyimide precursor layer 3 ′ has a structure. In addition, it is preferable that the drying step at this time is performed at a temperature of about 60 to 180 ° C. and only the solvent is removed so that dehydration ring closure and imidization of the polyimide precursor do not proceed. Further, by repeatedly applying the thermoplastic polyimide precursor solution in this manner, the surface layer portion of the low linear expansion polyimide precursor layer which has been previously coated and dried is dissolved to mix the respective polyimide precursor components. A sufficient interfacial adhesive force can be obtained when the film is heated and imidized in the subsequent step.

Next, the structure of the copper foil 1 / low linear expansion polyimide precursor layer 2 '/ thermoplastic polyimide precursor layer 3'is heated to a temperature of 300 ° C. or higher in an inert gas atmosphere. The polyimide precursor layers 2'and 3'are dehydrated and ring-closed to imidize. Devices such as a hot air circulation type heating furnace and a far infrared heating furnace are used for the above heating. When the heating temperature is 300 ° C. or lower, imidization does not proceed sufficiently and the characteristics peculiar to polyimide cannot be sufficiently exhibited. Further, if oxygen is present during imidization, not only the surface of the conductor is oxidized but also the thermoplastic polyimide resin may be thermally decomposed, which is not preferable. Usually, the oxygen concentration during heating is 4% or less, preferably 2% or less. By this step, the low linear expansion polyimide precursor layer 2 '/ thermoplastic polyimide precursor layer 3'is simultaneously imidized,
As shown in FIG. 2 (c), a structure of copper foil 1 / low linear expansion polyimide resin layer 2 / thermoplastic polyimide resin layer 3 is obtained, and at that time, at the bonding interface of both polyimide layers, The mixed layer 6 in which the polyimide resin is mixed is formed.

Next, the polyimide layers 2 and 3 which are insulating layers are penetrated in the thickness direction to form a through hole 4 as shown in FIG. 2 (d). The hole diameter x of this through hole can be set at any time depending on the application to which the substrate is applied, but is usually 10 to 200 μm
A size of the order is preferable. In addition, in the present invention, a plurality of the through holes are formed in the polyimide layer 10 over the entire surface of the polyimide layer at regular intervals. The interval y is 30 μm or more, preferably about 40 to 200 μm. Therefore, for example, for a 10 cm long and 10 cm wide substrate, 25
10,000 to 6.25 million through holes are formed. Examples of the method of forming the through hole include a wet etching method using an alkaline solution, a dry etching method of irradiating a laser or plasma, and a method of mechanically drilling with a drill or the like, but from the viewpoint of processing accuracy and processing speed. Is 4
An ablation process using an ultraviolet laser beam having a wavelength of 00 nm or less, particularly an excimer laser irradiation method is preferable. At this time, it is preferable to previously etch the conductor layer portion at the bottom of the through hole to form a bump-shaped groove communicating with the through hole.

Next, the through hole 4 is filled with a metal substance by a method such as electrolytic plating to form a conductive path 7 as shown in FIG. 2 (e), and from the conductive path 7 to the surface of the polyimide layer. A bump-shaped conductive protrusion 5 extending is formed. As for the metal to be filled, there is no particular problem if conduction can be obtained,
Metals such as gold, silver, copper, nickel, chromium, tin, solder, tungsten, rhodium and indium, or alloys thereof can be used alone or in combination of two or more.

The single-layer circuit board of the present invention is obtained by applying circuit processing to the conductor layer of the conductor-insulating resin composite composed of the copper foil / low linear expansion polyimide resin layer / thermoplastic polyimide resin layer having the above-mentioned constitution, The circuit pattern is formed. As shown in the schematic sectional view of FIG. 3, this single-layer circuit board has a circuit pattern P of the conductor 1 on the polyimide resin layer 10.
The two conductive paths 7a and 7b that are electrically connected to 1 are provided with the two conductive paths 7c and 7d that are electrically connected to the circuit pattern P2, and the surface of the polyimide layer 2 has a bump shape extending from the conductive paths 7a and 7b. The conductive protrusions 5a and 5b, and the conductive path 7
Bump-shaped conductive protrusions 5c and 5d extending from c and 7d are formed. A known method, for example, a method of coating a photoresist on a copper foil and exposing, developing, and wet etching the circuit pattern is adopted for forming the circuit pattern.

As shown in the schematic cross-sectional view of FIG. 4, the multilayer wiring board of the present invention is formed by laminating single-layer circuit boards 20 and 30 with an insulating synthetic resin layer 8 in between, and a circuit pattern P
1 and the circuit pattern P3 via the conductive path 7a and the bump-shaped metal projection 5a of the single-layer circuit board 30, the conductive path 7b and the bump-shaped metal projection 5b, and the circuit pattern P.
2 and the circuit pattern P4 are electrically connected to each other through the conduction path 7c of the single-layer circuit board 30 and the bump-shaped metal projection 5c, and the conduction path 7d and the bump-shaped metal projection 5d. This multilayer wiring board is manufactured by thermocompression bonding the circuit pattern side of the single-layer circuit board 20 and the bump-shaped metal protrusion side of the single-layer circuit board 30 via the insulating resin layer 8. As the thermocompression bonding method, a laminating roll or a hot press is used, and 1 to 500 kg at a temperature about 30 to 150 ° C. higher than the glass transition temperature of the thermoplastic polyimide resin.
It is obtained by applying a pressure of / cm ² and thermocompression bonding.

According to the above structure, the insulating resin layer of the single-layer circuit board is formed with a plurality of conductive paths of 10 μm or more at intervals of 30 μm or more, and the bump-shaped conductive paths extending from the conductive paths are formed on the surface thereof. Since a sex protrusion is formed,
It is not necessary to align the single-layer circuit boards to be laminated, and the insulating resin layer side of the single-layer circuit board and the conductor circuit pattern side of the other single-layer circuit board are simply opposed to each other and thermocompression-bonded to each other, and The circuit of each substrate can be surely conducted through the bump-shaped conductive protrusions. In the thermocompression bonding, the thermoplastic polyimide resin layer is laminated so as to be adjacent to the low linear expansion polyimide resin layer of the other single-layer circuit board to be laminated, but the conductor is etched in the previous step. Since the surface of the low linear expansion polyimide resin layer also becomes rough when processed to form a circuit, the adhesive strength with the thermoplastic resin is improved.

Hereinafter, the present invention will be described more specifically by showing experimental examples. Experimental Example 1 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine were used in N-
Polymerization in methyl-2-pyrrolidone to prepare a low linear expansion polyimide precursor solution, which was rolled copper foil (thickness 9μ
m) is casted uniformly using a comma coater, and 1
It was dried at 00 ° C. to form a low linear expansion polyimide precursor layer. Next, on the above-mentioned low linear expansion polyimide precursor layer, approximately equimolar amounts of bis (3,4-dicarboxyphenyl) ether dianhydride and bis [4- (4-aminophenoxy) phenyl] sulfone are added. Polymerization in N-methyl-2-pyrrolidone to prepare a thermoplastic polyimide precursor solution, which is cast and coated by the same method as above, 100 ° C.
And dried to form a thermoplastic polyimide precursor layer. The thickness of the obtained low linear expansion polyimide resin layer is 30 μm,
The thickness of the thermoplastic polyimide resin layer was 10 μm.
The thus-obtained three-layer substrate was placed in a continuous heating furnace in which the oxygen concentration was reduced to 1.5% or less by nitrogen gas substitution.
By heating to 50 ° C., dehydration ring closure and imidization treatment were carried out. When observing the cross section of the three-layer substrate with a scanning electron microscope, the interface between the low linear expansion polyimide resin layer and the thermoplastic polyimide resin layer does not exist clearly, and each resin component may be mixed. It could be confirmed.

Then, the surface of the polyimide resin layer of the three-layer substrate is irradiated with Kr-F excimer laser light having an oscillation wavelength of 248 nm through a mask to perform dry etching, and the polyimide resin layer has a diameter of 50 μm penetrating in the thickness direction.
Through holes having a pitch of 100 μm were formed on the entire surface of the thermoplastic polyimide resin layer. Then, a resist was applied to the surface of the copper foil, cured to insulate it, immersed in a chemical polishing liquid at 50 ° C. for 2 minutes, and then washed with water. This is immersed in a gold cyanide plating bath at 60 ° C., a copper foil is used as a cathode, electrolytic plating is performed between the counter electrode and the counter electrode to grow gold plating in the through holes, and the gold plating is bump-shaped on the surface of the thermoplastic polyimide resin layer. The plating process was terminated when the metal was deposited on the surface. Gold plating was formed on the surface of the polyimide resin layer so as to protrude from the surface by 5 μm. Finally, the resist layer applied to the copper foil surface was peeled off to obtain a copper foil-polyimide resin composite.

Next, the copper foil of the copper foil-polyimide resin composite was etched to form a copper layer circuit pattern. The three copper foil-polyimide resin composites on which this circuit pattern was formed were made to face each other with the thermoplastic polyimide resin layer side and the copper layer circuit side of the other composite, and the temperature was set to 350 ° C. by a vacuum hot press. Then, they were thermocompression bonded under a pressure of 100 kg / cm ² to obtain a multilayer wiring board having a three-layer structure.

When the peeling strength of this multilayer wiring board was measured by the 90 ° peel method, it was 1.5 kg / cm.
The peeling occurred at the interface between the polyimide resin layer and the copper foil, and did not occur between the polyimide resin layers. Also, 40
A solder dip test was performed at 0 ° C. for 30 seconds, but no void was generated and there was no problem in heat resistance.

Experimental Example 2 Almost equimolar amounts of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine / 4,4'-diaminodiphenyl ether (60:40 molar ratio) were used. Polymerization in N-methyl-2-pyrrolidone to prepare a low linear expansion polyimide precursor solution, which was uniformly cast-coated on a rolled copper foil (thickness 35 μm) using a comma coater, and at 100 ° C. It was dried to form a low linear expansion polyimide precursor layer. Then, on the above-mentioned low linear expansion polyimide precursor layer, almost equimolar amounts of bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride and bis [4- (3-aminophenoxy) phenyl] sulfone. , N-
Polymerization was carried out in methyl-2-pyrrolidone to prepare a thermoplastic polyimide precursor solution, which was cast and coated by the same method as above and dried at 100 ° C. to form a thermoplastic polyimide precursor layer. The thickness of the obtained low linear expansion polyimide resin layer was 30 μm, and the thickness of the thermoplastic polyimide resin layer was 10 μm. The thus-obtained three-layer substrate was heated to 420 ° C. in a continuous heating furnace having an oxygen concentration of 1.0% by nitrogen gas substitution, dehydration ring-closing and imidization treatment were performed. When observing the cross section of the three-layer substrate with a scanning electron microscope, the interface between the low linear expansion polyimide resin layer and the thermoplastic polyimide resin layer does not exist clearly, and each resin component may be mixed. It could be confirmed.

Next, the surface of the polyimide resin layer of the three-layer substrate is irradiated with Kr-F excimer laser light having an oscillation wavelength of 248 nm through a mask for dry etching, and the polyimide resin layer has a diameter of 40 μm which penetrates in the thickness direction.
Through holes having a pitch of 50 μm were formed on the entire surface of the thermoplastic polyimide resin layer. Then, a resist was applied to the surface of the copper foil, cured to insulate it, immersed in a chemical polishing liquid at 50 ° C. for 2 minutes, and then washed with water. This was immersed in a gold cyanide plating bath at 60 ° C., a copper foil was used as a cathode, electrolytic plating was performed between the counter electrode and the counter electrode to grow gold plating in the through holes, and the gold plating was deposited on the surface of the thermoplastic polyimide resin layer. By the way, the plating process was completed. Gold plating was formed on the surface of the polyimide resin layer so as to protrude by 7 μm from the surface. Finally, the resist layer applied to the copper foil surface was peeled off to obtain a copper foil-polyimide resin composite.

Then, the copper foil of the copper foil-polyimide resin composite was etched in the same manner as in Example 1 to form a copper layer circuit pattern. A thermoplastic polyimide resin film prepared separately in advance by making the thermoplastic polyimide resin layer side and the copper layer circuit side of another composite face the five copper foil-polyimide resin composites on which this circuit pattern is formed ( 15
(μm) sandwiched between them and replaced with nitrogen gas to a laminator with an oxygen concentration of 1.5% or less, temperature 370 ° C., pressure 50 kg.
It was heated and pressed under the condition of / cm ² to obtain a multilayer wiring board having a five-layer structure. The peel strength of this multilayer wiring board measured in the same manner as in Example 1 was 2.4 kg / cm, and peeling occurred at the interface with the copper foil and not between the polyimide resin layers. Further, a solder dip test was conducted at 400 ° C. for 30 seconds, but no void was generated and there was no problem in heat resistance.

Experimental Example 3 Pyromellitic dianhydride and p-phenylenediamine /
Almost an equimolar amount of 4,4′-diaminodiphenyl ether (50:50 molar ratio) was polymerized in N—N-dimethylformamide to prepare a low linear expansion polyimide precursor solution, which was used as an electrolytic copper foil (thickness: 12 μm) was evenly cast-coated with a roll coater and dried at 120 ° C. to form a low linear expansion polyimide precursor layer. Then, bis (3,4-dicarboxyphenyl) sulfone dianhydride and bis [4-
Almost equimolar amount of (4-aminophenoxy) phenyl] sulfone is polymerized in N-methyl-2-pyrrolidone to prepare a thermoplastic polyimide precursor solution, which is cast and coated by the same method as above. And dried at 120 ° C. to form a thermoplastic polyimide precursor layer. The obtained low linear expansion polyimide resin layer had a thickness of 15 μm, and the thermoplastic polyimide resin layer had a thickness of 6 μm. The three-layer substrate thus obtained was replaced with nitrogen gas so that the oxygen concentration was 1.0
In a continuous heating furnace adjusted to 100%, the mixture was heated to 500 ° C. to perform dehydration ring closure and imidization treatment. When observing the cross section of the three-layer substrate with a scanning electron microscope, the interface between the low linear expansion polyimide resin layer and the thermoplastic polyimide resin layer does not exist clearly, and each resin component may be mixed. It could be confirmed.

Next, the surface of the polyimide resin layer of the three-layer substrate is irradiated with Kr-F excimer laser light having an oscillation wavelength of 248 nm through a mask for dry etching, and the polyimide resin layer has a diameter of 50 μm which penetrates in the thickness direction.
Through holes having a pitch of 100 μm were formed on the entire surface of the thermoplastic polyimide resin layer. Then, a resist was applied to the surface of the copper foil, cured to insulate it, immersed in a chemical polishing liquid at 50 ° C. for 2 minutes, and then washed with water. This was immersed in a gold cyanide plating bath at 60 ° C., a copper foil was used as a cathode, electrolytic plating was performed between the counter electrode and the counter electrode to grow gold plating in the through holes, and the gold plating was deposited on the surface of the thermoplastic polyimide resin layer. By the way, the plating process was completed. On the surface of the polyimide resin layer,
Gold plating was formed protruding 3 μm from the surface. Finally, the resist layer applied to the copper foil surface was peeled off to obtain a copper foil-polyimide resin composite. Then, the copper foil of the copper foil-polyimide resin composite was etched in the same manner as in Example 1 to form a copper layer circuit pattern. The two copper foil-polyimide resin composites on which this circuit pattern was formed were subjected to a vacuum hot press in the same manner as in Example 1 at a temperature of 320 ° C.
By thermocompression bonding under the condition of a pressure of 250 kg / cm ² , a multilayer wiring board having a two-layer structure shown in FIG. 4 was obtained. This multilayer wiring board
The peel strength measured in the same manner as in Example 1 was 1.
The peeling occurred at the interface with the copper foil and did not occur between the polyimide resin layers. Also, 400 ° C, 30
A second solder dip test was conducted, but no void was generated and there was no problem in heat resistance.

Comparative Example 1 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine were used in an approximately equimolar amount with N-.
Polymerization in N-dimethylformamide was performed to prepare a low linear expansion polyimide precursor solution, which was rolled copper foil (thickness 9 μm
m) is casted uniformly using a comma coater, and 1
After drying at 00 ° C. to form a low linear expansion polyimide precursor layer, it was heated at 450 ° C. in a nitrogen gas atmosphere for dehydration ring closure and imidization treatment. Next, on the above low linear expansion polyimide layer, approximately equimolar amounts of bis (3,4-dicarboxyphenyl) ether dianhydride and bis [4- (4-aminophenoxy) phenyl] sulfone were mixed with N- Polymerization was carried out in methyl-2-pyrrolidone to prepare a thermoplastic polyimide precursor solution, which was cast and coated by the same method as above and dried at 100 ° C. to form a thermoplastic polyimide precursor layer. Then, this was heated to 450 ° C. in a continuous heating furnace having an oxygen concentration of 2.0% by nitrogen gas substitution, to perform dehydration ring closure and imidization treatment. The thickness of the obtained low linear expansion polyimide resin layer was 20 μm, and the thickness of the thermoplastic polyimide resin layer was 5 μm. When the cross section of the thus obtained three-layer substrate was observed with a scanning electron microscope, the interface between the low linear expansion polyimide resin layer and the thermoplastic polyimide resin layer was clearly present, and each resin component was mixed. It was confirmed that it was not done. Then, a copper layer circuit pattern was formed on the copper foil-polyimide resin composite copper foil in the same manner as in Example 1. The three copper foil-polyimide resin composites having this circuit pattern formed thereon were placed under vacuum thermal compression in the same manner as in Example 1 with the thermoplastic polyimide resin layer side facing the copper layer circuit side of the other composite. At the press
A multilayer wiring board having a three-layer structure was obtained by thermocompression bonding under the conditions of a temperature of 350 ° C. and a pressure of 100 kg / cm ² . The peel strength of this multilayer wiring board measured in the same manner as in Example 1 is
It was 0.1 kg / cm, easily peeled between the polyimide resin layers, and had almost no adhesive strength.

Comparative Example 2 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine were used in an approximately equimolar amount with N-.
Polymerization in methyl-2-pyrrolidone to prepare a low linear expansion polyimide precursor solution, which was rolled copper foil (thickness 35 μm
m) is casted uniformly using a comma coater, and 1
After drying at 00 ° C. to form a low linear expansion polyimide precursor layer, it is heated at 450 ° C. in a nitrogen gas atmosphere for dehydration ring closure and imidization treatment to obtain a copper foil-polyimide resin composite. It was The thickness of the obtained low linear expansion polyimide resin layer was 20 μm. Then, a copper layer circuit pattern was formed on the copper foil-polyimide resin composite copper foil in the same manner as in Example 1. On the other hand, bis (3,4-dicarboxyphenyl) sulfone dianhydride and bis [4- (4-aminophenoxy) phenyl] sulfone are almost equimolar,
After polymerizing in N-methyl-2-pyrrolidone to prepare a thermoplastic polyimide precursor solution, this is cast coated on a glass plate and dried at 100 ° C. to form a thermoplastic polyimide precursor layer, Further, this was heated to 450 ° C. in a heating furnace in which nitrogen gas was replaced to perform dehydration ring closure and imidization treatment. The thickness of the obtained thermoplastic polyimide resin layer is 15
was μm. Then, the two copper foil-polyimide resin composites having the circuit pattern are made to face the thermoplastic polyimide resin layer side and the copper layer circuit side of the other composite, and the thermoplastic polyimide resin layer is sandwiched therebetween. Then, in the same manner as in Example 1, it was thermocompression bonded under the conditions of a temperature of 350 ° C. and a pressure of 100 kg / cm ² by a vacuum hot press to obtain a multilayer wiring board having a two-layer structure. The peel strength of this multilayer wiring board measured in the same manner as in Example 1 was 0.4 kg / cm, and it was easily peeled between the polyimide resin layers and had almost no adhesive strength. In addition, as in Example 1, 40
When solder dipping was performed at 0 ° C., foaming occurred on the entire surface.

Comparative Example 3 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine were used in an approximately equimolar ratio to N-
Polymerization in methyl-2-pyrrolidone to prepare a low linear expansion polyimide precursor solution, and this was prepared using electrolytic copper foil (thickness 12 μm
m) is casted uniformly using a comma coater, and 1
It was dried at 00 ° C. to form a low linear expansion polyimide precursor layer. Next, bis [3,4-dicarboxyphenyl) ether dianhydride and bis [4- (4
-Aminophenoxy) phenyl] sulphone is polymerized in N-methyl-2-pyrrolidone to prepare a thermoplastic polyimide precursor solution, which is cast and coated in the same manner as above. Drying was carried out at 0 ° C. to form a thermoplastic polyimide precursor layer. The thickness of the obtained low linear expansion polyimide resin layer was 13 μm, and the thickness of the thermoplastic polyimide resin layer was 8 μm. The three-layer substrate thus obtained is not replaced with nitrogen gas (oxygen concentration is 18%)
When heated at 450 ° C. in a continuous heating furnace to perform dehydration ring closure and imidization treatment, the surface of the copper layer was oxidized and blackened, and the thermoplastic polyimide resin layer was blackened and deteriorated by thermal decomposition. The obtained copper foil-polyimide resin composite could not be subjected to the peeling strength test and the heat resistance test as in the above Examples.

[0033]

According to the conductor-insulating resin composite of the present invention, a plurality of holes having a diameter of 10 μm or more penetrating the insulating resin layer in the thickness direction are formed on the entire surface of the insulating resin layer of the composite at intervals of 30 μm or more. Through holes are formed, and the through holes are filled with a metal substance to form a large number of conducting paths. Therefore, even if any circuit pattern is formed on the conductor layer to produce a single-layer circuit board, The conductor circuit pattern can be surely conducted through the conduction path. In addition, a large number of conductive paths are formed on the single-layer circuit board at intervals of 30 μm or more, and bump-shaped conductive protrusions extending from the conductive paths are formed on the surface of the single-layer circuit board. Position of the conductive circuit and the conductive path (bump-shaped conductive protrusion) between the single-layer circuit boards only by facing the thermosetting resin layer side and the conductor circuit side of the other single-layer circuit board and thermocompression bonding. The circuit between the single-layer circuit boards can be surely conducted through the bump-shaped conductive protrusions without matching, and the circuit conduction reliability between the single-layer circuit boards can be improved. Further, since the low linear expansion insulating resin is used as the insulating resin and the conductor layer is formed on one surface of the low linear expansion insulating resin layer, the difference between the linear expansion coefficient of the conductive layer is small, It is possible to suppress deviation of the circuit pattern due to contraction or the like and curl after etching the conductor layer.
Further, since the low linear expansion insulating resin layer and the thermoplastic insulating resin layer are formed, the adhesiveness of each insulating resin layer is excellent, and the heat resistance, chemical resistance, and curl resistance are excellent. Become. Therefore, a multilayer wiring board formed by stacking two or more single-layer circuit boards obtained from the above composite easily and reliably conducts the circuits to improve the conduction reliability, and the multilayer wiring board. The substrate itself has excellent heat resistance, chemical resistance, and curl resistance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a conductor-insulating resin composite of the present invention.

FIG. 2 is a cross-sectional view illustrating the method for producing a conductor-insulating resin composite body of the present invention.

FIG. 3 is a cross-sectional view showing an example of a single-layer circuit board of the present invention.

FIG. 4 is a cross-sectional view showing an example of a multilayer wiring board of the present invention.

[Explanation of symbols]

 1 conductor 2 low linear expansion insulating resin layer 3 thermoplastic insulating resin layer 5,5a, 5b, 5c, 5d bump-like conductive protrusion 6 mixed layer 7, 7a, 7b, 7c, 7d conductive path 8 insulating Synthetic resin layer 20,30 Single layer circuit board P1, P2, P3, P4 Conductor circuit pattern

Claims (7)

[Claims] 1. A plurality of conductive paths having a hole diameter of 10 μm or more penetrating the insulating resin layer in the thickness direction at intervals of 30 μm or more in an insulating resin layer of a base material having a conductor layer formed on one surface, and the conductive paths. A conductor-insulating resin composite, characterized in that bump-shaped conductive protrusions extending from the conductor are formed. 2. The conductor-insulating material according to claim 1, wherein the base material is a three-layered base material in which a conductor layer is formed on one surface of a low linear expansion insulating resin layer and a thermoplastic insulating resin layer is formed on the other surface. Resin composite. 3. The conductor-electrically insulating resin composite according to claim 2, wherein the insulating interface between the low linear expansion insulating resin layer and the thermoplastic insulating resin layer is mixed with respective insulating resin components. . 4. The conductor-electrically insulating resin composite according to claim 2 or 3, wherein the low linear expansion insulating resin layer is formed by imidizing a polyimide resin precursor. 5. The thermoplastic insulating resin layer is formed by imidizing a polyimide resin precursor.
Alternatively, the conductor-electrically insulating resin composite according to item 3. 6. A single-layer circuit board obtained by subjecting the conductor layer of the conductor-electrically insulating resin composite according to claim 1 to circuit processing. 7. A single-layer circuit board according to claim 6, wherein at least two of the single-layer circuit boards are laminated directly or via an insulating synthetic resin, and a conductive path and bump-like conductivity are provided between the circuits of each of the single-layer boards. A multilayer wiring board that is electrically connected through a protrusion.