JP2001168502A - Smooth printed wiring board and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a durable smooth printed wiring board which is suitable for such application that electrodes are slid. SOLUTION: The printed wiring board is constituted in such a way that a circuit board 5 having etched circuit pattern sections 3 and insulating recessed sections 4 and through holes 7 formed at places in the recessed sections 4 is thermocompression bonded to a prepreg 10, and the recessed sections 4 are filled up with a resin 11 via the through holes 7 until the surface of resin 11 is flush with the surfaces of the circuit pattern sections 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board having smoothness and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, when a printed wiring board is a four-layer board as an example, a copper foil is thermocompression-bonded to an inner circuit board on which a circuit is formed via a semi-cured adhesive sheet (prepreg) to form a copper containing inner circuit. A laminated laminate was prepared, and then holes were formed and plated with copper to form an outer layer circuit.

[0003]

In such a printed wiring board, since the outer layer circuit and the insulating portion have irregularities, the electrode slides on the surface thereof. However, there is a problem that the shoulder of the circuit of the printed wiring board is shaved, the durability of the printed wiring board is deteriorated, and short circuit occurs between adjacent circuits due to shavings of the circuit. In addition, the sliding electrode itself also suffers from abrasion due to irregularities in the outer layer circuit and the insulating portion, resulting in a problem that durability is deteriorated.

[0004]

SUMMARY OF THE INVENTION The present invention has been studied to solve the problems of the prior art, and has the following features. That is, it has a circuit pattern portion 3 based on an etching process and an insulating concave portion 4, a through-hole 7 is provided in each part of the insulating concave portion 4, and the insulating concave portion 4 is flush with the circuit pattern portion 3 through the through-hole 7. A printed wiring board having a smoothness filled with a resin 11, a circuit pattern portion 3 based on an etching process, and an insulating recess 4; And the prepreg 10 are thermocompression-bonded, and the resin 11 is flush with the circuit pattern portion 3 through the through hole 7 in the insulating recess 4.
Is a method of manufacturing a printed wiring board having a smoothness and filling the circuit pattern portion, the printed wiring board having a smoothness plated with the circuit pattern portion 3 and a printed wiring board having a smoothness plating the circuit pattern portion 3. And a method for producing a printed wiring board having smoothness by thermocompression bonding with a vacuum press. Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a circuit board 5 used in the present invention. By etching and drilling a copper clad laminate, a circuit pattern portion 3 and an insulating recess 4 are formed. Through holes 7 are provided in some places.

FIG. 2 is a transparent perspective view of a printed wiring board 20 having smoothness according to the present invention. On the side on which the electrodes slide, the insulating recess 4 is filled with the resin 11 flush with the circuit pattern portion 3 through the through hole 7. Have been. The lower layer uses a copper foil 8 as a base material. In addition to copper foil, aluminum foil,
By etching and drilling a nickel foil, a substrate on which a circuit is formed, an insulating plate, and a copper-clad laminate as described above, a circuit pattern portion 3 'and an insulating recess 4' are formed. A circuit board 5 ′ having a through hole 7 ′ at each position ′ may be mentioned, but is not particularly limited.

FIG. 3 is a cross-sectional view schematically illustrating a method of manufacturing a printed wiring board 21 having smoothness according to another embodiment, and FIG. 4 is a cross-sectional view illustrating the configuration of the printed wiring board 21 having smoothness. Circuit board 5 and circuit board 5 processed in the same manner
′ Are overlapped with each other via a prepreg (semi-cured adhesive sheet) 10 and thermocompression-bonded. When the thermocompression bonding is performed, the resin in the prepreg melts, flows outward through the through holes 7 and 7 ′, and fills the insulating concave portions 4 and 4 ′ flush with the circuit pattern portions 3 and 3 ′, and the resin 11 is cured. Then, the circuit pattern portions 3, 3
And the electrode slides on this surface.

The resin used as the prepreg 10 may be a known resin such as an epoxy resin or a polyimide. As means for thermocompression bonding, any means capable of flowing out the resin in the prepreg may be used, for example, a hydraulic press,
Vacuum presses, such as a hydraulic vacuum press and an autoclave vacuum press, are mentioned. The use of a vacuum press is preferable because the resin has a smoother filling of the insulating recesses with very few bubbles.

FIG. 5 is a sectional view showing the structure of a printed wiring board 22 having plating on the circuit pattern portions 3 and 3 'and having smoothness. By forming the plated portions 6 and 6 ', the circuit pattern portions 3 and 3' are sufficiently protected, and the durability is further improved. Examples of plating include gold plating and nickel plating, but are not particularly limited. Examples will be described below.

[0010]

Example 1 A copper-clad laminate having a copper foil thickness of 35 μm was etched and drilled to form a through hole having a hole diameter of 0.9 mm in a circuit pattern portion and an insulating recess having no circuit pattern portion at 2.5 mm intervals. Circuit boards provided at 2.54 mm intervals were produced. Next, two epoxy resin prepregs were interposed between the circuit board and the copper foil, and the temperature was 170 ° C., the pressure was 10 kg / cm ² , and the time was 10 hours using a hydraulic press.
Thermocompression bonding was performed in 0 minutes. As a result, the epoxy resin flowed into the insulating recess through the through-hole, and a printed wiring board having smoothness and being flush with the circuit pattern portion was obtained.

[0011]

Example 2 Two circuit boards similar to those in Example 1 were prepared. Then, two epoxy resin prepregs were interposed between these circuit boards, and an autoclave vacuum press was used. The conditions during molding were a degree of vacuum of 50 mmHg, and a temperature of 170.
When thermocompression bonding was performed at 100 ° C. for 100 minutes, a printed wiring board having smoothness was obtained.

[0012]

Embodiment 3 A copper-clad laminate having a copper foil thickness of 70 microns is etched, drilled, and gold-plated to provide gold plating on a circuit pattern portion, and insulating recesses at 2.5 mm intervals without a circuit pattern portion. In this example, two circuit boards were provided in which through holes having a hole diameter of 0.9 mm were provided at intervals of 2.54 mm. Next, two epoxy resin prepregs were interposed between these circuit boards, and a hydraulic vacuum press was used. The conditions during molding were a degree of vacuum of 50 mmHg, a temperature of 170 ° C., and a time of 10 hours.
When thermocompression bonding was performed in 0 minutes, a printed wiring board having smoothness was obtained.

[0013]

The present invention is a printed wiring board in which the insulating concave portions adjacent to the circuit pattern portion are smoothed, so that even if the electrodes slide on the surface, the shoulders of the circuit are not scraped, and the durability is improved. Further, there is no short circuit between adjacent circuit portions due to circuit shavings.

Further, the wear of the sliding electrode is significantly reduced, and the durability of the electrode is also improved. Further, if the circuit pattern portion is plated as shown in FIG. 5, the durability is further improved, which is extremely preferable.

[Brief description of the drawings]

FIG. 1 is a perspective view of a circuit board 5 used in the present invention.

FIG. 2 is a printed wiring board 20 having smoothness according to the present invention.
FIG.

FIG. 3 is a printed wiring board 21 having smoothness according to the present invention.
FIG. 6 is a schematic cross-sectional view showing a method for manufacturing a semiconductor device.

FIG. 4 is a printed wiring board 21 having smoothness according to the present invention.
FIG.

FIG. 5 is a printed wiring board 22 having smoothness according to the present invention.
FIG.

[Explanation of symbols]

 Reference Signs List 3 circuit pattern portion 4 insulating concave portion 4 'insulating concave portion 5 circuit board 5' circuit board 6 plated portion 7 through hole 7 'through hole 8 copper foil 10 prepreg 11 resin 20 printed wiring board having smoothness 21 printed wiring having smoothness Board 22 Printed wiring board having smoothness

Claims (5)

[Claims] 1. A circuit pattern portion 3 based on an etching process and an insulating recess 4 are provided.
Wherein the insulating recess 4 is filled with the resin 11 flush with the circuit pattern portion 3 through the through hole 7. 2. An insulating recess 4 having a circuit pattern portion 3 based on an etching process, and a through hole 7
Wherein the circuit pattern portion 3 is plated, and the insulating recess 4 is filled with the resin 11 flush with the plating portion 6 through the through hole 7 to provide a smooth printed wiring board. 3. An insulating recess 4 having a circuit pattern portion 3 formed by etching and a through hole 7
The circuit board 5 provided with the prepreg 10 is thermocompression-bonded, and the insulating recess 4 is filled with the resin 11 flush with the circuit pattern portion 3 through the through hole 7. Manufacturing method of printed wiring board. 4. A circuit pattern portion 3 based on an etching process and an insulating concave portion 4 are provided.
The prepreg 10 is thermocompression-bonded with the circuit board 5 on which the circuit pattern portion 3 is plated, and the resin 11 is flush with the plating portion 6 in the insulating recess 4 through the through hole 7.
A method for producing a printed wiring board having smoothness, characterized by filling the substrate. 5. The method for producing a printed wiring board having smoothness according to claim 3, wherein thermocompression bonding is performed by a vacuum press.