JPH01124293A - Manufacture of double-sided printed-circuit board - Google Patents

Abstract

PURPOSE:To form a double-sided printed-circuit board at a low cost by a simple manufacturing process by a method wherein circuit patterns of a prescribed shape which are connected electrically to each other via a conductive part by a conductive material inside a through hole are formed on both faces of an insulating substrate. CONSTITUTION:A conductive thin-film body 3 composed of copper foil is applied, via an adhesive agent 4, to one face 1a of an insulating substrate 1 where through holes 2, 2 have been made; pasty conductive materials 5 are filled and coated inside the through holes 2, 2; a conductive thin-film body 6 is applied, via an adhesive agent 7, to the other face 1b of the insulating substrate 1. Then, the individual conductive thin-film bodies 3, 6 are etched; circuit patterns 3a, 6a of a prescribed shape are formed on both faces 1a, 1b of the insulating substrate 1. As a result, a double-sided printed-circuit board A which has the circuit patterns 3a, 6a electrically connected to each other via conductive parts 5a, 5a on both faces is formed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to electrically connecting circuit patterns formed on both sides of an insulating base plate to each other through conductive portions in through holes formed in the insulating base plate. The present invention relates to a method for manufacturing a double-sided printed circuit board that is connected.

[Prior art and its problems]

Conventional double-sided printed circuit boards are formed on both sides of the insulating base plate by forming through holes in the insulating base plate and forming conductive parts on the inner peripheral surface of the through holes by a solder dip method, solder plating method, etc. The connected circuit patterns are electrically connected through the conductive portions.

However, when using the solder dip method mentioned above,
The complicated work of dipping the insulating base plate into a bath of high-temperature molten solder and holding it in a fixed position is required, and when using the solder plating method, the plating conditions must be strictly controlled to ensure the reliability of the connection. This necessitates troublesome work such as having to Therefore, when forming conductive portions by the solder dipping method or the solder plating method, there are problems in that the manufacturing process becomes complicated and the manufacturing cost becomes high.

[Objective of the Invention 1 This invention was made in order to solve the above-mentioned problems, and an object thereof is to provide a method for manufacturing a double-sided printed circuit board that can form a double-sided printed circuit board at low cost through a simple manufacturing process. .

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention fills and coats a paste-like conductive material into a through hole for a conductive portion formed in an insulating base plate, and also coats both sides of the insulating base plate. By integrally depositing a conductive thin film body including each of the through holes and performing an etching process on each conductive thin film body, the conductive material in the through hole is formed on both sides of the insulating blank plate. The main point is that circuit patterns each having a predetermined shape are formed which are electrically connected to each other via conductive portions.

[Example] Hereinafter, an example of the method for manufacturing a double-sided printed circuit board of the present invention will be described in the order of steps shown in FIGS. 1A to 5B.

In FIG. 1A and FIG. 1B, an insulating blank plate 1 is shown. This insulating base plate 1 is made of an insulating resin film such as polyimide resin, and has one or a plurality of through holes 2, 2 for conducting portions formed at predetermined positions.

In this embodiment, first, on one side 1a of the insulating blank l in which the through hole 2.2 is formed, as shown in FIGS. 2A and 2B.
As shown in the figure, a conductive thin film body 3 made of copper foil is integrally adhered to the through hole 2.2 via an adhesive 4. This conductive thin film body 3 is integrally bonded to one side 1a of the insulating blank plate 1 so as to cover a predetermined area of the entire surface 1a of the insulating blank plate 1 including the through holes 2, 2. Note that this work of adhering the conductive thin film body 3 is performed on the insulating base plate l except for the through hole 2.2.
This is done by applying an adhesive 4 approximately evenly on one surface la of the , and then adhering the conductive thin film 3 onto the applied adhesive 4.

Next, as described above, a conductive thin film 3 is placed on one surface 1a of the insulating base plate 1.
After depositing the conductive material 5 in the form of a paste into the through hole 2.2 of the insulating base plate l, as shown in FIG.
Apply qpl cloth so that it contacts the J membrane body 3. Note that solder paste or the like is used for this paste-like conductive material 5.

Next, as shown in FIG. 4, on the other surface 1b of the insulating blank l, on which the conductive material 5 is filled and applied in the through holes 2 and z, as described above, including the through holes 2.2, A conductive g film body 6 made of copper foil, which is different from the conductive thin film body 3, is integrally attached via an adhesive 7. This conductive FI film body 6 has the through hole 2.2.
is bonded and integrated with the other surface ib of the insulating material plate l so as to cover the entire predetermined range on the other surface 1b of the insulating material plate l. In addition,
The work of bonding the conductive thin film body 6 is carried out by applying the adhesive 7 approximately evenly on the other surface 1b of the insulating plate l excluding the through hole 2.2, and then applying the adhesive 7 on the applied adhesive 7. conductive to 6tjH
This is done by gluing the body 6 together. By this adhesion, the conductive thin film body 6 is held in contact with the conductive material 5.

Next, by performing an etching process on each of the conductive thin film bodies 3.6 attached to both surfaces 1a and 1b of the insulating blank l,
5A and 5 on both surfaces 1a and 1b of the insulating base plate l.
As shown in figure B, circuit patterns 3a, 6a of a predetermined shape
form each. As a result, the circuit patterns 3a, 6a are electrically connected to each other via the conductive parts 5a, 5a formed by the conductive material 5.5 in the through hole 2.2.
A double-sided printed circuit board A having on both sides is formed.

According to the method for manufacturing a double-sided printed circuit board of the present invention, the paste-like conductive material 5 is filled and applied in the through holes 2.2 for the conductive portions of the insulating blank l, and the insulating blank l is After the conductive thin film bodies 3.6 are integrally deposited on both surfaces 1a and 1b, including the through holes 2.2, each of the conductive thin film bodies 3.6 is etched, thereby forming the insulating base plate. Circuit patterns 3a, 6a of a predetermined shape are electrically connected to each other via conductive parts 5a, 5a formed by the conductive materials 5, 5 in the through hole 2.2 on both sides 1a, lb of the through hole 2.2. Since they are formed separately, complicated and troublesome work such as the conventional solder dip method and solder plating method is no longer necessary, and the paste-like conductive material 5.5 is filled and applied inside the through hole 2.2 of the insulating base plate l. Moreover, the circuit patterns 3a and 6a electrically connected to each other can be formed on both sides simply by etching the conductive F1 film body 3.6, which simplifies the manufacturing process and makes a single-sided printed circuit board inexpensive. can be formed into

Moreover, if the insulating base plate 1 is made of an insulating resin film and the conductive thin film body 3.6 is made of copper foil as in the above-mentioned embodiment, an extremely thin double-sided printed circuit board can be easily and inexpensively made. Can be formed.

In the above embodiment, after the conductive thin film 3 is adhered to one surface 1a of the insulating base plate l, the through holes 2.2 of the insulating base plate l are
Although the paste-like conductive material 5 is filled and applied inside the insulating base plate 1, the present invention is not limited thereto.
After filling and applying the paste-like conductive material 5.5 inside Z, a conductive thin film body 3.
6 may be applied.

[Effects of the Invention] As explained above, the present invention is capable of filling and applying a paste-like conductive material into the through holes for conductive parts formed in an insulating base plate, and forming the through holes on both sides of the insulating base plate, respectively. By integrally depositing a conductive thin film body including the hole and etching each conductive thin film body, conductive parts formed by the conductive material in the through hole are formed on both sides of the insulating blank plate. Since circuit patterns of a predetermined shape are electrically connected to each other through the insulating plate, the complicated and troublesome work of the conventional solder dip method and solder plating method is no longer necessary, and the paste can be pasted into the through holes of the insulating base plate. Simply fill and apply a conductive material of the shape and process the conductive thin film.
Since circuit patterns of a predetermined shape that are electrically connected to each other can be formed on both sides, the manufacturing process can be simplified and a double-sided printed circuit board can be formed at low cost.

[Brief explanation of the drawing]

1A to 5B show an embodiment of the method of this invention in the order of steps, and FIG. 1A is a plan view of an insulating base plate;
Figure B is a cross-sectional view taken along the line II in Figure 1A, Figure 2A is a plan view of a state in which a conductive thin film is adhered to one surface of the insulating base plate, and Figure 2B is a cross-sectional view taken along line I-I in Figure 2A. ■Cross-sectional view along the line, 3rd
The figure is a cross-sectional view of the through hole of the insulating base plate filled with a paste-like conductive material, FIG. Fig. 5A is a plan view of the conductive thin film body after etching to form a circuit pattern, and Fig. 55B is a sectional view taken along line v--v in Fig. 5A. l...Insulating base plate, 2...Through hole, 3.
... Conductive thin film body, 3a ... Circuit pattern, 4 ... Adhesive, 5 ... Paste conductive material, 5a ... Continuity Part, 6... Conductive fj film body, 6a... Circuit pattern, 7...
··glue. Patent applicant Casio Computer Co., Ltd. Figure 1A Figure is Figure 2A Figure 28 Figure 4 Figure 5A Figure 58

Claims (1)

[Claims] A step of filling and applying a paste-like conductive material into a through hole for a conductive portion formed in an insulating base plate, and forming a conductive thin film on both sides of the insulating base plate, including the through hole, respectively. By performing an etching process on each of the conductive thin film bodies deposited on both sides of the insulating blank plate, the conductive material in the through hole is applied to both sides of the insulating blank plate. 1. A method for manufacturing a double-sided printed circuit board, comprising the step of forming circuit patterns each having a predetermined shape and electrically connected to each other via the formed conductive portions.