JPH054838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a printed circuit board.

[Conventional technology]

As methods for forming patterns on printed circuit boards, subtractive methods and additive methods are known.

The subtractive method uses a copper-clad laminate with a thin copper foil pasted on the surface (one or both sides) of a resin laminate, and forms a conductor pattern by dissolving and removing unnecessary copper foil parts other than the conductor pattern area using chemicals. The through-hole plating part is formed by applying a thin layer of electroless copper plating and then applying a thick layer of electroplating.

On the other hand, the additive method is a method in which thick electroless plating is applied only to the conductor pattern on a bare resin laminate with no copper foil attached.In this method, all through holes are formed as copper through holes. be done.

[Problem that the invention seeks to solve]

However, in the conventional pattern forming method for printed circuit boards, there is a process that allows batch processing of multiple materials at the same time, such as a plating process and an etching process, and a process that allows through-hole formation and various types of holes that serve as guide holes for printing and pressing. The problem is that it is difficult to increase production efficiency because the pattern forming process includes processes that can only be performed on each piece of material, such as a punching press for finishing cutting.

In other words, even if the drilling and pressing processes are automated and a small number of multiple materials can be processed simultaneously in this process, the number of sheets processed is far smaller than the number of sheets processed in the plating and etching processes, so it is difficult to form patterns. This is because each process cannot proceed at a synchronized process speed. Note that even for substrates without through holes, drilling guide holes for printing is essential.

[Means for solving problems]

The present invention is a printed circuit board manufacturing method that adopts a pattern forming method that can significantly improve production efficiency by changing the timing of machining such as drilling guide holes and press punching in the conventional pattern forming method as described above. The structure was made with the purpose of proposing a method for applying a conductive material to the surface of a substrate material that has been cut into a predetermined shape in advance, has undergone the necessary drilling process, and has a conductive material pasted on the surface. An etching resist layer made of a heat-fusible film having a lower melting temperature than that of the synthetic resin film having a high melting temperature is placed on the upper surface, and a heat press die having a circuit pattern engraved on the surface thereof is placed. By applying pressure to the substrate material from above the etching resist layer, the etching resist layer is left in accordance with the circuit pattern of the die, and after removing other parts of the resist layer, the substrate material is It is characterized by etching.

[Effect]

When manufacturing a printed circuit board, mechanical processing such as drilling holes and punching presses is performed prior to forming conductor patterns, so that it is easy to improve the efficiency and rationalize the printed circuit board manufacturing process.

〔Example〕

Next, an embodiment of the present invention will be described with reference to process diagrams shown in FIGS. 1a to 1c.

Reference numeral 1 denotes a non-conducting substrate material such as a plastic laminate, and a thin copper plate 2, which is a conductive material, is pasted on the surface (in this case, the upper surface, the upper surface, and the lower surface in some cases).

Here, the substrate material 1 is cut in advance into a predetermined unit size of a specific printed circuit board to be formed, and a long material with a continuous width of a predetermined printed circuit board is later cut into a predetermined length. Sometimes it is cut right away. Incidentally, in the prior art, the size of this board material was the size of multiple pieces of specific printed circuit boards, such as four or six pieces, but in the present invention, the size of this board material Either the size of one sheet is cut in advance to the size of one substrate material, or the substrate material is a long material having a continuous length.

Next, on the substrate material 1 to which the copper thin plate 2 is pasted,
An etching resist layer 3 made of hot melt synthetic resin is disposed over the entire upper surface of the thin copper plate 2.

The etching resist layer may be a coating layer made of a heat-fusible synthetic resin film instead of the hot-melt synthetic resin described above. here,
A synthetic resin film 3a with a high melting temperature is on the upper surface, and a hot melt synthetic resin film 3 with a lower melting temperature than the film 3a is on the lower surface of the film 3a.
A laminated film of heat-fusible films such as A is arranged as a coating layer.

It is sufficient that the etching resist layer 3 is disposed on the upper surface of the substrate material 1 before the hot pressing process described later.

Further, guide holes (not shown) for feeding the material and later machining are provided in advance at predetermined positions in the substrate material 1 at this stage.

Reference numeral 4 denotes a mold for forming the etching resist layer 3 on the upper surface of the substrate material 1 according to the circuit pattern by hot pressing.

That is, the mold 4 has pattern blades 4a engraved on its lower surface for forming circuit patterns, necessary holes, etc., and a pattern blade 4a for heating the pattern blades 4a inside the mold. A heater (not shown) is provided. In this case, it is desirable that the engraved surface of the mold 4 and the bonding surfaces of the synthetic resin films 3a and 3b be coated with a release agent to prevent the molten resin from adhering. On the other hand, the surface roughness of the upper surface of the thin copper plate 2 is made rougher than the engraved surface.

Therefore, the mold 4 is pressed against the substrate material 1 from above the etching resist layer 3 disposed on the upper surface of the thin copper plate 2, thereby forming the pattern blade 4a.
Only the part marked with etching resist layer 3 and substrate material 1
The thin copper plate 2 is pressurized.

As a result, the hot-melt synthetic resin film 3b of the etching resist layer 3 is adhered to the thin copper plate 2 of the substrate material 1 in the same pattern as the circuit pattern, as shown in FIG. Formed in a dist layer. In this pressing step, in addition to forming the pattern etching resist layer described above, other cutting tools provided in advance in the mold 4 can also perform necessary hole drilling at the same time.

In the two layers of films 3a and 3b of the etching resist layer in this embodiment, since the film 3a has a higher melting temperature than the film 3b, when the film 3b is fused to the surface of the thin copper plate 2, the film 3a
Since this is not melted, this is the pattern blade 4 of the mold 4.
It does not fuse to a.

When the release material is coated between the films 3a and 3b, only the film 3b is fused and remains on the thin copper plate 2 according to the pattern of the pattern blade 4a, as shown in FIG. 1b. film 3
When the mold release material is not coated between a and 3b, the film 3a of the resist layer 3,
3b remains on the thin copper plate 2 according to the pattern.

Therefore, when only the film 3b is fused onto the thin copper plate 2, the synthetic resin film 3a of the resist layer 3 and the hot melt resin film 3b are bonded together.
The unfused portion is transported, for example, to the right side in FIG. 1a, and removed from the upper surface of the substrate material 1.

That is, the film material forming the etching resist layer 3 in FIG. This will remove the remaining part. At this time, the substrate material 1 is moved in a direction perpendicular to the paper surface.

As shown in FIG. 1b, the substrate material 1 in which the upper surface of the thin copper plate 2 is covered with the etching resist layer 3 made of hot-melt resin 3b according to the circuit pattern is etched by a conventional method. The portions of the thin copper plate 2 which are not coated with the resist layer 3 are removed to form a substrate material 1 having a circuit pattern as shown in FIG. 1c.

Here, the etching resist layer 3 remaining on the upper surface of the thin copper plate 2 of the circuit pattern is then removed by a conventional method, and the substrate material 1 is formed into a printed circuit board.

〔Effect of the invention〕

The present invention is as described above, and in forming a conventional printed circuit board, the circuit pattern is formed first, and then mechanical processing such as drilling and cutting is performed. Since the machining process and the formation of the circuit pattern are performed at the same time, the manufacturing efficiency of printed circuit boards can be dramatically improved.

Therefore, the present invention is extremely useful as a method for manufacturing printed circuit boards.

[Brief explanation of the drawing]

FIGS. 1a, b, and c are cross-sectional views showing steps in an example of the manufacturing method of the present invention. 1... Substrate material, 2... Thin copper plate, 3... Etching resist layer, 4... Mold, 4a... Pattern blade.

Claims (1)

[Claims] 1. In a substrate material that has been cut into a predetermined shape in advance, has been subjected to the necessary drilling process, and has a conductive material pasted on its surface, a synthetic resin film with a high melting temperature is placed on top of the surface of the conductive material. While an etching resist layer made of a heat-fusible film with a low melting temperature is placed, a heat press die with a circuit pattern engraved on its surface is pressed against the substrate material from above the etching resist layer. A method of manufacturing a printed circuit board, characterized in that the etching resist layer is left in accordance with the circuit pattern of the die and other parts of the resist layer are removed, and then the substrate material is subjected to etching treatment.