JPS59232492A - Method of producing multilayer printed circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a multilayer printed wiring board.

[Background technology] Conventionally, in manufacturing multilayer printed wiring boards, multiple double-sided through-hole wiring boards, in which wiring patterns are formed on both the front and back sides and the wiring patterns on the front and back sides are electrically connected using conductive material in the through-holes, are laminated. However, this method has the disadvantage that in order to form a multilayer wiring pattern, it is necessary to laminate all the wiring boards for the same number of layers, making the thickness of the multilayer printed wiring board extremely thick. [Object of the Invention] The present invention has been made in view of the above-mentioned axis, and provides a multilayer printed wiring board that can be made thinner even though the entire multilayer wiring pattern is formed. [Disclosure of the Invention] In other words, the unexploded standard 1 has a first wiring pattern (
A second through hole (5 ) perforated metal foil with an electrically insulating layer (
6) are stacked so that the metal foil (7) is on the front side, and the metal foil (7) is stacked and integrated, and the second through hole (5) is aligned with the wiring pattern i11 position tfff of the second through hole (5).
) on the surface of the metal foil (7) in a pattern shape including the through-holes (5) of the metal foil (7), etching to completely form the second wiring pattern (9), and then remove the protective layer. A multilayer device characterized in that the through hole (5) shown below in 2 is filled with a conductive material [0] to fully electrically connect the wiring pattern (1) of the IJll and the second wiring pattern (9). The above object has been achieved by a method for manufacturing a printed wiring board.

The present invention will be explained in detail below with reference to Examples. The wiring board (4) is a resin board (with a first wiring pattern on both the front and back sides).
At the same time, the front and back wiring back-' ill + is electrically connected using a conductive material (3) such as a blind formed in the first through hole (2) drilled in the resin substrate (11). As shown in FIG. 1(b), second through holes (
5) is perforated and the 1c metal foil with electrical insulating layer (6) is stacked so that the entire metal foil (7) is on the front side to integrate the sum layer, and the 20th through hole (5) is connected to the first wiring pattern i1.
Align to position 1. Here, the electrical insulating layer Q31 can be formed of a resin coating layer, a resin coating, or the like. Next, a protective layer (not shown) is applied to the surface of the metal foil (7) in a pattern so as to include the second through holes (5). The protective layer may be formed by applying an etching resist, or may be formed behind tenting using a thermoplastic film. After protecting the through-hole land with the protective layer in this way, the second wiring pattern (9) is formed on the metal foil (7) by etching.
form. After that, the surface of the metal foil (7) and the second through hole (the protective layer inside 5i are removed, and then the second through hole [conductive material such as solder or conductive paste 00 inside 5i) is formed.
, to electrically connect the first wiring pattern +11 and the second wiring pattern (9).

Then, a layer is applied to the surface of the metal foil (7) in a pattern shape so as to include the second through hole (5), and etched to form a second wiring pattern (9) on the metal foil (7). After that, after removing all 9 layers, through holes (
6) The type of the wiring board (4) is determined by filling the conductive material (10) in the interior to electrically connect the first wiring pattern il+ and the second wiring pattern (9). Regardless of the type of wiring board (4), multilayer wiring can be easily formed, and the conductive material (10) can be connected by optically connecting it to the through hole (5). It is highly reliable because it is a circuit board, and it can be manufactured at low cost because it does not require any equipment for mounting.Furthermore, the electrical insulation is thinner than the wiring board (4). The wiring pattern (9) can be formed by fully laminating the layered metal foil (6).
) to create a multilayer wiring pattern tll I91
'(c') Even if the shadow is formed, the thickness of the multilayer printed wiring board can be completely reduced.

Note that FIG. 2 shows another embodiment, in which a metal base substrate (J4) with a corrugated insulating layer (15) on the surface of a metal core material (I4) is used as the substrate. In this case, it is possible to obtain a multilayer printed wiring board with good heat dissipation when combined with a thin insulating layer o:u5+.Furthermore, in the embodiment shown in Fig. ff13, the board is a film base board (16). It is formed with a multi-layer printing l
You can get a ¥ wire plate. In the figure, α71 is an adhesive. 1. In each of the above embodiments, the wiring pattern (9) is formed on both sides of the full-strength substrate (4), but it may be formed only on one side.

[Effects of the Invention] As described above, the present invention (at least one of the wiring substrates has a first wiring pattern formed on both sides and the wiring patterns on the front and back sides are connected by a conductive material formed in the first through hole). At Noba I1, the metal foil with the electrical insulation layer with the second through hole drilled All metal foil is stacked so that it is on the front side to integrate the lees layer, and the second through hole is connected to the first wiring pattern. According to the position, a protective layer is then applied to the surface of the metal foil in a pattern shape including the second through holes, a second wiring pattern is formed on the metal foil using an etching jig, and then the sand layer is removed. The through-hole shown in Figure 2 is fully filled with the electric abrasive to electrically connect the first wiring pattern and the second wiring pattern, so multilayer wiring can be easily formed regardless of the size of the wiring board. Moreover, it is highly reliable and can be manufactured at low cost.Furthermore, the wiring pattern can be formed by laminating electrically insulating metal foil, which is thinner than the wiring board. This makes it possible to manufacture thin multilayer printed wiring boards.

[Brief explanation of the drawing]

FIG. 1(aHb) is a partially cutaway sectional view showing the manufacturing method of the present invention-Embodiment, FIGS. 2(a) and (b) are partially cutaway sectional views of another embodiment of the same, and FIG. a) and (b) are -! of the above-mentioned still other embodiments. It is an IS notch view. il+ is the first wiring pattern, (2) is the first through hole, (3) is the conductive material, (4) is the wiring board, (6) is the second through hole, and (6) is the electrical insulation R layer. Metal foil with (
7) is metal foil, (9) is second wiring pattern, (10)
is a conductive material.

Claims (1)

[Claims] It+ ff1j of at least one of the wiring boards on which a first wiring pattern is formed on both the front and back surfaces and the wiring patterns on the front and back surfaces are connected by a conductive material formed in the first through hole.
Then, the metal foil with the electrically insulating layer in which the second through hole has been bored is stacked and integrated so that the metal foil is on the front side, and the second through hole is aligned with the first wiring pattern position, and then A protective layer 2 is coated on the surface of the gold PA foil in a pattern shape including through holes, and a second wiring pattern is formed on the metal foil by etching. 1. A method for manufacturing a multilayer printed wiring board, comprising filling a conductive material inside the board to electrically connect a first wiring pattern and a second wiring pattern.