JP2843401B2 - Multilayer structure wiring board - Google Patents

Description

The present invention relates to a multilayer wiring board having a conductor pattern on both sides.

2. Description of the Related Art A multilayer wiring board having a conductor pattern on both sides, such as a TAB (tape carrier device) or a printed board, usually has a five-layer structure.

FIG. 3 is a sectional view of a part of a conventional wiring board of this type.

As shown in the figure, conductor layers 13 and 14 are laminated on both surfaces of a substrate 10 made of an insulator layer via adhesive layers 11 and 12, respectively.

[0005] Conventional multilayer wiring board such described above, inevitably manufacturing cost because many manufacturing processes is increased.

Furthermore, since the adhesive layer is always laminated next to the conductor layer, even if the heat resistance of the insulator layer is high, there is a disadvantage that the heat resistance of the adhesive layer lowers the overall heat resistance. . For example, in the case of TAB, even if polyimide having heat resistance of 400 ° C. is used as the insulator layer, the heat resistance of the epoxy adhesive layer is about 150 ° C.,
The overall heat resistance is around 150 ° C.

In order to solve this problem of heat resistance, as shown in FIG. 4, a conductor layer 20, an insulator layer 21, and a conductor layer 22 are sequentially laminated.
It may have a layered structure, but this is difficult to manufacture. In particular, as shown in FIG.
And overhanging the conductor layers 20 and 22 thereon cannot be manufactured with a three-layer structure.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a multi-layer wiring board which can be manufactured at a low cost, has high heat resistance, and is relatively easy to manufacture.

[Means for Solving the Problems] A feature of the present invention that achieves the above object is that a first conductor layer and a second conductor layer are provided with an insulator layer having an opening interposed therebetween, and On the opening forming region,
The multilayer wiring board in which the first conductor layer or the second conductor layer is located, wherein the first conductor layer and the first conductor layer are laminated on the first conductor layer via an adhesive layer. It has a four-layer structure of an insulator layer and the second conductor layer directly laminated on the insulator layer.

[Operation] Since the second conductor layer side is directly laminated on the insulator layer without the adhesive layer, high-temperature connection is possible if these sides are used for outer lead bonding.

On the other hand, since the insulator layer is laminated on the first conductor layer side via the adhesive layer, the conductor layer can be easily formed on the insulator layer having holes.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a part of a four-layer wiring board as one embodiment of the present invention.

In the figure, reference numeral 30 denotes an insulator layer. This insulator layer 30
On one side, a conductor layer formed by patterning a conductor foil
31 is laminated via an adhesive layer 32.

On the other surface of the insulator layer 30, the conductor layer 33 is directly laminated without interposing an adhesive layer.

FIG. 2 is a process chart for explaining a manufacturing process of the four-layer wiring board of FIG.

As shown in FIG. 3A, first, an insulator layer 30 and a conductor layer 33 are formed.
Are laminated to form a two-layer structure.

Next, as shown in FIG. 3B, a character hole 34 is formed in the insulator layer 30 by etching, and a through hole 35 is formed by punching.

Next, the conductor layer 33 is patterned as shown in FIG.

Next, as shown in FIG. 3D, a conductor foil coated with an adhesive on one surface is laminated on the other surface of the insulator layer 30 to form a conductor layer 31 and an adhesive layer 32.

Next, as shown in FIG. 1E, a resist 36 for protecting the pattern of the conductor layer 33 is applied, and thereafter, as shown in FIG. 2F, the conductor layer 31 is patterned.

Then, as shown in FIG. 3G, the resist 36 is removed and an appropriate plating is performed. When different plating is performed on the conductor layer 33 and the conductor layer 31, it is only necessary to protect each side with a resist.

As described above, according to the present embodiment, since the number of the adhesive layers is one, the number of manufacturing steps is reduced by that amount, and thus the cost can be reduced.

In addition, high heat resistance can be obtained on the side of the conductor layer 33 having no adhesive layer. For example, if a polyimide having a heat resistance of 400 ° C. is used as the insulator layer 33, a high-temperature connection such as a metal eutectic method can be performed as outer lead bonding.

Moreover, the conductor layer 31 side is an insulator layer via the adhesive layer 32.
Since the layers 30 are stacked, the conductor layer 31 can be easily formed on the insulator layer 30 having the character hole 34.

[Effects of the Invention] As described in detail above, according to the present invention, the first conductor layer and the second conductor layer are provided with the insulator layer having the opening therebetween, and the opening is provided. A multilayer wiring board in which the first conductor layer or the second conductor layer is located on a formation region, wherein the first conductor layer and the first conductor layer are provided with an adhesive layer interposed therebetween. Has a four-layer structure of the insulator layer laminated by stacking and the second conductor layer directly laminated on the insulator layer, so that high heat resistance is provided on the second conductor layer side. And a high-temperature connection such as a metal eutectic method can be achieved, and the first conductive layer can be easily formed on the insulator layer provided with openings such as character holes and through holes. That is, an inexpensive multilayer wiring board having excellent heat resistance can be manufactured relatively easily. Therefore, it is very important to contribute to the spread of wiring boards such as double-sided TAB.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a part of a four-layer wiring board according to one embodiment of the present invention, FIG. 2 is a process diagram for explaining a manufacturing process of the four-layer wiring board of FIG. 1, and FIG. FIG. 4 is a cross-sectional view of a part of a conventional multi-layer wiring board, and FIG. 4 is a cross-sectional view of a part of a conventional three-layer wiring board. 30 ... insulator layer, 31, 33 ... conductor layer, 32 ... adhesive layer,
34 …… Character hall, 35 …… Through hole, 36…
... resist.

Claims (1)

(57) [Claims] 1. A first conductor layer and a second conductor layer are provided with an insulator layer having an opening interposed therebetween, and the first conductor layer or the second conductor layer is formed on the opening formation region. A multilayer wiring board in which two conductor layers are located, wherein the first conductor layer, the insulator layer laminated on the first conductor layer via an adhesive layer, and the insulator layer A multilayer wiring board having a four-layer structure including the second conductor layer directly laminated thereon.