JPH01117092A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To bore even a hole for forming a non-penetrating through-hole, and to execute plating easily and positively by a method wherein a through-hole is bored to an outer layer, the hole is plated, an inner layer and the outer layer are laminated and the non-penetrating through-hole is shaped. CONSTITUTION:Copper foils are formed to an inner layer base material 1 and an outer layer base material 3 through etching, and an inner layer and an outer layer are shaped. A drill hole in desired size is penetrated through the outer layer by a drill to prepare a surface-layer drill hole 6. Surface-layer through-hole plating 7 is executed onto the whole outer layer, a desired conductor pattern is shaped onto the internal side face of the outer layer being in contact with the inner layer at the time of laminating through etching, etc., the inner layer is laminated by prepreg 5 and bonded and fixed, and unified, and outer layer plating 10 is executed and the outer layer is etched, thus forming a desired conductor pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a multilayer printed wiring board having non-through holes.

[Prior Art] As electronic devices have become more sophisticated in recent years, printed wiring boards have become more dense and multilayered, and multilayer printed wiring boards are being produced with various specifications. Some types include non-penetrating through holes that connect the outer layer conductor and the inner layer conductor.

The third conventional manufacturing method for this type of multilayer printed wiring board is
There was one shown in Figure 4. Figure 3 is a sectional view showing the structure of a conventional multilayer printed wiring board of this type.
1) is the inner layer base material, (2) is the inner layer copper foil, and the inner layer base material (1)
etched on the surface. (3) is the outer layer base material, (
4) is an outer layer copper foil, which has been etched on the surface of the outer layer base material (3). (5) is a prepreg for laminating and adhesively fixing the inner layer base material (1) and the outer layer base material (3). (10) is an outer layer plating, and (11) is a non-penetrating through hole, which is plated at the same time as the outer layer plating (10).

FIG. 4 is a diagram for explaining the outline of the manufacturing process of the multilayer printed wiring board shown in FIG. 3. In the figure, the same reference numerals as in FIG. It is a through drill hole.

Next, the manufacturing process of a conventional multilayer printed wiring board will be explained using FIG. 4. Inner layer copper foil formed by etching (
Inner layer base material (1) provided with 2) (this is referred to as the inner layer)
and an outer layer base material (3) provided with an outer layer copper foil (4) formed in the same manner (this is referred to as an outer layer) are laminated with prepreg (5), adhesively fixed, and integrated, By accurately drilling a non-through drill hole (8) from the outer layer surface to the inner layer copper foil (2) using a drill of the desired thickness, and applying outer layer plating (10) to this non-through drill hole (8). It is manufactured by forming a non-penetrating through hole (11).

[Problems to be Solved by the Invention] In the conventional method for manufacturing multilayer printed wiring boards as described above, after the process of laminating the outer layer and the inner layer is completed, a non-through drill hole is precisely drilled to the desired depth using a drill. However, depending on the accuracy of the drill feed distance, there is a risk that the hole may not reach the inner layer copper foil, or on the other hand, if the feed distance is too long, the hole may end up drilling into other inner layers.

Also, in order to form a through hole, it is necessary to apply plating after drilling the hole, but since the hole is not a through hole, the plating solution may enter. There was a problem that the quality decreased.

The present invention has been made to solve these problems, and aims to provide a highly reliable method for manufacturing a multilayer printed wiring board having non-penetrating through holes.

[Means for Solving the Problems] In the method for manufacturing a multilayer printed wiring board according to the present invention, a through hole is formed in the outer layer, and then the hole is plated and laminated with the inner layer to form a non-through hole. This is something special.

[Function] In this invention, a through hole is made in the outer layer, and after the hole is plated, it is laminated with the inner layer. Therefore, the hole for forming the through hole can be easily made, and the through hole can be Because of this, plating can be applied easily.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing the structure of a multilayer printed wiring board according to the present invention. In the figure, the same reference numerals as in FIG. 3 indicate the same or corresponding parts, (7) is through-hole plating on the surface layer, This is a non-penetrating through hole in the invention.

FIG. 2 is a diagram for explaining the manufacturing process of the multilayer printed wiring board shown in FIG. 1. In the figure, the same reference numerals as in FIG. It's a hole.

Next, a manufacturing method according to the present invention will be explained. First, silver foil is provided on the inner layer base material (1) and the outer layer base material (3) by etching, as in the conventional method, to form an inner layer and an outer layer. A surface layer drill hole (6) is created by passing a drill hole of a desired thickness through this outer layer with a drill. Next, after performing surface layer through-hole plating (7) on the entire outer layer, a desired conductive pattern is formed by etching etc. on the inner surface of the outer layer that will contact the inner layer when laminated, and the inner layer is laminated with prepreg (5). After gluing and fixing and integrating, outer layer plating (1o)
The outer layer is then etched to form the desired conductor pattern.

That is, in this invention, a non-penetrating through hole is obtained by making a through hole in the outer layer, plating the hole, and laminating it on the inner layer, so that the hole for forming the through hole can be easily made. , and plating can be easily applied.

In the above embodiment, a double-sided printed wiring board is used as the outer layer, but the present invention is not limited to this, and a multilayer printed wiring board can also be used for the outer layer itself.

[Effects of the Invention] As explained above, in this invention, a non-penetrating through hole is obtained by forming a through hole in the outer layer and then plating the hole. The holes can be opened easily, and plating can be applied easily and reliably, resulting in a highly reliable non-through hole.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a multilayer printed wiring board according to the present invention, FIG. 2 is a diagram for explaining the manufacturing process of the multilayer printed wiring board shown in FIG. 1, and FIG. The cross-sectional view shown in FIG. 4 is a diagram for explaining the manufacturing process of a conventional multilayer printed wiring board. (1) is inner layer base material, (2) is inner layer copper foil, (3) is outer layer base material, (4) is outer layer copper foil, (5) is prepreg, (6) is surface layer drill hole, (7) is surface layer through-hole plating, (
9) is a non-penetrating through hole, and (10) is an outer layer plating. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A step of applying an inner layer copper foil to an inner layer base material to form an inner layer, a step of applying an outer layer copper foil to an outer layer base material to form an outer layer, a step of piercing a hole of a desired thickness in the outer layer, A step of applying through-hole plating to the entire surface of the outer layer provided with the holes, and forming a desired conductive pattern by etching on the surface where the outer layer contacts the inner layer when the outer layer is laminated; Multilayer printing characterized by comprising the following steps: laminating an inner layer and adhesively fixing it with prepreg; plating the outer layer on the surface of the adhesively fixed outer layer, and forming a desired conductive pattern on this surface by etching. Method of manufacturing wiring boards.