JPH05167261A - Manufacture of multilayer wiring board provided with semi-through-hole - Google Patents

Abstract

PURPOSE:To prevent a semi-through-hole which constitutes a terminal from being deformed and a conductive layer from separating by a method wherein a conductor foil layer is interposed between the laminated inner wiring base boards at a through-hole boring region. CONSTITUTION:An inner wiring base board 8 on the primary surface of which a required circuit pattern is formed, outer wiring boards 9, a prepreg 10, and a copper foil 11 are laminated. In the laminate concerned, the copper foil 11 is laminated on the through-hole boring predetermined region of the inner wiring board 8. In succession, the laminate is formed by thermocompression into a multilayer wiring main body 12. Thereafter, a through-hole 13 is bored in the formed multilayer wiring main body 12 at a prescribed point, a conductor layer is deposited in one piece on the inner wall of the through-hole 13 concerned to obtain a multilayer wiring board provided with a through-hole 13 whose inner wall is coated with a conductor layer. A press work is carried out so as to vertically cut the through-hole 13 into two. By this setup, a multilayer wiring board provided with a semi-through-hole excellent in dimensional accuracy can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer wiring board having a semi-through hole (terminal) having a concave end surface.

[0002]

2. Description of the Related Art As is well known, wiring boards (circuit boards) have been widely put to practical use in various electronic equipments as circuit parts in which electric circuits are made compact, or which can be detached and replaced. In this type of wiring board, a multilayer wiring structure is formed for the purpose of improving the circuit function, while lead terminals, which play a role of external connection to the circuit pattern, are integrally formed in the peripheral portion of the main surface of the wiring board. It is set up. In other words, when forming the required circuit pattern on one side or both sides,
It has a structure in which required lead terminals are formed on the periphery of the main surface.

However, in the case of a wiring board having a lead terminal of the above construction, there are the following practical problems. That is, since the lead terminals are formed on the main surface of the wiring board main body, the outer layer circuit pattern forming area and the mounting / mounting area of the electronic component are reduced accordingly. That is, high-density wiring or high-density mounting is hindered, which hinders downsizing of the circuit configuration.

Further, in the case of a wiring board having lead terminals, when the lead terminals and components are soldered, the soldering state cannot be easily observed. Can easily observe the soldering state.

As a solution to such a problem, as shown in a perspective view in FIG. 4, the end face of the multilayer wiring board body 1 is made concave,
A multilayer wiring board with a half through hole has been developed in which a conductive layer 2 is provided on the concave surface 1a to form a half through hole (terminal) 3.

However, such a multi-layer wiring board with a half through hole is manufactured by a means schematically showing the main part of the embodiment in FIGS. That is, the required inner layer wiring base plate and outer layer wiring base plate are laminated and heat-pressed to form the multilayer wiring board body 1. Next, as shown in a perspective view in FIG. 5, a through hole 4 is formed at a predetermined position of the multilayer wiring board body 1, and the conductor layer 2 is formed on the inner wall surface of the through hole 4.
6 is formed, the through hole 4 having the conductor layer 2 formed on the inner wall surface is vertically cut by a predetermined die 5 as shown in a perspective view in FIG. Manufactures multilayer wiring boards. As another means, as shown in a perspective view in FIG. 7, the conductor layer 2 is formed on the inner wall surface.
After filling the through hole 4 formed with the solder 6 with the solder 6 and rotating the router bit 7 in the direction of the arrow,
The through hole 4 filled with the solder 6 is vertically cut to obtain the solder 6
Is removed to manufacture the multilayer wiring board with a half through hole having the configuration shown in FIG.

[0007]

By the way, the manufacturing method of the multilayer wiring board with a half through hole has the following inconvenient problems. First, in the case of die (press) processing, when the through hole 4 having the conductor layer 2 formed on the inner wall surface of the through hole is longitudinally cut, the conductor layer 2 and the like on the inner wall surface of the through hole 4 is damaged (destroyed), and a required half through hole is formed. In many cases, it is not possible to obtain a multilayer wiring board with a semi-through hole that retains its shape, and there is a problem in that the yield is poor and it is not suitable for mass production. On the other hand, in the case of router processing, the operation of filling the solder 6 in the through hole 4 having the conductor layer 2 formed on the inner wall surface and the operation of longitudinally cutting the through hole 4 and then removing the filled solder 6 are performed. There is a problem that the process becomes complicated because it is necessary and the cost increases due to the use of solder.

The present invention has been made in consideration of the above circumstances, and provides a manufacturing method which can not only be manufactured with a high yield but also can easily obtain a multilayer wiring board having a highly reliable half-hole (terminal). For the purpose of provision.

[0009]

According to the method of manufacturing a multilayer wiring board with a half-through hole according to the present invention, an inner wiring board and an outer wiring board are laminated and heat-press molded to form a multilayer wiring board body. A step of forming a through hole at a predetermined position of the formed multilayer wiring board main body, forming a conductor layer on the inner wall surface of the through hole, and longitudinally cutting the through hole having a conductor layer formed on the inner wall surface by pressing. In the method for manufacturing a multilayer wiring board with a half through hole, the method comprises the step of forming a half through hole to form a half through hole.

The present invention adopting such means is
In the process of stacking the inner wiring base plate and the outer wiring base plate, if there is a conductor layer forming a circuit pattern in the through hole drilled area of the inner wiring base plate, if there is no conductor layer forming the circuit pattern, a dummy If a conductor foil layer is provided as an inner layer, it can be longitudinally cut by pressing without causing damage or damage to the conductor layer formed on the inner wall surface (maintaining a predetermined half-through hole shape). It is based on knowledge.

[0011]

According to the above-mentioned manufacturing means of the present invention, the destruction or damage of the end face of the base material in the half-through hole region is eliminated, and the peeling and damage of the conductor layer on the inner wall surface of the through hole is also eliminated completely, thereby improving reliability. A multi-layer wiring board with a high through-hole can be easily manufactured with high yield without requiring complicated steps.

[0012]

Embodiments of the present invention will be described below with reference to FIGS.

1 to 3 are perspective views schematically showing an embodiment of the method for manufacturing a multilayer wiring board with half-through holes according to the present invention, which is carried out as follows, for example.

First, the inner layer wiring base plate 8, the outer layer wiring base plate 9 and the prepreg on which the required circuit patterns are formed on the main surface.
10 and the copper foil piece 11 are prepared, and these are laminated as shown in FIG. In this stacking, the copper foil piece 11 is stacked on the surface of the inner layer wiring base plate 8 where the through hole is to be drilled. Next, the laminate is heat-pressed and molded by a conventional means to form a multilayer wiring board body 12 as shown in FIG.

Thereafter, the multilayer wiring board body 12 formed as described above
A through hole 13 is formed at a predetermined position of the through hole by a conventional means, and a required conductor layer (not shown) is integrally deposited and formed on the inner wall surface of the through hole by, for example, chemical plating and electroplating. A multilayer wiring board in which a conductor layer is formed on the inner wall surface of the through hole 13 as shown in 3 is obtained. Next, the multilayer wiring board obtained above is press-worked so that the through hole 13 in which a required conductor layer is adhered and formed on the inner wall surface is cut into two substantially vertically and cut. The embodiment of the press working itself is the same as that shown in FIG. By cutting the through hole 13 in half by the above press work and cutting it vertically, no damage is observed in the half through hole part (half through hole surface) (in other words, it functions as a highly reliable connection terminal) With a half through hole A multilayer wiring board can be easily obtained.

In the above description, the conductor foil piece 11 is interposed on the surface of the through hole drilling region of the inner layer wiring base plate in the process of laminating the inner layer wiring base plate 8 and the outer layer wiring base plate 9. If a land for connection is formed on the surface of the through hole of the plate, it is not necessary to interpose the conductive foil piece 11 again. Further, in the above, the outer layer wiring base plate 9
Although the case of laminating and integrating the circuit pattern is illustrated, after forming a required conductive layer on the inner wall surface of the through hole 13,
The outer layer wiring base plate 9 may be patterned into a circuit.

[0017]

As described above, according to the method for manufacturing a multilayer wiring board according to the present invention, the required multi-layer with a half through hole can be formed without the shape of the half through hole forming the terminal being deformed or the conductive layer being peeled off. The wiring board can be manufactured without requiring complicated operations. That is, it is possible to manufacture a multilayer wiring board with a half through hole, which is electrically highly reliable and has good dimensional accuracy (shape accuracy), at relatively low cost and with good yield.

[Brief description of drawings]

FIG. 1 is a perspective view showing a laminated state of an inner layer wiring base plate and an outer layer wiring base plate in an embodiment example of a method for manufacturing a multilayer wiring board with half-holes according to the present invention.

FIG. 2 is a perspective view showing a state in which an inner layer wiring base plate and an outer layer wiring base plate are laminated and integrated in an embodiment example of a method for manufacturing a multilayer wiring board with half-through holes according to the present invention.

FIG. 3 is a perspective view showing a state in which a conductive layer is formed on an inner wall surface of a through hole formed at a predetermined position of a multilayer wiring board main body in an embodiment example of a method for manufacturing a multilayer wiring board with a half through hole according to the present invention.

FIG. 4 is a perspective view showing a configuration example of a main part of a multilayer wiring board with a half through hole.

FIG. 5 is a perspective view showing a state in which a conductive layer is formed on an inner wall surface of a through hole formed at a predetermined position of a multilayer wiring board main body in an embodiment of a conventional method for manufacturing a multilayer wiring board with a half through hole.

FIG. 6 is a perspective view showing a state in which a through hole having a conductive layer formed on an inner wall surface thereof is vertically cut by a mold in an embodiment of a conventional method for manufacturing a multilayer wiring board with a half through hole.

FIG. 7 is a perspective view showing a state in which a conductive layer is formed on an inner wall surface and a through hole filled with a half is vertically cut by a router in an embodiment of a conventional method for manufacturing a multilayer wiring board with a half through hole.

[Explanation of symbols]

1, 12 ... Multilayer wiring board main body 2 ... Conductive layer 3 ... Half through hole (terminal) 4, 13 ... Through hole 5 ... Mold
6 ... Half 7 ... Router bit 8 ... Inner wiring board
9 ... Outer layer wiring board 10 ... Prepreg 11 ... Copper foil piece

Claims (1)

[Claims] 1. A step of stacking an inner layer wiring base plate and an outer layer wiring base plate and forming the multilayer wiring board main body by heating and pressurizing, and forming a through hole at a predetermined position of the formed multilayer wiring board main body. A method for manufacturing a multilayer wiring board with a half-through hole, comprising: a step of forming a conductor layer on the inner wall surface of the through-hole; and a step of longitudinally cutting the through-hole having the conductor layer formed on the inner wall by press working to form a half-through hole. 2. The method for manufacturing a multilayer wiring board with a half through hole, wherein a conductor foil layer is interposed on the surface of the through hole punching region of the laminated inner wiring board.