JPS6038878B2 - Pattern connection structure of multilayer printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pattern connection structure for a multilayer printed wiring board that enables semi-finished production of the multilayer printed wiring board.

Conventionally, the inner layer pattern of a multilayer printed wiring board and the mounted electronic component terminal are connected through a through-hole plating hole into which the electronic component terminal is inserted, that is, a through hole with a plating layer formed on the inner wall, as shown in Figure 1. It was carried out in

In FIG. 1, 1 is a 4-layer printed wiring board manufactured by a conventional manufacturing method, 2 is a 1/4 layer outer layer pattern, 3 is a 2/Komiya inner layer pattern, 4 is a 3/4 layer inner layer pattern, and 5 is a 4/4 layer pattern. The outer layer pattern, 6 is a through-hole plating hole into which an electronic component terminal is inserted, 7 is an electronic component such as an IC or a composite resistor, and 8 is an electronic component terminal. In FIG. 1, the inner layer pattern and the electronic component terminals are connected by through-hole plating holes 6 into which electronic component terminals 8 are inserted.

Figure 2 shows an electronic component 7 in which multilayer printed wiring boards are often used.
This figure shows an example of a printed circuit assembly board on which a large number of are mounted.

In FIG. 2, reference numeral 9 indicates a power supply state of the electronic component 7, and 101 indicates a ground terminal of the electronic component 7.

In a multilayer printed wiring board as shown in FIG. 2, the inner layer pattern is often used for supplying a common power source and a common ground to electronic components 7. However, the positions of the terminals to be connected to the power source and ground of the mounted electronic component 7 vary depending on the type of component and circuit connection. In such cases, in the conventional multilayer printed wiring board manufacturing method, it is necessary to create a master film for the inner layer pattern for each printed circuit assembly board in which the position of the electronic component terminal to be connected to the inner layer pattern changes. In addition to increasing film production costs, the multilayer board lamination process could not be carried out until the inner layer pattern was determined, which was the main reason for prolonging the production period for multilayer printed wiring boards. This invention was made to eliminate these drawbacks, and includes a first through hole that is not in contact with the inner layer pattern into which a terminal of an electronic component is inserted, a second through hole that is connected to the inner layer pattern, By providing a surface layer pattern that connects the first and second through holes, the inner layer pattern can be standardized, and the process up to the lamination process of the multilayer printed wiring board can be stocked as a semi-finished product. The present invention provides a pattern connection method for multilayer printed wiring boards with high manufacturing efficiency.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 8.

FIG. 3 is a printed circuit assembly board using a multilayer printed wiring board for explaining one embodiment of the present invention, and FIG. 4 is a perspective sectional view of FIG. 3. In Figures 3 and 4, the second
The same or corresponding parts as in the figures are designated by the same reference numerals.

Reference numeral 11 denotes a four-layer multilayer printed wiring board, in which a common power source for electronic components is supplied to the 2/4 inner layer pattern, and a common ground for the electronic components is supplied to the 3/4 layer inner layer pattern.

12 is the power supply terminal of the IC, 13 is the ground terminal of the IC, 14 is the power supply state of the IC2, 15 is the ground terminal of the IC2, 16 is the through hole plated hole connected to the 2/4 layer inner layer pattern 3, 17 is the 3 /4 layer The through-hole plating holes 18 to 21 connected to the inner layer pattern 4 are the through-hole plating hole \16 and the IC terminal 12, the through-hole plating hole 17 and the IC terminal 13, and the through-hole plating hole 16, respectively.
This is an outer layer pattern that connects the terminal 15 to the IC terminal 14 and the through-hole plating hole 17. The multilayer printed wiring board 11 will be further explained using FIG. 5.

In FIG. 5, reference numeral 22 indicates grid lines for explanation that do not exist in the actual product. The grid lines 22 divide the printed wiring board 11 at regular intervals and indicate the pattern on the printed wiring board 11 and the positions of the through-hole plating holes. shall be placed on the intersection of Reference numeral 23 denotes a through-hole plating hole that connects both the outer layer patterns of 1'4 Mushroom and 4/Genfu which are not connected to the inner layer pattern.

The through-hole plating holes 16 and 17 connected to the 2'4 inner layer pattern 3 and the 3/4 inner layer pattern 4 are formed respectively according to the predetermined arrangement of the electronic components 7 on the printed wiring board as shown in FIG. Install it at an appropriate position around the electronic components.

2' Gentomi inner layer pattern 3 and 3/4 layer inner layer pattern 4
, except for the positions corresponding to the through-hole plating holes 16 and 17, even if through-hole plating holes are provided at the intersections of arbitrary grids, the through-holes will not be located in the inner layer pattern 3.
The pattern is omitted so that it is not connected to and 4.

Through-hole plating holes 16,
17 and 23 are shown. Multilayer printed wiring board 11
The electrical connection from the inner layer patterns 3 and 4 to the electronic component 7 will be explained using FIG. 4.
[or 3/4 layer inner layer pattern 4] → Through-hole plating hole 16 [or 17] connected to the inner layer pattern →
Outer layer pattern 18 [or 19] → Through-hole plating hole 6 for inserting electronic component terminal → Electronic component terminal 12 [or 13]
].

With the structure described above, even if the position of the terminal connected to the inner layer pattern of the electronic component mounted on the printed wiring slope changes, there will be no through-hole plating holes that connect to each inner layer pattern and through-hole plating that does not connect to the inner layer pattern. Since the positions of the holes are determined, the pattern shape of the master film for pattern etching of the 2/4 or 3'4 inner layer pattern is determined.

Therefore, it is only necessary to produce one type of master film for inner layer patterns for 2/4 or 3'4 layers depending on the outer shape of the printed wiring board 11. Furthermore, since each inner layer pattern is fixed, 1/4 and 4/4
The four layers are copper-plated without etching, and the 2/4 and 3/4 layers are each etched, so that they can be used as materials for a predetermined multilayer printed wiring board. Then, from the stage where the components to be mounted on the printed wiring board have been determined and the electrical circuit connections have been determined, a multilayer printed wiring board can be manufactured by going through the manufacturing process that is exactly the same as that of a normal double-sided copper-clad printed wiring board. can. of course,
It goes without saying that the outer layer patterns such as the 1/4 layer outer layer patterns 18 and 19 are formed at the same time as the other electric circuit connection outer layer patterns 2 in the same etching process. As described above, according to an embodiment of the present invention, there is no need to create a master film for the inner layer pattern every time the position of the twill connection terminal to the inner layer pattern of the mounted component changes, as is the case in the past, and the cost of creating the master film can be reduced. .

It is possible to proceed with the work up to the lamination process as a multi-layer board in advance and handle it in terms of materials. That is, it is possible to semi-finish a multilayer printed wiring board, and it is expected to have a mass production effect and a cost reduction effect due to smoothing of the factory load and shortening of the construction period.
Although the above description has been about a standard four-layer multilayer printed wiring board, this invention is not limited to this, and can be applied to multilayer printed wiring boards with any number of layers, not just four layers, as long as the inner layer pattern is common. Applicable.

In addition, if a printed wiring board manufacturing method is used in which through-hole plating holes 23 for front and back conduction are provided in advance on all the intersection points of the grid shown by grid lines 22 in FIG. It is also possible to produce a semi-finished product through the processes of drilling and through-hole plating, and in some cases, plating the terminals of printed wiring boards. As described above, according to the present invention, the inner layer pattern and the electronic component terminal are not connected directly through the electronic component terminal insertion hole, but are connected through the through-hole plating hole of the fixed position other than the component terminal insertion hole. Therefore, the inner layer pattern can be standardized, reducing the cost of inner layer pattern design and master film production for the inner layer pattern, and by processing the lamination process of multilayer boards in advance and handling them as materials, it is possible to increase the efficiency of mass production, smooth the factory load, and shorten the construction period. It has low effectiveness.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a through-hole plating hole for inserting an electronic component terminal in a printed circuit assembly board using a conventional multilayer printed wiring board, and Figure 2 shows an example of a printed circuit assembly board using a multilayer printed wiring board. FIG. 3 is an explanatory diagram showing a printed circuit assembly board using a multilayer printed wiring board for establishing an embodiment of the present invention, and FIG. An enlarged cross-sectional view, FIG. 5 is a diagram for explaining the multilayer printed wiring board shown in FIG. 3, and FIGS. 6 to 8 are cross sections of through-hole plating holes for inner layer reinforcement in the printed wiring board shown in FIG. 3. It is an enlarged view. In the figure, 2 to 5 are 1/4 layer to 4/4 layer patterns, 6 is a through-hole plating hole for inserting an electronic component terminal, and 7 is a through-hole plated hole for inserting an electronic component terminal.
1 is an electronic component, 11 is a 4-layer multilayer printed wiring board, 16 and 1
7 is a through-hole plating hole for inner layer connection, 18 to 21 are 1/
In the four-layer outer layer pattern, 23 is a through-hole plating hole that is not connected to the inner layer pattern either. Note that the same parts and corresponding parts are indicated by the same reference numerals. Figure 1 Figure 6 Figure 2 Figure 3 Figure 7 Figure 8 Figure 4 Figure 5

Claims (1)

[Claims] 1 In a pattern connection structure for electrically connecting an inner layer pattern of a multilayer printed wiring board and an electronic component mounted on the wiring board, the pattern connection structure is formed on the multilayer printed wiring board without contacting the inner layer pattern, and the electronic component is formed on the multilayer printed wiring board without contacting the inner layer pattern. The first terminal into which the terminal of
a second through hole connected to the inner layer pattern provided at a predetermined position determined according to the arrangement of electronic components of the multilayer printed wiring board, and a second through hole provided on the surface of the multilayer printed wiring board. and a surface layer pattern electrically connecting both of the through holes.