JPS5913397A - Method of extending and altering circuit of multilayer 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 of invention The present invention relates to a method for expanding and modifying circuits of multilayer boards.

1. Technical background of Komei] Conventionally, a multilayer board is made by laminating several cypress boards with circuit patterns formed on them and performing high-density wiring using the circuit patterns formed on each layer. It has been known.

In this case, the connection between the circuit patterns formed on each wiring printed circuit board-L is performed by forming a metallized layer in a through hole formed by penetrating the circuit pattern of the wiring printed circuit board.

Therefore, when changing or expanding the circuits on such a multilayer board, the conventional method is to change the layout of the circuit pattern itself on each wiring print 1, or to connect new circuit patterns with jumper wires etc. between each circuit pattern. Wiring is being done.

[Problems of Background Art] However, the above-described method for expanding and changing the circuit of a multilayer board has the following problems.

In other words, when changing the layout of the circuit pattern of each wiring printed circuit board, it takes the same amount of time and money as creating a new board, resulting in high costs. In some cases, it is easy to connect circuit patterns on the surface of a multilayer substrate, but it is impossible to connect circuit patterns on inner layers that do not appear on the surface of the multilayer substrate.

[Object of the Invention] The present invention is directed to circuit expansion and
This was done with the aim of eliminating the drawbacks when changing circuit patterns, and it also makes it easy to connect inner layer printed circuit boards without changing the circuit pattern or connecting between circuit patterns using jumper wires etc. The present invention provides a method for expanding and changing the circuit of a multilayer board.

Summary of the Invention 1 The method for expanding and changing the circuit of a multilayer board according to the present invention is a wiring print!・A circuit pattern for expansion/change is formed at the mutually overlapping position of at least two wiring printed circuit boards 10 of a multilayer board C by laminating a plurality of boards, and at least -h of the multilayer board J3 is formed. A connection hole is bored through the insulating layer between the circuit patterns for expansion and modification from the surface, and a curable conductive resin composition is injected into the connection hole and hardened to form a circuit for expansion and modification. It is characterized by the fact that there is no conduction between the patterns.

"Embodiment of the Invention" The details of the present invention will be explained below with reference to an embodiment shown in the drawings.

1 and 2 are cross-sectional views of a multilayer substrate for explaining the present invention in detail.

First, an insulating layer 2.3, which is a printed circuit board for wiring, on which a predetermined circuit pattern (not shown) forming an electronic circuit is formed.
A multilayer substrate 1 in which four layers are stacked is prepared. This multilayer board 1
On the insulating layer 2.3.4 constituting the circuit, there is a circuit pattern 2a for circuit extension/change, which is different from the above-mentioned predetermined circuit pattern.
3a, 4. A and C are formed respectively.

These circuit expansion/change circuit patterns 2a, 3a,
4a is formed in advance at a predetermined position in a pattern shape expected for circuit expansion and circuit modification.

If it becomes necessary to expand or change the circuit on the multilayer board 1, as shown in FIG.
A blind hole 5 passes through a predetermined position and reaches the circuit pattern 3a.
Drill the hole.

Next, as shown in FIG. 2, a curable conductive composition 6 made of, for example, a conductive resin is injected into the blind hole 5 and solidified to prevent electrical continuity between the circuit expansion/change patterns 2a and 3a.

Figure 3 shows each inner layer 3 of each insulating layer 2.3.4.
．． Expansion/change circuit pattern 3b' formed in 4
This figure shows the case where the insulating layers 2.b and 2.b are electrically connected to each other.
3.4 Each circuit pattern 21+, 3b, 3b formed on
31)' and 4b out of ', 4b are used as a circuit pattern for circuit expansion/change, and in order to conduct between these circuit expansion/change patterns 3b', 4L1, a blind hole 5 is made as shown in the figure. Drill through the insulation layer 2.3.4. Then, as shown in FIG. 4, curable conductive composition 6 is poured into this blind hole 5 by 21 people and solidified, and the circuit pattern 3b'
and 41) are connected.

[Effects of the Invention] As explained above, according to the present invention, the multilayer substrate consists of η
The circuit pattern formed on each insulating layer is designed in a layout that takes into account circuit expansion and modification, and a conductive resin composition is injected into the connection hole by drilling connection holes at predetermined positions. Since the circuit can be easily expanded or changed just by solidifying it, the time required to prepare the circuit film 81 can be shortened compared to the conventional method, and it is inexpensive and economical. Furthermore, it is also possible to change the inner layer circuit pattern. Extreme 'C easy if
It has several advantages.

[Brief explanation of drawings]

1 and 2 are cross-sectional views for explaining an embodiment of the method for expanding and changing the circuit of a multilayer board according to the present invention, and FIGS.
The figure is a sectional view illustrating another embodiment. 1・・・・・・・・・・・・Multilayer board 2.3.4
...Insulating layer (printed circuit board for wiring) 2a, 2b, 3a
, 3b', 4a......Circuit pattern for circuit expansion/change 5.7...Connection hole 6.8... ... Curable conductive composition attorney Suyama Sasa - Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A multilayer board formed by laminating a plurality of printed circuit boards for wiring has an expansion/change circuit pattern formed at a position overlapping the layers on at least two printed boards for wiring, and at least one side of the multilayer board. A connection hole is drilled through the insulating layer between the circuit patterns for expansion and modification from the surface thereof, and a curable conductive resin composition is injected into the connection hole and solidified to form the circuit pattern for expansion and modification. A method for expanding and changing a circuit of a multilayer board, which is characterized by providing conduction between the circuits.