JPH10270860A - Multilayered printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate testing whether conductor-depositing order or the like is appropriate or not, by providing through holes for checking, connected to a common through hole via the conductors, corresponding to the number of conductors, and checking conduction between the conductors and checking circuits of the same number as that of the conductors. SOLUTION: Through holes 7a to 7e include a common through hole 7a and four checking through holes 7b to 7e of the same number as that of conductors 6a to 6d. The common through hole 7a is connected to the through holes for checking 7b to 7e respectively via connection portions 8a to 8d. The multilayered printed circuit board is completed by depositing the conductors 6a to 6d and a prepreg, and forming the through holes 7a to 7e and the like. Thereafter, to examine whether or not the structure and order of the conductors 6a to 6d are appropriate, one end of a tester is abutted against the through holes for checking 7b to 7e while the order end is abutted against the common through hole 7a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board, which can easily inspect whether or not the order of conductors is appropriate.

[0002]

2. Description of the Related Art In order to reduce the size, increase the density, and increase the speed of electronic components, a multilayer printed wiring board in which a plurality of printed wiring boards are stacked is provided.

FIG. 3 shows a multilayer printed wiring board having a four-layer structure in which, for example, three printed wiring boards are stacked among the multilayer printed wiring boards. In the figures, 1a to 1c are substrates, 2a to 2d are conductors formed by copper foil or copper plating, and 3a to 3g are through holes. The bold lines on the conductors 2a to 2d indicate the connection parts connecting the through holes, and between the through holes 3b and 3c, between the through holes 3c and 3d, between the through holes 3e and 3f, and between the through holes 3f and 3g. They are connected by connecting parts 4a, 4b, 4c, 4d, respectively.

[0004] Such a multilayer printed wiring board is manufactured by the following procedure. First, unnecessary portions of a copper foil having a thickness of 70 μm (35 μm or 18 μm is used for a high-density circuit) are dissolved by an etching method with a chemical to form conductors 2 a to 2 d having an electric circuit. Next, a semi-cured insulating material called a prepreg is heated and compressed between the conductors 2a to 2d to form substrates 1a to 1c between the conductors 2a to 2d. Next, a hole is formed in a portion where electrical conduction is required between the conductors 2a to 2d and a portion where a lead wire of a component is inserted, and an electroless copper plating process and an electrolytic copper plating process are performed to form a through hole. 3a to 3g are formed.

[0005]

However, in the laminating step in which the conductor and the prepreg are stacked and heated and compressed, the following mistakes are likely to occur. In some cases, the number of conductors 2a to 2d is insufficient. In this case, a circuit is not formed and the thickness is insufficient, so that it is easy to find. In some cases, the order of the conductors 2a to 2d may be incorrect. In this case, the circuit cannot be found from the external appearance, and the circuit is configured. Performs unstable operation to stabilize circuit characteristics, making it difficult to find the cause. Further, there may be a case where a plurality of certain conductors are laminated and other conductors become insufficient. In this case, a circuit is not formed, but the thickness does not change, so that it is difficult to find out.

Therefore, an object of the present invention is to provide a multilayer printed wiring board which has solved the above-mentioned problems.

[0007]

According to a first aspect of the present invention, there is provided a multilayer printed wiring board comprising a plurality of thin plate-like conductors constituting a circuit, and a plurality of conductors provided between the conductors. In a multilayer printed wiring board composed of an insulating member, a common through-hole penetrating the conductor or the like is provided, and a confirmation through-hole individually connected to the common through-hole via a connection part that is a part of the conductor. Holes are provided by the number of the conductors penetrating the conductors and the like.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

(A) Embodiment 1 The configuration of the multilayer printed wiring board according to Embodiment 1 of the present invention is as follows.
As shown in FIG. In this embodiment, the prepreg is interposed between the four conductors 6a to 6d, respectively.
The entirety of 6d is not shown, and the connecting portion 8 which is a part thereof is not shown.
Only the portions a to 8d are shown, and illustration of the prepreg is omitted.

In the multilayer printed wiring board according to the present invention,
In the extra space near the outer edge away from the center, which is a part constituting the circuit, the five through holes 7a to 7 in FIG.
e is provided penetrating the conductors 6a to 6d and the like. The through holes 7a to 7e are common through holes 7a and four confirmation through holes 7 of the same number as the number of conductors 6a to 6d.
b to 7e. Common through hole 7
a is an individual connection part (a part of the conductors 6a to 6d
a to 8d) are individually connected to the confirmation through holes 7b to 7e via 8a to 8d.

Next, the operation of the multilayer printed wiring board will be described. The conductors 6a to 6d and the prepreg are laminated and heated and compressed, so that the through holes 7a to
7e and the like are formed to complete a multilayer printed wiring board. Thereafter, in order to inspect whether the configurations and the order of the conductors 6a to 6d are proper, one end of the tester is brought into contact with the common through hole 7a and the other end is connected to the confirmation through hole 7a.
What is necessary is just to make contact with b-7e in order. If conduction can be confirmed for all of the confirmation through holes 7b to 7e, the result is a pass, and if not, the result is a failure.

(2) Second Embodiment Next, FIG. 2 shows a second embodiment of the multilayer printed wiring board according to the present invention. In this embodiment, four confirmation through holes 7a, 7b, 7d, 7e are provided for the common through hole 7c. Confirmation through holes 7b, 7a, 7 are connected to the common through hole 7c through the connection portions 8a to 8d.
e and 7d are individually connected.

The other configuration and operation are the same as those of the first embodiment, and the description is omitted.

[0014]

As can be seen from the above description, claim 1
According to the multilayer printed wiring board according to the above, the same number of conductors is provided as the number of conductors for confirmation which are individually connected to the common through holes via the respective conductors constituting the multilayer printed wiring board. By checking the continuity of the check circuit, it is possible to easily check whether or not the order of lamination of the conductors is appropriate.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a main part of a multilayer printed wiring board according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of a main part of a multilayer printed wiring board according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a conventional multilayer printed wiring board.

[Explanation of symbols]

 6a to 6d: conductors 7a to 7e: through holes 8a to 8d: connection portion

Claims (1)

[Claims] 1. A multilayer printed wiring board comprising a plurality of thin plate-like conductors constituting a circuit and an insulating member provided between the conductors, wherein a common through hole penetrating the conductors and the like is provided.
A multi-layer printed wiring, wherein a number of confirmation through holes individually connected to the common through hole via a connection portion that is a part of the conductor are provided by the number of the conductors penetrating the conductor or the like. Board.