JPS59161897A - Multilayer printed circuit 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 Field of the Invention The present invention relates to a multilayer printed circuit board having through-holes and multiple through-holes.

[Prior art]

FIG. 1 is a cross-sectional view showing an example of a conventional multilayer printed circuit board, in which 1 is a base material, 2 is a through-hole pole, and
Reference numeral 6 indicates multiple through holes, and reference numeral 4 indicates an adhesive for thermocompression bonding of prepreg. The inner layer 5 serving as the power supply layer has no clearance other than the clearance 3 for the penetrating through hole 2. In such a structure, the adhesion strength between the layers is insufficient, and peeling of the substrate is likely to occur.

To address this, traditional multilayer printed circuit boards include
Some have a structure in which the inner layer serving as the power supply layer has a clearance with the same diameter as the clearance for the through-hole.

FIG. 2 is a partially sectional plan view showing such a structure,
The same parts as in FIG. 1 are given the same reference numerals. 3' is the added clearance.

It is clear that this structure increases the bond strength within the layer by the additional 30 minutes of clearance.

However, on the other hand, since the resistance of the inner layer 5 as a power supply layer increases, there is a problem that the stability of the power supply voltage supplied to the mounted components through the inner layer 5 deteriorates.

[Purpose of the invention]

In view of the above-mentioned problems, the present invention aims to provide a multilayer printed wiring board that has sufficient interlayer adhesive strength and stabilizes the power supply voltage.

[Summary of the invention]

The present invention has through-holes and multiple through-holes.
In a multilayer printed circuit board, the above object is achieved by providing a small clearance (which is smaller in diameter than the clearance for a through-hole) in an inner layer used as a power supply layer or the like.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG.

FIG. 3 is a cross-sectional view of a multilayer printed circuit board according to the present invention, and FIG. 4 is a partially cross-sectional plan view thereof.

Note that the same parts as in FIG. 1 are designated by the same reference numerals and will not be described.

In this embodiment, a through hole 2 is provided in the inner wI5.
In addition to the clearance 3 having a diameter of φ1, a clearance 7 having a diameter of φ2 (however, φ2 minus φ1) is provided corresponding to the multiple through hole 6.

The diameter φ2 of this clearance 7 is determined so that the resistance (pressure drop) of the inner layer 5 does not exceed the upper limit determined by the stability of the voltage supplied to the mounted components, and so that the necessary interlayer adhesive strength is obtained. It is something that can be done. In this example, φ1 =
1.6 mm, φ2 = 0.8 mm.

The grid spacing is 1.905 mm, and φ2=
The resistance value (voltage drop) of the inner layer 5 is reduced to approximately 65% compared to the conventional product (with the structure shown in Figure 2) with a diameter of 6 mm.
It was possible to significantly improve the stability of the power supply voltage, and to obtain almost the same sufficient interlayer adhesion strength.

〔Effect of the invention〕

As mentioned above, the present invention provides a multilayer printed wiring that has sufficient interlayer adhesion strength and greatly improves power stability by providing a clearance smaller in diameter than the clearance for the through-hole in at least the inner layer serving as the power supply layer. This has the effect of realizing a substrate.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional example of a multilayer printed circuit board;
The figure is a partially sectional plan view showing another conventional example, FIG. 3 is a sectional view showing an embodiment of the present invention, and FIG. 4 is a partially sectional plan view showing the same embodiment. 2... Penetrating through hole, 3.7... Clearance, 5... Inner layer (source layer). Representative Patent Attorney Akio Takahashi...゛.ゝゝFigure 3''!Figure f-4

Claims (1)

[Claims] (In a multilayer printed circuit board having 11X through-holes and multiple through-holes, a multilayer printed circuit board is characterized in that a clearance smaller in diameter than that for a 1-through through-hole is provided in an inner layer serving as a power supply layer.) substrate.