JPH0548231A - Packaging structure of printed-circuit board with different density - Google Patents

Abstract

PURPOSE:To enable cost to be reduced and at the same time provide a partially and highly dense packaging printed-circuit board with an improved operability. CONSTITUTION:A title item is constituted by a high-density printed-circuit board with a cut through-hole 3 at four end faces and a low-density printed- circuit board 1 with a hole for burying the high-density printed-circuit board and the cut through-hole 3 and the high-density printed-circuit board is sandwiched by the low-density circuit substrates 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-density mounting structure for a circuit board used in electronic equipment such as personal computers.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing a mounting structure of a high-density circuit board according to the prior art. A mounting structure in which a pad 9 is provided on the low-density circuit board 8 and a high-density circuit board 10 having cut-through holes on the four end faces is soldered to the pad 9 and the cut-through hole.

[0003]

In the above-mentioned mounting structure of the prior art, it is difficult to accurately position and mount the pad and the through hole due to the bending and warping of the board due to heat during soldering. In addition, metal fittings are required to prevent bending and warping, and circuit boards made of board materials that are less likely to be deformed by heat such as bending and warping are used. There was a problem that the cost would increase. Then, this invention solves such a problem, and an object of this invention is to improve the workability | operativity by easy mounting, and to obtain the means to reduce cost.

[0004]

In a structure in which high density circuit boards having different pattern densities are mounted on a low density circuit board, the high density circuit board has cut through holes at four end surfaces, and the low density circuit board is An external shape hole into which the high-density circuit board can be embedded, and a through hole on the inner end surface of the hole, and the high-density circuit board is embedded in the hole having the through hole. The high density circuit board is mounted on the low density circuit board by soldering.

[0005]

EXAMPLES The present invention will be described in detail below based on examples.

FIG. 1 is an embodiment of the present invention and is a perspective view showing a mounting structure of a circuit board in which a high-density circuit board 4 is fitted and mounted on a low-density circuit board 1.

FIG. 2 is a perspective view showing the structure of the high-density circuit board of the present invention.

FIG. 3 is a perspective view showing the structure of the low density circuit board of the present invention.

In FIG. 2, the high-density circuit board 4 is a multi-layer board, and the IC surface of the QFP package 1
1 and TAB (Tape Automated Bond)
ing) chip ICs, SMT components such as chip resistors and chip capacitors are mounted, and cut through holes 5 obtained by cutting the through holes at the center are provided on the four end faces of the high density circuit board 4 to achieve high density with the mounted components. The structure is electrically connected by a pattern.

FIG. 4 shows the structure of the through hole 5. A land 7 is provided from the disconnection through hole 5 to the inside of the substrate surface, and is connected to a pattern for mounting components to form an electric circuit.

In FIG. 3, the low density circuit board 1 is
A hole 2 having a size equal to or smaller than the external dimensions of the high-density circuit board 4 is provided, and a cut-through hole is provided on the end face thereof, and is electrically connected to a pattern of mounted components of the low-density circuit board 1.

High-density circuit board 4 to hole 2 of low-density circuit board 4
By fitting and soldering the broken through hole 3 of the low density circuit board 1 and the broken through hole 5 of the high density circuit board 4, both circuit boards are electrically connected.

[0013]

As described above, according to the present invention, the structure in which the high-density circuit board is fitted into the low-density circuit board enables
It is possible to accurately and easily mount the broken through holes of both boards. Further, the above-described structure can absorb deformation such as bending and warping of the high-density circuit board due to heat generated when soldering the broken through holes, and has an effect of improving reliability. Further, since no fixing metal fittings are required and a board made of a material having a large amount of flexure and warpage can be used, the cost can be reduced and the degree of freedom in design can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a mounting structure of a circuit board of the present invention.

FIG. 2 is a perspective view showing the structure of a high-density circuit board according to the present invention.

FIG. 3 is a perspective view showing a structure of a low density circuit board of the present invention.

FIG. 4 is a perspective view showing the structure of a through hole.

FIG. 5 is a perspective view showing a conventional circuit board mounting structure.

[Explanation of symbols]

 1 ... Low-density substrate 2 ... Hole 3 ... Low-density substrate disconnection through hole 4 ... High-density substrate 5 ... High-density substrate disconnection through-hole 6 ... Short-circuit prevention hole 7. ..Land 8 ... Conventional low-density substrate 9 ... Pad 10 ... Conventional high-density substrate 11 ... IC

Claims (1)

[Claims] 1. A structure for mounting a high-density circuit board having different pattern densities on a low-density circuit board, wherein the high-density circuit board has first cut-through holes at four end faces, and the low-density circuit board is The high-density circuit board has an outer shape hole into which a high-density circuit board can be embedded, and a second cut-through hole on an inner end surface of the hole, and the second cut-through hole is formed in the hole. A mounting structure for circuit boards of different densities, characterized in that the high-density circuit board is mounted on the low-density circuit board by embedding and soldering the first and second disconnection through holes.