JP2003309365A - Flexible compound-type multilayer substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible compound-type multilayer substrate in which warpage of a substrate, when an electronic part is mounted on the substrate can be prevented, without changing a thickness of a waste substrate or without changing substrate manufacture man-hours. <P>SOLUTION: In the flexible compound-type multilayer substrate 10, two hard substrates 12 and 14, a flexible substrate 16 for electrically connecting the hard substrates 12 and 14 and hard waste substrates 18 and 19 holding the hard substrates 12 and 14 via detaching junction parts 20 are integrally formed. A hard part is removed from the waste substrate in a position, corresponding to the flexible substrate 16 between the waste substrates 18 and 19 and a flexible substrate 22 is exposed. The hard substrates 12 and 14 can be bent into positions of the flexible substrates 16 and 22, before the waste substrates 18 and 19 are detached. The warpage which occurs in soldering by reflow of the electronic components is set free in parts of the flexible substrates 16 and 22, and influence of the warpage on the hard substrates 12 and 14 is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible composite type multilayer substrate, and more particularly to a flexible composite type multilayer substrate in which a plurality of hard substrates are electrically connected via a flexible substrate.

[0002]

2. Description of the Related Art Conventionally, when an electronic component is placed on a hard substrate and soldering is performed by reflow, the soldering may be performed in a state where the hard substrate is warped due to insufficient strength of the hard substrate. The hard substrate having this warp is difficult to mount the electronic component, and when the warp of the hard substrate on which the electronic component is mounted is returned when the substrate is assembled into the electronic device,
There is a problem in that stress is applied to the soldered portion and solder defects such as solder cracking occur.

As a method of preventing the warp of the hard substrate, a method of providing a waste substrate is known. JP 200
Japanese Laid-Open Patent Publication No. 1-7453 discloses a technique in which the thickness of the discarded substrate is made thicker than that of the substrate body to further improve the strength of the substrate and prevent the substrate body from warping during soldering. .

On the other hand, there is conventionally known a flexible composite type multilayer substrate in which a plurality of hard substrates are electrically connected via a flexible substrate.

FIG. 3 is a plan view showing an example of a conventional flexible composite type multilayer substrate. This flexible composite type multilayer substrate 1 is
Two hard substrates 2 and 3, a flexible substrate 4 for electrically connecting the hard substrates 2 and 3, and a hard discard substrate 5 are integrally formed.

Between the hard substrates 2 and 3 and the discarded substrate 5,
A plurality of joints 6 for separation are provided, and the hard substrates 2 and 3 are held on the discarded substrate 5 via the joints 6.

[0007]

However, in the case of the flexible composite type multilayer substrate 1 described above, due to its structure, the substrate strength of the portion in which the flexible substrate 4 is formed is insufficient, and in FIG. There is a problem that the substrate 5 is warped. On the other hand, as described in Japanese Patent Laid-Open No. 2001-7453, when the plate thickness of the discarded substrate is made thicker than the substrate body to improve the strength of the substrate, the number of substrate manufacturing steps is increased and the cost is increased. There's a problem.

The present invention has been made in view of the above circumstances, and prevents warpage of a board when mounting an electronic component on the board without changing the thickness of the board and without changing the number of board manufacturing steps. An object of the present invention is to provide a flexible composite multi-layer substrate that can be manufactured.

[0009]

In order to achieve the above-mentioned object, the invention according to claim 1 is to provide a plurality of rigid substrates, and a flexible substrate for electrically connecting the rigid substrates.
In a flexible composite multi-layer substrate integrally formed with a hard discard substrate that holds the plurality of hard substrates via a joint for separation, a discard substrate at a position corresponding to the flexible substrate of the discard substrates. It is possible to expose the flexible board by removing the hard part from the, or also remove the flexible board together with the hard part, and to make it possible to fold between the plurality of hard boards at the position of the flexible board before separating the waste board. It has a feature.

That is, before separating the discarding substrate from the flexible composite type multilayer substrate, the hard portion is removed from the discarding substrate at the position corresponding to the flexible substrate so that it can be actively bent at the position of the flexible substrate. The substrate is exposed or the flexible substrate is removed together with the hard portion so as to separate the discarded substrates for each hard substrate. In this way, before separating the discarded board from the flexible composite multilayer board, it is possible to freely bend between the hard boards on which electronic parts are mounted, and at this point the warpage caused by soldering due to reflow of electronic parts To avoid the influence of warpage on each hard substrate.

The flexible composite multilayer substrate according to claim 2 is
After mounting the electronic components on the plurality of hard substrates, the joints are cut to separate the discarded substrates.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the flexible composite multilayer substrate according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing an embodiment of a flexible composite multilayer substrate according to the present invention.

As shown in the figure, the flexible composite multilayer substrate 10 includes two hard substrates 1 on which electronic components are mounted.
2, 14, a flexible substrate 16 for electrically connecting the hard substrates 12, 14 and hard discard substrates 18, 19 are integrally formed.

The abandoned substrates 18, 19 are formed so as to surround the two hard substrates 12, 14 and between the abandoned substrates 18, 19 and the hard substrates 12, 14.
A plurality of joints 20 for separation are formed. As a result, the hard substrates 12 and 14 are held by the discarding substrates 18 and 19 via the joint portion 20, respectively.

The discarded substrates 18 and 19 are the hard substrates 1
It is added around the hard substrates 12 and 14 for handling and positioning of the hard substrates 12 and 14.
After soldering the electronic components to 14, the hard substrates 12, 14
It is separated from and discarded. Further, 18A in FIG. 1 is a positioning hole formed on the discarded substrate 19.

On the other hand, a flexible substrate 22 is formed between the abandoned substrate 18 and the abandoned substrate 19 so as to be exposed. That is, the flexible substrate 22 is exposed by removing the hard portion in a part of the discarded substrate formed so as to surround the hard substrates 12 and 14.

The flexible substrate 16 on which the wiring pattern is formed and the two flexible substrates 22 between the discarded substrates 18 and 19 on which the wiring pattern is not formed are linearly arranged. Two
2, the flexible composite type multilayer substrate 10 becomes the discarded substrate 1
Before the separation of 8 and 19, the hard substrate 12 and the hard substrate 14 can be bent.

FIG. 2 is a sectional view taken along line 2-2 of the flexible composite type multilayer substrate 10 in FIG.

As shown in FIG. 1, the flexible composite multi-layer substrate 10 includes a flexible substrate made of a flexible material (eg, polyimide) and a plurality of hard substrates made of a hard material (eg, glass epoxy). It is composed of sandwiches.

Between the hard substrates 12 and 14 and the discarding substrate 18, a groove is punched out by a mold leaving the joint 20. Further, the flexible substrate 16 is exposed by removing only the hard part with another mold. At this time, the flexible substrate 22 between the discarding substrates 18 and 19 is also removed with the separate mold. Exposed by.

That is, the flexible substrate 22 can be exposed in the same process as the process for exposing the flexible substrate 16, which does not increase the cost.

Electronic components such as IC circuits and connectors are soldered to the hard substrates 12 and 14 of the flexible composite multilayer substrate 10 manufactured as described above by reflow. At this time, the hard substrate 12 and the hard substrate 12 are discarded. The board 18, and the hard board 14 and the waste board 19 can maintain their planarity during soldering by reflowing, respectively, and the electronic equipment can be mounted well.

The flexible composite multi-layer substrate 10 on which electronic parts are mounted is then cut at the joint portion 20, and the discarded substrate 1
After the flexible substrates 22 and 8 and 19 are separated, the flexible substrate 16 is assembled into an electronic device. At this time, the flexible substrate 16 is appropriately bent.

In this embodiment, the flexible substrate 22 is left between the discarded substrate 18 and the discarded substrate 19 so that only the hard portion is removed. However, the invention is not limited to this, and the flexible substrate 22 is also cut. , Discarded board 18 and discarded board 1
9 and 9 may be completely separated. Further, the number of hard substrates on which electronic components are mounted in the flexible composite multilayer substrate is not limited to two.

[0026]

As described above, according to the present invention, the position corresponding to the flexible substrate can be positively bent so that the flexible substrate can be actively bent at the position before the discarded substrate is separated from the flexible composite multilayer substrate. Since the hard part is removed from the abandoned board to expose the flexible board, or the flexible board is removed together with the hard part so as to separate the abandoned boards for each hard board, it is possible to separate the hard boards on which electronic components are mounted. It is possible to freely bend. This makes it possible to remove (eliminate) the warpage caused by the soldering due to the reflow of the electronic component at the bendable portion, and prevent the respective hard substrates from warping.

The step of exposing the flexible board by removing the hard portion from the discarded board or the step of removing the flexible board together with the hard portion can be performed simultaneously with the existing board manufacturing step, increasing the number of board manufacturing steps. There is nothing to do.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a flexible composite type multilayer substrate according to the present invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of the flexible composite multilayer substrate in FIG.

FIG. 3 is a plan view showing an example of a conventional flexible composite type multilayer substrate.

[Explanation of symbols]

10 ... Flexible composite type multi-layer substrate, 12, 14 ... Hard substrate,
16, 22 ... Flexible substrate, 18, 19 ... Discarded substrate, 20 ... Joined portion

Claims (2)

[Claims] 1. A plurality of rigid substrates, a flexible substrate for electrically connecting the rigid substrates, and a rigid waste substrate for holding the plurality of rigid substrates through a joint for separating. In the flexible composite multi-layer substrate integrally formed with, the hard portion is removed from the waste substrate at a position corresponding to the flexible substrate of the waste substrate to expose the flexible substrate, or the flexible substrate is removed together with the hard portion. A flexible composite multi-layer substrate, wherein the plurality of hard substrates can be bent at the position of the flexible substrate before the discarding substrate is separated. 2. The flexible composite multilayer substrate according to claim 1, wherein after mounting electronic components on the plurality of hard substrates, the joint portion is cut and the discarded substrate is separated.