JP2003309364A - 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 the thickness of a waste substrate and without changing substrate manufacture man-hours. <P>SOLUTION: In the flexible compound-type multilayer substrate 10, two hard substrates 12, 14, a flexible substrate 16 for electrically connecting the hard substrates 12 and 14 and the hard waste substrate 18 holding the hard substrates 12 and 14 via detaching junction parts 20 are formed integrally. A reinforcing hard substrate 22, which does not restrict a necessary bend in the flexible substrate 16, is left in a part of the flexible substrate 16, and the reinforcing hard substrate 22 is kept by the waste substrate 18 via junction parts 22A. <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. 4 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 above flexible composite type multilayer substrate 1, there is a problem in that the substrate strength near the flexible substrate 4 is insufficient due to its structure. 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 type multi-layer substrate integrally formed with a hard waste substrate that holds the plurality of hard substrates via a joint for separation, a part of the flexible substrate has a required bending in the flexible substrate. The reinforcing hard substrate that does not interfere is left, and the reinforcing hard substrate is held by the discarding substrate through the joint portion.

That is, with respect to the flexible substrate, a reinforcing hard substrate is left at a position where the required bending of the flexible substrate is not hindered, and the reinforcing hard substrate and the discarding substrate are connected via a joint portion. I am trying to do it. Thereby, the exposed portion of the flexible substrate can be connected to the discarded substrate, and the strength of the entire substrate is improved.

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. In this flexible composite type multi-layer substrate, a hard substrate for reinforcement remains on the flexible substrate, but the rigid hard substrate for reinforcement is a flexible substrate which is required to bend when the flexible composite type multi-layer substrate is incorporated into an electronic device. It doesn't get in the way.

[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 a hard discard substrate 18 are integrally formed.

The discard board 18 is composed of two hard boards 1.
It is formed so as to surround the circumferences of 2 and 14, and a plurality of joints 20 for separation are formed between the waste substrate 18 and the hard substrates 12 and 14. As a result, the hard substrates 12 and 14 are held by the discarding substrate 18 via the joint portion 20.

The discarded substrate 18 is the hard substrates 12, 14
Hard substrates 12, 1 for handling and positioning
4 is added to the periphery of the hard substrates 12 and 14, and is separated from the hard substrates 12 and 14 and discarded after the electronic components are soldered to the hard substrates 12 and 14. Also, 18A in FIG.
Is a positioning hole formed on the discarded substrate 18.
On the other hand, a hard substrate 22 for reinforcement is left in a part of the flexible substrate 16 (that is, a portion of the flexible substrate 16 that does not hinder the required bending when assembled into the set). The hard substrate 22 for reinforcement is connected to the discarded substrate 18 via the joint 22A.

That is, in FIG. 1, the upper side portion and the lower side portion of the discarded substrate 18 are connected via the reinforcing hard substrate 22, whereby the strength of the discarded substrate 18 near the flexible substrate 16 is increased. As a result, the flexible composite type multilayer substrate 1
The overall strength of 0 is reinforced.

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

As shown in FIG. 1, the flexible composite type multi-layer substrate 10 comprises 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 joints 20 and 22A. Further, the flexible substrate 16 is exposed by pulling it out with a separate mold, but at this time, the flexible substrate 16 is pulled out with the separate mold so that the hard substrate 22 remains. That is, the hard substrate 22 for reinforcement can be formed in the same process as the process for exposing the flexible substrate 16, so that a stronger substrate can be manufactured without increasing the cost.

Electronic components such as an IC circuit and a connector are soldered to the hard substrates 12 and 14 of the flexible composite type multilayer substrate 10 manufactured as described above by reflowing. At this time, the strength is reinforced. Flexible composite type multilayer substrate 1
No warpage occurs at 0, so that good soldering can be performed.

The flexible composite multi-layer substrate 10 on which electronic components are mounted is then cut into the joint portions 20 and 22A (see FIG. 1), and the waste substrate 18 is cut off before being incorporated into an electronic device. The flexible substrate 16 is appropriately bent when incorporated into an electronic device, but the rigid substrate 22 remaining on the flexible substrate 16 at this time does not hinder the bending.

FIG. 3 is a plan view showing another embodiment of the flexible composite type multilayer substrate according to the present invention. The same parts as those of the flexible composite multilayer substrate 10 shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The flexible composite type multi-layer substrate 30 shown in FIG.
Reinforcing hard substrate 3 formed on flexible substrate 16
2 and 34 are different from those of the flexible composite type multilayer substrate 10 shown in FIG.

That is, on the flexible substrate 16 of the flexible composite type multilayer substrate 30, two reinforcing hard substrates 3 are provided.
2, 34 are formed. These reinforcing hard substrates 32 and 34 are connected to the discarding substrate 18 via the joint portions 32A and 34A.

These reinforcing hard substrates 32, 34 are
When the flexible substrate 16 is bent at the center, it does not hinder the bending.

The number, shape and the like of the reinforcing hard substrates formed on the flexible substrate are not limited to those in this embodiment. Moreover, the number of hard substrates on which electronic components are mounted in the flexible composite multilayer substrate is not limited to two.

[0028]

As described above, according to the present invention, as compared with the flexible substrate in the flexible composite type multilayer substrate,
A portion where the flexible substrate is exposed because the reinforcing hard substrate is left in a position that does not hinder the required bending of the flexible substrate and the reinforcing hard substrate and the discarding substrate are connected through a joint portion. Can also be connected to a waste board, and the strength of the entire board can be improved without changing the thickness of the waste board and without changing the number of board manufacturing steps, and warpage of the board when mounting electronic components on the board Can be prevented.

[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 another embodiment of the flexible composite multilayer substrate according to the present invention.

FIG. 4 is a plan view showing an example of a conventional flexible composite type multilayer substrate.

[Explanation of symbols]

10, 30 ... Flexible composite type multilayer substrate, 12, 14 ... Hard substrate, 16 ... Flexible substrate, 18 ... Discarded substrate, 2
0, 22A, 32A, 34A ... Joints, 22, 32, 3
4 ... Hard substrate for reinforcement

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 type multilayer substrate integrally formed with, in a part of the flexible substrate, while leaving a reinforcing hard substrate that does not hinder the required bending in the flexible substrate, the reinforcing hard substrate via a joint portion. A flexible composite type multi-layer substrate characterized in that it is held by the above-mentioned discarded substrate. 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.