JPH0745942A - Printed-circuit board device - Google Patents

Abstract

PURPOSE:To surely position printed-circuit boards with each other by a method wherein a first printed-circuit board having a pattern for fixation and a second printed-circuit board having a receiver pattern are formed. CONSTITUTION:A first printed-circuit board 1 is placed on a second printed- circuit board 2, external connecting electrodes 12 are maple to coincide with corresponding connecting electrodes 22, and the boards 1, 2 are positioned relatively. Simultaneously with their positioning operation, patterns 16 for fixing the first: printed-circuit board 1 are overlapped with receiver patterns 26 on the second printed-circuit board 2. Then, after their positioning operation, extended and installed parts in the patterns 16 for fixing the first printed-circuit board 1 are soldered to the receiver patterns 26 on the second printed-circuit board 2. Thereby, the first printed-circuit board 1 is temporarily fixed surely to the second printed-circuit board 2. Consequently, when a heating head is brought into contact with the external connecting electrodes 12 in a row shape and it is pressed, the external connecting electrodes 12 can be connected electrically to the connecting terminals 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board device constructed by combining a plurality of printed circuit boards.

[0002]

2. Description of the Related Art When a printed circuit board device is formed by combining two or more printed circuit boards, a semiconductor device such as an LSI is mounted on one printed circuit board and this printed circuit board is attached to the other printed circuit board. Signals are transmitted and received between the printed circuit boards by electrically connecting the printed circuit boards. Electrical connection between both printed circuit boards is made by joining a number of outer leads provided on one printed circuit board and connecting terminals provided on the other printed circuit board so as to face the outer leads by soldering or the like. ing. In order to accurately make such electrical connection between the printed circuit boards, it is necessary to position both printed circuit boards relatively. Therefore, conventionally, after the outer lead of one printed board is positioned so as to face the connection terminal of the other printed board, the end portion of the outer lead is temporarily fixed to the connection terminal.

[0003]

In the prior art, the outer leads of the printed circuit board are used for temporary fixing, but the outer leads are also electrically connected to the electrodes of the semiconductor device. If the electrode pitch becomes narrower as the density increases, and if the outer lead pitch becomes narrower at a similar narrow pitch, it is necessary to form the outer lead at a similar narrow pitch.
However, when the pitch of the outer leads is narrowed in this way, it cannot function as a temporary fixing to the other printed circuit board, which causes a problem that the printed circuit boards cannot be temporarily fixed to each other.

The present invention has been made in consideration of the above circumstances. By providing a new temporary fixing mechanism without using the outer lead for temporary fixing of the printed boards to each other, accurate positioning of the printed boards to each other is possible. It is an object of the present invention to provide a printed circuit board device capable of performing the above.

[0005]

A printed circuit board device of the present invention includes a film substrate, a semiconductor device attached to the film substrate, a large number of external connection electrodes electrically connected to the semiconductor device, and the film. A first printed circuit board having a fixing pattern extending from the substrate; a connection terminal electrically connected to the external connection electrode; and a receiving pattern to which the fixing pattern is fixed And two printed circuit boards.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a card type electronic device such as an electronic calculator, a data storage device, and a printed circuit board device having two printed circuit boards 1 and 2 arranged inside a case (not shown) of an electronic watch. Show. This printed circuit board device includes a first printed circuit board 1 made of a film substrate and a second printed circuit board 2 to which the first printed circuit board 1 is attached on the back surface. A contact electrode (not shown) is formed on almost the entire surface of the second printed board 2, and a film liquid crystal device 3 is attached to one side portion (left side portion). The film liquid crystal device 3 displays predetermined information by a digital value or the like, and is electrically connected to the second printed board 2 by the heat seal 4 to receive a display signal. Reference numeral 5 is an electric component such as a resistor and a capacitor attached to the back surface of the second printed circuit board 2. In such a printed circuit board device, the first printed circuit board 1 is positioned and attached to the second printed circuit board 2.

FIG. 2 shows a plan view of the first printed circuit board 1. In this embodiment, the first printed circuit board 1 is TAB.
TCP manufactured by tape automated bonding (tape carrier p)
package) is used. That is, the first printed circuit board 1 is a film substrate 1 cut into a substantially square shape.
0 and the LSI mounted on the central portion of the film substrate 10.
And the like, and a large number of external connection electrodes 12 that are arranged around the semiconductor device 11 and serve as outer leads. The semiconductor device 11 is inserted into the opening 13 formed in the central portion of the film substrate 10, and the electrodes (not shown) exposed on the outer surface and the film substrate 11 are exposed.
The lead portions 14 patterned in the above are connected by solder bumps. Each lead portion 14 is connected to the corresponding external connection electrode 12, whereby the semiconductor device 11 and the external connection electrode 12 are electrically connected.

The external connection electrode 12 is formed by exposing and etching a copper foil laminated on the film substrate 10. An opening window 15 is formed in the film substrate 10 in the region where the external connection electrode 12 is formed, and each external connection electrode 12 passes through the opening window 15 to form a second window.
The printed circuit board 2 is soldered to the connection terminals 22 (see FIG. 5) for electrical connection.

A fixing pattern 16 is formed on such a first printed circuit board 1. The fixing pattern 16 is made of a square-shaped copper foil and is formed on the surfaces of the two opposite corners of the film substrate 10. The fixing pattern 16 is formed so as to extend from the corner of the film substrate 10. That is, as shown in FIGS. 2, 3 and 4, the two opposite corners of the film substrate 10 are cut by the oblique cutting lines 10a, so that the corners are notched. The fixing pattern 16 is provided so as to cover the cutout portion as well, so that the fixing pattern 16 extends from the corner portion of the film substrate 10. The fixing pattern 16 has the extending portion 16a formed on the receiving pattern 26 of the second printed circuit board 2.
It is used for temporarily fixing the first printed circuit board 1 to the second printed circuit board 2 by soldering (see FIG. 5), and is formed at the same time when the external connection electrode 12 is formed. It

FIG. 5 shows a second printed circuit board 2 in which a connection terminal 22 made of copper foil is patterned on a rigid or film-shaped substrate 20. The connection terminal 22 is electrically connected to the external connection electrode 12 of the first printed board 1 by soldering or the like, and is formed to have the same pattern as the external connection electrode 12 of the first printed board 1. At the same time, solder is applied on the upper surface.

A receiving pattern 26 corresponding to the fixing pattern 16 of the first printed board 1 is formed on the second printed board 2. The receiving pattern 26 is made of a square-shaped copper foil having solder applied on its upper surface, and is disposed at a portion of the first printed circuit board 1 facing the fixing pattern 16, and the fixing pattern 16 is soldered or the like. To be joined. As a result, the first printed board 1 can be temporarily fixed to the second printed board 2.

6 to 8 show a state in which the first printed board 1 is attached to the second printed board 2. This mounting is performed by connecting the first printed circuit board 1 to the second printed circuit board 2
The connection terminal 22 placed on the external connection electrode 12 and corresponding to the external connection electrode 12
This is done by matching and with the relative positioning of the substrates 1 and 2. Simultaneously with this positioning, the first printed circuit board 1 is formed on the receiving pattern 26 of the second printed circuit board 2.
The fixing patterns 16 of are overlapped with each other. After this positioning, as shown in FIGS. 7 and 8, the extending portion 16a of the fixing pattern 16 of the first printed board 1 is soldered to the receiving pattern 26 of the second printed board 2. As a result, the first printed board 1 is securely temporarily fixed to the second printed board 2. So after that,
By bringing a heating head (not shown) into contact with and pressing the columnar external connection electrodes 12, the external connection electrodes 12 and the connection terminals 22 can be electrically connected. In this embodiment, since the external connection electrodes 12 serving as outer leads are not used for temporary fixing, even if the pitch of the external connection electrodes 12 becomes narrower as the semiconductor device becomes higher in density,
The first and second printed circuit boards 1 and 2 can be temporarily fixed. Therefore, the first printed board 1 and the second printed board 2 can be assembled with high precision.

9 and 10 show another embodiment of the present invention. In this embodiment, as shown in FIG. 9, a recess 27 is formed in the second printed circuit board 2, and the semiconductor device 11 is inserted into the recess 27, so that the first
The printed circuit board 1 is attached. By housing the semiconductor device 11 in the recess 27 of the second printed circuit board 2 in this way, the entire printed circuit board device can be thinned. Further, even if a load acts on the second printed circuit board 2, it is not transmitted to the semiconductor device 11 as it is. Therefore, as shown in FIG. 10, the contact electrode 28 can be formed on the portion of the second printed circuit board 2 corresponding to the semiconductor device 11. The contact electrode 28 corresponds to a contact (not shown) provided in a case (not shown) in which the printed circuit board device is mounted.
The contact contacts the contact electrode 28 to perform switching. Even if such a pressing operation is applied to the contact point, the semiconductor device 11 is not subjected to a weight, so that the semiconductor device 11 is
There is no failure or omission and it can operate well. In FIG. 10, reference numeral 30 denotes a lower case inside a case to which the printed circuit board device is assembled.

11 to 14 show a method of mounting the resistor and the capacitor 5 (hereinafter referred to as the capacitor 5). An opening 33 for mounting is formed in the first printed board 1. Further, an external connection electrode 34 extending in the opening 33 is patterned on the surface of the first printed board. The capacitor 5 has a chip shape,
It is attached on the support tape 31 made of adhesive tape,
The first printed board 1 is inserted into the opening 33 from below (see FIG. 11). Then, by attaching the support tape 31 to the lower surface of the first printed circuit board 1,
The capacitor 5 is temporarily fixed (see FIG. 12). At this time,
The external connection electrode 34 of the film substrate is pushed up by the capacitor 5 and bent.

Thereafter, the external connection electrode 34 is brought into contact with the heating head 35 from above and the electrode 34 is pressed down (see FIG. 1).
3). Since the external connection electrode 34 is made of a flexible copper foil and the downward movement of the capacitor is restricted by the support tape 31, the external connection electrode 34 is easily bent on the capacitor 5 by pressing the heating head 35. To do. Then, by heating the heating head 35, the electrodes (bumps) of the capacitor 5 and the external connection electrodes 34 are joined, and these are electrically connected (see FIG. 14). With such mounting, the capacitor 5 is temporarily fixed by the support tape 31, so that the capacitor 5 can be mounted with high accuracy and the mounting strength is increased. Also, a large number of semiconductor devices 11 can be mounted at the same time. Note that it can be similarly applied to a semiconductor device and other electric parts.

[0016]

As described above, according to the present invention, since a plurality of printed circuit boards are temporarily fixed by joining the fixing pattern and the receiving pattern, the plurality of printed circuit boards can be assembled with high precision.

[Brief description of drawings]

FIG. 1 is a front view of an example of a printed circuit board device.

FIG. 2 is a front view of a first printed circuit board.

FIG. 3 is an enlarged front view showing a fixing pattern.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a front view of a second printed circuit board.

FIG. 6 is a front view showing the assembling of the first and second printed circuit boards.

FIG. 7 is a front view showing joining of a fixing pattern and a receiving pattern.

8 is a cross-sectional view taken along line BB of FIG.

FIG. 9 is a sectional view of another embodiment of the present invention.

FIG. 10 is a sectional view of another embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the process of assembling the capacitor of the present invention.

FIG. 12 is a sectional view showing the assembling process.

FIG. 13 is a cross-sectional view showing the assembling process.

FIG. 14 is a perspective view showing a completed state of the assembling.

[Explanation of symbols]

 1 First Printed Circuit Board 2 Second Printed Circuit Board 10 Film Board 11 Semiconductor Device 12 External Connection Electrode 16 Fixing Pattern 22 Connection Terminal 26 Receiving Pattern

Claims (1)

[Claims] 1. A film substrate, a semiconductor device attached to the film substrate, a large number of external connection electrodes electrically connected to the semiconductor device, and a fixing pattern extending from the film substrate. And a second printed circuit board having a connection pattern electrically connected to the external connection electrode and a receiving pattern to which the fixing pattern is fixed. Printed circuit board device.