JPH1154878A - Flexible printed circuit board mounted on electrical component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible printed circuit board whose mount part is miniaturized and mounted on an electric component, while keeping insulation with surrounding components without deteriorating the assembling workability and the soldering workability. SOLUTION: A flexible printed circuit board 1 is mounted on an electrical component, that is placed in a space narrower than the width of an electronic component mounting part 1b of the flexible printed circuit board 1. A cover lay opening 4a and a conductive pattern 3 for electrical connection exposed on the cover lay opening 4a are formed to the electrical component mounting part 1b, and is provided up to an external end of the flexible printed circuit board with respect to the electrical component mounting part 1b. A conductive pattern is not formed in the vicinity of the external end, and the flexible printed circuit board is mounted to the electrical component, with the vicinity of the external end of the electrical component mounting part 1b being folded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit board mounted on an electric component.

[0002]

2. Description of the Related Art Flexible printed circuit boards are currently used in many devices such as cameras and notebook computers due to their advantages of thinness and flexibility, and are indispensable for miniaturization of these devices. It has become. As shown in FIG. 2, the flexible printed circuit board 21 forms a predetermined conductive pattern 23 by etching a conductive foil adhered to a flexible synthetic resin base 22 via an adhesive (not shown). Then, a coverlay 24 is attached to protect the conductive pattern. A connection land for electrically connecting the electric component and the flexible printed board is formed in a predetermined portion of the flexible printed board 21. In the connection land, an opening 24a is formed in a cover lay at an electrical connection point, and the conductive pattern 23 is exposed. By soldering the exposed conductive pattern 23 and the terminal of the electric component, the electrical connection between the electric component and the flexible printed board is completed.

[0003] L1 in FIG. 2 is an "outer shape-pattern interval" provided in consideration of an error in manufacturing the flexible printed circuit board, that is, deviation of the outer shape from the conductive pattern.
L2 is the “coverlay cover amount” similarly set in consideration of the displacement of the coverlay with respect to the conductive pattern.
In general, L1 = 0.5 mm, L2 = 0.3 m
m.

When an electric component is mounted on the flexible printed board, as shown in Japanese Utility Model Publication No. 59-768, as shown in FIG. Hole 31a in 31b
The cover lay 34 is provided with an opening 34a to expose the conductive pattern 33 around the hole 31a.
The terminal 35a of the electric component 35 inserted in 1a and the exposed conductive pattern 33 are mounted by soldering. Naturally, the “outer shape-pattern interval” L1 and the “coverlay covering amount” L2 must be ensured in the flexible printed circuit board at this time in consideration of an error at the time of manufacturing.

FIG. 4 (conventional example 2) shows a flexible printed circuit board such as that shown in FIG.
In order to prevent the width of the electrical component mounting portion of the flexible printed circuit board 41 from being increased by the “outer shape-pattern interval” L1 in FIG. b, in order to insert the terminal 45a of the electrical component 45, not a hole but a U-shaped notch 41a is used. This is the flexible printed circuit board 41 obtained.

When mounting a flexible printed circuit board on an electric component, it may be necessary to mount the flexible printed circuit board on an electric component disposed in a space smaller than the width of the electric component mounting portion of the flexible printed circuit board. For example, as shown in FIG. 5 (conventional example 3), there is a case where a flexible printed board is mounted on a photo interrupter of a shutter blade detecting mechanism of a camera.

FIG. 5 is a sectional perspective view showing a case where the flexible printed circuit board of FIG. 3 is applied to a shutter blade detecting mechanism of a camera. Reference numeral 51 denotes a flexible printed circuit board, which includes a base 52, a conductive pattern 53, and a coverlay 5.
4 is laminated via an adhesive (not shown), L1 is the “outer shape-pattern interval”, and L2 is the “coverlay covering amount”. Reference numeral 55 denotes a photo interrupter whose terminals 55 a are connected to holes 51 of the flexible printed circuit board 51.
a, and are mounted by soldering and electrically connected. The signal of the photo interrupter 55 that has sensed the operation of the shutter blade 56 is transmitted by the flexible printed circuit board 51. The conductive pattern 53 is exposed around the hole 51a of the flexible printed board 51 by the opening 54a of the cover lay 54. And insulation is maintained.

Reference numeral 57 denotes a shutter base plate which has conductivity by being mixed with carbon or the like in order to prevent influence on the shutter blades 56 due to static electricity. Since the photo interrupter 55 is mounted in the space of the shutter base plate 57, the connection land of the flexible printed substrate 51 is mounted in the space of the shutter base plate 57 to electrically connect the flexible printed board 51 and the photo interrupter 55. Then, it must be soldered to the terminal 55a of the photo interrupter 55.

On the other hand, FIG. 6 (conventional example 4) is a sectional perspective view when the flexible printed circuit board as shown in FIG. 4 is applied to a shutter blade detecting mechanism of a camera. Reference numeral 61 denotes a flexible printed circuit board, which is formed by laminating a base 62, a conductive pattern 63, and a cover lay 64 via an adhesive (not shown).
The electric component 65 is not a hole but a U-shaped notch 61a. 65 is a photo interrupter whose terminal 65a is connected to the flexible printed circuit board 6
It is inserted into one U-shaped notch 61a, mounted by soldering, and electrically connected. The signal of the photo interrupter 65 that has sensed the operation of the shutter blade 66 is transmitted by the flexible printed board 61. The conductive pattern 63 is exposed around the hole 61 a of the flexible printed board 61 at the opening 64 a of the cover lay 64. That is, the end of the electric component mounting portion of the flexible printed circuit board of Conventional Example 4 is not covered with the coverlay, and the conductive pattern is exposed.

Reference numeral 67 denotes a shutter base plate, which has conductivity by being mixed with carbon or the like in order to prevent influence on the shutter blades 66 due to static electricity. In the fourth conventional example, the photointerrupter 65 is mounted in the space of the shutter base plate 67 similarly to the third conventional example. Therefore, in order to electrically connect the flexible printed board 61 and the photointerrupter 65, the space of the shutter base plate 67 is required. The connection lands of the flexible printed circuit board 61 must be mounted inside and soldered to the terminals 55a of the photo interrupter 55.

[0011]

However, in the flexible printed circuit board according to the above-mentioned prior art example 1, the flexible printed board is provided by the "outer-pattern interval" L1 provided in consideration of an error in manufacturing, that is, a deviation of the outer shape from the conductive pattern. There is a disadvantage that the width of the substrate becomes large.

In the conventional example 2, since the terminals 45a of the electric component 45 are inserted into the U-shaped notches 41a instead of the holes and mounted, the flexible printed circuit board is easily detached from the terminals of the electric component during the soldering operation. A portion having no conductive pattern is partially formed around the terminal, and there is a disadvantage that the soldering workability is deteriorated.

On the other hand, since the shutter unit of the camera must accommodate various mechanisms at a high density, the space is very limited, and conversely, the compact shutter unit greatly contributes to the miniaturization of the whole camera.

However, in the conventional example 3 shown in FIG. 5, since the flexible pull printed board 51 which is larger by the "outer shape-pattern interval" L1 must be mounted in the space of the shutter base plate 57, the shutter base plate 57 is stepped. The escape portion 57a must be provided, and the space for other parts is correspondingly compressed, leading to an increase in the size of the entire shutter unit. If the gap between the shutter base plates is configured to be the same as the width of the photo-interrupter 55 as shown by the broken line in the figure to avoid this, the width becomes smaller than the width of the flexible printed board 51, and Is covered with a coverlay, so that it is difficult to bend and the assembling workability is poor. In addition, a large stress is applied to the mounted flexible printed circuit board 51 to cause disconnection of the conductive pattern.

In the conventional example 4, since the width of the connection portion of the flexible printed board 61 is narrowed, there is a high possibility that the solder flows to and adheres to the outer edge of the flexible printed board 61 in consideration of manufacturing errors. There is a drawback that short-circuit occurs due to contact with the shutter base plate 67 having a problem. If a shutter-shaped relief portion 67a is provided on the shutter base plate 67 as shown by a broken line in FIG. 6 to avoid a short circuit, the space for other components is pressed by that much, as in the conventional example 3, thereby increasing the size of the entire shutter unit. The drawback is that it leads to the

In view of the above problems, the problem to be solved by the present invention is to mount a flexible printed circuit board while maintaining insulation from surrounding components without deteriorating assembly workability and soldering workability. An object of the present invention is to provide a flexible printed circuit board mounted on an electric component whose size has been reduced.

[0017]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present application mounts an electric component mounted on an electric component mounted in a space narrower than a width of an electric component mounting portion of a flexible printed circuit board. A flexible printed circuit board, wherein a cover lay opening and a conductive pattern for electrical connection exposed at the cover lay opening are formed in the electric component mounting portion, and the cover lay opening is formed in the electric component mounting portion. The flexible printed circuit board is provided up to the outer end, the conductive pattern is not formed near the outer end, and the electric component mounting portion is mounted on the electric component in a bent state near the outer end. It is characterized by having.

According to the above-described structure, it is possible to reduce the size of the mounting portion without deteriorating the workability of assembling and soldering, which is a problem to be solved by the present invention, and maintaining the insulation from the surrounding components. It is achievable to provide a flexible printed circuit board mounted on an electric component achieving the above.

[0019]

FIG. 1 is a view showing an embodiment of the present invention. FIG. 1A is a plan view of a flexible printed board used in the present invention, and FIG. FIG. 1 is a cross-sectional view of the component mounting unit taken along line AA.
(C) is a sectional perspective view when the present invention is applied to a shutter blade detecting mechanism of a camera.

In FIGS. 1A and 1B, reference numeral 1 denotes a flexible printed circuit board, which is formed by laminating a base 2, a conductive pattern 3, and a coverlay 4 via an adhesive (not shown), and 1b denotes a flexible printed circuit board. This is a connection land formed at the end of the substrate. L1 is the “outer shape-pattern interval” of the connection land, and L2 is the “coverlay covering amount”. 4a is a cover lay opening, and the conductive pattern 3 is exposed in the cover lay opening. The exposed conductive pattern 3 is provided with an electrical connection hole 1a for inserting a terminal of an electric component. I have.

As is clear from FIGS. 1A and 1B,
In the electrical component mounting portion 1b of the flexible printed board used in the present invention, the conductive pattern 3 is exposed by the cover lay opening 4a, and the conductive pattern 3 is separated from the outer shape of the flexible printed board 1 by a predetermined “outer shape-pattern gap”. L
Only one is formed inside. Further, the cover lay 4 is provided with an opening 4a so as to overlap the conductive pattern 3 by the "cover lay cover amount" L2 so that the adjacent conductive pattern is not exposed even if a displacement occurs. In the electrical component mounting portion, the conductive pattern and the cover lay are completely removed in the vicinity of the outer end along the longitudinal direction of the flexible printed circuit board. Therefore, the flexible printed circuit board 1
In the vicinity of the outer end portion, the conductive pattern 3 and the cover lay 4 are not provided, and only the base 2 is formed.

FIG. 1C is a sectional perspective view for explaining a state in which the flexible printed circuit board shown in FIGS. 1A and 1B is mounted on an electric component mounted in a space smaller than the width of the connection land. FIG. FIG. 1C shows a flexible printed circuit board mounted on a photo interrupter in a shutter blade detecting mechanism of a camera. The shutter base plate 7 includes a shutter blade 6 and a shutter blade 6.
The space for mounting the flexible printed circuit board on the photo interrupter 5 is smaller than the width of the electrical component mounting portion of the flexible printed circuit board. The shutter base plate 7 has conductivity by being mixed with carbon or the like in order to prevent the shutter blades 6 from being affected by static electricity.
Since the vicinity of the outer end of the electric component mounting portion 1b of the flexible printed board 1 of the present invention is constituted only by the base 2, the terminal 5a of the photointerrupter 5 can be easily bent and bent near the outer end. To be implemented. Although not shown in FIG. 1C, the terminal 5 a of the photo interrupter 5 and the exposed portion 3 of the conductive pattern 3 around the hole 1 a of the flexible printed circuit board 1 are provided.
is soldered to complete the electrical connection. The vicinity of the outer end of the electrical component mounting portion 1b of the flexible printed board 1 is bent at the time of mounting to function as an insulating portion, and the conductive pattern 3 and the solder do not contact the shutter base plate 7.

Therefore, even if the interval W between the shutter base plates 7 is smaller than the width of the flexible printed circuit board 1, FIG.
, So that it can be mounted with good workability, does not press down on the space for other parts, and does not lead to an increase in the size of the entire shutter unit. Only two,
Since the conductive pattern 3 and the solder are bent and function as an insulating portion during mounting, there is no possibility that the conductive pattern 3 and the solder come into contact with the conductive shutter base plate 7 to cause a short circuit, and the workability of mounting the photointerrupter is good.

The scope of application of the present invention is not limited to a single-sided flexible printed circuit board as described in the above embodiment, but is also applicable to a double-sided flexible printed circuit board. Needless to say, the present invention can be applied to a flexible printed circuit board on which a surface mount component or a liquid crystal display device is mounted.

Also, in the above description, the flexible printed circuit board is mounted on the electric components installed in the device in advance. However, even when the electric components are mounted on the flexible printed circuit board first and then mounted on the device. Of course, it is applicable.

[0026]

As described above, according to the first aspect of the present invention, since the vicinity of the outer end of the electric component mounting portion of the flexible printed circuit board is constituted only by the base, the electric component is provided. Even if the space for mounting is smaller than the width of the electrical component mounting part, it can be easily bent near the outer edge at the time of mounting, so the mountability of the flexible printed circuit board is good, and the bent outer edge is the insulating part. , And the insulation with the components around the solder and the conductive pattern is maintained. Since the electric component mounting portion of the flexible printed board is bent, it is possible to mount the electric component on a smaller electric component, which can contribute to downsizing of the device.

According to the second aspect of the present invention, the shutter unit on which the photo interrupter is mounted without deteriorating the workability of assembling or soldering the shutter blade detecting mechanism in the camera and maintaining the insulation from the shutter base plate. Can be reduced in size, and as a result, the size of the camera can be reduced.

[Brief description of the drawings]

FIG. 1A is a plan view of a flexible printed circuit board used in the present invention, FIG. 1B is a cross-sectional view taken along the line AA, and FIG. 1C is a cross-sectional perspective view of a shutter blade detecting mechanism of a camera to which the present invention is applied. .

FIG. 2 is a cross-sectional view of a general flexible printed circuit board.

FIG. 3 is a view showing a conventional flexible printed circuit board mounted with electric components as a first conventional example.

FIG. 4 is a diagram showing a conventional example 2 in which electrical components are mounted on a miniaturized flexible printed circuit board.

FIG. 5 is a cross-sectional perspective view of a shutter blade detection mechanism of a camera as Conventional Example 3.

FIG. 6 is a cross-sectional perspective view of a shutter blade detecting mechanism of a camera as Conventional Example 3.

[Explanation of symbols]

 1: Flexible printed circuit board 2: Base 3: Conductive pattern 4: Cover lay 5: Photo interrupter 6: Shutter blade 7: Shutter base plate

Claims (2)

[Claims] 1. A flexible printed circuit board mounted on an electric component mounted in a space narrower than a width of an electric component mounting section of the flexible printed circuit board, wherein the cover lay opening and the cover lay opening in the electric component mounting section are provided. A conductive pattern for electrical connection exposed at the portion is formed, and a cover lay opening is provided up to the outer edge of the flexible printed circuit board of the electrical component mounting portion, and a conductive pattern is also formed near the outer edge. A flexible printed circuit board mounted on an electric component, wherein the flexible printed circuit board is mounted on the electric component in a state where the vicinity of the outer end of the electric component mounting portion is bent. 2. The flexible printed circuit board according to claim 1, wherein the electric component is a photo interrupter in a shutter blade detecting mechanism of the camera.