JP2539615Y2 - Flexible printed circuit board - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention relates to a shield box for shielding a sensor or the like.

[Prior art] Flexible printed wiring boards (hereinafter referred to as FPCs) placed inside equipment are used as a structure to shield sensors etc. installed in small precision equipment such as cameras with built-in electric circuits. A proposal has been made in which a part is entirely printed with a metal foil in advance, and this part is appropriately bent so as to surround a target shielded component.

In this type of shield structure disclosed in Japanese Utility Model Laid-Open No. 55-88300, when forming a shield body with FPC, an FPC for shielding is formed on the back surface of an insulating plate to which electric components are attached.
After the FPC extended from the edge of the insulating plate is folded back so as to cover the electrical components, the protrusion provided on a part of the FPC is Of the above-mentioned insulating plate.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, providing a shield member without any gap is an important requirement for blocking electromagnetic waves. Is also complicated. Therefore, when trying to maintain a complicated shape by this conventional technique, projections for hooking are required at many points on the edge of the FPC, and the projections are also inserted into the insulating plate with this. Not only is it very difficult to design a stable three-dimensional shield box,
There is a drawback that the work for inserting the projection becomes complicated.

The purpose of the present invention is to solve the above-mentioned conventional problems and to realize a FPC without a complicated and poorly workable structure such as insertion of a projection.
An object of the present invention is to provide a shield box in which the FPC itself can easily maintain the box shape after bending.

[Means for Solving the Problems] The shield box according to the present invention is a shield box for shielding a sensor or the like, and has a predetermined bent shape due to plastic deformation of the metal foil itself formed along its main surface. A flexible printed wiring board which is adapted to be maintained is bent into a box shape, and a hole is formed in the bent portion, and a sensor section and a shield box for shielding the sensor section are provided. And a flexible printed circuit board and a part of the same flexible printed circuit board in which a box-shaped bent shape is maintained by plastic deformation of the metal foil itself formed along its main surface. It is characterized by being constituted as.

[Action] The metal foil portion provided at the bending position is plastically deformed by the bending against the elasticity of the substrate film of the FPC,
The box shape after bending is maintained by the action of the metal foil itself.

Hereinafter, the present invention will be described with reference to the illustrated embodiments.

FIG. 1 is a plan view of an FPC for forming an embodiment of the present invention before bending, and FIG. 2 is a perspective view after bending. This embodiment has a sensor mounting piece 2 and a shield box forming piece 3 integrally extending from an FPC main body 1, respectively. The sensor (not shown) mounted on the mounting piece 2 is used to convert the FPC into a box type. This is a case in which the shield box forming piece 3 that is bent is covered.

The FPC body 1 is formed by forming an electric circuit by a copper foil on a base film made of a material such as polyimide, as is well known, and covering the circuit with a coverlay film as necessary. The extended sensor mounting piece 2 has a wide mounting portion 2a at the distal end, and bends a bent portion 2b near the base indicated by a dashed line downward to fix the sensor to the mounting portion 2a.

On the other hand, the shield box forming piece 3 is formed of an inverted L-shaped extending piece extending from the FPC main body 1 to the right (in FIG. 1) of the sensor mounting piece 2, and has a tip end portion. And the left and right side edges near the tip
3a, 3b, 3c are formed to extend. The shield box forming piece 3 has bent portions 4a to 4e at positions indicated by alternate long and short dash lines, respectively.
The shield box 5 (see FIG. 2) is formed by folding the shield box 5 at angles of 0 ° and 90 °. Also, cut holes 6a to 6d indicating bending positions are formed at both ends of the bent portion 4c and both ends of the bent portions 4d and 4e, respectively. Since the cut holes 6a to 6d indicate bending positions, the cut holes 6a to 6d may be round holes or the like formed on the bent portions 4c to 4e.

Then, in the present invention, a metal foil 7 made of copper foil is provided on the entire front and back surfaces of the shield box forming piece 3 thus formed, as shown by a hatched diagram. When the metal foil 7 is bent, the metal foil 7 is plastically deformed against the elasticity of the base film of the FPC constituting the forming piece 3, and the metal foil itself is provided with an amount for maintaining the box-shaped shape by bending. . In this embodiment, the amount is adjusted by adjusting the thickness of the metal foil 7, but may be adjusted by adjusting the area.

In the embodiment configured as described above, the bent portion 2b of the sensor mounting piece 2 is bent downward at a right angle, and a sensor (not shown) is fixed to the mounting portion 2a at the tip thereof. 180 with the bent part 4a of 3 facing the FPC body 1
Fold at an angle of °. Next, the bent portion 4b is bent downward at a right angle, and the bent portions 4c, 4d, and 4e are further valley-folded and bent inward at a right angle. Then, as shown in FIG.
A shield box 5 is formed, and the shield box 5 is
And the sensor on the mounting portion 2a.

Then, when each of the bent portions 4a to 4e is bent in this manner, the metal foil (copper foil) resists the elasticity of the base film.
Since 7 itself is plastically deformed, the shape after bending is maintained by this plastic deformation. Further, since the metal foil 7 made of copper foil is provided on both the front and back surfaces of the shield box forming piece 3, the shield box 5 formed by bending is exactly the same as the shield case formed by the metal plate. Thus, a sufficient shielding effect can be obtained.

FIG. 3 is a plan view of the FPC related to the present invention before bending. This FPC does not form a shield box for completely shielding the sensor as in the above-described embodiment, but is intended to simply maintain a bent state to simply constitute a cover. .

When only the box cover is formed by bending as described above, the FPC1A in which the sensor mounting piece 2 and the box forming piece 3 are formed in the same manner as in the above embodiment, the bent portions 4a to 4e of the formed piece 3 As shown by the diagonal lines in the key parts including
Metal foils 7A and 7B made of copper foil are provided. Then, if each of the bent portions 4a to 4e provided with the metal foils 7A and 7B is bent in the same manner as in the above embodiment, each of the bent portions 4a to 4e is made of metal against the elasticity of the base film. Since the foils 7A and 7B themselves are plastically deformed, the box cover formed by bending maintains its shape.

In this case, portions where the metal foils 7A and 7B are not provided are soft, and the box cover has no shielding effect. Also
Since the FPC is originally manufactured to have flatness, it is easy to manufacture such a shape.

4 and 5 show another FPC related to the present invention. This FPC takes full advantage of the advantage of plastic deformation of the metal foil itself to maintain a bent shape. For example, as shown in FIG. 5, a shape having steps such as a step-like structure 10 is used. In this case, the FPC11 is arranged so as to be completely aligned with the above.

In the case where an FPC is attached to a member having such a shape, in the related art, a curved type FPC is used in which a necessary portion is connected with a spline. However, according to this technique, the FPC can be accurately bent into a shape corresponding to the step of the step-like structure 10, and the bent shape can be maintained by itself.

That is, as shown in FIG. 4, when the FPC 11 on which the pattern 12 constituting a circuit is formed in a strip shape is arranged along the step-like structure 10 shown in FIG. The positions respectively corresponding to the step and the plane portion are bent portions 14a to 14c indicated by dashed lines, and metal foils (copper foils) are respectively provided at portions corresponding to both side edges of the bent portions 14a to 14c of the FPC 11. 13 will be provided. Then, marks for the bent portions of the bent portions 14a to 14c and cut holes 16 for facilitating bending are formed at both ends of the bent portions 14a to 14c.

With this configuration, the bent portions 14a to 14c of the FPC 11 are formed.
By folding the crest into a mountain and a valley, the FPC 1 is formed so as to correspond to the step and the flat portion of the step-like structure 10, respectively.
1 can be bent, and the FPC 11 can be disposed exactly corresponding to the step-like structure 10. In addition, since the metal foil 13 is plastically deformed against the elasticity of the base film at the time of bending, the shape of the bent portion can be accurately maintained. Therefore, since the bent shape is maintained even after the bending, the effect that the FPC 11 can be mounted without disturbing other parts or the like can be obtained.

In the above embodiment, the plastically deformable metal foils 7, 7A, 7B, 1
A copper foil similar to that used for a printed circuit was used as 3, but it is not limited to this, and it goes without saying that any metal that can maintain plastic deformation may be used.

[Effects of the Invention] As described above, according to the present invention, the FPC itself can maintain the bent shape when the seal box is made. It can be easily manufactured only by bending work without using a hook shape and insertion hole.

In addition, since the positional relationship between the sensor unit to which the sensor etc. is attached and the shield box unit is specified in advance on the same flexible printed circuit board, simply fold the flexible printed circuit board in the shield box unit easily Can be formed.

And the like, and it is possible to provide a shield box in which this type of conventional disadvantage is eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of an FPC showing an embodiment of the present invention, FIG. 2 is a perspective view showing a state where a shield box is formed by bending the FPC of the above embodiment, and FIG. Fig. 4 is a plan view of a main part of the FPC related to the present invention, Fig. 4 is a rear view of a main part of another FPC related to the present invention, and Fig. 5 is a folding of the FPC of Fig. 4 to be attached to a step-like structure. It is a perspective view which shows the state which provided. 1,1A, 11 …… FPC 4a ～ 4e, 14a ～ 14c …… Bend position (bend part) 7,7A, 7B, 13 …… Metal foil

Claims (2)

(57) [Scope of request for utility model registration] A shield box for shielding a sensor or the like, wherein a flexible printed wiring is formed so that a predetermined bent shape is maintained by plastic deformation of a metal foil formed along a main surface of the shield box. A shield box wherein a substrate is bent into a box shape, and a hole is formed in the bent portion. 2. A box-shaped bent shape is maintained by plastic deformation of a sensor portion and a metal foil formed along a main surface of the shield box for shielding the sensor portion. A shield box comprising a flexible printed circuit board made as a part and another part of the same flexible printed circuit board.