JPH0536872U - Flexible board mounting structure - Google Patents

Abstract

(57) [Summary] [Purpose] A mounting structure for connecting a flexible board directly to the circuit board by soldering. A flexible board is sandwiched and fixed between the mounting plate and the circuit board. [Structure] A large number of connection terminal portions 10a are arranged in a line substantially at the center of the circuit board 10. Flexible board 1
Reference numeral 2 denotes a pattern of a large number of wirings 18 exposing the connection terminal portion 18a to be soldered to the terminal portion 10a.
The escape holes 12b are formed between the wirings 18 at the same intervals as the protruding intervals of the terminal pins 16a, and the escape holes 12 are formed at the same pitch as the boss insertion holes 10b on the circuit board 10 side.
A boss insertion hole 12c having a diameter smaller than b is formed. The mounting plate 14 has a rectangular shape that is arranged orthogonal to the flexible substrate 12, and has a plurality of boss portions 14a, which are inserted into the boss insertion holes 12c, provided in a row on the back surface side so as to project.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mounting structure for connecting a flexible board directly to a circuit board by soldering.

[0002]

[Prior Art]

 Flexible boards are used for wiring connections between rigid circuit boards, or between circuit boards and other devices, and are generally connected to the circuit board side via a connector, but for the purpose of reducing the number of parts, etc. Some of them are directly soldered to the terminal pattern formed on the board side.

In the case of this type of direct connection, in order to position and fix the terminal portion at the end of the flexible board in accordance with the terminal pattern on the circuit board side, conventionally, as shown in FIG. The reinforcing sheet 2 is attached to the back surface and then fixed to the circuit board 4 side with a double-sided adhesive tape or adhesive 3, and then the terminal portion 1a at the front end is formed on the circuit board 4 side. They were connected by soldering 5 while being pressed against the portion 4a side.

[0004]

[Problems to be solved by the device]

 However, in this mounting structure, the positioning work of the terminal portion 1a corresponding to each terminal portion 4a is troublesome and the fixing strength is uncertain, and the mounting fixed to the circuit board 4 as shown in the figure. Since the terminal pin 6a of the component 6 protrudes from the mounting surface of the flexible substrate 1, the mounting work cannot be performed. Therefore, the circuit board side 4 is located at a position where interference of the mounted components 6 is avoided, such as an edge of the substrate. The terminal pattern had to be formed at this location, which caused restrictions on the wiring design of the circuit board 4. Further, in this structure, when pulling out force or bending stress is applied to the flexible substrate 1, the force extends to the soldering portion 5, and there is a fear of disconnection.

The present invention is intended to remedy the above drawbacks, and its purpose is to reliably and easily position and fix the mounting surface of a flexible board on a circuit board without receiving interference of mounted components, and also to withdraw force. Another object is to provide a flexible board mounting structure that does not exert the force on the soldering portion even when bending stress is applied.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, a feature of the present invention is a structure in which a large number of terminals arranged at the tip of a flexible board are connected to terminals formed on a circuit board by soldering. On the mounting surface for the board, a large number of escape holes and boss insertion holes for inserting mounting components protruding on the surface of the circuit board are opened, and on the surface of the flexible board, the boss insertion holes are provided to the circuit board side. A mounting plate made of synthetic resin having a plurality of boss portions to be inserted is arranged, and the insertion end of the boss portion is fixed to the back surface side of the circuit board.

[0007]

[Action]

 According to the above configuration, the mounting component protruding on the surface of the circuit board penetrates the flexible board through the escape hole, and the mounting surface of the flexible board can be positioned and installed on the circuit board front surface side. By disposing the mounting plate on the surface of the flexible board and fixing the insertion end of the boss portion to the back surface side of the circuit board, the flexible board is sandwiched and fixed between the mounting plate and the circuit board. When a pulling force or a bending force is applied to the flexible board, the stress is applied only to the relief hole, the boss insertion hole periphery, or the periphery of the mounting plate.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In the mounting structure shown in the drawing, a flexible circuit board 12 is mounted on a rigid circuit board 10 via a mounting plate 14 made of synthetic resin, and a large number of connection terminal portions 10a are arranged in a line at substantially the center of the circuit board 10. ing. A plurality of switches 16 are mounted on the back surface side of the circuit board 10 between the terminal portion 10a and the edge portion of the circuit board 10, and each pair of terminal pins 16a is arranged in parallel with the terminal portion 10a. The surface of 10 is projected in a horizontal row. Further, boss insertion holes 10b penetrating the front and back of the circuit board 10 are formed at positions alternating with the paired protruding positions of the terminal pins 16a.

The flexible board 12 is connected to a connector (not shown) at one end, and at the other end thereof, a pattern of a large number of wirings 18 exposing a connection terminal portion 18a to be soldered to the terminal portion 10a is provided. In the vicinity of the terminal portion 18a, the substrate 12 has a trapezoidal shape and spreads laterally, and an escape hole 12b having the same spacing as the protruding interval of the terminal pin 16a is formed between the wirings 18 at this spreading portion. In addition, a boss insertion hole 12c having a diameter smaller than that of the escape hole 12b is formed at the same pitch as the boss insertion hole 10b on the side of the circuit board 10.

The mounting plate 14 has a rectangular block shape that is arranged orthogonal to the flexible substrate 12, and has a plurality of boss portions 14a that are inserted into the boss insertion holes 12c on the back side and project in a line. Further, a plurality of notches 14b for avoiding interference with the terminal pins 16a are formed on both sides of the back surface in the width direction.

In the above structure, the flexible board 12 can be fixed to the surface of the circuit board 10 with the escape holes 12b inserted into the respective terminal pins 16a. In the fixed state, the boss insertion holes 10b and 12c are aligned with each other, and the terminal portions 10a and 18a are also aligned with each other. In this state, if each boss portion 14a of the mounting plate 14 is inserted into the boss insertion holes 10b and 12c and the mounting plate 14 is installed on the front surface of the flexible board 12, the boss portion 14a projects to the back surface of the circuit board 10. Further, the terminal pin 16a is housed inside the notches 14b on both sides of the mounting plate 14, and interference between the terminal pin 16a and the mounting plate 14 is also prevented. Next, if the rear surface side protruding end 14b of the boss portion 14a is crushed into a rivet shape by a welding means such as ultrasonic welding, the mounting plate 14 is fixed to the circuit board 10, and the flexible board 12 is sandwiched and fixed between them. To do.

Then, the terminals 10a and 18a are soldered to complete the connection. Even if a pulling force is applied to the flexible board 12 in the connection completed state, the pulling force is only applied to the peripheral edges of the escape hole 12b and the boss insertion hole 12c, and the force is not applied even to the solder portion, and the disconnection or the like occurs. Can be prevented.

In FIG. 3, the circuit board 10 having the mounting structure of the above embodiment is arranged vertically, and the main circuit board 20 is arranged horizontally close to the flexible board 12 between the boards 10 and 20. In the connected state, one end of the flexible board 12 is connected to the main circuit board 20 via a connector 22. When the distance d between the two circuit boards 10 and 20 is narrow as shown in the figure, the flexible board 12 bends, but this bent shape is almost along the arrangement shape while being pressed against the top surface of the mounting plate 14. Since it bends in an S shape, there is no excessive bending stress, and since the outer side of the terminal pin 16a protruding from the circuit board 10 is covered by the mounting plate 14, the flexible board 12 is prevented from being torn or the pattern is damaged. .

In the above embodiment, the insertion end of the boss portion 14a is fixed to the circuit board side by welding, but the boss portion 14a may be crushed by cold crimping, or the shape of the boss portion 14a may be locked. If it is formed in the shape of a resin clip with a claw, it can be mechanically retained when it is inserted through one end, so that the labor for welding can be saved.

[0015]

[Effect of the device]

 As described above, in the mounting structure of the flexible board according to the present invention, the mounting parts protruding on the surface of the circuit board penetrate the flexible board through the clearance holes, and the mounting surface of the flexible board can be positioned and installed on the surface side of the circuit board. Positioning of terminals can be done easily. By disposing the mounting plate on the surface of the flexible board and fixing the insertion end of the boss to the back side of the circuit board, the flexible board is sandwiched and fixed between the mounting plate and the circuit board. The fixing work is easy and the fixing strength is high. When pull-out force or bending stress is applied to the flexible board, that stress is applied only to the escape holes, boss insertion holes, or the periphery of the mounting plate, so there is no wire breakage and it is highly shock resistant.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a mounting structure of a flexible substrate according to the present invention.

FIG. 2 is a cross-sectional view showing a completed mounting state of the mounting structure.

FIG. 3 is a side view showing an application example of the above attachment structure.

FIG. 4 is a cross-sectional view showing a conventional mounting structure.

[Explanation of symbols]

 10 Circuit Board 10a Connection Terminals 10b, 12b Boss Through Hole 12 Flexible Board 14 Mounting Plate 14a Boss 16 Switch (Mounting Parts) 16a Terminal Pin

Claims (1)

[Scope of utility model registration request] 1. In a structure in which a large number of terminal portions arranged at the tip of a flexible substrate are connected to a terminal portion formed on a circuit board by soldering, the circuit board is attached to a mounting surface of the flexible board with respect to the circuit board. While opening a large number of escape holes and boss insertion holes through which mounting components protruding on the surface are inserted, a synthetic resin having a plurality of boss portions which are inserted into the circuit board side through the boss insertion holes on the surface of the flexible substrate. Place the mounting plate made of
A mounting structure for a flexible board, wherein an insertion end of the boss portion is fixed to a back surface side of a circuit board.