JPH10341087A - Connection structure of frame and printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure capable of preventing damages of a connection part between a frame and a printed circuit board even if distortions are developed at the connection part. SOLUTION: This connection structure includes a frame 1 made of a metallic plate and a printed circuit board 2 disposed within the frame. The frame has a sidewall 1a and a tongue piece 1b, integrally formed with the sidewall. The tongue piece 1b has a holder piece 1c, extended in a longitudinal direction of the sidewall, which is flush with the sidewall, a bent piece 1d extending from the holder so as to slant inward of the frame, and a loose end 1e extended parallel to the side wall of the frame and downward from one end of the bent piece. The board 2 and the loose end 1e of the tongue piece of the frame are fixed by soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic apparatus having a structure in which a printed circuit board, such as a television tuner or a modulator, having an electronic circuit is disposed in a metal frame. And a connection structure for a printed circuit board.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a main part of a conventional electronic device, FIG. 5 is an exploded perspective view for explaining the assembly of the electronic device of FIG. 4, and FIG. FIG. 7 is a perspective view of a main part for describing a connection structure with a printed circuit board.
It is principal part sectional drawing in the -B line. As shown in FIGS. 4 to 7, a rectangular box-shaped frame 10 made of a metal plate includes a side wall 10 a surrounding four sides, and an upper opening 10 b and a lower opening 10 c formed by the side wall 10 a. Have.
Below the side wall 10a, a plurality (for example, four) of notches 10d are formed. The printed circuit board 11
Has a rectangular shape, and electronic components (not shown) such as an integrated circuit, a coil, and a chip component are mounted on the front and back surfaces thereof. And a plurality of conductive patterns 11b are formed at predetermined positions on the ends. The conductive pattern 11b is provided to be grounded to the frame 10.

A gap 13 having a predetermined width t2 is provided between the side wall 10a of the frame 10 and the end face of the printed circuit board 11.
(See FIG. 7). The gap 13 is provided to facilitate the incorporation of the printed board 11 into the frame 10. The printed circuit board 11 is disposed in the frame 10, and the conductive pattern 11 b formed on the end of the printed circuit board 11 and the side wall 10 a of the frame 10 are soldered by the solder 12 to form the conductive pattern. 11b is grounded to the frame 10

[0004] The assembly of the above electronic equipment will be described. First, the printed circuit board 11 is connected to the opening 10 c below the frame 10.
From the frame body 1
The printed circuit board 11 is temporarily fixed to the frame body 10 by engaging with the notch 10d of No. 0. Next, cream-like solder 12 is applied to the conductive pattern 11b formed at a predetermined location at the end of the printed circuit board 11, and the frame 10 is placed in a heating furnace (not shown) with the cream-like solder 12 applied. 2), the solder 12 is melted, and the conductive pattern 11b of the printed circuit board 11 and the side wall 10a of the frame 10 are soldered.
At this time, the solder 12 is in a state of connecting the frame 10 and the printed board 11 so as to straddle through the gap 13 between the frame 10 and the printed board 11.

[0005]

However, in the conventional connection structure between the frame and the printed circuit board, the distortion due to the expansion and contraction due to the difference in thermal expansion between the frame 10 and the printed circuit board 11 in a temperature cycle test or the like causes X. -It occurs in the Y direction (see Fig. 4). For example, when the printed board 11 expands due to expansion (in the directions indicated by arrows X1 and Y1), a pressing force is applied to each solder 12 and when the printed circuit board 11 contracts due to contraction (arrows X2 and Y2). Direction), a tensile force is applied to each solder 12. When a tensile force or a pressing force is applied to the solder 12 due to the expansion and contraction of the printed circuit board 11, the solder 12 is cracked or divided, and the connection between the frame 10 and the printed circuit board 11 is caused. However, there is a problem that it is damaged and is not stable. In the conventional connection structure between the frame and the printed circuit board, the solder 12 is connected only between the side wall 10a of the frame 10 and the conductive pattern 11b on the upper surface of the printed circuit board 11, and the connection area is small. Therefore, there is a problem that the mechanical connection between the frame and the printed circuit board is weak.

An object of the present invention is to provide a connection structure in which the connection portion is not damaged even if the connection portion between the frame and the printed circuit board is distorted. It is.

[0007]

According to the present invention, there is provided a connection structure between a frame and a printed circuit board according to the present invention, the frame comprising a metal plate and having a side wall and a tongue piece formed integrally with the side wall; A printed circuit board having a land portion disposed on the side surface, wherein the tongue piece is coplanar with the side wall, extends in the lateral direction of the side wall, and has one end portion connected to the side wall; A bent piece which is provided continuously with the other end of the holding portion and is provided to be inclined from the inner surface of the side wall toward the inside of the frame; and the frame body extends in the longitudinal direction of the side wall from the other end of the bent bent piece. The land portion of the printed circuit board and the free end portion of the tongue piece of the frame are fixed by soldering.

In the connection structure of the frame and the printed board according to the present invention, a notch is formed at a position corresponding to the free end of the tongue of the frame on the printed board, and the notch is formed. That is, a conductive pattern was formed on the inner peripheral surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a main part for describing a connection structure between a frame and a printed board according to the present invention.
Is a cross-sectional view of a main part taken along the line AA in FIG. 1, and FIG. 3 is a perspective view of the main part for describing a printed circuit board according to the electronic apparatus of the present invention. As shown in FIGS. 1 to 3, the connection structure between the frame body and the printed board is made of a metal plate, and includes a rectangular box-shaped frame body 1 and a printed board 2 arranged inside the frame body 1. ing. The frame 1 includes a side wall 1a surrounding four sides, and open portions (not shown) formed above and below the side wall 1a. Also, a plurality of tongue pieces 1b are punched out and bent at each part of the four side walls 1a to be formed integrally with the side walls 1a. A tongue piece 1b formed by punching and bending a side wall 1a made of a metal plate is provided on the same plane as the side wall 1a and extends in the lateral direction of the side wall 1a. And a holding portion 1c connected to the other end of the holding portion 1c,
A bent piece 1d is provided to be inclined into the inside of the frame from the inner surface of the side wall 1a. And a rectangular free end 1e.

An electronic component (not shown) such as an integrated circuit, a coil, or a chip component is mounted on the front and back surfaces of the printed circuit board 2, and is cut out at a position corresponding to the tongue 1 b of the frame 1. A portion 2a is formed, and a land portion 2c for soldering formed by electroless plating or the like is formed on the inner peripheral surface 2b of the notch portion 2a. Also,
A conductive pattern 2d is formed on the surface of the printed circuit board 2, and a land 2e is formed at an end of the conductive pattern 2d.
Is provided. The land 2e on the surface of the printed circuit board 2 is connected to the land 2c of the cutout 2a. The lower end of the free end 1e of the tongue 1b faces the inner peripheral surface 2b of the cutout 2a of the printed circuit board 2. A gap 4 having a predetermined width t1 is formed between the notch 2a and the free end 1e. The solder 3 is soldered to the land 2c of the inner peripheral surface 2b of the cutout 2a and the land 2e of the printed board 2.
The solder 3 allows the notch 2a of the printed circuit board 2 to be formed.
The land 2c formed at the end of the tongue 1b and the land 2e at the end of the conductive pattern 2d are connected to the free end 1e of the tongue 1b. The notch 2a and the free end 1e are connected by the solder 3 by soldering to the land 2c.

Next, the assembly of the connection structure between the frame and the printed circuit board will be described. First, the printed board 2 is assembled into the frame 1 from an opening (not shown) below the frame 1, and the printed board 2 is temporarily fixed to the frame 1. In this temporarily fixed state, the free end 1e of the tongue piece 1b of the frame 1 faces the cutout 2a of the printed circuit board 2. next,
A creamy solder 3 is applied to a land 2c formed at a position where the free end 1e and the notch 2a face each other, and a land 2e at the end of the conductive pattern 2d. 3 and the printed circuit board 2
Is passed through a heating furnace (not shown), so that the solder 3 is melted, and the printed board 2 and the tongue piece 1b of the frame 1 are soldered.
At this time, the creamy solder 3 also adheres to the land 2c formed on the inner peripheral surface 2b of the notch 2a, so that the lower end of the free end 1e and the land on the inner peripheral surface 2b of the notch 2a. 2c is soldered.

The printed circuit board 2 and the free end are connected by the solder 3 connecting the free end 1e and the land 2c and the solder 3 connecting the free end 1e and the land 2e at the end of the conductive pattern 2d. The lower end of 1e is firmly connected by a sufficient area of solder. The printed circuit board 2 is connected to the frame 1 by this soldering, and the assembly is completed. And
A temperature cycle test or the like is performed on the electronic device having the connection structure between the frame and the printed board of the present invention, and a difference in expansion and contraction occurs between the frame 1 and the printed board 2 due to thermal expansion and the like due to the temperature cycle. However, the distortion due to the difference in expansion and contraction is absorbed by the movement of the tongue piece 1b of the frame 1, and the connection by the solder 3 is not impaired.

Next, the absorption of distortion due to the difference in expansion and contraction of thermal expansion by the tongue piece 1b of the frame 1 will be described. First,
When the printed circuit board 2 moves in the directions of arrows X1 and Y1 shown in FIG. 1 with respect to the frame 1 due to thermal expansion, a pressing force is applied to the solder 3 fixed to the lands 2c and 2e of the printed circuit board 2. In addition, this pressing force is absorbed by the holding portion 1c and the bent piece 1d that constitute each tongue piece 1b. This is the printed circuit board 2 with respect to the frame 1
Is moved in the directions of the arrows X1 and Y1 so that the bent piece 1
The bent parts at both ends of the printed circuit board d are hinged to be further bent or extended to be deformed, and the holding part 1c is deformed outward from the side wall 1a, so that the arrow of the printed board 2 is formed. The pressing force against the solder 3 due to the movement in the X1 and Y1 directions is absorbed.

Next, the printed circuit board 2 is
When the solder 3 moves in the directions of arrows X2 and Y2 shown in FIG. 1 due to shrinkage, a tensile force is applied to the solder 3. The tensile force is expanded by the holding portion 1c and the bent piece 1d constituting each tongue 1b. The tensile force on the solder 3 is absorbed by the same movement as the above.

[0015]

According to the connection structure between the frame and the printed circuit board of the present invention, the free end 1e and the land of the printed circuit board 2 constitute a plurality of tongue pieces 1b integrally provided on the side wall 1a of the frame 1. By soldering the land 2e and the land 2e, the tongues allow the printed circuit board to move a small distance in the X and Y directions with respect to the frame. When the printed circuit board 2 is displaced with respect to the frame 1 due to expansion and contraction due to the difference in thermal expansion between them, the tensile force and the pressing force applied to the solder 3 are not equal to those of the holding section 1c. The tongue piece 1b composed of the piece 1d and the free end 1e has an effect that the distortion is absorbed and the connection by the solder 3 is not impaired.

Further, in the connection structure between the frame and the printed board according to the present invention, the land is formed on the inner peripheral surface of the cutout portion of the printed board, so that the connection of the printed board to the frame by soldering can be performed. In addition to the connection with the land part of the printed circuit board, solder connection between the land part on the inner peripheral surface and the tongue piece of the frame is also added, and it is said that stable connection can be obtained because it is connected with solder of sufficient area It works.

[Brief description of the drawings]

FIG. 1 is an essential part perspective view for explaining a connection structure between a frame and a printed board according to the present invention.

FIG. 2 is a sectional view of an essential part taken along line AA of FIG. 1;

FIG. 3 is an essential part perspective view for explaining a printed circuit board according to the electronic apparatus of the present invention.

FIG. 4 is a perspective view showing a conventional electronic device.

FIG. 5 is an exploded perspective view for explaining assembly of the electronic device of FIG. 4;

FIG. 6 is an essential part perspective view for explaining a conventional connection structure between a frame and a printed circuit board.

FIG. 7 is a sectional view of a main part taken along line BB of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Frame 1a Side wall 1b Tongue piece 1c Holding part 1d Bend part 1e Free end part 2 Printed circuit board 2a Notch part 2b Inner peripheral surface 2c, 2e Land part 2d Conductive pattern 3 Solder 4 Gap

Claims (2)

[Claims] 1. A frame made of a metal plate and having a side wall and a tongue piece formed integrally with the side wall, and a printed board having a land portion disposed in the frame body, wherein the tongue piece is provided. A holding portion provided on the same plane as the side wall, extending in the lateral direction of the side wall, and having one end portion connected to the side wall and the other end portion of the holding portion; A bent piece that is inclined from the inner surface into the inside of the frame, and a play piece that extends from the other end of the inclined bent piece in the longitudinal direction of the side wall in parallel with the side wall of the frame. An end structure, wherein a land of the printed circuit board and a free end of a tongue piece of the frame are fixed by soldering. 2. A notch is formed at a position corresponding to a free end of a tongue of the frame body of the printed circuit board, and a land is formed on an inner peripheral surface of the notch. A connection structure between a frame and a printed circuit board according to claim 1.