JP2006278962A - Electronic circuit unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit unit in where there is no rattling between a frame and a circuit board, and which can be mounted with accuracy, is small and inexpensive. <P>SOLUTION: In the electronic circuit unit, a pair of mounting legs 2b located on the side wall 2 of a frame 1 has an arm 2e and a protrusion 2f positioned near the tip of the arm 2e, and the protrusion 2f elastically contacts with the wall inside the through hole 5a of the circuit board 5 to hold the circuit board 5, whereby, there is no rattling between the frame 1 and the circuit board 5, and the mounting position between the frame 1 and the circuit board 5 is fixed even in soldering etc. by reflowing. Therefore, the electronic circuit unit can be accurately mounted. Moreover, the tip of the arm 2e is flush with the circuit board 5 or slightly protrudes from the circuit board 5, whereby, the electronic circuit unit can be downsized in a upward/downward direction (a thickness direction). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic circuit unit suitable for application to a transmission / reception unit used in a mobile phone.

  FIG. 9 shows an exploded perspective view of a conventional electronic circuit unit. Next, the configuration of the conventional electronic circuit unit will be described with reference to FIG. 9. A frame 51 made of a metal plate has four side walls 52 surrounding four sides. The side wall 52 has openings 52a and 52b provided at the upper and lower portions, and a plurality of mounting legs 52d extending linearly downward from the lower end portion 52c.

The flat circuit board 53 has a plurality of through holes 53a. Although not shown here, the circuit board 53 is provided with a wiring pattern and mounted with electronic components so that a desired electric circuit is provided. Is formed.
The circuit board 53 and the frame 51 are attached by attaching the attachment legs 52d to the through holes 53a and soldering the attachment legs 52d to the wiring pattern to form a conventional electronic circuit unit.

  When the frame 51 and the circuit board 53 are attached, the opening 52b of the frame 51 is closed with the circuit board 53, and the lower end 52c of the side wall 52 is in contact with the upper surface of the circuit board 53. The mounting legs 52d that are longer than the thickness project greatly from the lower side of the circuit board 53 (see, for example, Patent Document 1).

However, in the conventional electronic circuit unit, the mounting leg 52d of the frame body 51 is inserted into the through hole 53a of the circuit board 53. Therefore, the mounting leg 52d is rattled in the range of play in the through hole 53a, and is caused by reflow. In soldering or the like, the mounting position between the frame 51 and the circuit board 53 varies.
Since the mounting leg 52d protrudes greatly from the through hole 53a, the mounting leg 52d increases in the vertical direction (thickness direction), and the mounting leg 52d protrudes linearly from the lower end 52c. In order to form the through-hole 53a, a margin part protruding from the outer surface of the side wall 52 is required. Therefore, the circuit board 53 becomes large, and the cost increases and the electronic circuit unit becomes laterally large.

JP 2002-94279 A

In the conventional electronic circuit unit, the mounting leg 52d of the frame body 51 is simply inserted into the through hole 53a of the circuit board 53. Therefore, the mounting leg 52d is rattled in the range of play in the through hole 53a, and soldering due to reflow is performed. In addition, there is a problem that the mounting position between the frame 51 and the circuit board 53 varies.
Since the mounting leg 52d protrudes greatly from the through hole 53a, the mounting leg 52d increases in the vertical direction (thickness direction), and the mounting leg 52d protrudes linearly from the lower end 52c. This requires a margin for forming the through-holes 53a. Therefore, there is a problem that the circuit board 53 becomes large, the cost is high, and the electronic circuit unit becomes laterally large.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic circuit unit that is free from backlash between the frame and the circuit board, can be mounted with high accuracy, and is small and inexpensive.

  As a first means for solving the above problems, a box-shaped frame made of a metal plate and having side walls surrounding four sides, and a desired electric circuit mounted on the frame and mounted with electronic components A plurality of through holes are provided in the circuit board, and a pair of mounting legs are provided on the one side wall or the two side walls facing each other, The pair of mounting legs includes an arm portion extending from the side wall and a convex portion provided in the vicinity of the tip of the arm portion and projecting in a direction facing each other or in a direction opposite to each other. Each of the portions is inserted into the through-hole, and the convex portion elastically contacts the wall surface in the through-hole to hold the circuit board, and the back surface of the convex portion and the wall surface in the through-hole A gap is provided between them and inserted into the through hole. Tip of the arm portion which is the circuit board flush, or has a structure obtained by slightly protruding from the circuit board.

As a second solution, a conductor is provided on the wall surface in the through hole, and the arm portion located in the through hole and the conductor are soldered, and the circuit board is attached to the frame. It was set as the structure attached to the body.
Further, as a third solving means, an outer surface of the convex portion located between a tip of the arm portion and a top portion of the convex portion is an inclined surface, and the inclined portion is inserted when the circuit board is inserted into the arm portion. The surface is in contact with the edge portion of the through hole to guide the insertion of the arm portion into the through hole.

As a fourth solution, the arm portion of the mounting leg includes a first extending portion extending in the frame body direction at a right angle to the side wall, and an end portion of the first extending portion. It has the 2nd extension part extended in parallel with the said side wall in the outward direction of the said frame, and set it as the structure by which the said convex part was provided in the said 2nd extension part.
As a fifth solution, the convex portions of the arm portions provided on the two opposite side walls are formed in the thickness direction of the side walls.
As a sixth solution, the convex portion of the arm provided on one of the side walls is formed in a width direction perpendicular to the thickness direction of the side walls.

As a seventh solution, an open part is provided on one of the upper and lower parts of the frame, and the circuit board closes the open part with the electronic component positioned in the frame. The circuit board is positioned in the vertical direction by contacting the end of the side wall.
Further, as an eighth solving means, the circuit board exposed to the outside of the frame body is provided with a blocking wall on the other of the upper side and the lower side of the frame body on the side opposite to the opening to which the circuit board is attached. A shield conductor is provided on the outer surface of the substrate or in the laminated circuit board.

An electronic circuit unit of the present invention includes a box-shaped frame body made of a metal plate and having side walls that surround four sides, and a circuit board that is attached to the frame body and on which electronic components are mounted to form a desired electric circuit. The circuit board is provided with a plurality of through holes, and a pair of mounting legs are provided on one side wall or two side walls facing each other. An extending arm part and a convex part provided in the vicinity of the tip of the arm part and projecting in a direction facing each other or in a direction opposite to each other, and each of the convex parts of the pair of mounting legs are inserted into the through holes The convex portion elastically contacts the wall surface in the through hole to hold the circuit board, and a gap is provided between the back surface of the convex portion and the wall surface in the through hole so that the arm portion inserted into the through hole The tip should be flush with the circuit board or slightly protrude from the circuit board. It was constructed.
That is, the pair of mounting legs provided on the side wall of the frame has an arm part and a convex part provided near the tip of the arm part, and the convex part elastically contacts the wall surface in the through hole of the circuit board. Since the circuit board is held, there is no backlash between the frame body and the circuit board, and the mounting position between the frame body and the circuit board is constant even when soldering by reflow, etc., and accurate mounting is possible. In addition, since a gap is provided between the back surface of the convex portion and the wall surface in the through hole, the mounting leg can be used even if an error occurs in the dimension between the pair of through holes or the pair of mounting legs due to processing or the like. Can be easily changed by the gap, and an easy assembly is obtained, and the tip of the arm is flush with the circuit board or slightly protrudes from the circuit board. It can be downsized in the thickness direction).

  In addition, a conductor is provided on the wall surface in the through hole, and the arm portion and the conductor located in the through hole are soldered, and the circuit board is attached to the frame, so that the circuit board and the mounting leg are soldered. And the amount of protrusion of the soldered portion outside the circuit board can be reduced.

  Also, the outer surface of the convex portion located between the tip of the arm portion and the top of the convex portion is an inclined surface, and when the circuit board is inserted into the arm portion, the inclined surface contacts the edge portion of the through hole and penetrates Since the insertion of the arm portion into the hole is guided, the insertion operation of the arm portion into the through hole is facilitated, and a good assembly operation can be obtained.

  The arm portion of the mounting leg extends in a direction perpendicular to the side wall in the frame body direction, and extends from the end of the first extension portion to the outside of the frame body in parallel with the side wall. Since it has the 2nd extension part and the convex part was provided in the 2nd extension part, the arm part can be lengthened, and a good thing of the change of the convex part side is obtained, The conventional margin portion for forming the through-hole can be eliminated, so that the circuit board can be made small, inexpensive, and the electronic circuit unit can be downsized in the lateral direction.

  In addition, since the convex portions of the arm portions provided on the two side walls facing each other are formed in the thickness direction of the side walls, the outer surface of the convex portions becomes smooth, and the convex portions are smoothly inserted into the through holes. Can be.

  In addition, since the convex part of the arm part provided on one side wall is formed in the width direction orthogonal to the thickness direction of the side wall, the arm part and the convex part can be formed by punching a metal plate, and workability Can be obtained.

  In addition, an open part is provided on one of the upper and lower parts of the frame, and the circuit board is in contact with the end of the side wall so as to close the open part with the electronic component positioned in the frame. Therefore, the circuit board can be easily positioned with high accuracy.

  In addition, a blocking wall is provided on the other side of the upper and lower parts of the frame opposite to the opening to which the circuit board is attached, and the outer surface of the circuit board exposed outside the frame or in the stack of circuit boards Since the shield conductor is provided, the circuit board can also serve as a shield, and the number of components is small and a thin one can be obtained.

  FIG. 1 is an exploded perspective view according to a first embodiment of the electronic circuit unit of the present invention, and FIG. 2 is a main portion according to the first embodiment of the electronic circuit unit of the present invention. FIG. 3 is an enlarged cross-sectional view of the main part according to the first embodiment of the electronic circuit unit of the present invention, and FIG. 4 is an enlarged cross-sectional view of the main part according to the second embodiment of the electronic circuit unit of the present invention. 5 is an enlarged perspective view of the main part according to the third embodiment of the electronic circuit unit of the present invention, FIG. 6 is an enlarged perspective view of the main part according to the fourth embodiment of the electronic circuit unit of the present invention, and FIG. FIG. 8 is an enlarged perspective view of the main part according to the sixth embodiment of the electronic circuit unit of the present invention, and FIG. 8 is an enlarged perspective view of the main part according to the sixth embodiment of the electronic circuit unit of the present invention.

  Next, the configuration according to the first embodiment of the electronic circuit unit of the present invention will be described with reference to FIGS. 1 to 3. A box-shaped frame body 1 made of a metal plate includes four side walls 2 surrounding four sides, An opening 3 provided on one side (upper part) of the side wall 2 and a blocking wall 4 that closes an opening on the other side (lower part) of the side wall 2 are provided.

  The side wall 2 is provided with a plurality of mounting legs 2b protruding from the end 2a on the opening 3 side. The mounting legs 2b extend inwardly in the frame 1 at right angles to the side wall 2. And an arm portion comprising a second extending portion 2d extending in parallel with the side wall 2 in the direction of the opening 3 (outward direction of the frame 1) from the end portion of the first extending portion 2c. 2e and a convex portion 2f formed in the width direction orthogonal to the thickness direction of the side wall 2 and provided in the vicinity of the end portion of the arm portion 2e and rounded.

  One side plate 2 is provided with a pair of two mounting legs 2b spaced apart from each other, and the convex portions 2f of the pair of mounting legs 2b are arranged to protrude in opposite directions, The outer surface of the convex part 2f located between the tip of the part 2e and the top of the convex part 2f (upper part side) is formed on the inclined surface 2g.

  The circuit board 5 made of a ceramic substrate or the like has a plurality of through holes 5a provided corresponding to the convex portions 2f of the mounting legs 2b, and the circuit board 5 has a conductive material provided on the entire surface on one side. Connected to the shield conductor 6, the conductor 7 connected to the shield conductor 6, provided on the wall surface in the through hole 5 a, and a wiring pattern (not shown) provided on the other surface side, The circuit board 5 includes various electronic components 8 mounted on the other side, and has a desired electric circuit.

  The circuit board 5 having such a configuration is placed on the end portion 2a of the side wall 2 in a state where the electronic component 8 is housed in the frame body 1 so as to close the open portion 3 of the frame body 1. Positioning in the downward direction (vertical direction) is performed, and the outer peripheral portion of the circuit board 5 is flush with the outer surface of the side wall 2.

  The downward positioning of the circuit board 5 may be performed by appropriate means instead of the end 2a of the side wall 2. In this case, a configuration in which the entire circuit board 5 can be accommodated in the frame 1 is possible. The circuit board 5 can be downsized.

Further, when the circuit board 5 is attached, the inclined surface 2g of the convex portion 2f contacts the edge portion of the through hole 5a, the arm portion 2e changes along the inclined surface 2g, and the entire convex portion 2f is formed in the through hole. When located in 5a, as shown in FIG. 3, the top of the convex portion 2f is elastically contacted with the wall surface in the through hole 5a, and the circuit board 5 is elastically pressed in the direction of the arrow A1 by the pair of mounting legs 2b. 5 is held.
At this time, the tip of the arm 2e is flush with the outer surface of the circuit board 5 or slightly protrudes from the outer surface of the circuit board 5, and the back surface of the convex part 2f and the wall surface in the through hole 5a. There is a gap between them.

The arm 2e and the conductor 7 located in the through hole 5a of the mounting leg 2b are soldered 9 in the through hole 5a, and the frame 1 is connected to the shield conductor 6 and grounded. Thus, the electronic component 8 in the frame body 1 is electrically shielded by the side wall 2, the closing wall 4, and the shield conductor 6.
The solder 9 is transferred to a reflow furnace in a state where cream solder is filled in the through-hole 5a, and the solder 9 is applied. However, the circuit board 5 is held by the mounting legs 2b. Therefore, there is no backlash at the time of conveyance or the like, and attachment with high accuracy can be performed.

FIG. 4 shows a second embodiment of the electronic circuit unit according to the present invention. In the second embodiment, the convex portions 2f provided on the pair of mounting legs 2b are arranged to face each other, and the pair of mounting legs. By 2b, the circuit board 5 is pressed in the direction of the arrow A2 to hold the circuit board 5.
Other configurations are the same as those in the first embodiment, and the same parts are denoted by the same reference numerals, and the description thereof is omitted here.

FIG. 5 shows a third embodiment of the electronic circuit unit of the present invention. In this third embodiment, the arm portion 2e of the mounting leg 2b extends linearly from the end portion 2a of the side wall 2 upward. It is formed.
Other configurations are the same as those in the first embodiment, and the same parts are denoted by the same reference numerals, and the description thereof is omitted here.

FIG. 6 shows a fourth embodiment of the electronic circuit unit according to the present invention. In the fourth embodiment, the arm portion 2e of the mounting leg 2b extends linearly from the end portion 2a of the side wall 2 upward. It is formed.
Other configurations are the same as those of the second embodiment, and the same parts are denoted by the same reference numerals, and the description thereof is omitted here.

FIG. 7 shows a fifth embodiment of the electronic circuit unit according to the present invention. The fifth embodiment will be described. A pair of mounting legs 2b are provided on two side walls 2 facing each other. The convex portions 2f provided on the arm portions 2e of the legs 2b are formed in the thickness direction of the side wall 2, and the convex portions 2f of the pair of mounting legs 2b are arranged to protrude in opposite directions.
Other configurations are the same as those in the first embodiment, and the same parts are denoted by the same reference numerals, and the description thereof is omitted here.

FIG. 8 shows a sixth embodiment of the electronic circuit unit of the present invention. The sixth embodiment will be described. A pair of mounting legs 2b are provided on two side walls 2 facing each other. The convex part 2f provided in the arm part 2e of the leg 2b is formed in the thickness direction of the side wall 2, and the convex part 2f of the pair of mounting legs 2b is arranged facing each other.
Other configurations are the same as those of the second embodiment, and the same parts are denoted by the same reference numerals, and the description thereof is omitted here.

In addition, the arm part 2e of the attachment leg 2b in the said 5th, 6th Example may be extended and formed linearly from the edge part 2a of the side wall 2 upwards.
In the above embodiment, the shield conductor 6 is provided on the outer surface of the circuit board 5. However, the shield conductor 6 may be provided in the laminated circuit board 5.

The disassembled perspective view which concerns on 1st Example of the electronic circuit unit of this invention. The expanded perspective view of the principal part which concerns on 1st Example of the electronic circuit unit of this invention. The expanded sectional view of the principal part which concerns on 1st Example of the electronic circuit unit of this invention. The expanded sectional view of the principal part which concerns on 2nd Example of the electronic circuit unit of this invention. The expanded perspective view of the principal part which concerns on 3rd Example of the electronic circuit unit of this invention. The expanded perspective view of the principal part which concerns on 4th Example of the electronic circuit unit of this invention. The expanded perspective view of the principal part which concerns on 5th Example of the electronic circuit unit of this invention. The expanded perspective view of the principal part which concerns on 6th Example of the electronic circuit unit of this invention. The disassembled perspective view which concerns on the conventional electronic circuit unit.

Explanation of symbols

1: Frame body 2: Side wall 2a: End 2b: Mounting leg 2c: First extending portion 2d: Second extending portion 2e: Arm portion 2f: Convex portion 2g: Inclined surface 3: Opening portion 4: Blocking Wall 5: Circuit board 5a: Through hole 6: Conductor for shield 7: Conductor 8: Electronic component 9: Solder

Claims (8)

A box-shaped frame made of a metal plate and having side walls that surround four sides, and a circuit board mounted on the frame and mounted with electronic components to form a desired electric circuit, the circuit board includes: A plurality of through holes are provided, and a pair of mounting legs are provided on one side wall or the two side walls facing each other, and the pair of mounting legs includes arm portions extending from the side walls. , Provided in the vicinity of the tip of the arm portion, and having a convex portion projecting in a direction facing each other or in the opposite direction, each of the convex portions of the pair of mounting legs is inserted into the through hole, The convex portion elastically contacts the wall surface in the through hole to hold the circuit board, and a gap is provided between the back surface of the convex portion and the wall surface in the through hole, and is inserted into the through hole. The tip of the arm portion is flush with the circuit board, Electronic circuit unit have is characterized in that is slightly protruding from the circuit board. A conductor is provided on the wall surface in the through hole, the arm portion located in the through hole and the conductor are soldered, and the circuit board is attached to the frame. The electronic circuit unit according to claim 1. The outer surface of the convex portion located between the tip of the arm portion and the top of the convex portion is an inclined surface, and when the circuit board is inserted into the arm portion, the inclined surface becomes an edge portion of the through hole. The electronic circuit unit according to claim 1, wherein the electronic circuit unit is in contact with each other to guide insertion of the arm portion into the through hole. The arm portion of the mounting leg includes a first extending portion extending in the frame body direction at a right angle to the side wall, and the side wall extending outward from the end portion of the first extending portion. 4. The electronic circuit unit according to claim 1, further comprising: a second extending portion extending in parallel with the second extending portion, wherein the convex portion is provided in the second extending portion. 5. 5. The electronic circuit unit according to claim 1, wherein the convex portions of the arm portions provided on the two opposite side walls are formed in a thickness direction of the side walls. 5. The electronic circuit according to claim 1, wherein the convex portion of the arm portion provided on one side wall is formed in a width direction orthogonal to a thickness direction of the side wall. unit. An open portion is provided on one of the upper and lower portions of the frame body, and the circuit board abuts against an end portion of the side wall so as to close the open portion in a state where the electronic component is located in the frame body. The electronic circuit unit according to claim 1, wherein the circuit board is positioned in a vertical direction. The other of the upper and lower parts of the frame opposite to the opening to which the circuit board is attached is provided with a blocking wall, and the outer surface of the circuit board exposed outside the frame or the circuit board 8. The electronic circuit unit according to claim 7, wherein a shield conductor is provided in the laminate.

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