JP2015061037A - Substrate structure and substrate support structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate structure capable of easily and firmly connecting two printed substrates to each other while preventing any unnecessary stress from being generated in the case of connecting the printed substrates and a substrate support structure to be used for the substrate structure.SOLUTION: A substrate structure includes: a first printed substrate 11 having at least one through-hole 17; a second printed substrate 21 having a protrusion 27 fitted into the through-hole; and a connection reinforcement tool 31 interposed between the through-hole of the first printed substrate and the protrusion of the second printed substrate for reinforcing the connection of the first and second printed substrates. The connection reinforcement tool includes: a bottom part having at least one opening; and a pair of leg parts erected from the bottom part, and opposed to each other with an interval. The leg parts are fitted into the through-hole, and the protrusion is fitted in a gap between the pair of leg parts, and the top end part of the protrusion is fitted in the opening.

Description

  The present invention relates to a substrate structure obtained by combining a plurality of printed circuit boards and a substrate support structure used therefor.

  For example, it has been conventionally performed to join two printed circuit boards vertically to each other. As an example, in Patent Document 1, a through hole is formed in one printed circuit board, and the printed circuit boards are inserted into the through hole by inserting a plug terminal portion projecting from one end edge of the other printed circuit board. A structure in which is bonded is disclosed. Further, in Patent Document 2, a plurality of long holes are formed on one printed circuit board so as to be offset from each other so that the center lines in the longitudinal direction are not aligned on a straight line, and the other printed A substrate structure in which substrates are joined by inserting a convex insertion portion provided at an edge of the substrate is disclosed.

JP 2011-222826 A JP 2008-288359 A

  In the case where the substrates are joined together by the structure disclosed in Patent Document 1, if the thickness of the substrate having the plug terminal portion is too thin, the substrate cannot be maintained in the state before the solder fixing step. In the fixing process, it is necessary to support the substrate by some means, and there is a disadvantage that the working efficiency is poor. Further, when the printed circuit boards are joined to each other by the structure disclosed in Patent Document 2, since the printed circuit boards are fixed by bending stress, mechanical distortion occurs in the printed circuit boards, which adversely affects the life of the printed circuit boards. There was a fear.

  The present invention has been made in view of the above points. For example, a substrate structure capable of achieving strong bonding between substrates by a simple bonding operation while preventing unnecessary stress from being generated on the substrates to be bonded. And it aims at providing the substrate support structure used for this.

  The substrate structure of the present invention includes a first printed circuit board having at least one through hole, a second printed circuit board having a protrusion that fits into the through hole, and a through hole of the first printed circuit board. A board reinforcing body interposed between projecting portions of the second printed circuit board to reinforce the bonding of the first and second printed circuit boards, wherein the bonding reinforcement is at least A bottom portion having one opening, a pair of leg portions that rise from the bottom portion and face each other at a predetermined interval, and a locking portion that is provided on at least a part of a tip edge portion of the leg portion The leg portion is fitted in the through hole, the locking portion is engaged with the peripheral edge portion of the through hole, and the protruding portion is fitted between the pair of leg portions, and the protruding portion The tip of the part is fitted in the opening

FIG. 1A is a perspective view of a substrate structure according to an embodiment of the present invention, and FIG. 1B is an exploded perspective view of the substrate structure of FIG. It is a perspective view of the joining reinforcement tool contained in the board | substrate structure of FIG. It is a disassembled perspective view of the structure shown in FIG. 1 for demonstrating insertion of the printed circuit board to a joining reinforcement tool. FIG. 4 is a vertical sectional view taken along line 4-4 of FIG.

  Below, the substrate structure which is an Example of this invention is demonstrated, referring an accompanying drawing. As shown in FIG. 1A and FIG. 1B, the substrate structure according to the present invention has a first printed board 11 and a second printed board 21 joined vertically via a joining reinforcement 31. It is a structure.

  The first printed circuit board 11 includes a plate-like insulator base material 13, conductor wiring 15 formed on both surfaces of the insulator base material 13, and through-holes 17 formed in the insulator base material 13 (FIG. 1 (b)). The conductor 19 is formed in 1 (b)). In FIG. 1, the conductor wiring 15 on the back surface of the insulator base material 13 is omitted. The through-hole 17 is formed so as to penetrate the insulator base material 13 at a predetermined position of the insulator base material 13, and has a cross-sectional shape (that is, an oval shape) in which a pair of opposed straight portions are terminated and joined by a curve. ) (FIG. 1B). The conductor 19 is covered on the inner surface of the through hole 17, and the conductor wiring 15 reaches the central region of the longitudinal side of the through hole 17 and is electrically connected to the conductor 19 on the inner surface of the through hole 17. Conductor wirings 15 formed on both surfaces of 13 are electrically connected to each other through a conductor 19.

  The second printed circuit board 21 includes a plate-like insulator base material 23 and conductor wiring 25 formed on the surface of the insulator base material 23. One end edge 23A (FIG. 1 (b)) of the insulator base 23 protrudes outward in the direction (plate surface direction) along the main surface 23B (FIG. 1 (b)) of the insulator base 23. A protruding portion 27 is formed. The projecting portion 27 has a two-stage structure, and includes a first projecting portion 27A at the first stage and a second projecting portion 27B (at the leading end) as the leading end portion. The conductor wiring 25 formed on the second printed circuit board 21 extends to the leading edge of the second projecting portion 27B on the surface of the insulator base material 23, and the conductor wiring 25 is a surface area of the second projecting portion 27B. In FIG. 4, it is electrically connected to the conductor wiring 15 of the first printed circuit board 11 through solder (see FIG. 4).

  The joint reinforcing tool 31 is a member arranged at the joint between the first printed board 11 and the second printed board 21. The joint reinforcing tool 31 is fitted into the through hole 11 of the first printed circuit board 11 and receives the protrusion 27 of the second printed circuit board 21.

  FIG. 2 is an enlarged perspective view of the joint reinforcing tool 31. As shown in FIG. 2, the joint reinforcing tool 31 has a hook-like shape having a hook-like shape that fits into the through hole 17 of the first printed board 11 and receives the fitting of the protruding portion 27 of the second printed board 21. 33, and a locking portion 35 that is formed at both ends of the upper edge portion of the hook-shaped portion 33 and engages with the peripheral edge portion of the through hole 17 of the first printed circuit board 11.

  The hook-shaped portion 33 has a substantially U-shaped cross section in a plane perpendicular to the longitudinal direction of the joint reinforcing tool 31. That is, the bowl-shaped portion 33 is a pair of legs that are flat plate-shaped portions facing each other with a bottom 33A formed of a semi-cylindrical curved surface and a gap rising from the bottom 33A and into which the protruding portion 27 of the second printed circuit board is fitted. It consists of part 33B. The locking portion 35 is formed by bending the end edge portion of the leg portion 33 </ b> B of the flange-shaped portion 33 outward and engages with the opening edge portion of the through hole 17.

  The hook-shaped portion 33 is made of an elastic metal material, and the width W of the hook-shaped portion 33 is smaller than the width of the through-hole 17 in the short direction so as to be fitted into the through-hole 17 by being fitted into the through-hole 17. It is made slightly larger or substantially the same as the width of the through hole 17 in the short direction, and is formed so that the length L of the hook-shaped portion 33 is equal to or less than the length of the long side of the through hole 17. The Further, the height H of the leg portion 33B of the hook-shaped portion 33 is such that the bottom 33A of the hook-shaped portion 33 protrudes downward from the bottom surface of the first printed circuit board 11. It is formed higher than the thickness of the base material 13.

  A notch 33 </ b> C is provided in the central region of each upper edge of the flange 33. The notch 33 </ b> C is formed at a position facing the portion where the conductor wiring 15 is formed at the peripheral edge of the through hole 17 of the first printed circuit board 11.

  Four hemispherical projections 37 are provided on the inner side surface of the leg portion 33B of the bowl-shaped portion 33 so as to face each other, for example, two on each side surface. Further, an opening 33D into which the second protrusion 27B of the second printed circuit board 21 is fitted, that is, the tip of the protrusion 27 is fitted, is provided at the center of the bottom 33A of the bowl-shaped portion 33. Further, the opening 33D serves as an intrusion path through which molten solder enters during a soldering process described later.

  FIG. 3 is a perspective view showing the insertion of the second printed circuit board 21 into the joint reinforcing tool 31 inserted into the first printed circuit board 11. As shown in FIG. 3, the joining reinforcement tool 31 is fitted into the through hole 17 of the first printed circuit board 11, and the second printed circuit board 21 has the distal end of the first projecting portion in the direction of arrow A. Until it is in contact with the bottom 33A of the steel plate and is fitted into the joint reinforcement 31.

  When the joining reinforcement tool 31 is inserted into the through hole 17, the locking portion 35 is engaged with the opening edge of the through hole 17, and the joining reinforcement tool 31 is locked to the first printed board 11. As described above, the hook-shaped portion 33 is preferably made of a material having a hook shape and elasticity, and the joint reinforcing tool 31 has, for example, a width W of the hook-shaped portion 33 in the short direction of the through hole. Even if a dimensional error occurs in the direction of increasing, the hook-like portion 33 bends, so that the printed circuit board is securely fitted to the through hole 17 without being damaged.

  As described above, the notch 33C is formed at a position facing the portion of the peripheral portion of the through hole 17 of the first printed circuit board 11 where the conductor wiring 15 is formed. Thus, when the joint reinforcing tool 31 is fitted into the through hole 17, the joint reinforcing tool 31 is in the vicinity of the connection portion between the conductor wiring 15 at the peripheral edge of the through hole 17 and the conductor 19 formed on the inner surface of the through hole. Do not touch.

  FIG. 4 is a cross-sectional view of the periphery of the joint reinforcing tool 31 of the substrate structure taken along line 4-4 of FIG. As shown in FIG. 4, the second protrusion 27 </ b> B fitted in the opening 33 </ b> D passes through the opening 33 </ b> D and protrudes from below the hook-shaped part 33. The solder 41 is formed by a soldering process such as supplying molten solder after the first printed board 11 and the second printed board 21 are fitted and joined. The solder 41 is formed between the first printed circuit board 11 and the second printed circuit board 21, and mechanically joins the first printed circuit board 11 and the second printed circuit board 21 together with the conductor wiring 25 and the second printed circuit board 21. The electrical connection with the conductor wiring 15 around the through hole 17 of one printed circuit board 11 is formed.

  As shown in FIG. 4, the second printed circuit board 21 is held by the joining reinforcing tool 31 by being in contact with each vertex of the protrusion 37 and the inner surface of the bottom 33 </ b> A of the flange 33. Therefore, the second printed circuit board 21 is held in a vertical direction with respect to the first printed circuit board 11 only by being fitted into the gap between the two leg portions 33 </ b> B of the joining reinforcement tool 31. Further, at the time of the self-supporting holding, the portion where the protrusion 37 on the inner surface of the bowl-shaped portion 33 is not formed and the second printed circuit board 21 are separated from each other, and are held with a gap. In order to enable the second printed circuit board 21 to be self-supported, the distance D between the apexes of the projecting portions 37 facing each other is equal to or slightly smaller than the thickness of the insulator base material 23 of the second printed circuit board 21. Has been.

  In the substrate structure of the present embodiment, a joining reinforcing tool 31 is inserted into the through hole 17 of the first printed board 11 by, for example, an automatic mounter to form a supporting board structure, and then the second printed board 21 is joined. After being fitted into the reinforcing tool 31, it is fixed by soldering with solder 41 formed by supplying molten solder from below the joining reinforcing tool 31. During this soldering, the molten solder spreads along the bottom 33A of the bowl 33, and fillet-like between the second protrusion 27B of the second printed circuit board 21 and the back surface of the first printed circuit board 11. The solder structure is formed. As a result, a strong solder joint is formed between the first printed circuit board 11 and the second printed circuit board 21, and the conductor wiring 15 formed on the back surface of the first printed circuit board 11 and the second printed circuit board 21. The electrical connection of the conductor wiring 25 formed on the surface of the protruding portion 27 is also performed well. Further, the molten solder enters from the opening 33D of the joint reinforcement 31 and spreads wet along the gap between the inner surface of the flange 33 and the second printed circuit board. The second printed circuit board 21 is firmly soldered.

  According to the substrate structure of the present embodiment, the printed circuit boards 11 and 21 are joined via the joining reinforcement tool 31 without directly contacting each other. Therefore, even if the solder 41 is removed and the printed circuit boards 11 and 21 are separated from each other, the separated printed circuit boards 11 and 21 are not damaged by the mating contact between the printed circuit boards 11 and 21, and the separated printed circuit boards are not damaged. The substrates 11 and 21 can be used again.

  Further, according to the substrate structure of the present embodiment, there is a slight error in the thickness of the substrate or the size of the through hole by bonding the printed circuit boards 11 and 21 to each other through the elastic bonding reinforcement 31. However, it is possible to smoothly join the printed circuit boards 11 and 21 by fitting them without damaging the printed circuit boards 11 and 21. Therefore, assembly by an automatic mounter is possible, and it is possible to improve productivity while increasing the bonding strength between printed circuit boards.

  In the above embodiment, the hook-shaped portion 33 has a substantially U-shaped cross section, but the hook-shaped portion 33 can be fitted into the through hole 17 and can hold the second printed circuit board 21 independently. If possible, it may have other cross-sectional shapes such as a U-shaped cross section or a V-shaped cross section. In the joint reinforcement tool 31, the position and the number of the locking portions 35 are not limited to the illustrated example. When the joint reinforcement tool 31 is fitted into the through hole 17, the joint reinforcement tool 31 engages with the peripheral edge of the through hole 17. It is sufficient if 31 can be locked.

  In addition, the number and position of the protrusions 37 in the joint reinforcing tool 31 are not limited to the illustrated example. When the second printed board 21 is fitted into the joint reinforcing tool 31, the second printed board 21 is held by itself. If possible. Alternatively, the second printed circuit board 21 may be held by itself over the entire inner surface of the leg portion 33B of the bowl-shaped portion 33 without forming the protruding portion 37.

  Further, in the above-described embodiment, the height H of the leg portion 33B of the bowl-shaped portion 33 is set to be higher than the thickness of the insulator base material 13 of the first printed circuit board 11. By making the height H of 33B larger than the thickness of the insulator base material 13 of the first printed circuit board 11, the protruding portion 27 is positioned at the previous position after passing through the through-hole 17 and is attached to the joint reinforcing tool 31. It is possible to stabilize the holding of the first printed circuit board 11 by being held.

  Further, the notch 33C is not necessarily required for the joint reinforcing tool 31 when the protection of the conductor wiring need not be considered. A plurality of openings 33D may be formed, and in that case, a plurality of second protrusions 27B may be formed at positions corresponding to the plurality of openings 33D.

  In the above embodiment, the protrusion 27 of the second printed circuit board 21 has a two-stage structure, but the protrusion 27 may have a one-stage structure or a structure of three or more stages, or other polygons such as a triangle. You may make it a shape.

  In the above embodiment, one through hole 17 is formed in the first printed circuit board 11. However, a plurality of through holes 17 are formed in the first printed circuit board 11, and a plurality of second holes 17 are formed. The printed circuit board 21 may be bonded to the first printed circuit board 11. Alternatively, a plurality of through holes may be formed in the first printed circuit board 11, and the second printed circuit board 21 having a plurality of protrusions corresponding to the through holes may be joined.

  Moreover, you may form the joining reinforcement tool 31 by giving metal plating to resin material etc. partially or entirely. For example, the joint reinforcing tool 31 may be formed of a resin material in which metal plating is applied only to the surface of the bowl-shaped portion 33 in consideration of solder wetting.

  Various materials, configurations, shapes, and the like in the above-described embodiments are merely examples, and can be appropriately selected depending on the application and the like.

11 1st printed circuit boards 13, 23 Insulator base material 15, 19, 25 Conductor wiring 17 Through-hole 21 2nd printed circuit board 27 Protruding part 27A 1st projecting part 27B 2nd projecting part 31 Joining reinforcement 33 bowl-shaped part 33A Bottom part 33B Leg part 33C Notch part 33D Opening part 35 Locking part 37 Protrusion part 41 Solder

Claims (8)

A first printed circuit board having at least one through hole;
A second printed circuit board having a protrusion fitted into the through hole;
A joining reinforcement tool that reinforces the joining of the first and second printed circuit boards interposed between the through hole of the first printed circuit board and the protruding portion of the second printed circuit board,
The joint reinforcing tool is provided on at least a part of a bottom portion having at least one opening, a pair of legs rising from the bottom and facing each other at a predetermined interval, and a tip edge of the leg. A stop portion, the leg portion is fitted in the through hole, the locking portion engages with a peripheral edge portion of the through hole, and the protruding portion is interposed between the pair of leg portions. A substrate structure, wherein the substrate structure is inserted, and a distal end portion of the protruding portion is inserted into the opening.   The substrate structure according to claim 1, wherein the bottom portion and the leg portion of the joint reinforcement have a bowl shape as a whole.   The substrate structure according to claim 1, wherein the bottom portion of the joint reinforcement has a semi-cylindrical shape.   The substrate structure according to any one of claims 1 to 3, wherein a notch portion is provided at a central portion of an upper end of each of the leg portions of the joining reinforcement tool.   5. The substrate structure according to claim 1, wherein a protrusion structure is provided on an inner side surface of the leg portion of the joining reinforcement tool.   6. The substrate structure according to claim 1, wherein at least a part of the joining reinforcement tool has elasticity.   The soldering part which couple | bonds the periphery of the said through-hole of the said 1st printed circuit board, the said joint reinforcement tool, and the protrusion part of the said 2nd printed circuit board mutually, The one of Claim 1 thru | or 6 characterized by the above-mentioned. 2. The substrate structure according to claim 1. A first printed circuit board having at least one through hole;
A joining reinforcement tool that reinforces the joining of the first and second printed circuit boards interposed between the through hole of the first printed circuit board and the protruding portion of the second printed circuit board,
The joint reinforcing tool is provided on at least a part of a bottom portion having at least one opening, a pair of legs rising from the bottom and facing each other at a predetermined interval, and a tip edge of the leg. A board supporting structure, wherein the leg part is fitted in the through hole, and the locking part is engaged with a peripheral part of the through hole.

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