JP4462174B2 - Electronic circuit equipment - Google Patents

Description

  The present invention relates to an electronic circuit device having a printed circuit board, and more particularly to a structure for fixing the printed circuit board to a base that forms a cover or a cooling substrate of the electronic circuit device.

  Conventionally, in vehicle electronic circuit devices such as motor control devices for electric vehicles and DC-DC converters for vehicles, there has been a strong demand for device volume reduction due to restrictions on circuit device mounting space. For this reason, a system is adopted in which the required space, particularly the required area, is reduced by using a two-storied structure of the printed circuit board and another wiring board or a cooling plate for cooling circuit components. In particular, heavy components and high-power components are generally mounted or fixed on a metal base plate for heat dissipation, and a printed circuit board is arranged in parallel on the base plate, and the printed circuit board is generally fixed to the base plate. In addition, an electronic circuit device having a printed circuit board is usually sealed in a case. In this case, the printed circuit board is fixed to the case.

In such a conventional printed circuit board fixing structure, the printed circuit board is fixed to the case or the base plate by passing the loose holes (fastening holes) of the printed circuit board through the screw holes provided in the case or the base plate and fastening the screws. It was common. Patent Document 1 below describes an example of a structure for fastening a printed circuit board with screws. Moreover, it was also fixed by caulking.
JP-A-7-297573

  However, the above-described conventional printed circuit board fixing method by screw fastening requires a fastening work space above the fastening hole of the printed circuit board due to the screw fastening work, and there is a problem that the component mounting density on the printed circuit board is reduced. It was. Of course, the fastening work space can be reduced by reducing the diameter of the screw. However, in a strong vibration environment such as a product directly mounted on a vehicle engine, there is a limit to downsizing the screw. Further, it has been considered that there is no possibility that the screw is loosened in a strong vibration environment such as a product directly mounted on the engine of the vehicle due to a failure of the screw fastening operation or the like.

  Also, when caulking a printed circuit board by bending a metal nail provided on a case or the like, caulking stress will be applied in the vicinity of the caulking area of the printed circuit board, so it is not preferable to mount components near the caulking area, As a result, as with the screw fastening, the component mounting density on the printed circuit board decreased.

  Furthermore, whether the above-described screw fastening or caulking is performed, the printed circuit board fixing operation becomes more difficult as the degree of component integration increases, and the workability deteriorates.

  The present invention has been made in view of the above-mentioned problems, and it is possible to simplify the printed board fixing work and improve the component mounting density of the printed board, and an electronic device having a novel printed board that does not cause a problem in vibration resistance. The object is to provide a circuit device.

Electronic circuit device according to claim 1, wherein the through hole of the wiring terminal fixed part of the terminal is soldered are inserted through, and a substrate fixing holes, the substrate fixing Yoshirube body pattern is formed and a printed circuit board and the lower surface substrate for mounting a mounting surface of the printed circuit board, and has a base with a substrate fixing pin made of metals, wherein the printed circuit board, the board fixing pin, before be one that is fixed to the base by Rukoto is soldered to serial board fixing holes on Nuki挿be Rutotomoni the board fixing Yoshirube body pattern, soldered solder on the board fixing conductive pattern And a pair of projecting portions projecting radially outward of the substrate fixing hole from the substrate fixing hole at both ends of the substrate fixing hole, and the base includes the substrate fixing pin. The overhang around the circumference It is characterized by having a groove for accommodating a.

That is, in this invention, printed circuit board has a substrate fixing holes which board fixing pins erected on the substrate mounting surface of the base through the conductive pattern of the printed circuit board fixed to the board fixing hole is provided, it is joined by solder to the substrate fixing Yoshirube body pattern and the substrate fixing pin. In this way, the printed circuit board is subjected to a series of soldering processes and a soldering apparatus performed simultaneously with the soldering operation for electrically and mechanically joining the terminals of each electronic component to the conductive pattern for wiring of the printed circuit board. Can be fixed to the base, so that the reduction in the component mounting density of the printed circuit board caused by the screw fastening method or the caulking method can be reduced, and there is no problem that the screw is loosened, excessively caulked or caulked sweetly. The reliability of the printed circuit board fixing process can be improved. In addition, processes that are completely different from electronic component soldering operations such as screw fastening operations and caulking operations can be omitted, and the manufacturing process can be simplified. As the base, a resin or metal cover, a cooling substrate, a wiring substrate, or a heavy electronic component mounting substrate can be adopted.

The board fixing hole is a so-called through hole in which a conductive pattern is formed on the inner peripheral surface, like a normal through hole for fixing a wiring terminal. In this way, the board fixing conductor pattern and the board fixing pin are firmly bonded by the solder poured into the through hole, and the surface tension of the solder at the opening at both ends of the through hole causes the printed board to face the surface. A pair of overhanging portions of solder that protrudes can further have a function of suppressing displacement of the printed board in the major axis direction of the board fixing pin, so that both displacement in the surface direction and thickness direction of the printed board can be improved. It becomes possible to regulate, and the printed circuit board can be firmly fixed. Further, since the base has a groove portion that surrounds the periphery of the substrate fixing pin and accommodates the protruding portion, the base-side protruding portion of the pair of protruding portions of the solder for fixing the substrate is accommodated in the groove portion. can do.

In a preferred aspect, the base is a resin molded product in which the substrate fixing pin is press-fitted or insert-molded. If it does in this way, lightweight resin parts, such as a case and a cover, can be employ | adopted as a base, and an apparatus weight can be reduced.

In a preferred aspect, the board fixing pin and the board fixing hole are formed in a square shape and provided at four corners of the printed board. If it does in this way, support of a printed circuit board will become favorable.

In a preferred aspect, the conductive pattern of the substrate fixing hole is set to a floating potential. Thereby, this board | substrate fixing hole can be freely arrange | positioned in the position without the conductive pattern for wiring .

In a preferred aspect, the board fixing pin has a larger cross-sectional area in a direction perpendicular to the major axis direction than a terminal of a component mounted on the printed board. Thereby, a printed circuit board can be firmly fixed to a base.

  Preferred embodiments of an electronic circuit device having a printed circuit board according to the present invention will be described with reference to the following examples. In the following description, it should be noted that the vertical direction is merely set for convenience.

Example 1
An electronic circuit device having a printed circuit board according to Embodiment 1 will be described below with reference to FIGS. FIG. 1 is a perspective view of the electronic circuit device, and FIG. 2 is a plan view of the electronic circuit device.

  Reference numeral 1 denotes an electronic circuit device, 2 a resin case which forms the base referred to in the present invention, 3 a printed circuit board, 4 a and 4 b external connectors, and 5 a resin or metal cover. The resin case 2 has a printed circuit board 3 having an open upper end and a recess 6 for housing a component mounted on the printed circuit board 3. The external connectors 4 a and 4 b are formed integrally with the resin case, and are erected from the upper end surface outside the recess 6. In this embodiment, the external connector 4a is a communication and control connector, and 4b is a power connector. The cover 5 is a lid plate for closing the opening of the recess 6.

  A metal base plate is fixed to the bottom (not shown) of the recess 6 by insert molding or the like, and various power components (not shown) are fixed to the base plate. The resin case 2 is insert-molded with a metal piece for wiring, and ends of the metal piece for wiring serving as external terminals are disposed on the external connectors 4a and 4b. A large number of end portions of the wiring metal pieces connected to the printed board 3 are provided as wiring terminals 7 in the recess 6. Of the terminals of the power component described above, for example, control terminals and detection terminals to be connected to the printed circuit board 3 side are connected to the wiring terminals 7 and are connected to the printed circuit board 3 through the wiring terminals 7. Among the power component terminals described above, power terminals through which a large current flows are connected to each other by wiring metal pieces, or connected to wiring metal pieces that extend to the external connector 4b and form terminals of the external connector 4b. Yes.

  Each wiring terminal 7 is individually inserted into each through hole of the printed circuit board 3 and protrudes to the upper surface side of the printed circuit board 3 as in the prior art, and a conductive pattern (not shown) of the printed circuit board 3 provided in these through holes. Soldered. Various circuit components are mounted on the printed circuit board 3, but are not shown in FIGS. 1 and 2.

  Next, fixing of the printed circuit board 3 which is a main part of this embodiment will be described below.

  In this embodiment, substrate fixing pins 8 a to 8 d made of square pin-shaped metal pieces protrude upward from the side wall portion of the resin case 2. However, the tips of the substrate fixing pins 8 a to 8 d are accommodated in the recess 6 of the resin case 2. The board fixing pins 8a to 8d are inserted into square through holes that are board fixing holes provided at the four corners of the printed circuit board 3, and are joined to the conductive patterns provided in the square through holes by solder. FIG. 3 shows an enlarged view of the bonding state between the substrate fixing pin 8a and the conductive pattern of the square through hole. The bonding state of the substrate fixing pins 8b to 8d and the conductive pattern of the square through hole is the same as that in FIG.

  Reference numeral 2 a denotes a side wall portion of the resin case 2 surrounding the recess 6, and a substrate placement surface 2 b for placing the printed circuit board 3 in the vicinity of the opening of the recess 6 is formed on the side wall portion 2 a. The board fixing pins 8 a are provided so as to project upward from the board mounting surface 2 b and pass through the rectangular through holes 3 a that are board fixing holes of the printed board 3. Reference numeral 2c denotes a groove portion that is provided on the substrate mounting surface 2b so as to surround the substrate fixing pins 8a to 8d.

  Conductive patterns (not shown in FIG. 3) are provided on the inner peripheral surface of the rectangular through hole 3a and the soldering regions on both surfaces of the printed circuit board 3 surrounding the rectangular through hole 3a. Reference numeral 9 denotes solder for fixing the printed circuit board 3 to the resin case 2, and the solder 9 joins the substrate fixing pins 8 a and this conductive pattern. Due to its wettability, the solder 9 protrudes in a direction parallel to the main surface of the printed circuit board 3 at both side openings of the square through hole 3a and covers both side openings of the square through hole 3a. A gel 10 seals various components mounted on the printed circuit board 3 and components housed in the recess 6. In this embodiment, the substrate fixing pins 8a to 8d are fixed to the resin case 2 by insert molding.

  FIG. 4 shows the shape of the conductive pattern 11 for soldering the substrate fixing pin 8a formed around the square through hole 3a at one end opening of the square through hole 3a. The square through hole 3a is actually chamfered and has a substantially elliptical shape as shown in FIG.

(Production method)
In this embodiment, the rectangular through hole 3a which is a hole for fixing the substrate in the same process as the conductive pattern formed on the inner peripheral surface of the through hole for fixing the wiring terminal 7 around the rectangular through hole 3a. Conductive patterns 11 are formed on the inner peripheral surface and in the vicinity thereof, and similarly, the soldering process for fixing the printed circuit board is performed continuously or simultaneously with the soldering process for fixing the wiring terminals 7. For example, if a jet solder process is used, it can carry out simultaneously.

(effect)
If it does in this way, it prints by the series of soldering processes and soldering apparatus performed simultaneously with the soldering operation | work which joins the terminal of each electronic component to the electrically conductive pattern for wiring of the printed circuit board 3 electrically Since the board can be fixed to the base, the decrease in the component mounting density of the printed circuit board caused by the screw fastening method and the caulking method can be reduced, and the problem that the screw is loosened, excessively caulked, and the caulking is sweet may occur. In addition, the reliability of the printed circuit board fixing process can be improved. In addition, processes that are completely different from electronic component soldering operations such as screw fastening operations and caulking operations can be omitted, and the manufacturing process can be simplified. As the base, a resin or metal cover, a cooling substrate, a wiring substrate, or a heavy electronic component mounting substrate can be adopted.

  In particular, since a conductive pattern is formed on the inner peripheral surface of the rectangular through hole 3a, which is a hole for fixing the substrate, similarly to the through hole for fixing the normal wiring terminal 7, the printed substrate 3 and the substrate are fixed. The pins 8a to 8d can be easily and firmly joined. In this embodiment, the conductive pattern 11 around the square through hole 3a, which is a hole for fixing the substrate, is set to a floating potential. Further, the board fixing pins 8a to 8d have a larger cross-sectional area in the direction perpendicular to the major axis direction than the wiring terminal 7, and thereby it is possible to sufficiently secure the bonding strength between the printed board 3 and the resin case 2. it can. The metal piece, for example, the wiring terminal 7 and the board fixing pins 8a to 8d are made of copper, and the surface thereof is tin-plated for improving solderability.

(Modification)
The modification is shown in FIGS. In this modification, the substrate fixing pins 8a are press-fitted into the resin case 2. FIG. 5 shows the state before press-fitting and FIG. 6 shows the state after press-fitting.

(Modification)
In addition, as a method for fixing the substrate fixing pins 8a to 8d to the resin case 2, it is obvious that various conventionally known methods such as caulking can be adopted.

1 is a perspective view showing an electronic circuit device of Example 1. FIG. 1 is a plan view of an electronic circuit device of Example 1. FIG. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. It is a principal part enlarged partial top view of FIG. It is a partially expanded side view of FIG. 1 which shows a deformation | transformation aspect. It is a partially expanded side view of FIG. 1 which shows a deformation | transformation aspect.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic circuit device with a printed circuit board 2a Side wall part 2b Board | substrate mounting surface 2c Groove part 2 Resin case 3a Square through hole 3 Printed circuit board 4a External connector 4b External connector 5 Cover 6 Concave part 7 Wiring terminal 8a-8d Board fixing pin 11 Conductive pattern

Claims (5)

Through holes of the wiring terminal fixed to wiring terminals are soldered are inserted through, and a printed circuit board and the board fixing holes, the substrate fixing Yoshirube body pattern is formed,
The substrate mounting surface for placing the lower surface of the printed circuit board, and a base having a board fixing pin made of metals,
Have
The printed circuit board, the board fixing pin, there is fixed to Nuki挿be Rutotomoni the board fixing Yoshirube body pattern before Symbol board fixing holes on the basis Rukoto soldered,
The solder soldered to the board fixing conductor pattern is a pair of projecting portions projecting radially outward of the board fixing hole from the board fixing hole at both ends of the board fixing hole. Have
The base is characterized as to that electronic circuit device to have a groove which accommodates the protruding portion surrounds the periphery of the substrate fixing pin. The electronic circuit device according to claim 1,
The base is an electronic circuit device made of a resin molded product to which the substrate fixing pins are fixed . In sub-circuit device conductive as claimed in claim 2, wherein,
The board fixing pins and board fixing holes are formed in a square shape and are provided at four corners of the printed board . In sub-circuit device conductive as claimed in claim 2, wherein,
An electronic circuit device in which a conductive pattern of the substrate fixing hole is set to a floating potential . In sub-circuit device conductive as claimed in claim 1, wherein,
The board fixing pin is an electronic circuit device having a larger cross-sectional area in a direction perpendicular to a major axis direction than a terminal of a component mounted on the printed board .

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