JP4879069B2 - Metal core board - Google Patents

Description

  The present invention relates to a metal core substrate.

  Conventionally, a metal core substrate has been used as a circuit substrate that satisfactorily dissipates the mounted electrical components (see, for example, Patent Document 1). If this metal core substrate is used, heat equalization can be achieved by the metal core (that is, metal plate) of the metal core substrate.

  By the way, it is well known that the press-fit terminal is used in a form that is press-fitted and fixed to the circuit board. For example, as shown in FIG. 7, the connector 73 includes an electrical connection portion 71 that is a contact end portion that is pushed through the printed circuit board, and a protrusion 72 that is a flexible region that is press-fitted into the printed circuit board. A press-fit terminal 70 that is mounted on a printed circuit board in a stored state is known (see, for example, Patent Document 2).

JP 2001-119838 A JP 60-44983 A

  A press-fit terminal cannot be used for a metal core substrate formed by molding an insulating layer on a metal core. This is because the press-fit terminal is forcibly inserted into the hole by press-fitting, and there is a possibility that whitening, cracking, etc. may occur in the portion around the exposed hole of the insulating layer.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a metal core substrate capable of press-fitting and fixing a press-fit terminal.

1) A metal core substrate according to the present invention includes a first circuit board, a second circuit board, and a metal plate disposed between the first circuit board and the second circuit board,
The first circuit board, the second circuit board and the metal plate are independently arranged;
A first through hole capable of press-fitting and fixing a press-fit terminal is a metal core substrate that penetrates the first circuit board, the second circuit board, and the metal plate in their plate thickness direction,
When the press-fit terminal is press-fitted into the first through hole, the metal plate is attached to the first circuit so as to allow a slight relative movement of the metal plate with respect to the first circuit board and the second circuit board. A holding mechanism is further provided between the board and the second circuit board.

  In the first aspect of the invention, the metal plate is held by the holding mechanism so as to allow a slight relative movement of the metal plate with respect to the first circuit board and the second circuit board when the press-fit terminal is press-fitted into the first through hole. Is held between the first circuit board and the second circuit board. This holding structure relieves stress when the press-fit terminal is inserted into the metal core substrate.

2) The metal core substrate according to the present invention is the metal core substrate of 1) above,
The holding mechanism includes a second through hole penetrating the first circuit board, the second circuit board, and the metal plate in a thickness direction thereof, and the first circuit board and the second circuit board of the metal plate. A holding member for holding the metal plate between the first circuit board and the second circuit board in cooperation with a part of the second through hole so as to allow a slight relative movement with respect to It is characterized by having.

  According to the second aspect of the invention, the holding member cooperates with a part of the second through hole, so that the first circuit is held while holding the metal plate between the first circuit board and the second circuit board. Since a slight relative movement of the metal plate with respect to the substrate and the second circuit substrate is allowed, the stress when the press-fit terminal is inserted into the metal core substrate is relieved.

3) The metal core substrate according to the present invention is the metal core substrate of 2) above,
The holding member is a press-fit fixing member that is press-fitted and fixed in the second through hole,
The press-fit fixing member partially defines the second through hole, and a first protrusion that is in pressure contact with an inner peripheral surface of the first circuit board that partially defines the second through hole, and the second through hole that partially defines the second through hole. A second protrusion that is in pressure contact with the inner peripheral surface of the second circuit board; and a metal plate movement allowing portion that is formed between the first protrusion and the second protrusion.
The diameter of the part formed in the said metal plate of the said 2nd through hole is larger than the outer diameter of the said metal plate movement permissible part, It is characterized by the above-mentioned.

  According to the above invention 3), the metal plate is securely held between the first circuit board and the second circuit board while the metal plate is movable relative to the first circuit board and the second circuit board. can do.

4) A metal core substrate according to the present invention is the metal core substrate of 3) above,
The first circuit board and the second circuit board each have an insulating plate and a conductive circuit pattern formed on the outer surface of the insulating plate opposite to the metal plate side,
The first protrusion of the press-fit fixing member is in pressure contact with the inner peripheral surface of the insulating plate of the first circuit board partially defining the second through hole;
The second protrusion of the press-fit fixing member is in pressure contact with an inner peripheral surface of the insulating plate of the second circuit board that partially defines the second through hole.

  According to the invention of 4), since the first circuit board and the second circuit board are single-sided circuit boards, the cost as the metal core board is reduced, and it is not necessary to consider the insulation from the metal plate. High design freedom. Further, whitening or cracking of the insulating plate can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the metal core board | substrate which can insert a press fit terminal without trouble can be provided.

  Hereinafter, a plurality of preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
A first embodiment of a metal core substrate according to the present invention will be described.
1 to 4 illustrate a first embodiment of a metal core substrate according to the present invention, and FIG. 1 is an exploded perspective view of an electrical junction box to which the metal core substrate according to the first embodiment of the present invention is applied. 2 is an exploded perspective view of the metal core substrate of FIG. 1, FIG. 3 is a longitudinal sectional view of the press-fit terminals and press-fit fixing members in the metal core substrate of FIG. 1, and FIG. It is a longitudinal cross-sectional view.

  As shown in FIG. 1, the metal core substrate 10 is different from a conventional metal core substrate formed by molding an insulating layer on a metal plate, a first circuit substrate 11, a second circuit substrate 12, a metal plate 13, Is provided independently. That is, in FIG. 1, the metal core substrate 10 having a laminated structure in which the metal plate 13 is sandwiched between the first circuit board 11 and the second circuit board 12 is connected to the upper case 2 and the lower case 3 constituting the electrical connection box 1. The housed form is shown.

  The first circuit board 11 is printed on the surface of the first insulating plate 14 so as to form a predetermined circuit with the first insulating plate 14 made of, for example, glass epoxy resin having good insulation and low thermal conductivity. And a first conductive circuit pattern (see FIG. 3) 15 made of a conductive metal (for example, copper). That is, the first circuit board 11 does not have a through hole made of a conductive metal.

  Similarly to the first circuit board 11, the second circuit board 12 forms a predetermined circuit with the second insulating plate 16 made of, for example, glass epoxy resin having good insulation and low thermal conductivity. This is a single-sided circuit board provided with a second conductive circuit pattern (see FIG. 3) 17 made of a conductive metal (for example, copper) printed on the back surface of the second insulating plate 16. That is, the second circuit board 12 also does not have a through hole made of a conductive metal.

  The metal plate 13 is a metal plate material having excellent thermal conductivity, such as a copper alloy or an aluminum alloy, has a predetermined thickness, and is the same as the first circuit board 11 and the second circuit board 12. It is formed in the size.

  As shown in FIG. 2, the first circuit board 11, the metal plate 13, and the second circuit board 12 have a first through hole 18, a second through hole 19, and a terminal metal through hole 20 at predetermined positions. A plurality of through holes are formed in the plate thickness direction.

  A press-fit terminal 21 can be press-fitted into the first through hole 18 from the front surface of the first circuit board 11 or the back surface of the second circuit board 12. A press-fit fixing member 22 can be press-fitted into the second through hole 19 from the front surface of the first circuit board 11 or the back surface of the second circuit board 12. The terminal fitting 23 can be inserted into the terminal fitting through hole 20 from the front surface of the first circuit board 11 or the back surface of the second circuit board 12.

  As shown in FIG. 3, a first conductive circuit pattern 15 is formed on the surface of the first insulating plate 14 of the first circuit board 11. Further, a second conductive circuit pattern 17 is formed on the back surface of the second insulating plate 16 on the second circuit board 12.

  The press-fit terminal 21 </ b> A is a press-fit type tuning fork terminal, and integrally includes an electrical connection portion 24 and a circuit board side fixing portion 25. A protrusion 26 is formed as a so-called needle eye type pressure contact portion having a substantially elliptical hole in the circuit board side fixing portion 25.

  The press-fit fixing member 22 has a sufficient length corresponding to the combined thickness of the first circuit board 11, the metal plate 13, and the second circuit board 12. A first protrusion 28 having a substantially elliptical hole is formed on the upper side of the metal plate movement allowing portion 27 formed at the center, and a substantially elliptical shape is also formed on the lower side of the metal plate movement allowing portion 27. A second protrusion 29 having a hole is formed. That is, the first protrusion 28 and the second protrusion 29 are also so-called needle eye type pressure contact portions.

  In the first through hole 18, the inner diameter D1 of the inner peripheral surface 30 of the metal plate 13 portion is larger than the inner diameter D2 of the inner peripheral surface 31 of the first circuit board 11 portion and the inner peripheral surface 32 of the second circuit board 12 portion. Is formed. Therefore, on the right side in FIG. 3, the press-fit terminal 21 is pressed and inserted from the front surface side of the first circuit board 11 with the circuit board side fixing portion 25 first, so that the protrusion 26 is formed in the first through hole 18. The first insulating plate 14 is in pressure contact with the inner peripheral surface 31. Thereby, the electrical connection portion 24 is electrically connected to the land 33 of the first conductive circuit pattern 15. At this time, in the press-fit terminal 21A, the circuit board side fixing portion 25 excluding the protruding portion 26 is formed on the inner peripheral surface 30 of the metal plate 13 portion of the first through hole 18 and the inner peripheral surface 32 of the second insulating plate 16 portion. Arranged without contact with a gap.

  Further, on the left side in FIG. 3, a press-fit terminal 21 </ b> B of another form is pressed and inserted from the back surface side of the second circuit board 12 with the circuit board side fixing portion 25 first, so that a substantially elliptical hole is formed. The protruding portion 26 having the first through hole 18 is in pressure contact with the inner peripheral surface of the portion of the second insulating plate 16 that partially defines the first through hole 18. Thereby, the electrical connection portion 24 is electrically connected to the land 34 of the second conductive circuit pattern 17. At this time, in the press-fit terminal 21B, the circuit board side fixing portion 25 excluding the protrusion 26 is formed on the inner peripheral surface 30 of the metal plate 13 portion of the first through hole 18 and the inner peripheral surface 31 of the first insulating plate 14 portion. Arranged without contact with a gap.

  In the second through hole 19, the inner diameter D3 of the inner peripheral surface 35 of the metal plate 13 portion is larger than the inner diameter D4 of the inner peripheral surface 36 of the first circuit board 11 portion and the inner peripheral surface 37 of the second circuit board 12 portion. Is formed. Therefore, at the center in FIG. 3, the first protrusion 28 partially defines the second through hole 19 by pressing and inserting the press-fit fixing member 22 from the surface side of the first circuit board 11. The first insulating plate 14 is in pressure contact with the inner peripheral surface 36 and the second protrusion 29 is in pressure contact with the inner peripheral surface 37 of the second insulating plate 16 that partially defines the second through hole 19. Is done. Thereby, the 1st circuit board 11 and the 2nd circuit board 12 are assembled | attached integrally on both sides of the metal plate 13. As shown in FIG. At this time, the press-fit fixing member 22 is arranged in a state in which the metal plate movement allowing portion 27 is not in contact with the inner peripheral surface 35 of the metal plate 13 with a gap. In the above description, the press-fit fixing member 22 is pressed and inserted from the front surface side of the first circuit board 11, but needless to say, it may be from the back surface side of the second circuit board 12.

  Next, the substrate structure of the portion of the metal core substrate 10 where the terminal fitting 23 is inserted will be described.

  As shown in FIG. 4, the terminal fitting 23 is integrally provided with an electrical connection portion 38 and a circuit board side fixing portion 39. In the through hole 20 for terminal fitting, the inner diameter D5 of the inner peripheral surface 40 of the metal plate 13 portion is larger than the inner diameter D6 of the inner peripheral surface 41 of the first circuit board 11 portion and the inner peripheral surface 42 of the second circuit board 12 portion. Largely formed.

  On the left side in FIG. 4, the terminal fitting 23 is inserted into the terminal fitting through hole 20 from the surface side of the first circuit board 11 with the electrical connection portion 38 first, and the second circuit board. The electric connection part 38 part is penetrated from the back surface side of 12. Then, the circuit board side fixing portion 39 protruding to the surface side of the first circuit board 11 is soldered to the land 33 of the first conductive circuit pattern 15. As a result, the terminal fitting 23 is assembled and fixed in a state where the electrical connection portion 38 protrudes on the second circuit board 12. At this time, the circuit board side fixing portion 39 is not in contact with the inner peripheral surface 41 of the first insulating plate 14, the inner peripheral surface 40 of the metal plate 13, and the inner peripheral surface 42 of the second insulating plate 16 with a gap. Placed in a state.

  Further, on the right side in FIG. 4, the terminal fitting 23 is inserted into the terminal fitting through-hole 20 from the back surface side of the second circuit board 12 with the electrical connection portion 38 first. The electrical connection portion 38 is penetrated from the surface side of the circuit board 11. Then, the circuit board side fixing portion 39 protruding to the back surface side of the second circuit board 12 is soldered to the land 34 of the second conductive circuit pattern 17. As a result, the terminal fitting 23 is assembled and fixed in a state where the electrical connection portion 38 protrudes on the first circuit board 11. At this time, the circuit board side fixing portion 39 is not in contact with the inner peripheral surface 41 of the first insulating plate 14, the inner peripheral surface 40 of the metal plate 13, and the inner peripheral surface 42 of the second insulating plate 16 with a gap. Arranged in a state.

  Thus, at least one of the terminal fittings 23 electrically connected to the first conductive circuit pattern 15 protrudes from the second circuit board 12 through the terminal fitting through-hole 20, and the second conductive At least another one electrically connected to the conductive circuit pattern 17 protrudes from the first circuit board 11 through the through hole 20 for terminal fitting. Therefore, the metal core substrate 10 is formed to have a function equivalent to that of a double-sided circuit substrate having a through hole. Further, as compared with the case where double-sided circuit boards having the same thickness as those of the first circuit board 11 and the second circuit board 12 are employed, it is not necessary to consider the insulation of the soldered portion on the metal plate 13 side. The metal core substrate 10 can be formed thin.

  Returning to FIG. 3, in the metal core substrate 10, the first circuit board 11 and the second circuit board 12 are integrally assembled by press-fitting the press-fit fixing member 22 into the second through hole 19. Then, the press-fit terminal 21 is press-fitted and fixed to the first circuit board 11 or the second circuit board 12 by being press-fitted into the first through hole 18. Further, the metal plate 13 is attached to the first circuit board 11 and the second circuit board 12 so that the press-fit fixing member 22 allows a slight relative movement of the metal plate 13 with respect to the first circuit board 11 and the second circuit board 12. Can be held between.

  In the metal core substrate 10, the terminal fittings 23 are inserted into the terminal fitting through holes 20 from the front surface side of the first circuit board 11 or the back surface side of the second circuit board 12. Then, it is soldered to the land 34 of the second conductive circuit pattern 17 on the back surface side of the second circuit board 12 or the land 33 of the first conductive circuit pattern 15 on the front surface side of the first circuit board 11. That is, the terminal fitting 23 inserted through the terminal fitting through-hole 20 and electrically connected to the first conductive circuit pattern 15 of the first circuit board 11 passes through the terminal fitting through-hole 20 and passes through the second circuit board. 12 and projecting from 12. The terminal fitting 23 inserted through the terminal fitting through-hole 20 and electrically connected to the second conductive circuit pattern 17 of the second circuit board 12 passes through the terminal fitting through-hole 20 and passes through the first circuit board. 11 so as to protrude from 11.

  As described above, according to the metal core substrate 10 of the present embodiment, when the press-fit terminal 21 is press-fitted into the first through hole 18 by the press-fit fixing member 22, the first circuit board 11 and the second circuit board. The metal plate 13 is securely held between the first circuit board 11 and the second circuit board 12 so as to allow a slight relative movement of the metal plate 13 with respect to 12. Thereby, since stress when the press-fit terminal 21 is inserted can be relieved, the press-fit terminal 21 can be inserted without any trouble.

  Furthermore, according to the metal core substrate 10 of the present embodiment, since the first circuit board 11 and the second circuit board 12 are each a single-sided circuit board, the cost is lower than a metal core board formed by molding. Since there is no need to consider insulation from the metal plate, the degree of freedom in design is high. Further, whitening, cracks, and the like of the first insulating plate 14 and the second insulating plate 16 can be prevented.

(Second Embodiment)
Next, a second embodiment of the metal core substrate according to the present invention will be described.
FIG. 5 shows a second embodiment of the metal core substrate according to the present invention, and FIG. 5 is a longitudinal sectional view of the metal core substrate according to the second embodiment of the present invention. In the following embodiments, components that are the same as those in the first embodiment described above or functionally similar components are simplified or omitted by giving the same reference numerals or equivalent symbols in the drawings. To do.

  As shown in FIG. 5, the metal core substrate 50 according to the present embodiment is integrally assembled by sandwiching the outer sides of the first circuit board 11 and the second circuit board 12 sandwiched with the metal plate 13 between the fixing members 51. It has been.

  The fixing member 51 is formed in a U-shape, and after the flange portion 52 is externally fitted to the front surface of the first circuit board 11 and the back surface of the second circuit board 12, the fixing means 53 such as a screw is attached to the first means. The flange portion 52 is screwed to the first circuit board 11 and the second circuit board 12 by being screwed into the circuit board 11 and the second circuit board 12.

  The metal core substrate 50 of the present embodiment has the same effects as the first embodiment, but in particular, since no press-fit fixing member is used, it is not necessary to form the second through hole, and the first circuit board 11 and The metal plate 13 can be held between the first circuit board 11 and the second circuit board 12 so as to allow a slight relative movement of the metal plate 13 with respect to the second circuit board 12.

(Third embodiment)
Next, a third embodiment of the metal core substrate according to the present invention will be described.
FIG. 6 shows a third embodiment of the metal core substrate according to the present invention, and FIG. 6 is a longitudinal sectional view of the metal core substrate according to the third embodiment of the present invention.

  As shown in FIG. 6, in the metal core substrate 60 according to the present embodiment, a bush 61 is inserted into the second through hole 19, and from the first circuit board 11 side and the second circuit board 12 side to the bush 61, respectively. The bush 61 is screwed and fixed to the first circuit board 11 side and the second circuit board 12 by screwing a fixing means 62 such as a screw.

  The metal core substrate 60 of the present embodiment has the same effects as those of the first embodiment. In particular, the metal plate 13 with respect to the first circuit board 11 and the second circuit board 12 is not very small without using a press-fit fixing member. The metal plate 13 can be held between the first circuit board 11 and the second circuit board 12 so as to allow relative movement.

  In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  Of course, in the metal core substrate of the present invention, a metal plate (that is, a metal core) is sandwiched between two circuit boards. A configuration in which the circuit board is sandwiched between them is also conceivable.

It is a disassembled perspective view of the electrical junction box to which the metal core board concerning a 1st embodiment of the present invention is applied. It is a disassembled perspective view of the metal core board | substrate of FIG. FIG. 2 is a longitudinal sectional view around a press-fit terminal and a press-fit fixing member in the metal core substrate of FIG. 1. It is a longitudinal cross-sectional view around the terminal metal fitting in the metal core board | substrate of FIG. It is a longitudinal cross-sectional view of the metal core board | substrate which concerns on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the metal core board | substrate which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the conventional press fit terminal.

Explanation of symbols

10, 50, 60 Metal core board 11 First circuit board 12 Second circuit board 13 Metal plate 14 First insulating plate (insulating plate)
15 First conductive circuit pattern (conductive circuit pattern)
16 Second insulating plate (insulating plate)
17 Second conductive circuit pattern (conductive circuit pattern)
18 First through hole 19 Second through hole (holding mechanism)
21 Press-fit terminal 22 Press-fit fixing member (holding mechanism, holding member)
27 metal plate movement allowance portion 28 first protrusion portion 29 second protrusion portion 36, 37 inner peripheral surface 51 fixing member (holding mechanism, holding member)
61 Bush (holding mechanism, holding member)
62 Fixing means (holding mechanism, holding member)

Claims (4)

A first circuit board;
A second circuit board;
A metal plate disposed between the first circuit board and the second circuit board;
With
The first circuit board, the second circuit board and the metal plate are independently arranged;
A first through hole capable of press-fitting and fixing a press-fit terminal is a metal core substrate that penetrates the first circuit board, the second circuit board, and the metal plate in their plate thickness direction,
When the press-fit terminal is press-fitted into the first through hole, the metal plate is attached to the first circuit so as to allow a slight relative movement of the metal plate with respect to the first circuit board and the second circuit board. A metal core board, further comprising a holding mechanism for holding the board between the board and the second circuit board. The holding mechanism is
A second through hole penetrating the first circuit board, the second circuit board, and the metal plate in the plate thickness direction;
In cooperation with a part of the second through hole, the metal plate is moved with the first circuit board so as to allow a slight relative movement of the metal plate with respect to the first circuit board and the second circuit board. A holding member held between the second circuit board;
The metal core substrate according to claim 1, comprising: The holding member is a press-fit fixing member that is press-fitted and fixed in the second through hole,
The press-fit fixing member is
A first protrusion that is in pressure contact with an inner peripheral surface of the first circuit board that partially defines the second through hole;
A second protrusion that is in pressure contact with an inner peripheral surface of the second circuit board that partially defines the second through hole;
A metal plate movement allowance portion formed between the first protrusion and the second protrusion;
Have
3. The metal core substrate according to claim 2, wherein a diameter of a portion of the second through hole formed in the metal plate is larger than an outer diameter of the metal plate movement allowing portion. The first circuit board and the second circuit board each have an insulating plate and a conductive circuit pattern formed on the outer surface of the insulating plate opposite to the metal plate side,
The first protrusion of the press-fit fixing member is in pressure contact with the inner peripheral surface of the insulating plate of the first circuit board partially defining the second through hole;
The said 2nd projection part of the said press fit fixing member press-contacts to the internal peripheral surface of the said insulating board of the said 2nd circuit board which partially defines the said 2nd through-hole. The metal core substrate described.

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