JP5291016B2 - Core plate structure and metal core substrate of metal core substrate for in-vehicle electrical junction box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal core substrate capable of providing a function suitable for an onboard electrical connection box, particularly, of ensuring reduced size and improved mounting efficiency, as well, as improved durability. <P>SOLUTION: In the structure of a core plate 31 of a metal core substrate for an onboard electrical connection box which is mounted on the onboard electrical connection box, an island section 34 surrounded by a plurality of slits 32 and a separating connection 33 interposed between the slits 32 is formed, with the width of the slit 32 being set to be a narrow width W. A bent section 38, which changes the extending direction of the slit 32, is formed at the slit 32 to suppress the occurrence of deflection and stress. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a metal core substrate mounted on an in-vehicle electrical junction box (junction box). More specifically, the present invention has a heat dissipation effect, can form a plurality of circuits, and can be downsized and improved in mounting efficiency. It is related with the metal core board | substrate for such vehicle-mounted electrical connection boxes.

  In the present invention, the “metal core substrate” means an insulating substrate (laminated board) before the wiring pattern is formed, a metal core printed wiring board in which the wiring pattern is formed on the laminated board, and an electronic component on the metal core printed wiring board. It means a substrate having a metal core plate in an intermediate layer, such as a mounted metal core printed circuit board.

  Up to now, there are two types of in-vehicle electrical junction boxes: a bus bar type in which the internal wiring is constituted by a bus bar, and a printed board type that is constituted by a printed board. Compared with the busbar type, the printed circuit board type has the advantage that the circuit pattern design can be changed according to the vehicle type, grade, and destination, and the circuit pattern can be formed in a short period of time. .

  However, even with a printed circuit board, heat from a mounted electronic component or circuit pattern is insulated by an insulating layer in a printed circuit board based on a general glass epoxy material, so that heat concentrates on the circuit pattern. As a result, there was a problem that the temperature easily increased. Moreover, since the generated individual heat is separated on the printed circuit board, it is not possible to collect the heat and dissipate it in a batch.

  Therefore, it is known to use a metal core substrate to equalize the heat of electronic components and circuit patterns with a core plate and to radiate heat over the entire substrate.

  However, even if the metal core substrate is adopted simply by changing the material of the base material, there is a limit to the reduction in size and improvement in mounting efficiency.

  On the other hand, although not intended for an in-vehicle electrical junction box, there is a metal core substrate disclosed in the following Patent Document 1 that can form a plurality of circuits.

  In this metal core substrate, in order to form a square island-shaped separation portion on the metal core (core plate), two connection portions are left to form a U-shaped punched portion, and insulating plates are laminated on both surfaces of the metal core. Thereafter, the connecting part is removed by making a hole in the connecting part from the outside. By removing the connecting part, the separation part is independent from the surroundings, that is, the metal core is divided into a plurality of parts.

  Moreover, the width | variety of the said extraction part is a width | variety which interrupts | blocks the heat transfer from the circumference | surroundings of a separation location to a separation location.

  Therefore, a plurality of circuits can be formed, and the heat conduction is also blocked by the presence of the extracted portion of the metal core.

JP-A-8-288606

  However, the punched portion formed in the metal core blocks heat conduction and is wide.

  For this reason, the heat generated for each circuit is separated. In other words, it does not dissipate heat by dispersing and soaking the whole, and a local temperature rise cannot be suppressed. Therefore, even if the technique disclosed in Patent Document 1 is simply adopted for a metal core substrate for an in-vehicle electrical junction box, a necessary heat dissipation effect cannot be obtained.

  Further, since the width of the punched portion is wide, it is impossible to expect a reduction in size and an improvement in mounting efficiency.

  However, the narrower the width of the punched portion and the longer the straight portion of the punched portion, the more the punched portion acts like a fold line, so warp and stress are likely to occur in the metal core. If there is warping or stress, distortion will occur due to long-term use, which will impair the durability of the metal core substrate.

  Accordingly, the present invention is intended to provide a metal core substrate for an in-vehicle electrical junction box that can achieve downsizing, improvement in loading efficiency, etc., and particularly good heat dissipation effect and durability. Main purpose.

  The means for this is a core plate structure of a metal core substrate for an in-vehicle electric junction box mounted on the in-vehicle electric junction box, and is surrounded by a plurality of slit portions and a separation connecting portion interposed between these slit portions. This is a core plate structure of a metal core substrate for an in-vehicle electrical junction box in which an island portion is formed and the width of the slit portion is set to a narrow width.

  Specifically, the width of the slit portion may be a width that enables heat transfer between opposing portions sandwiching the slit portion.

  Further, in order to further suppress the occurrence of warpage and stress on the core plate and to obtain durability, it is preferable to form a bent portion in the slit portion that changes the extending direction of the slit portion. This bent portion is preferably bent at an obtuse angle.

  Another means uses the core plate having the core plate structure, and the island connecting portion is removed in a state where the island portion is sandwiched between insulating layers laminated on both surfaces of the core plate, and the island portion is removed. Is a metal core substrate for an in-vehicle electrical junction box that is electrically independent from other parts in the insulating layer.

  According to this invention, since the core plate has the island portion that is electrically independent, a metal core substrate optimal for an on-vehicle electrical junction box that can be miniaturized and improved in mounting efficiency can be obtained. In addition, since the slit portion is narrow, further downsizing can be achieved.

  In addition, it is possible to exhibit the heat dissipation effect by soaking, and it is possible to suppress the occurrence of distortion due to warpage and stress that may occur during processing and subsequent handling by the shape of the slit part, and durability Therefore, it is possible to provide a metal core substrate suitable for an in-vehicle electrical junction box that may be mounted in a high-temperature engine room.

The top view and sectional drawing which show schematic structure of a metal core board | substrate. The disassembled perspective view of a vehicle-mounted electrical junction box. The schematic explanatory drawing of the manufacturing process of a metal core board | substrate. The top view which shows an example of a core board. FIG. 5 is a partially enlarged view of FIG. 4. The top view which shows the transition in the manufacturing process of the connection part vicinity for isolation | separation of a core board. The top view of the connection part vicinity for isolation | separation of a core board. The top view of the connection part vicinity for isolation | separation of the core board which concerns on another example. The top view of the connection part vicinity for isolation | separation of the core board which concerns on another example. The enlarged plan view of a slit part. Sectional drawing of the metal mold | die which punches a slit part. Explanatory drawing which shows the formation order of the through-hole for core board division | segmentation. Sectional drawing which shows a metal core board | substrate and a contact part.

An embodiment for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic structure of a metal core substrate 11 for an in-vehicle electrical junction box, (a) is a plan view showing a part of the metal core substrate 11, and (b) is a cross-sectional view taken along line AA. In FIG. 1A, the circuit pattern is omitted for convenience.

  The metal core substrate 11 is mounted on, for example, an in-vehicle electrical connection box 21 illustrated in FIG. 2, and a plurality of slit portions 32 are formed on a core plate 31 that constitutes an intermediate layer of the metal core substrate 11. An island portion 34 surrounded by a separation connecting portion 33 interposed between the slit portions 32 is formed (see FIG. 4). Then, in the state where the island portion 34 is sandwiched between the insulating layers 41 laminated on both surfaces of the core plate 31, the separation connecting portion 33 is removed, and the island portion 34 is in the other portion in the insulating layer 41. Is electrically independent from.

  That is, the core plate 31 before the island portion 34 is independent is the core plate in which the island portion 34 surrounded by the plurality of slit portions 32 and the separation connection portion 33 interposed between the slit portions 32 is formed. It has 31 structures.

  In FIG. 2, 12 is a metal core substrate (metal core printed circuit board) on which an electronic component 12a is mounted, and 13 is a metal core substrate (metal core printed wiring board) excluding the electronic component 12a. Reference numeral 22 denotes a lower case, and reference numeral 23 denotes an upper case.

  The metal core substrate 11 as the metal core printed wiring board 13 is manufactured through a process as shown in FIG. The outline of this process will be described first, and then the details of the core plate 31 and the like will be described.

  First, a metal plate (for example, a copper plate or an aluminum plate) having a predetermined thickness to be the core plate 31 is cut to obtain a material 31a (see FIG. 3A).

  Subsequently, the core plate 31 is formed by drilling a predetermined hole 35 and the slit portion 32 at a predetermined position of the material 31a (see FIG. 3B). An example of the core plate 31 is shown in the plan view of FIG.

  Next, the surface of the core plate 31 is subjected to a roughening process for improving the adhesiveness of the resin.

  Thereafter, the prepreg 41 and the copper foil 42 are sequentially stacked on both surfaces of the roughened core plate 31 (see FIG. 3C) and sandwiched between stainless plates (not shown), and these are laminated by a hot press. They are integrated (see FIG. 3D). At the time of this integration, the resin of the prepreg 41 is filled into the hole 35 and the slit portion 32.

  By this lamination and integration, a structure in which the copper foil 42 exists on both surfaces of the core plate 31 via the insulating layer 41a formed of the prepreg 41 is obtained. What is integrated is a copper clad laminate 14.

  Subsequently, through holes 45 and 47 are formed at predetermined positions for forming the through holes, and through holes 46 are formed at the positions of the connecting portions 33 for separation between the slit portions 32 (see FIG. 3E). The island portion 34 of the core plate 31 is separated from the periphery by the through hole 46 formed at the position of the separation connecting portion 33 and becomes electrically independent, so that the core-divided metal core substrate 11 is obtained.

  The formation of the through hole 46 for dividing the core may be performed at any stage after the lamination integration.

  Next, the through holes 45 and 47 for the through holes are plated after performing a necessary process such as desmearing, and current-carrying portions are formed on the inner peripheral surfaces of the through holes 45 and 47 and in the vicinity thereof. (See FIG. 3 (f)). The plating of the through-hole 45 is a well-known through-hole plating 45a, and the through-hole plating 45a and the core plate 31 are not in contact with each other. On the other hand, the plated layer 47 a is electrically connected to the core plate 31 in the through hole 47. The plated layer 47a is a current-carrying part for using the core plate 31 as a part of the circuit, and a terminal (not shown) is inserted into the through hole 47 and soldered.

  Thereafter, when necessary processing such as formation of the circuit pattern 48 and formation of the solder resist 49 is performed, the metal core substrate 11 as the metal core printed wiring board 13 is obtained (see FIG. 3G).

  Next, the structure of the core plate 31 for obtaining the metal core substrate 11 will be described. The core plate 31 is configured so that the core plate 31 can be reduced in size, improved in mounting efficiency, improved in heat dissipation effect by soaking, and is not warped or stressed.

  As illustrated in FIG. 4, a plurality of the slit portions 32 are formed in a closed loop shape on the inner side in the surface direction of the core plate 31, and by forming these slit portions 32, the separation connection portions 33 and the islands are formed. The part 34 will be formed. In other words, the separation connection portion 33 and the island portion 34 are formed by intermittently forming the slit portion 32 in a closed loop shape.

  The slit portion 32 can be formed by a known router, etching, drilling, punching with a mold, or the like. Among these, punching with a mold is superior in terms of production efficiency and dimensional accuracy because it can be done with one action.

  The separation connecting portion 33 is formed in such a size that a portion sandwiching the slit portion 32 can be separated by forming one through hole 46 formed at this position. As shown in FIG. 5 showing an enlarged view of one of the plurality of island portions 34 shown in FIG. 4, through holes 46 indicated by phantom lines are formed between the slit portions 32, that is, in the separation connection portion 33. For example, the island portion 34 of the core plate 31 is divided from its periphery.

  FIG. 6 is a plan view showing the end portions of the separation connecting portion 33 and the slit portion 32 in the order of the manufacturing process. The prepreg 41 and the copper foil 42 are formed on both surfaces of the core plate 31 as shown in FIG. Are laminated to form the copper clad laminate 14 (see FIG. 3D), the slit portion 32 is filled with the resin 41b as shown in FIG. 6B. And as shown in FIG.6 (c), if the said through-hole 46 is opened, the opposing part which pinches | interposes the slit part 32 in the core board 31 will be divided | segmented.

  Further, the width of the slit portion 32 is reduced in size, improved in mounting efficiency, improved in heat dissipation effect by soaking, and inflow of resin in the laminating step (see FIGS. 3C and 3D). Is set to a narrow width W. The narrow width W is a narrow width in view of conditions such as the thickness of the core plate 31 and the length of the slit portion 32. Specifically, the opposing portion sandwiching the slit portion 32 even when the resin 41b is filled. Set to a width that allows heat transfer between.

  The narrow width W is determined in consideration of the inflow property of the resin, and is preferably as narrow as possible. For example, when the thickness of the core plate 31 is 0.4 mm, the narrow width W is about 1 mm to 2 mm, preferably about 1.5 mm.

  Further, if the through hole 46 for division is large, the portion where the circuit can be formed in the metal core substrate 11 is reduced, so that the size and width of the separation connecting portion 33 can be reduced. ) Is also set small, for example, about 1 mm to 2 mm.

  Thus, in order to reduce the width of the slit portion 32 and reduce the size of the separation connecting portion 33, warping or deformation of the core plate 31 during or after the formation of the slit portion 32 or the through-hole 46 is formed. Stress can easily be generated. For this reason, as shown in a partially enlarged view in FIG. 5, a square round portion 36 is formed at the end of the slit portion 32 for forming the separation connecting portion 33.

  The corner round portion 36 may be formed at a part of the end portion of the slit portion 32, but it may be formed in a semicircular shape in plan view so as to form one corner round portion 36 as shown in the drawing.

  With such a rounded corner portion 36, when the through-hole 46 as shown in FIG. 6C is drilled, the end of the slit portion 32 is at a right angle, It can prevent stress from concentrating on some parts. That is, the stress concentration can be reduced, and the occurrence of distortion in the core plate 31 and the insulating layer 41a can be suppressed.

  Further, when punching with a mold or the like, the life of the mold is prolonged as compared with the case where it is perpendicular, and as a result, the cost is reduced.

  Further, when the corner rounded portion 36 is provided at the end portion of the slit portion 32, the stress concentration can be reduced even when the separation connecting portion 33 is made smaller than when the end portion of the slit portion 32 is perpendicular. Since the strength of the core plate 31 can be obtained, the handleability in the manufacturing operation such as the laminating step (see FIGS. 3C and 3D) is good.

  That is, as shown in FIGS. 7B and 7C, when the end portion of the slit portion 32 is a right angle, the separation connecting portion 33 is small as shown in FIG. An overload is applied to the connection portion 33 and the vicinity thereof, and the form of the core plate 31 is not stable and the handleability is poor. For this reason, as shown in FIG.7 (c), you have to enlarge the connection part 33 for isolation | separation. On the other hand, when the slit part 32 is provided with the corner | angular round part 36 as mentioned above, as shown to Fig.7 (a), the distance L between the slit parts 32 can be shortened. That is, the separation connecting portion 33 can be made small.

  As a result, the size of the through hole 46 to be formed can be made as small as possible. If the through hole 46 is small, the metal core substrate 11 can be used widely, which contributes to downsizing and improved mounting efficiency. Further, when soldering is performed after mounting the electronic component 12a (see FIG. 2), since the through hole 46 is small, it is possible to prevent the solder from blowing out from the through hole 46 as much as possible.

  Even if the through-hole 46 is small, the core plate 31 exposed in the through-hole 46 in a later manufacturing process is etched so that its end face is removed, so that the insulation distance (creeping distance) can be increased. it can.

  The corner rounded portion 36 at the end of the slit portion 32 may be a circle having a larger diameter than the width of the slit portion 32, for example, as shown in FIG. In other words, the diameter of the rounded corner portion 36 having a substantially circular shape is set larger than the width of the slit portion 32. Further, as shown in FIG. 8B, the slit portions 32 forming the separation connecting portion 33 may not be aligned on a straight line but may be adjacent to each other with an appropriate angle.

  Further, when the through hole 46 for dividing the core plate 31 has a long hole shape as shown in FIG. 8C, the core plate can be surely formed even if the through hole 46 is displaced. 31 divisions can be performed.

  In order to ensure the necessary creepage distance even when the position where the through hole 46 for dividing the core plate 31 is formed is shifted, the separation connecting portion 33 is longer than the width of the slit portion 32. It may be formed by being sandwiched between the hole-shaped portions 37. That is, as shown in FIG. 9A, the end of the slit portion 32 can be formed in a T shape in plan view. That is, the slit portion 32 has an elongated hole-shaped portion 37 extending in a direction orthogonal to the longitudinal direction of the slit portion 32 at the end. Both ends of the long hole portion 37 are corner round portions 36.

  When the separation connecting portion 33 is sandwiched between the slit portions 32 having such a shape, even when the formation position of the through hole 46 by the drill is shifted in the longitudinal direction of the long hole-shaped portion 37 (the left-right direction in the drawing), A predetermined large through-hole 46 can be reliably formed in the separation connecting portion 33, so that a necessary creepage distance can be secured.

  Further, as shown in FIG. 9B, the separation connecting portion 33 may be formed by arranging the ends of the slit portions 32 extending linearly in the same direction in parallel. The same applies to the separation connecting portion 33 having such a configuration, and even when the formation position of the through hole 46 is shifted in the longitudinal direction of the long hole-shaped portion 37 (the vertical direction in the drawing), the separation connecting portion 33 is surely secured. Since a predetermined large through-hole 46 can be formed, a necessary creepage distance can be secured.

  In addition, in the configuration of the slit portion 32 and the separation connecting portion 33, the elongated hole portion 37 functions to facilitate the deformation of the separation connecting portion 33 and the vicinity thereof to release stress, so that the through hole 46 is formed by a drill. Sometimes the generation of stress can be mitigated.

  On the other hand, between the end portions of the slit portion 32 formed in the narrow width W (intermediate in the longitudinal direction), as shown in FIG. 5 and FIG. 10A, the bending that changes the extending direction of the slit portion 32. A portion 38 is formed. In other words, the shape of the slit portion 32 in plan view is a shape having a bent portion 38 that forms a non-linear shape that strengthens the restraint of the core plate 31 when punched by a mold. The bent portion 38 may be bent in an arc shape or a waveform, or may be bent at an appropriate angle as in the illustrated example. In this case, it is preferable that the bent portion 38 bends at an obtuse angle (the tangential direction of the slit portion 32 in the bent portion 38 intersects at an obtuse angle).

  If the slit portion 32 extends linearly, the longer the slit portion 32, the more likely it will warp in a substantially V-shaped cross section with the slit portion 32 as a boundary when the slit portion 32 is formed by a mold. This is because the long slit portion 32 acts like a fold line. Moreover, the restraint of the material is weakened at the linear portion, and the slip of the core plate 31 which is the material is promoted, and this also tends to cause the warp. On the other hand, when the slit portion 32 has a bent portion 38 as shown in FIG. 10A and the like, the surface rigidity at the facing portion sandwiching the slit portion 32 is increased, so that warpage can be suppressed. In other words, since the force is dispersed in an attempt to generate a plurality of warpages having different directions due to the punching of the slit portion 32 by the mold, the generation of a large warp can be suppressed as a whole.

  In addition, when the slit portion 32 is linearly long, even after the slit portion 32 is formed, the core plate 31 is easily bent into a substantially V-shaped cross section at the slit portion 32, and warpage is likely to occur. For this reason, it becomes difficult to handle the core plate 31, but when the slit portion 32 has the bent portion 38, the warp can be suppressed and the surface rigidity is increased as described above, so that the handleability can be improved. By forming a plurality of bent portions 38 for one slit portion 32, the surface rigidity can be further increased, and the length of the linear portion in the slit portion can be shortened, and the generation of warpage and stress can be suppressed. By forming the plurality of bent portions 38 in various bending directions, for example, in a zigzag shape, the generation of warpage and stress can be further suppressed.

  As described above, the slit portion 32 is preferably formed by punching with a metal mold. However, the slit portion 32 is wide (for example, as shown in FIG. 10B) with the slit portion 32 shown in FIG. In the case of the slit portion 32 set to the narrow width W, in general, warping is likely to occur at the time of punching. At the same time, the core plate 31 that is a material tends to slip in a portion that extends linearly. However, the configuration having the bent portion 38 like the slit portion 32 may suppress the occurrence of warping and slipping as described above.

  Further, in addition to the metal mold 51 (see FIG. 11) for forming the slit portion 32, the narrower the slit portion 32 is, the thinner the blade 52 for punching becomes, and the blade 52 and the like are easily damaged, resulting in durability. There was a difficulty that was bad. However, if the slit portion 32 has a bent portion 38, FIG. 11 (FIG. 11 (a) is a transverse sectional view of the blade 52, and FIG. 11 (b) is a longitudinal sectional view of the mold 51). As shown, the blade 52 is thin, but has a bent portion 52 a corresponding to the bent portion 38 of the slit portion 32, so that the blade 52 has high rigidity. Further, the binding force of the core plate 31 by the stripper 54 can also be increased. For this reason, it is possible to prevent the blade 52 from coming out from between the die 53 and the stripper 54 during the punching process, and to prevent the mold 51 from being worn or damaged, thereby ensuring workability. For this reason, a favorable effect is obtained also for the punching die 51.

  The slit portion 32 and the separation connecting portion 33 and the bent portion 38 of the slit portion 32 are appropriately formed according to the desired position, size, etc. of the island portion 34. In consideration of the treatment, it is formed so that the current density is improved.

  In addition, the number, arrangement, and size of the connection portions 33 for separation are particularly set so that the slit portions 32 and the connection portions 33 for separation and the bent portions 38 of the slit portions 32 can have a strength that can ensure the handleability of the core plate 31. Etc. are set. Furthermore, the arrangement is such that the stress can be relaxed even a little.

  The core plate 31 configured in this manner is laminated and integrated with the resin as described above, and then the through hole 46 is formed at the position of the separation connecting portion 33 of the core plate 31 so that the core plate 31 is divided. The

  The separation connecting portion 33 is removed by forming the through hole 46 for dividing the core plate 31 in order according to the shape of the slit portion 32 and the separating connecting portion 33 and the arrangement of the separating connecting portion 33. The As an example, it is possible to increase the order in which a portion that is easily deformed is opened first, and then a portion that is easily deformed far from the previously opened portion. In the case of the metal core substrate 11 having the core plate 31 having the slit portion 32 and the separation connection portion 33 as shown in FIG. 12, for example, through holes 46 are formed in the order of a to n, and the separation connection portion. 33 may be removed.

  In this way, the stress generated when the through hole 46 for division is formed can be suppressed as much as possible. As a result, it is possible to suppress the occurrence of distortion and to obtain durability that can withstand long-term use.

  Further, it is not always necessary to form the through holes 46 for division at the positions of all the separation connecting portions 33. In other words, the necessity of forming the through hole 46 may be determined according to the vehicle type, grade, and destination, and this determination may be performed. As a result, the circuit pattern can be changed depending on how the through holes 46 are formed. Further, it is possible to discriminate the vehicle type, grade, and the like from the appearance of the metal core substrate 11, that is, the opened through hole 46.

  The through holes 46 formed for dividing the core plate 31 are appropriately used as necessary in the manufacturing process and the assembling process of the metal core substrate 11 as shown in FIG. That is, the contact portion 61 that is in contact with the end surface of the core plate 31 exposed on the inner peripheral surface of the through hole 46 is held in the through hole 46.

  The contact portion 61 may be formed by covering or a member that fits into the through hole 46. Particularly in the latter case, the contact portion 61 may be a part of the in-vehicle electrical junction box 21 or its constituent elements.

  Since the end surface of the core plate 31 cut by the formation of the through hole 46 is exposed on the inner peripheral surface of the through hole 46, the inserted member is less than the case where the inner peripheral surface is only resin. There is a gripping force. For this reason, a firm holding state is obtained.

  FIG. 13 shows an example of a member that fits into the through hole 46. FIG. 13A is an example of a pin member 62 having a pin shape as a member fitted into the through hole 46. The pin member 62 is formed in an appropriate shape and is used for positioning and fixing in the manufacturing process and the assembling process.

  FIG. 13B shows a protective cap 63 that covers the end surface of the core plate 31 exposed in the through hole 46, and is formed in a cylindrical shape, and a flange 63 a is formed at one end.

  FIG. 13C similarly shows a closing cap 64 that covers and protects the end face of the core plate 31 and actively and completely closes the through hole 46. A hollow portion 64a is formed at one end. If the through hole 46 is closed in this way, it is possible to prevent the solder from blowing up even when soldering by the flow method.

  Further, the insulation performance between the end faces of the core plate 31 exposed in the through hole 46 can be improved by the protective cap 63 and the blocking cap 64, and even if moisture is generated near by condensation or the like, Can be reduced, and the occurrence of leakage can be prevented.

  These protective caps 63 and closing caps 64 may have a solid structure, but the internal space can be used for insertion into the through-hole 46, and even if there is a dimensional error in the through-hole 46, the protective cap 63, etc. However, because of the hollow structure, there is an advantage that deformation is possible and the load on the core plate 31 can be reduced.

  FIG. 13D shows a fixing protrusion 65 formed on the in-vehicle electrical junction box 21. The fixing protrusion 65 may be, for example, a fixing protrusion 65 formed as a part of the upper case 23 or the lower case 22 in FIG. In some cases, the fixing protrusion 65 may be used as a part of the terminal holder that holds the terminal that is responsible for the electrical connection. If the metal core substrate 11 is assembled using the fixing protrusion 65 of the in-vehicle electrical junction box 21 in this way, the same positioning and fixing effect as the pin member 62 at the time of assembly, or the protective cap 63 and the blocking cap for improving the insulation performance. The same effect as 64 can be obtained, the number of parts can be reduced, and the size can be reduced.

  Insulating materials are used for the pin member 62, the protective cap 63, the closing cap 64, and the fixing protrusion 65. For example, when the pin member 62, the rubber cap containing the high thermal conductive material is used, the insulating member has high thermal conductivity. In addition, heat conduction in the through-hole 46 can be ensured, and the heat radiation effect by soaking can be improved.

  Further, as described above, the metal core substrate 11 has the through hole 47 having the plated layer 47a on the inner peripheral surface (see FIGS. 3E and 3F). That is, a through-hole 47 that penetrates in the thickness direction is formed so as to penetrate the core plate 31, and a plating layer 47 a as an energization portion that is electrically connected to the core plate 31 is formed on the inner peripheral surface of the through-hole 47. The The plated layer 47a is formed by electroless plating and electrolytic plating, as with the through-hole plating 45a.

  Since this plating layer 47a is integrated with the core plate 31, the adhesion strength is high and the plating layer 47a is structurally excellent. For this reason, when a connection terminal (not shown) is inserted into the through hole 47, a good connection state can be secured.

  In addition, since the plated layer 47a is formed in the through hole 47, it is possible to increase the degree of freedom in using the metal core substrate 11 by effectively using the thick core plate 31, and a new way of using it. Can also meet high demands such as improving loading efficiency.

  As described above, since the metal core substrate 11 using the core plate 31 has the island portion 34 that is electrically independent, it is possible to reduce the size and improve the mounting efficiency. For this reason, the metal core board | substrate 11 optimal for the vehicle-mounted electrical connection box 21 with a high request | requirement of function increase or vehicle interior space ensuring is obtained.

  In addition, since the plated layer 47a is formed in the through hole 47 formed in the portion corresponding to the island portion 34, the thick core plate 31 is effectively used to increase the degree of freedom in using the metal core substrate 11. It is possible to open up new ways of use and meet high demands such as improved loading efficiency.

  The downsizing can be remarkably improved by the narrow width of the slit portion 32 and the small size of the through hole 46 for dividing the core plate 31.

  Moreover, even if the slit portion 32 is narrowed, the occurrence of warpage and stress can be suppressed due to the presence of the rounded corner portion 36, the elongated hole portion 37, and the bent portion 38. For this reason, generation | occurrence | production of the distortion by long-term use can be suppressed and durability can be improved. This effect is further enhanced by reducing the occurrence of stress when forming the through hole 46 for dividing the core.

  Further, since the surface strength is increased by the corner rounded portion 36 and the bent portion 38 of the slit portion 32, it is possible to ensure workability when stacking and integrating with the prepreg 41 and the like.

  In addition, the corner rounded portion 36 and the bent portion 38 of the slit portion 32 can suppress the wear and damage of the mold 51 when forming the slit portion 32 and ensure workability, so that the processing cost can be reduced.

  Further, since the width of the slit portion 32 is narrow, when a part of the metal core substrate 11 generates heat at a temperature higher than that of the other part of the core plate 31, the slit portion 32 conducts heat to the surroundings immediately after the heat generation. Although it shuts off, it conducts heat gradually and can achieve heat distribution and soaking. In this way, the temperature difference in the entire metal core substrate 11 is eliminated, and heat is concentrated in the core plate 31 so as to dissipate heat at a time, so that a good heat dissipation effect can be obtained. In automobiles, there are high demands for increasing functions and securing vehicle compartment space. In particular, from the standpoint of securing the latter vehicle compartment space, the in-vehicle electrical junction box 21 may be mounted in a high-temperature engine room and has good heat dissipation. Therefore, it will meet such a demand.

  In addition, if the contact portion 61 is held in the through hole 46 for dividing the island portion 34, the contact portion 61 having a high coupling force can be inserted, and the end surface of the core plate 31 exposed in the through hole 46 is contacted. By protecting with the portion 61, it is possible to prevent leakage between the divided core circuits and to prevent excessive adhesion of solder. In addition, the through hole 46 can be used effectively by using it for positioning in the manufacturing process and fixing in the assembly process, etc. When used for positioning, the processing accuracy of the process can be easily increased, and a highly accurate product can be obtained. can get. If used for fixing, the number of parts can be reduced, contributing to miniaturization and improved mounting efficiency, and also to the efficiency of assembly work.

  The contact portion 61 can be formed by molding or coating, but the cost can be reduced by using the pin member 62, the protective cap 63, the closing cap 64, and the fixing protrusion 65 as described above.

  The configuration of the one form is one form for carrying out the present invention, and the present invention is not limited to the above-described structure, and other forms can be adopted.

DESCRIPTION OF SYMBOLS 11 ... Metal core board 21 ... In-vehicle electrical connection box 31 ... Core board 32 ... Slit part 33 ... Separation connection part 34 ... Island part 38 ... Bending part W ... Narrow width

Claims (5)

A core plate structure of a metal core substrate for an in-vehicle electrical junction box mounted on the in-vehicle electrical junction box,
An island portion surrounded by a plurality of slit portions and a separation connecting portion interposed between these slit portions is formed,
A core plate structure of a metal core substrate for an in-vehicle electrical junction box in which the width of the slit portion is set to a narrow width. The core plate structure of a metal core substrate for an on-vehicle electrical junction box according to claim 1, wherein the width of the slit portion is a width that enables heat transfer between opposing portions sandwiching the slit portion. The core plate structure of the metal core substrate for an on-vehicle electrical junction box according to claim 1 or 2, wherein a bent portion for changing a direction in which the slit portion extends is formed in the slit portion. The core plate structure of a metal core substrate for an in-vehicle electrical junction box according to claim 3, wherein the bent portion is bent at an obtuse angle. Using a core plate having the core plate structure according to any one of claims 1 to 4,
In the state where the island portion is sandwiched between the insulating layers laminated on both surfaces of the core plate, the separation connecting portion is removed, and the island portion is electrically independent from other portions in the insulating layer. Metal core board for in-vehicle electrical junction box.

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