JP2003101177A - Metal core wiring board, production method therefor and circuit component utilizing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal core wiring board for high heat resistance and high temperature heat radiation, with which a mechanical strength is improved by preventing a metal substrate and an insulating layer from being detached even by heating of a packaged component. SOLUTION: A metal core wiring board 10 for packaging electronic components on the surface of a plate-like metal substrate is produced by forming a through hole 12 on one part of a metal substrate 11 (A), forming a shallow groove 13 around the through hole 12 on both the upper and lower faces of the metal substrate 11 by half etching (B), forming an insulating layer 14 by filling these through hole 12 and groove 13 with insulating members (C), and forming the wiring pattern of a bonding pad 30 or the like on the surface of this integrally filled insulating layer 13 by a flat through hole, for example (D). Besides, an electronic component 20 is packaged on the surface of this metal core wiring board 10, and a terminal thereof is electrically connected on the wiring pattern 30 so that the circuit component can be completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal core wiring board which is a wiring board using a metal substrate for high heat resistance and high temperature heat dissipation, and more particularly to a metal core wiring board excellent in mechanical strength and a method for manufacturing the same. Relates to a circuit component using such a metal core wiring board.

[0002]

2. Description of the Related Art Conventionally, for example, a metal substrate has been used as a wiring substrate for mounting a circuit having a relatively large amount of heat generation, including a power element and the like in a package substrate, a power control circuit for driving a motor, It is already known that a circuit element is mounted on the surface together with a circuit pattern by utilizing high heat transfer property. This is shown, for example, in the attached FIG. 9 (A).
As also shown in, a metal core wiring board formed by applying and printing an insulating member of a predetermined shape on a metal substrate surface, forming and fixing it in a layer, and forming a circuit pattern on the upper surface thereof,
Alternatively, as shown in FIG. 9B, it is a metal core wiring board or the like in which a sheet of an insulating member is attached on the surface of a metal substrate and a predetermined circuit pattern is formed on the surface of the insulating sheet.

Further, as a metal core wiring board using a metal substrate, for example, Japanese Patent Laid-Open No. 5-12185 is known.
According to Japanese Unexamined Patent Publication No. 2 and Japanese Unexamined Patent Publication (Kokai) No. 5-13903, an insulator is made uniform by an electrophoretic method by immersing the whole of a metal plate having a through hole in one or a plurality of sheets in a solution. A predetermined circuit pattern is formed on the surface of the attached insulator, and a through hole is formed in the through hole portion. Then, by making the corners of the through holes of the metal plate chamfered, the adhesion of the insulator at the corners is made uniform, so that the dielectric withstand voltage between the wiring conductor of the through hole and the metal plate is increased. What improves is already known.

[0004]

However, in the above-mentioned prior art, the following problems have still been pointed out. That is, particularly in the former technique shown in the former case, when an electronic component having a relatively large heat generation amount is actually mounted on such a metal core wiring board, the heat dissipation efficiency is low, and the difference in the coefficient of thermal expansion between the metal member and the insulating member is large. As a result, heat stress is repeatedly applied to both of them due to heat generation of the electronic component. As a result, particularly after long-term use, the bond between the insulating layer fixed on the surface and the metal substrate is destroyed, and the insulating layer peels off from the surface or groove of the metal substrate and falls off. However, there is a problem in that the circuit pattern formed on the surface or the electrical connection between the circuit pattern and the mounted electronic component is damaged.

Also in the latter conventional metal core wiring board, similarly to the above, due to the repeated thermal stress due to the heat generation of the electronic component, the insulating layer adhered to the surface of the metal board by the electrophoretic method. Are destroyed or peeled off. Therefore, there is a problem that the circuit pattern formed on the surface or the electrical connection between the circuit pattern and the mounted electronic component is damaged.

The present invention has been made in view of the above-mentioned problems in the prior art, and in particular, the circuit pattern and the mounting caused by the peeling of the metal substrate and the insulating layer even when the mounted electronic components generate heat. It is an object of the present invention to provide a metal core wiring board which is suitable for use as a wiring board for high heat resistance and high temperature heat dissipation, which is not damaged by electrical connection with an electronic component and has excellent mechanical strength.

[0007]

According to the present invention, in order to achieve the above object, first, a metal core wiring board having electronic components mounted on at least one surface of the upper and lower surfaces of a plate-shaped metal substrate is provided. A through hole is formed in a part of the metal substrate, and a groove is formed around the through hole on both upper and lower surfaces of the metal substrate, and the through hole and the groove are filled with an insulating member. There is provided a metal core wiring board in which an insulating layer is formed and a wiring pattern is formed on the surface of an insulating layer which is integrally filled in the through hole and the groove.

Further, according to the present invention, in the above-mentioned metal core wiring board, the wiring pattern formed on the surface of the filled insulating member is one of a through conductive hole, a non-through conductive hole, and a filled conductive hole. And / or the wiring pattern formed on the surface of the filled insulating member is a flat through hole.

Further, according to the present invention, there is also provided a method of manufacturing a metal core wiring board in which electronic components are mounted on at least one surface of a plate-shaped metal substrate, so as to achieve the above-mentioned object. Through holes are formed in a part of the plate-shaped metal substrate; (B) Grooves are formed around the through holes on the upper and lower surfaces of the metal substrate respectively; (C) In the through holes and the groove portions. Filling the insulating member to form an insulating layer,
Further, there is provided (D) a method of manufacturing a metal core wiring board in which a wiring pattern is formed on the surface of an insulating member that is integrally filled in the through hole and the groove.

According to the present invention, in the above method for manufacturing a metal core wiring board, in the step (B), the peripheries of the through holes on the upper and lower surfaces of the metal substrate are
Recesses or grooves are formed by half etching.

In addition, according to the present invention, there is provided a metal core wiring board described above, or a circuit component using the metal core wiring board manufactured by the manufacturing method described above, which is a part of the metal core wiring board. A heat-generating electronic component is mounted, and a terminal portion of the electronic component is electrically connected to a wiring pattern formed on the surface of the insulating member that is integrally filled in the through hole and the groove of the metal core wiring board. Circuit components are provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, FIG. 1 shows a metal core wiring board according to an embodiment of the present invention. Here, an electronic component that generates a relatively large amount of heat is mounted on one surface of the metal core wiring board. hand,
It shows a so-called circuit component.

In FIG. 1, reference numeral 10 in the figure denotes a metal core wiring board of the present invention made of a plate-shaped metal substrate. As is clear from the figure, the metal core wiring board is provided at a substantially central portion of its surface (upper surface). Is mounted with an electronic component 20 having a relatively large amount of heat generation, such as the above-described power element. Further, on the surface of the metal core wiring board 10, which is a kind of a circuit pattern for electrically connecting the input / output terminals of the mounted electronic component 20 to the outside, for example, circular or rectangular bonding pads 30, 30. , Are formed so as to surround the above electronic components in this example. Although only two bonding wires 35, 35 connecting the input / output terminals of the electronic component 20 are shown in this example, however, the electronic component 20 is actually connected to the metal core wiring board 10.
When mounted on top, more bonding wires can be used to bond the I / O terminals of the electronic components and the bonding pads 3
0, 30 ... Are electrically connected. Further, on the surface of the metal core wiring board 10, as will be described later in detail, an insulating coating film made of an insulating material (resin) (reference numeral 1 in the drawing).
5) is formed. In this example, as the electronic component having a relatively large heat generation mounted on the upper surface of the metal core wiring board, for example, an electronic component including a so-called power element such as a power transistor, a thyristor, or a diode therein, or Alternatively, for example, as represented by an arithmetic circuit element, since an electric circuit is formed therein with a high density and a high degree of integration, the heat generation amount of the electric circuit is relatively large.

Next, in FIG. 1 above, the alternate long and short dash line II
A sectional structure of the metal core wiring board 10 taken along the section indicated by -II is shown in FIG. 2 attached hereto. In addition, also in this figure, the components to which the same reference numerals as above are attached indicate the same components as above.

As is apparent from FIG. 2, the metal core wiring board 10 of the present invention is, for example, a plate-shaped copper (Cu).
And a part of the metal substrate 11 made of a metal having good thermal conductivity (the bonding pad 3 in this example).
.. are formed at the positions where 0 is formed), and the through holes 12 are directed toward the surroundings on both surfaces (upper and lower end surfaces) of the metal core wiring board 10. Each of which extends to a shallow groove 1
3, 13, ... Are formed. Then, the metal substrate 1
The through hole 12 and the groove portion 13 formed in 1 are filled with an insulating member 14, and the surface of the filled insulating member (insulating layer) 14 has, for example, the above-mentioned bonding pads 30, 30 ... A wiring pattern is formed.
In addition, on the surface of the metal core wiring board 10 thus formed, the above-described insulating film 15 surrounds the bonding pad 30 including the mounting position of the electronic component 20, for example. Has been formed.

The shallow groove 13 formed by extending the upper and lower end surfaces of the through hole 12 formed in the metal substrate 11 around the through hole 12 is shown by a broken line in FIG. In addition, in this example, although not shown in the figure, the electronic components are mounted not only on one surface (top surface) of the metal core wiring board 10 but also on the other surface (specifically, the bottom surface thereof), Alternatively, a wiring pattern can be formed,
A so-called double-sided wiring board is shown. Therefore, in this example, the bonding pad 30 forming the wiring pattern will be described in detail later, but the so-called non-penetration in which the upper and lower surfaces of the resin material filled in the plated through holes are covered with metal conductors. It is formed by a flat through hole which is a connection hole, whereby the input / output terminals of the electronic component 20 are taken out to the other surface (lower surface) of the metal core wiring board 10.

Next, a method for manufacturing the metal core wiring board 10 of the present invention having the above-described structure will be described in detail below with reference to the attached FIG. Here, the cross-sectional structure of the metal core wiring board 10 taken along the cross section indicated by the alternate long and short dash line III-III in FIG. 1 is shown.

First, as shown in FIG. 3A, a metal substrate 11 made of a plate-like metal having good thermal conductivity is prepared.
A through hole 12 having a predetermined diameter is formed in a part thereof by, for example, drilling or laser processing. Here, as the metal having good thermal conductivity which becomes the metal substrate 11, for example, oxygen-free copper or copper alloy is preferable, or, instead of this, for example, aluminum or its alloy may be used. Further, for example, in the case where an electronic circuit which is arranged in a magnetic field, such as a motor control circuit, which requires an electromagnetic shield to suppress the influence of the magnetism, is mounted, the metal substrate 11 is It is also possible to use an iron plate. Furthermore, for example, for an electronic component mounted in a measuring instrument used in an environment such as an acid environment, for example, a stainless steel plate having excellent rust prevention property can be used.
The shape of the metal substrate 11 is not limited to a plate shape having a predetermined size at this stage, and it is also possible to manufacture, for example, an elongated sheet-shaped metal plate rolled.

Next, as shown in FIG. 3B, a photosensitive film such as a dry film 100 is formed on both sides of the metal substrate 11 so as to surround the through hole 12 formed, and thereafter, As shown in FIG. 3C, the periphery of the upper and lower ends of the through hole 12 is removed by etching to form the groove 13 having a predetermined depth (so-called half-cut etching is performed). Here, reference numeral 12 'indicates a through hole after half-cut etching.
Then, as shown in FIG. 3D, the through hole 12 ′ thus formed after half-cut etching and both ends (upper and lower ends) of the through hole 12 ′ in the vicinity of both surfaces of the metal substrate 11 are surrounded by the peripheral direction. An insulating resin is embedded in the inside of the groove portion 13 formed to extend (in the lateral direction of the drawing) and cured. After that, if necessary, the surface thereof is flattened by, for example, polishing, and the insulating member (insulating layer) 14 is formed on the same surface of both surfaces of the metal substrate 11. Then, finally, as shown in FIG. 3 (E), the coating 15 of the insulating resin material described above is applied and cured in a predetermined shape, or adhered, and the metal core wiring board 10 is manufactured. The insulating resin filled in the through hole 12 ′ and the groove 13 after the half-cut etching is preferably an insulating material whose surface can be plated.

According to the metal core wiring board 10 manufactured as described above, as is clear from the sectional structure thereof, the insulating layers 14 formed in the shape of floating islands on the upper and lower surfaces of the metal substrate 11 are the metal substrate. Through holes 12 (more strictly speaking, through holes 12 ′ after half-cut etching) formed through 11 are integrally formed on the upper and lower sides, and the upper and lower portions thereof are expanded into the groove portion 13. Thus, a so-called wedge shape is formed. Therefore, the electronic component having a relatively large heat generation amount as described above is actually mounted on the metal core wiring board 10, and the metal substrate 11 and the insulating layer 14 are generated by the heat generation of the electronic component.
Even if thermal stress is repeatedly applied between the insulating layer 14 and the insulating layer 14, the insulating layer 14 does not peel off from the groove portion 13 of the metal substrate 11 and fall off. Further, according to the structure of the metal core wiring board 10 described above, the coating 15 of the insulating resin material finally attached to the surface thereof is integrally joined to the insulating layer 14, and the bonding strength between them is the same as that of the metal. It is possible to maintain the bonding strength with the insulating resin material higher than that of the insulating resin material. Even if the coating film 15 is peeled from the surface of the metal substrate 11 due to repeated thermal stress, the insulating layer 14 can be maintained.
As long as it is bonded with high strength against
Does not fall off the surface of the metal substrate 11. That is, on the surface of the metal core wiring board 10, the circuit pattern formed on the surface of the insulating layer 14 (bonding pad 30 by a flat through hole in this example).
With this, the electrical connection with the electronic components mounted on the wiring board is not damaged, and according to this,
It is possible to provide a metal core wiring board which has excellent mechanical strength and is suitable as a wiring board for high heat resistance and high temperature heat dissipation.

The metal core wiring board 1 described above is used.
The insulating layer 14 formed in the shape of a floating island on the surface of No. 0 will be described in more detail. For example, as shown in the attached FIG. The diameter D of the through hole 12 ′) after etching is 0.5φ to 0.7φ, whereas the diameter d of the groove portion 13 formed around it is 1.0φ to 2.0φ.
A degree is preferable. Further, as is clear from FIGS. 1 and 2, in particular, when a plurality of through holes 12 ′ are formed adjacent to each other, the plurality of through holes 12 ′ are formed so as to be continuous between the adjacent through holes 12 ′. It is also possible to form the groove portion 13.

Further, as also shown in FIG. 5 above,
The relationship between the thickness W of the metal substrate 11, the depth h of the floating island-shaped insulating layer 14 and the thickness w inside the metal substrate 11 is such that they are substantially equal to each other (specifically, , W = 2h + w = 3h = 3w), it has been confirmed by various experiments by the inventors. The depth h of the insulating layer 14 is h = 10 μm
The optimum range is ˜500 μm.

Next, referring to the attached FIG. 4, in the insulating layer 14 formed in a floating island shape on the surface of the metal core wiring board 10 described above, it is provided so that the upper and lower surfaces of the wiring board are electrically connected. The manufacturing process of the flat through hole (bonding pad 30 in this example), which is the formed circuit pattern, will be described below.

First, as shown in FIG. 4A, the through holes 12 (more strictly speaking, the through holes 12 'after half-cut etching) of the metal substrate 11 and the groove portion 13 formed around them are integrally formed. The through hole 200 is formed by drilling or laser processing at a predetermined position of the filled insulating layer 14, specifically, at the position where the through hole 12 ′ is formed. After that, as shown in FIG. 4B, a conductive (conductor) layer 210 is formed on the inner wall of the formed through hole 12 ′ and both surfaces of the insulating layer 14 around the through hole 12 ′ by, for example, a plating method and the like. As shown in FIG. 4C, the through hole 200 having the conductive layer 210 formed on the inner wall surface thereof is filled with an insulating resin 220 to flatten the surface and cure. After that, as shown in FIG. 4D, on both surfaces of the insulating layer 14, including both end surfaces of the filled insulating resin 220,
The conductive (conductor) layer 230 is formed again. Then, a photosensitive film such as a dry film is formed on the surface of the formed conductive layer 230, a predetermined circuit pattern (circular in this example) is exposed from above to form a resist film, and then the above is formed by etching. By removing the two conductive layers 210 and 230, as shown in FIG. 4 (E), a predetermined circuit pattern, that is, the upper and lower surfaces of the insulating resin material filled in the plated through holes are covered with metal conductors. The bonding pad 30 is formed of a flat through hole which is a non-penetrating connection hole. When a conductive paste is used, the through hole 200 is filled with the conductive paste by a printing method or the like in the state shown in FIG. 4, and a conductive (conductor) layer 210 is formed by a plating method or the like, and thereafter, a photographic method is used. A flat through hole is formed by the same process as.

According to the bonding pad 30 composed of a flat through hole, the manufacturing process of which is described in detail above, as is apparent from the above figures, an insulating layer formed in a floating island shape on the surface of the metal core wiring board 10. The circuit pattern formed on the surface of 14 is electrically connected to the surface (back surface) on the opposite side. Then, according to this, the metal core wiring board 10 can be a double-sided wiring board on which circuit patterns can be formed on the upper and lower surfaces of the wiring board or electronic components can be mounted.

However, the metal core wiring board 10 of the present invention is not limited to the above double-sided wiring board. That is, FIG. 6 attached herewith shows an example in which the circuit pattern 30 ′ is formed only on one surface (the upper surface in the figure) of the insulating layer 14 by the metal core wiring board 10 of the present invention. Note that, in this figure as well, the components denoted by the same reference numerals as above are the same as those described above, except that the circuit pattern 30 ′ is the same as the bonding pad 3 described above.
Unlike 0, it is a conductor layer formed in a stripe shape only on the surface of the insulating layer 14.

That is, in the metal core wiring board 10 of FIG. 6 according to another embodiment of the present invention, since the flat through hole as described above is not formed in the insulating layer 14, the single-sided wiring board is formed. Has become. Further, the input / output terminals of the electronic component 20 mounted on the wiring board are connected to the stripe-shaped circuit pattern 30 'formed on the surface of the insulating layer 14 as shown in the figure, which allows external Will be electrically connected to the circuit.

In addition, in the metal core wiring board 10 according to the other embodiment, as is clear from the sectional structure thereof, the insulating layers 14 formed in the floating island shape on the upper and lower surfaces of the metal substrate 11 are the metal substrate. Through hole 12 formed through 11 (through hole 1 after half-cut etching
2 ') is integrally formed in the upper and lower portions, and the upper and lower portions thereof are expanded into the groove portion 13 to form a so-called wedge shape. Therefore, the electronic component having a relatively large heat generation amount as described above is actually mounted on the metal core wiring board 10, and the heat generated by the electronic component causes repeated thermal stress between the metal substrate 11 and the insulating layer 14. Even if added, the insulating layer 14 does not peel off from the groove 13 of the metal substrate 11 and fall off. Further, since the coating 15 of the insulating resin material is integrally joined to the insulating layer 14, the bonding strength between them can be kept higher than the bonding strength between the metal and the insulating resin material. Even if the coating film 15 is peeled from the surface of the metal substrate 11 due to repeated thermal stress, as long as the coating film 15 is bonded to the insulating layer 14 with high strength, the coating film 15 can be removed from the surface of the metal substrate 11. Never fall out of. That is, similar to the above-described embodiment, on the surface of the metal core wiring board 10, the circuit pattern (in this example, the striped circuit pattern 30 ′) formed on the surface of the insulating layer 14 and the wiring board are formed. The electrical connection with the mounted electronic components is not damaged, in other words, the metal core wiring board having excellent mechanical strength and suitable as a wiring board for high heat resistance and high temperature heat dissipation is provided. It becomes possible.

In addition, in the other embodiments, since the above-mentioned electronic parts and circuit patterns are not formed on the lower surface side of the metal core wiring board 10, the metal core wiring board 10 is used for a mother board, a heat sink, or the like. When mounting on another substrate, the lower surface of the metal substrate 11 can be directly contacted and attached. From this, the heat generated from the electronic component 20 mounted on the substrate passes through the metal core wiring board 10 to the mother board,
This is preferable because it is more effectively conducted to another substrate such as a heat sink.

Further, FIG. 7 attached herewith shows a metal core wiring board 10 according to still another embodiment of the present invention.
Note that this wiring board also shows an example of a single-sided wiring board in which electronic components are mounted only on the surface of the insulating layer 14 and a circuit pattern is formed, like the metal core wiring boards according to the other embodiments described above. ing. In addition, also in this other embodiment, the components having the same reference numerals as above are the same as those described above, except that the circuit pattern is the bonding pad 30 or the striped conductor. Unlike the layer 30 ', the so-called plated through hole 30 "
Is formed.

In this other embodiment, as is apparent from the figure, the input / output terminals of the electronic component 20 mounted on the metal core wiring board 10 are formed on the surface of the insulating layer 14. After being inserted into the plated through hole 30 ″, the inside thereof is filled with a solder layer 31 so as to be mechanically fixed and electrically connected. In this further embodiment, metal is also used. The insulating layers 14 formed in the shape of floating islands on the upper and lower surfaces of the substrate 11 also form a wedge shape in the cross-sectional shape, and therefore, the heat generated by the electronic components 20 mounted thereon causes the metal substrate 1
Even if heat stress is repeatedly applied between the insulating layer 14 and the insulating layer 14, the insulating layer 14 does not peel off from the groove portion 13 of the metal substrate 11 and fall off as described above. In addition, the coating 15 of the insulating resin material is also used as the insulating layer 1.
Since it is integrally bonded to the insulating layer 14, even if the coating 15 is peeled off from the surface of the metal substrate 11 due to repeated thermal stress, as long as the coating 15 is bonded to the insulating layer 14 with high strength. 15 does not fall off the surface of the metal substrate 11. That is, similar to the above-described embodiment, the electrical connection between the circuit pattern formed on the surface of the insulating layer 14 and the electronic component mounted on the wiring board is damaged on the surface of the metal core wiring board 10. In other words, it is possible to provide a metal core wiring board which has excellent mechanical strength and is suitable as a wiring board for high heat resistance and high temperature heat dissipation.

In the case of still another embodiment shown in FIG. 7, the insulating layer 14 has plated through holes 3 formed therein.
Since 0 ″ is formed, it is possible to easily electrically connect the upper and lower surfaces of the insulating layer 14 by using the through hole 30 ″. From this,
Another embodiment of the metal core wiring board 1 shown in FIG.
0, it is also possible to form a circuit pattern on the back surface (lower surface) of the insulating layer 14 and / or to mount the electronic component 20. In other words, a double-sided wiring board can be used. Is. When the metal core wiring board 10 is a double-sided wiring board, the back surface (lower surface) of the wiring board 10
However, the coating 15 of the insulating resin material may be formed if necessary. Further, the plated through hole 30 ″ is shown here in the form of a through conduction hole, but instead of this, it may be in the form of a non-through conduction hole.

Finally, in the above-described embodiment of the present invention, only the rectangular shape of the metal core substrate 10 constituting the metal core substrate 10 has been described. However, the present invention is not limited to this. For example, as shown in the attached FIG. 8, the shape of the metal core substrate 10 ′ can be made substantially circular. Note that, also in this example, the components to which the same reference numerals as above are attached indicate the same components as above.

More specifically, in this example, an electronic component 20 which is a control circuit for a motor, for example, a hall element 60 and other elements 61, etc. are provided on a circular metal core substrate 10 '. It is included in the section and installed. In this case, as described above, in order to electromagnetically shield the control circuit, it is preferable to use the metal core substrate 10 'having the base substrate 11 made of, for example, zinc steel plate or silicon steel plate. In addition, main circuit portions constituting the control circuit for the motor are denoted by reference numerals 30, 30 ', 3 in the drawing.
It is configured by a circuit pattern indicated by 0 ". Further, reference numeral 70 in the drawing is a mounting hole formed for mounting the formed metal core substrate 10,
Further, reference numeral 80 is a through hole through which the shaft penetrates when the metal core substrate 10 is attached to a part of the motor.

In addition, in the above description, in the embodiment,
The through hole 12 (through hole 12 'after half-cut etching) formed in the metal substrate 11 constituting the metal core substrate 10 or 10' according to the present invention has been described as having a circular cross-sectional shape. However, the present invention is not limited to this, and it is also possible to form the cross-sectional shape into, for example, an elliptical shape, a rectangular shape, or another polygonal shape. As described in.

[0036]

As is clear from the above detailed description, according to the metal core wiring board and the manufacturing method thereof and the circuit component using the metal core wiring board of the present invention, the electronic components mounted can be Even when heat is generated, there is no damage to the circuit pattern or electrical connection between the mounted electronic components due to the peeling of the metal substrate from the insulating layer, and it has excellent mechanical strength, high heat resistance, and high temperature heat dissipation. The excellent effect that it becomes possible to provide a metal core wiring board suitable as a wiring board is exhibited.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which an electronic component is mounted on a metal core wiring board according to an embodiment of the present invention and a circuit component is formed accordingly.

FIG. 2 is a cross-sectional view showing the internal structure of a metal core wiring board taken along the cross-section indicated by alternate long and short dash line II-II in FIG.

FIG. 3 is an alternate long and short dash line III-II in FIG. 1 for explaining the method of manufacturing the metal core wiring board of the present invention.
FIG. 3 is a cross-sectional view of the metal core wiring board cut along the cross section indicated by I.

FIG. 4 is a partially enlarged cross-sectional view showing a process of manufacturing a bonding pad on an insulating layer formed on a metal substrate of the metal core wiring board of the present invention.

FIG. 5 is an enlarged perspective view including a partial cross section for showing an example of specific dimensions of through holes and grooves formed in the metal substrate of the metal core wiring board of the present invention.

FIG. 6 is an enlarged perspective view including a partial cross section for showing an internal structure of a metal core wiring board according to another embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view showing the internal structure of a metal core wiring board according to yet another embodiment of the present invention.

FIG. 8 is a perspective view showing an example of a modification of the metal core wiring board according to the above embodiment in which the shape of the metal core substrate is circular.

FIG. 9 is a partially enlarged sectional view showing an example of a structure of a metal core substrate according to a conventional technique.

[Explanation of symbols]

10, 10 'metal core wiring board 11 Metal substrate 12 through holes 12 'Through hole after half-cut etching 13 groove 14 Insulation member (insulation layer) 15 Insulating film 20 electronic components 30 Bonding pad (flat through hole) 30 'striped circuit pattern 30 "plated through hole 31 Solder layer 35 Bonding wire

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kimihide Ichinose             Nagano Prefecture Shimoina-gun Shimojo Village Yosou 1608 Stock             Company Yamagishi AIC (72) Inventor Masaaki Mizuno             Nagano Prefecture Shimoina-gun Shimojo Village Yosou 1608 Stock             Company Yamagishi AIC (72) Inventor Masayuki Sakurai             1-31-1 Nishigotanda, Shinagawa-ku, Tokyo Sun             Standing AIC Co., Ltd. F term (reference) 5E315 AA05 AA11 CC14 CC21 DD19                       DD20 DD25 GG13 GG14                 5E317 AA24 BB05 CC31 CD27 CD32                       GG03 GG14 GG16                 5F036 AA01 BB08 BC22

Claims (6)

[Claims] 1. A metal core wiring board having an electronic component mounted on at least one surface of an upper surface and a lower surface of a plate-shaped metal substrate, wherein a through hole is formed in a part of the metal substrate, and the metal substrate is provided above and below the metal substrate. Around the through hole on both sides,
Each of them has a groove formed therein, an insulating member is formed by filling the through hole and the groove with an insulating member, and a wiring pattern is formed on the surface of the insulating layer integrally filled in the through hole and the groove. A metal core wiring board characterized by that. 2. The metal core wiring board according to claim 1, wherein the wiring pattern formed on the surface of the filled insulating member is one of a through conductive hole, a non-through conductive hole, and a filled conductive hole. A metal core wiring board characterized by being one. 3. The metal core wiring board according to claim 1, wherein the wiring pattern formed on the surface of the filled insulating member is a flat through hole. 4. A method of manufacturing a metal core wiring board, in which electronic components are mounted on at least one surface of a plate-shaped metal substrate: (A) forming a through hole in a part of the plate-shaped metal substrate; (B) Grooves are formed around the through holes on the upper and lower surfaces of the metal substrate, respectively. (C) An insulating member is filled in the through holes and the groove to form an insulating layer, and D) A method of manufacturing a metal core wiring board, characterized in that a wiring pattern is formed on a surface of an insulating member that is integrally filled in the through hole and the groove. 5. The method of manufacturing a metal core wiring board according to claim 4, wherein in the step (B), the peripheries of the through holes on the upper and lower surfaces of the metal substrate are each half-etched. A method of manufacturing a metal core wiring board, wherein a groove is formed. 6. A circuit component using the metal core wiring board according to claim 1 or the metal core wiring board manufactured by the manufacturing method according to claim 4.
A heat-generating electronic component is mounted on a part of the metal core wiring board, and a terminal portion of the electronic component is formed on a surface of the insulating member that is integrally filled in the through hole and the groove portion of the metal core wiring board. A circuit component characterized by being electrically connected on a wiring pattern.