JP2010109036A - Printed circuit board and circuit device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed circuit board and a circuit device for reducing warp and weight of the board and improving heat radiating property. <P>SOLUTION: The printed circuit board includes a flat circuit board material 11, a through-hole 16 formed to the circuit board material 11, a copper chip 17 as a heat conductive member provided within the through-hole 16, wiring patterns 12, 13 formed on both surfaces of the circuit board material 11, and a heat generating element 14 mounted on the wiring pattern 12 at the front surface side as the one surface of the circuit board material 11. In the wiring pattern 13 at the rear surface side as the other surface of the circuit board material 11, a part provided opposed to the heat generating element 14 is formed thicker than the other part and the copper chip 17 is thermally connected to both heat generating element 14 and the thick wiring pattern 13a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printed circuit board and a circuit device.

In the prior art disclosed in Patent Document 1, an adhesive insulating layer containing a filler is provided on a metal base, and a multilayer circuit board is provided thereon. The multilayer circuit board has a thin circuit conductor formed on the surface of the wiring board and a thick circuit conductor formed on the back side. And the site | part in which the heat-emitting component of the thin circuit conductor of a surface is mounted is connected to the thick circuit conductor of the back side by the through hole.
With this configuration, heat from the heat generating component is transferred from the thin circuit conductor on the surface to the thick circuit conductor on the back side through the through hole, and from the thick circuit conductor through the adhesive insulating layer. It is said that heat is dissipated well by being transmitted to the metal base.
Japanese Patent Laid-Open No. 9-36553 (pages 3 to 4, FIG. 1)

  However, in the metal-based multilayer circuit board disclosed in Patent Document 1, since the thick circuit conductor is provided on the entire back side of the wiring board, it is caused by a difference in thermal expansion coefficient between the wiring board and the circuit conductor under high temperature conditions. There is a problem of warping of the multilayer circuit board. Further, since it is necessary to form a thick circuit conductor on the entire back side, there is a problem that the circuit board becomes heavy.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a printed circuit board and a circuit device capable of reducing warpage and weight of the circuit board and improving heat dissipation. It is in.

In order to achieve the above object, the invention according to claim 1 is a printed circuit board, in which a flat base material, a through hole formed in the base material, and a heat conductive member provided in the through hole are provided. A wiring pattern formed on both surfaces of the substrate, a mounting portion for mounting a heating element is formed on the wiring pattern on one surface of the substrate, and the wiring pattern on the other surface of the substrate A thick film part formed thicker than other parts is formed, and at least a part of the mounting part and at least a part of the thick film part are opposed to each other with the substrate interposed therebetween, and the heat conduction The conductive member is thermally connected to both the portion of the mounting portion that faces the thick film portion and the portion of the thick film portion that faces the mounting portion. In addition, the through hole in this invention refers to the hollow hole formed between the wiring pattern of the one side of a base material, and the wiring pattern of the other side, and the thing by which the inner surface is not plated is also included. The mounting portion refers to a place where the heating element is mounted in the wiring pattern.
According to the first aspect of the present invention, the wiring pattern on the other surface of the base material is formed with a thicker film portion formed thicker than the other portions, so that the entire thickness of the wiring pattern is formed. Compared to the case, warpage and weight of the substrate can be reduced. In addition, at least a part of the mounting portion of the heating element and at least a part of the thick film portion are opposed to each other with the base material interposed therebetween, and the heat conductive member is a portion facing the thick film portion of the mounting portion and the thick film portion When the heat generating element is mounted on the mounting part by thermally connecting to both the mounting part and the part facing the thick part, the heat generated by the heat generating element is thickened via the heat conductive member. Can be quickly transmitted to the part, and heat dissipation can be improved.

According to a second aspect of the present invention, in the printed circuit board according to the first aspect, the thick film portion is formed thicker than other portions of the wiring pattern on the other surface of the base material.
According to the invention of claim 2, the wiring pattern on the other side of the substrate has a thick film part formed thicker than the other part and a part formed thinner than the thick film part, Compared with the case where the entire thickness of the wiring pattern on the other side of the substrate is formed thicker, the warpage and weight of the substrate can be reduced.

According to a third aspect of the present invention, in the circuit device, a flat substrate, a through hole formed in the substrate, a heat conductive member provided in the through hole, and both surfaces of the substrate The wiring pattern formed and a heating element mounted on the wiring pattern on one side of the base material, and at least a part of the portion facing the heating element in the wiring pattern on the other side of the base material A thick film portion formed to be thicker than the thickness of the other portion is formed, and the thermally conductive member is formed on both the heating element and the portion of the thick film portion facing the heating element. It is characterized by being thermally connected. The heating element in the present invention refers to an element that generates a large amount of heat through a relatively large current, such as a power element for power control or a passive element.
According to the invention described in claim 3, the same effects as in claims 1 and 2 can be obtained.

According to a fourth aspect of the present invention, in the circuit device according to the third aspect, the thick film portion is connected to a heat radiating member.
According to the fourth aspect of the present invention, the heat generated by the heat generating element is transmitted to the thick film portion through the heat conductive member, and is transmitted to the heat radiating member connected to the thick film portion. Is possible.

According to a fifth aspect of the present invention, in the circuit device according to the fourth aspect, the connection to the heat radiating member is connected to the heat radiating member via a heat conductive sheet that is insulative and thermally conductive. It is characterized by that.
According to the invention described in claim 5, since it is connected to the heat radiating member via the heat conductive sheet having insulation and heat conductivity, the heat transmitted to the wiring pattern while maintaining the electric insulation. Can be promptly transmitted to the heat radiating member.

According to a sixth aspect of the present invention, in the circuit device according to any one of the third to fifth aspects, the wiring pattern on one surface of the base material is formed thinner than the thickness of the thick film portion, and the base material A non-heat-generating element is mounted on a portion other than the portion facing the thick film portion of the wiring pattern on one side.
According to the sixth aspect of the present invention, the non-heat generating element can be mounted on a portion other than the portion facing the thick film portion of the wiring pattern on one side of the base material. There is no need to provide a separate substrate, and cost and installation space can be reduced. In addition, since the non-heat-generating element is mounted on the thin part other than the part facing the thick film part, the heat resistance of the thin part is high, so the heat from the thick film part to the non-heat-generating element is high. Transmission can be suppressed. Therefore, the temperature rise of the non-heat generating element can be prevented. In addition, the non-heat generating element in the present invention refers to an element with a relatively small power and a small amount of heat generation, such as a signal control IC or a passive element.

A seventh aspect of the present invention is the circuit device according to any one of the third to fifth aspects, wherein the thickness of the portion facing the thick film portion of the wiring pattern on one side of the base material is other. The non-heat-generating element is mounted on a portion other than the portion facing the thick film portion of the wiring pattern on one side of the base material.
According to the seventh aspect of the present invention, the thickness of the portion facing the thick film portion is formed to be thicker than the thickness of the other portion, and the heating element is mounted on the thickly formed portion. Heat dissipation can be improved through the thick part. In addition, since the non-heat-generating element is mounted on the thin part other than the part facing the thick film part, the heat resistance of the thin part is high, so the heat from the thick film part to the non-heat-generating element is high. Transmission can be suppressed. Therefore, the temperature rise of the non-heat generating element can be prevented.

  According to the present invention, by forming a part of the wiring pattern on the substrate thick, it is possible to reduce the warpage and weight of the substrate and improve the heat dissipation.

(First embodiment)
Hereinafter, the circuit device according to the first embodiment will be described with reference to FIGS. FIG. 1 schematically shows a configuration of a circuit device, and some dimensions are exaggerated for easy understanding, and are different from actual dimensions.
As shown in FIG. 1, the circuit device 10 includes a flat and insulating circuit base material 11 made of an epoxy resin or the like as a base material, and a front side that is one side of the circuit base material 11 and a back side that is the other side. Conductive wiring patterns 12 and 13a, 13b are formed in the. On the wiring pattern 12 formed on the front side, a heating element 14 such as a power element and a non-heating element 15 such as a control IC are joined by solder. In the present embodiment, the non-heating element 15 is provided on the same substrate adjacent to the heating element 14. A place where the heating element 14 is mounted on the wiring pattern 12 corresponds to a mounting portion of the heating element 14.

A thick (thick film) wiring pattern 13 a corresponding to the thick film portion is formed on the back side of the circuit substrate 11 facing the heating element 14, and faces the non-heating element 15 of the circuit substrate 11. A thin (thin film) wiring pattern 13b is formed on the back side. In this embodiment, the wiring pattern 13a and the wiring pattern 13b are in a connected state.
The front wiring pattern 12 is a thin film pattern. The wiring patterns 12, 13 a, and 13 b are each formed in a desired shape on the front side and the back side of the circuit substrate 11 by etching the copper foil.

The circuit substrate 11 directly below the heating element 14 mounted on the circuit substrate 11 is formed with a large-diameter through-hole 16 having a circular cross section and corresponding to a heat conductive member in the through-hole 16. A cylindrical copper chip 17 is fitted and fixed. In a state where the copper chip 17 is fitted into the through hole 16, the front side and the back side of the copper chip 17 are formed flush with the front side and the back side of the circuit substrate 11. Wiring patterns 12 and 13a are formed on the front side and the back side. For this reason, the wiring pattern 12 on the front side to which the heating element 14 is bonded and the wiring pattern 13a on the back side are connected via the copper chip 17.
Further, as shown in FIG. 1, the thick wiring pattern 13 a is formed not only from the portion facing the copper chip 17 but also from the portion facing the copper chip 17 to the outside.

  The circuit substrate 11 directly below the non-heat generating element 15 mounted on the circuit substrate 11 is formed with a through hole 18 having a small cross-sectional shape and a small diameter, and copper plating is applied to the through hole 18. Yes. Thus, the front-side wiring pattern 12 to which the non-heat generating element 15 is connected and the back-side wiring pattern 13b are connected via the through hole 18.

Thus, the thickness of the wiring pattern 13a in the portion facing the heat generating element 14 in the backside wiring pattern 13 is thicker than the thickness of the wiring pattern 13b in the other portion.
This thick film wiring pattern 13a is connected to a metal heat radiating member 20 via a heat conductive sheet 19 that is insulative and heat conductive. The heat conductive sheet 19 is formed of a material such as an elastic resin.
The heat generated in the heat generating element 14 is conducted to the back side wiring pattern 13 a through the front side wiring pattern 12 and the copper chip 17, and is radiated to the heat radiating member 20 through the heat conductive sheet 19.

Next, the manufacturing procedure of the circuit device 10 will be described with reference to FIG.
First, in S101, the through holes 16 and 18 are formed through the circuit substrate 11 with a drill tool. The through hole 16 is formed using a large diameter drill tool, and the through hole 18 is formed using a small diameter drill tool.
Next, the copper chip 17 is fitted and fixed to the through hole 16 in S102. In this case, the outer diameter of the copper chip 17 is slightly larger than the inner diameter of the through hole 16, and the copper chip 17 is fitted into the through hole 16. The front side and the back side of the copper chip 17 are the front side and the back side of the circuit substrate 11. And fixed to be flush with each other.

Next, with the copper chip 17 fitted in the through-hole 16 in S103, the entire front side and back side are subjected to copper plating. The back side is thicker than the front side. Thereby, both end surfaces of the copper chip 17 are connected to the copper plating layer. Further, the copper plating process is also performed in the through hole 18.
Next, in S104, a thin wiring pattern 12 is formed on the front side of the circuit substrate 11 by etching. The wiring pattern 12 formed on the copper chip 17 is connected to the copper chip 17, and the wiring pattern 12 formed on the through hole 18 is connected to the through hole 18.

The formation of the wiring patterns 13a and 13b on the back side of the circuit substrate 11 is performed in two steps S105 and S106.
First, in S105, a mask is applied to the wiring pattern 13a on the back side of the circuit substrate 11, and etching is performed to the thickness of the wiring pattern 13b to form a thick film pattern and a thin film.
In step S106, the wiring patterns 13a and 13b are masked and the back side of the circuit substrate 11 is etched again. As a result, a thick film wiring pattern 13a and a thin film wiring pattern 13b are formed on the back side of the circuit base material 11, respectively. The wiring pattern 13 a formed under the copper chip 17 is connected to the copper chip 17, and the wiring pattern 13 b formed under the through hole 18 is connected to the through hole 18.

Next, in S107, the heating element 14 is disposed on the wiring pattern 12 on the copper chip 17 via solder, and the non-heating element 15 is disposed on the wiring pattern 12 on the through hole 18 via solder. The heating element 14 and the non-heating element 15 are soldered together by heating at a predetermined temperature in the furnace.
In step S108, the circuit board 11 is fixed to the heat radiating member 20 with screws (not shown) by interposing the heat conductive sheet 19 between the thick wiring pattern 13a on the back side and the heat radiating member 20. As a result, the wiring pattern 13 a is connected to the heat radiating member 20 through the heat conductive sheet 19.

Next, the operation of the circuit device 10 having the above configuration will be described with reference to FIG.
When the heating element 14 such as a power element operates, it generates a large amount of heat. As shown in FIG. 3A, the heat generated in the heating element 14 is transmitted to the copper chip 17 through the wiring pattern 12 as shown by the arrow 21, and the wiring pattern 13 a on the back side connected to the copper chip 17. Is transmitted to.
The heat transferred to the wiring pattern 13 a on the back side is transferred to the heat radiating member 20 through the heat conductive sheet 19 as indicated by an arrow 22.
By the way, since the wiring pattern 13a is formed of a thick film, the heat capacity of the wiring pattern 13a itself can be increased, so that the heat from the copper chip 17 can be effectively absorbed into the wiring pattern 13a, and The cross-sectional area of the heat transfer path passing through the pattern 13a is widened, and a part of the heat transferred to the wiring pattern 13a is in the direction indicated by the arrow 23 parallel to the substrate surface of the circuit substrate 11 in the wiring pattern 13a. Effectively spread and transmitted.
Then, the heat transmitted by diffusing in the wiring pattern 13 a is radiated to the heat radiating member 20 through the heat conductive sheet 19 as indicated by an arrow 24.

On the other hand, in the comparative example shown in FIG. 3B, the wiring pattern 13c on the back side is formed of a thin film, and the other configuration is the same as the above configuration.
In this case, the heat transferred to the wiring pattern 13 c on the back side is transferred to the heat radiating member 20 through the heat conductive sheet 19 as indicated by an arrow 26.
By the way, since the wiring pattern 13c is formed of a thin film, a part of the heat transferred to the wiring pattern 13c diffuses in the direction indicated by the arrow 27 parallel to the substrate surface of the circuit substrate 11 in the wiring pattern 13c. However, since the wiring pattern 13c is a thin film, the heat capacity is small, and the heat transmission path in the direction parallel to the substrate surface is narrow as shown by the arrow 27, and is shown in FIG. Since the thermal resistance is higher than that of the form, the amount of heat transferred from the heating element 14 to the heat radiating member 20 is small compared to the form shown in FIG.

As described above, in the first embodiment shown in FIG. 3A, the back side wiring pattern 13a is formed of a thick film, so that heat is effectively diffused, and the heat conductive sheet 19 has a large area. The heat radiating member 20 can dissipate heat via That is, by expanding the cross-sectional area of the heat transfer path in the direction parallel to the substrate surface in the wiring pattern 13a, the thermal resistance between the heat generating element 14 and the heat radiating member 20 can be reduced, and the heat dissipation is improved. Can be achieved.
On the other hand, the thin-film wiring pattern 13b formed adjacent to the wiring pattern 13a has a small heat capacity and a high thermal resistance. Therefore, heat conduction to the non-heat generating element 15 connected to the wiring pattern 13b can be suppressed.

  Further, in the wiring pattern 13 formed on the back side of the circuit substrate 11, the thickness of the portion facing the heating element 14 is formed to be thicker than the thickness of the other portions. When the thickness of the entire wiring pattern 13 on the back side is formed thick as in the prior art, there is a risk that the substrate warps due to the difference in thermal expansion coefficient between the circuit substrate 11 and the wiring pattern 13. Since only a part of the wiring pattern 13 on the back side is thick, the warpage of the substrate can be reduced.

The circuit device 10 according to the first embodiment has the following effects.
(1) Of the wiring pattern 13 formed on the back side of the circuit substrate 11, the thickness of the portion facing the heating element 14 is formed to be thicker than the thickness of the other portions. Compared with the case where the thickness is increased, the warpage of the substrate can be reduced and the weight of the substrate can be reduced.
(2) A through hole 16 is formed through the circuit substrate 11 directly below the heating element 14 mounted on the circuit substrate 11, and a copper chip 17 is fitted and fixed in the through hole 16. Of the wiring pattern 13 formed on the back side of the circuit substrate 11, the thickness of the wiring pattern 13a at the portion facing the heating element 14 is formed as a thick film. Therefore, the heat capacity of the wiring pattern 13a itself can be increased and the thermal resistance can be reduced by increasing the cross-sectional area of the heat transfer path passing through the wiring pattern 13a. 12 is quickly absorbed and transmitted to the wiring pattern 13a on the back side through the copper chip 17 and the copper chip 17, and after being diffused in the wiring pattern 13a, it is effectively applied to the heat radiation member 20 through the heat conductive sheet 19 in a large area. Heat can be dissipated. Therefore, by expanding the heat radiation area to the heat radiating member 20, the thermal resistance between the heat generating element 14 and the heat radiating member 20 can be reduced, and the heat dissipation can be improved.
(3) When the circuit substrate 11 is attached to the heat radiating member 20, the heat conductive sheet 19 having elasticity is interposed between the wiring pattern 13 a on the back side of the circuit substrate 11 and the heat radiating member 20. Therefore, the adhesiveness between the circuit substrate 11 and the heat dissipation member 20 can be improved, and the heat dissipation effect can be further improved.
(4) Since the non-heat generating element 15 can be mounted on the circuit base material 11 in addition to the heat generating element 14, it is not necessary to newly provide a substrate for mounting the non-heat generating element 15, and cost and installation space can be reduced. It is.
(5) Since the non-heat generating element 15 is mounted in connection with the thin-film wiring pattern 13b, heat transfer through the wiring pattern 13b is suppressed, and the temperature rise of the non-heating element 15 can be prevented.

(Second Embodiment)
Next, the circuit device 30 according to the second embodiment will be described with reference to FIG.
In this embodiment, the shape of the copper chip 17 in the first embodiment is changed, and other configurations are common.
Therefore, here, for convenience of explanation, some of the reference numerals used in the previous explanation are used in common, explanation of common configurations is omitted, and only the changed parts are explained.

  As shown in FIG. 4, in the state where the copper chip 33 is fitted in the through hole 16, the front side of the copper chip 33 is formed flush with the front side of the circuit substrate 31, but the back side of the copper chip 33 is a circuit. It is formed to protrude from the back side of the base material 31. A thick wiring pattern 32 a is formed around the protruding copper chip 33. The amount of protrusion to the back side of the copper chip 33 is formed so as to protrude from the circuit base 31 in advance so as to be equal to the film thickness of the wiring pattern 32a, and the wiring pattern 32a is plated with copper around the protruding copper chip 33. And when it is formed by etching, it has the same height. The thin wiring pattern 32b is formed in the same manner as the wiring pattern 13b in the first embodiment.

Thus, by providing the copper chip 33 protruding on the back side, the contact area between the copper chip 33 and the wiring pattern 32a can be increased, and the copper chip 33 and the wiring pattern 32a can be reliably bonded. It is. Further, since the copper chip 33 and the heat radiating member 20 are directly connected via the thermal conductive sheet 19, a part of the heat transferred from the heating element 14 through the copper chip 33 is connected to the copper chip 33. It can be directly transmitted to the heat dissipation member 20 via the thermal conductive sheet 19 without passing through the joint portion with the wiring pattern 32a, and even when the thermal resistance is increased due to the joint failure of the joint portion, the heat dissipation is improved. Can be planned.
About other than that, since an effect equivalent to 1st Embodiment can be acquired, description is abbreviate | omitted.

(Third embodiment)
Next, a circuit device 40 according to a third embodiment will be described with reference to FIG.
In this embodiment, the shape of the surface wiring pattern 12 in the first embodiment is changed, and other configurations are common.
Therefore, here, for convenience of explanation, some of the reference numerals used in the previous explanation are used in common, explanation of common configurations is omitted, and only the changed parts are explained.

  As shown in FIG. 5, the wiring pattern 42 formed on the front side of the circuit substrate 41 is composed of two types of wiring patterns 42a and 42b having different thicknesses, and the heating element 14 is mounted on the thick wiring pattern 42a. The non-heat generating element 15 is mounted on the thin film wiring pattern 42b. Of the wiring pattern 13 formed on the back side of the circuit substrate 41, the non-heat generating element 15 is mounted on the thin-film wiring pattern 13b.

In this way, two types of wiring patterns having different thicknesses are formed on both surfaces of the circuit substrate 41, and the front-side wiring pattern 42a joined to the heating element 14 is formed of a thick film. The generated heat is transmitted to the wiring pattern 13a on the back side through the wiring pattern 42a and the copper chip 17, and at the same time, the inside of the wiring pattern 42a on the front side is directed in the direction indicated by the arrow 43 parallel to the substrate surface of the circuit substrate 41. Spread and transmitted. And since a part of the heat diffused and transmitted in the wiring pattern 42a is directly radiated to the outside air, the heat dissipation of the heating element 14 can be improved.
Further, since the non-heat generating element 15 can be mounted on the thin film wiring pattern 13b on the back side in addition to the thin film wiring pattern 42b on the front side of the circuit substrate 41, the substrate size can be further reduced.
About other than that, since an effect equivalent to 1st Embodiment can be acquired, description is abbreviate | omitted.

(Fourth embodiment)
Next, a circuit device 50 according to a fourth embodiment will be described with reference to FIGS.
In this embodiment, the manufacturing procedure of the circuit device 10 in the first embodiment is changed.
Therefore, here, for convenience of explanation, some of the reference numerals used in the previous explanation are used in common, explanation of common configurations is omitted, and only the changed parts are explained.

As shown in FIG. 6, in the circuit device 50, the through-hole 16 is plated and the wiring patterns 52 and 53 a are formed on the front and back surfaces of the circuit substrate 51, and then the copper chip 55 is fitted and fixed. A plated layer 54 is formed on the inner surface of the through hole 16, and the wiring patterns 52, 53 a on the front and back surfaces are connected via the plated layer 54.
In a state where the copper chip 55 is fitted in the through hole 16, the front side and the back side of the copper chip 55 are formed so as to be flush with the wiring patterns 52 and 53 a on the front surface and the back surface of the circuit substrate 51. The heating element 14 is soldered to the front side of the copper chip 55 and the wiring pattern 52 formed on the same surface, and the heat conductive sheet 19 is interposed on the back side of the copper chip 55 and the wiring pattern 53a formed on the same surface. The heat radiating member 20 is attached and fixed.

As shown in FIG. 7, the manufacturing procedure of the circuit device 50 is as follows. After the through holes 16 and 18 are formed through the circuit substrate 51 with a drill tool in S201, the copper chip 55 is inserted into the through hole 16 in S202. Copper plating is applied to the entire surface of the front side and the back side without fitting. At this time, the plated layer 54 is formed in the through hole 16. Next, in S203, a thin wiring pattern 52 is formed on the front side of the circuit substrate 51 by etching, and then wiring patterns 53a and 53b are formed on the back side of the circuit substrate 11 in two steps S204 and S205.
In S206, the copper chip 55 is fitted into the through hole 16 and fixed. In this case, the front and back sides of the copper chip 55 are fixed so as to be flush with the wiring patterns 52 and 53a on the front and back surfaces of the circuit substrate 51. The height dimension of the copper chip 55 is set in advance in consideration of the film thickness of the wiring patterns 52 and 53a on the front surface and the back surface.

  Next, in S207, the heating element 14 is joined to the front side of the copper chip 55 and the wiring pattern 52 via solder. Next, in step S <b> 208, the circuit board 51 is fixed to the heat radiating member 20 with screws (not shown) by interposing the heat conductive sheet 19 between the back side of the copper chip 55 and the thick wiring pattern 53 a and the heat radiating member 20. . As a result, the copper chip 55 and the wiring pattern 53 a are connected to the heat radiating member 20 through the heat conductive sheet 19.

  As described above, in this embodiment, the plated layer 54 is formed on the inner surface of the through hole 16, and the copper chip 55 is protruded and fixed by the film thickness of the front surface and the back surface. The heat generated in step 1 can be transmitted to the wiring pattern 53a on the back side and the heat conductive sheet 19 through the copper chip 55 and the plating layer 54, and the heat dissipation of the heat generating element 14 can be further improved.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.
In the first to fourth embodiments, the copper chips 17, 33, 55 have been described as the heat conductive members provided in the through holes 16, but copper paste may be used, and other metal materials other than copper, It is good also as a conductive resin member containing a conductive filler.
In the first to fourth embodiments, the circuit base materials 11, 31, 41, 51 have been described as a single layer configuration, but a multilayer configuration may be used.
In the first to fourth embodiments, the cross-sectional shape of the through hole 16 is a round hole, but it may be a rectangular hole or an irregular hole. In this case, the outer shape of the copper chip fitted into the through hole 16 is a rectangular prism or an irregular prism.
In the first and second embodiments, the heating element 14 is described as being bonded on the front wiring pattern 12, but the heating element 14 is bonded directly on the copper chips 17 and 33 without the wiring pattern 12 being interposed. May be.
In the first embodiment, it has been described that the thick wiring pattern 13a is formed not only from the portion facing the copper chip 17 but also from the portion facing the copper chip 17 to the outside. Only a portion facing 17 may be formed of a thick film, or only a portion of a portion facing copper chip 17 may be formed of a thick film.
In the first to fourth embodiments, the thick wiring patterns 13a, 32a, 53a formed on the back surface and the thin wiring patterns 13b, 32b, 53b are described as being connected to each other. It may be formed separately without being connected.
In the fourth embodiment, it has been described that the front side and the back side of the copper chip 55 are formed so as to be flush with the front and back wiring patterns 52 and 53a of the circuit substrate 51. The front side and the back side are formed so as to be flush with the front side and the back side of the circuit base 51, and the conductive member is formed by plating or the like between the heating element 14 and the copper chip and between the copper chip and the heat conductive sheet 19. The conductive member may be formed so as to be flush with the wiring patterns 52 and 53a.
In the first and second embodiments, the front side wiring pattern 12 and the back side wiring pattern 13a have been described as being electrically and thermally connected via the copper chips 17 and 33, but the present invention is not limited to this. However, the heat generating element 14 and the thick wiring pattern 13a may be thermally connected via the copper chips 17 and 33, and other configurations may be employed. For example, the wiring pattern 12 on the front side may be configured not to be connected to the copper chips 17 and 33, or may be an insulating and thermally conductive member instead of the copper chips 17 and 33.

1 is a cross-sectional view illustrating a schematic configuration of a circuit device according to a first embodiment. It is a flowchart which shows the manufacture procedure of the circuit device which concerns on 1st Embodiment. It is a schematic diagram for explaining the operation of the circuit device according to the first embodiment. (A) The schematic diagram of 1st Embodiment, (b) The schematic diagram of a comparative example. It is sectional drawing which shows schematic structure of the circuit apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows schematic structure of the circuit apparatus which concerns on 3rd Embodiment. It is sectional drawing which shows schematic structure of the circuit apparatus which concerns on 4th Embodiment. It is a flowchart which shows the manufacture procedure of the circuit device which concerns on 4th Embodiment.

Explanation of symbols

10, 30, 40, 50 Circuit devices 11, 31, 41, 51 Circuit base materials 12, 42 (42a, 42b), 52 Front side wiring patterns 13 (13a, 13b), 32 (32a, 32b), 53 (53a) 53b) Back side wiring patterns 12, 13b, 32b, 42b, 52, 53b Thin wiring pattern 13a, 32a, 42a, 53a Thick film wiring pattern 14 Heating element 15 Non-heating element 16, 18 Through hole 17, 33, 55 Copper Chip 19 Thermal Conductive Sheet 20 Heat Dissipation Member

Claims (7)

A flat substrate, a through hole formed in the substrate, a thermally conductive member provided in the through hole, and a wiring pattern formed on both surfaces of the substrate;
A mounting portion for mounting a heating element is formed on the wiring pattern on one surface of the base material, and a thick film portion formed thicker than the other portion is formed on the wiring pattern on the other surface of the base material. And
At least a part of the mounting part and at least a part of the thick film part are opposed to each other with the base material interposed therebetween, and the thermally conductive member is a part of the mounting part that faces the thick film part and the thickness. A printed circuit board characterized in that it is thermally connected to both the part of the film part facing the mounting part. The printed circuit board according to claim 1, wherein the thick film portion is formed thicker than other portions of the wiring pattern on the other surface of the base material. A flat substrate, a through hole formed in the substrate, a heat conductive member provided in the through hole, a wiring pattern formed on both surfaces of the substrate, and one of the substrates A heating element mounted on the wiring pattern in the direction,
Of the wiring pattern on the other side of the base material, a thick film part is formed in which the thickness of at least a part of the part facing the heating element is thicker than the thickness of the other part,
The circuit device, wherein the thermal conductive member is thermally connected to both the heating element and a portion of the thick film portion facing the heating element. The circuit device according to claim 3, wherein the thick film portion is connected to a heat dissipation member. The circuit device according to claim 4, wherein the connection to the heat radiating member is connected to the heat radiating member through a heat conductive sheet that is insulative and thermally conductive. The wiring pattern on one side of the substrate is formed thinner than the thickness of the thick film portion, and a non-heat generating element is mounted on a portion other than the portion facing the thick film portion of the wiring pattern on the one surface of the substrate. The circuit device according to claim 3, wherein the circuit device is a circuit device. Of the wiring pattern on one side of the base material, the portion facing the thick film portion is formed thicker than the thickness of the other portion, and the thick film portion of the wiring pattern on one side of the base material The circuit device according to any one of claims 3 to 5, wherein a non-heat generating element is mounted on a portion other than the facing portion.