JP3266505B2 - Multilayer circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer circuit board used as a circuit board in electronic circuit modules and the like of various electronic devices and devices.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for various electronic devices and electronic devices to be reduced in size, thickness, and functionality, and accordingly, electronic devices and electronic devices have been used for electronic circuit modules. There is also a strong demand for small, thin, high-density circuit boards as well as for high-performance signal processing.

[0003] Such a circuit board generally uses a multilayer circuit board mainly composed of a ceramic material such as alumina. In order to further reduce the size and density of the circuit board, an integrated circuit (IC) is required. 2. Description of the Related Art A multilayer circuit board employing a chip-on-board (COB) technique for mounting a semiconductor element such as a circuit) directly on a board and mounting the semiconductor element on the board has been widely used.

On the other hand, since a ceramic material mainly containing alumina (Al ₂ O ₃ ) must be fired at a high temperature of about 1400 to 1650 ° C., it is difficult to form a wiring pattern inside a multilayer circuit board. Tungsten (W) and molybdenum (Mo), which are high melting point metals, had to be used. However, since these high-melting metals have high specific resistance, there has been a problem that an electronic circuit for performing high-speed signal processing cannot be configured with a wiring pattern using them.

On the other hand, a low-temperature fired multilayer circuit board made of a substrate material obtained by adding an inorganic filler such as alumina to glass frit has been proposed and put into practical use. In this low-temperature fired multilayer circuit board, gold (A
u) -based, silver (Ag) -based and copper (Cu) -based metal materials having a low melting point and a small specific resistance can be used, thereby realizing a circuit board for high-speed signal processing. Development for miniaturization, higher density, and lower cost is being pursued for practical use in the consumer electronics field.

Since the amount of heat generated by the semiconductor element mounted on the circuit board has increased with the miniaturization, high density, and high power of the element, the heat is transferred to the inside of the circuit board immediately below the semiconductor element mounting portion. By providing a large number of via holes for the purpose of heat conduction for promoting heat radiation, that is, thermal via holes, thermal destruction of semiconductor elements and deterioration of reliability have been prevented.

As an example of a multilayer circuit board having such thermal via holes formed therein, for example, Japanese Utility Model Laid-Open No. 3-96075 discloses an integrated circuit 1 and a multilayer mounting the integrated circuit 1 as shown in a sectional view of FIG. The integrated circuit 1 includes a printed board 2, a plurality of conductor holes (thermal via holes) 5 connected to the component side pattern 3 and the back side pattern 4 of the multilayer printed board 2, and the integrated circuit 1 is mounted on the component side pattern 3. There has been proposed an integrated circuit heat dissipation mounting structure in which heat generated from the inner layer pattern 6 and the back surface pattern 4 of the multilayer printed circuit board 2 is radiated through the conductor holes 5. Reference numeral 7 denotes a soldered portion that also serves as heat dissipation of the integrated circuit 1, and the back surface pattern 4 and the inner layer pattern 6 are usually power supply patterns or ground patterns. According to this, the mounting of the integrated circuit 1 is simplified, and the effect that the mounting area can be reduced can be obtained by further reducing the mounting area.

[0008]

In a conventional multilayer circuit board, as disclosed in Japanese Utility Model Application Laid-Open No. 3-96075, the surface of the multilayer printed board 2 on which the integrated circuit 1 is mounted is conventionally the same as the integrated circuit 1. A component surface pattern 3, which is a conductor wiring having an area larger than the bonding area of the integrated circuit 1, is provided to electrically connect the circuit board and the multilayer printed circuit board 2, and a large number of conductors immediately below the mounting portion are provided by the component surface pattern 3. The structure was such that all the holes 5 were covered. Therefore, when mounting the integrated circuit 1,
It is necessary to perform image recognition of the component surface pattern 3 on the surface of the multilayer printed circuit board 2 near the mounting position and an image recognition mark (not shown) separately formed in the vicinity thereof to position the integrated circuit 1.

On the other hand, as the miniaturization of the semiconductor element (integrated circuit 1) progresses, the formation density of thermal via holes (conductor holes 5) formed in the semiconductor element mounting portion of the multilayer circuit board is approaching its limit. In order to make full use of the limited thermal density via holes, it is necessary to improve the mounting accuracy of the semiconductor element.

However, when the conductor hole 5 is covered with the component pattern 3 formed thereon as in the prior art, a large number of conductor holes are provided immediately below the integrated circuit 1 as shown in FIG. It is difficult to accurately position the integrated circuit 1 with respect to the conductor hole 5 in order to dispose the integrated circuit 5 with high accuracy. Due to variations in the manufacture of the substrate 2 and variations in the mounting accuracy of the integrated circuit 1, the plane shown in FIG. As shown in the figure, there is a problem that the integrated circuit 1 is mounted so as to be shifted from the arrangement of the conductor holes 5. Such misalignment of the semiconductor element deteriorates the heat radiation state of the semiconductor element, and in the worst case, the semiconductor element exceeds the maximum rated junction temperature, so that the original performance of the semiconductor element cannot be sufficiently exhibited. As a result, There is a problem that the function as an electronic circuit module is reduced.

The positional deviation between such a semiconductor element and a thermal conductive member such as a thermal via hole is caused by the positional deviation of the surface wiring of the multilayer circuit board, the formation accuracy of the thermal via hole, the positional accuracy of the internal and surface wiring, and the multilayer structure. As a result of the lamination accuracy of each layer of the circuit board being accumulated, it cannot be ignored and appears as the above-mentioned problem.

The present invention has been accomplished in view of the above problems and has been accomplished by the inventors of the present invention. The object of the present invention is to generate heat from the semiconductor element when mounting the semiconductor element on a multilayer circuit board. A multi-layer circuit that can accurately and reproducibly arrange a large number of heat conducting members arranged on the semiconductor element mounting part directly under the semiconductor element in order to efficiently conduct heat to heat conduction members such as thermal via holes and radiate heat. It is to provide a substrate.

[0013]

According to a first aspect of the present invention, there is provided a multilayer circuit board comprising a plurality of low-temperature fired ceramic layers stacked on each other, and a multilayer board formed on a surface of the multilayer board.
A mounting portion conductor layer on which a semiconductor element is partially mounted, a back surface conductor layer formed on the back surface of the laminated substrate facing the mounting portion conductor layer, and the mounting portion for conducting heat generated from the semiconductor element; Disposed through the laminated substrate from a part of the partial conductor layer to an outer peripheral region of a mounting position of the semiconductor element,
A multilayer circuit board comprising a plurality of heat conductive members for connecting the mounting portion conductive layer and the back surface conductive layer, wherein at least one of the plurality of heat conductive members is located outside a semiconductor element mounted on the mounting portion conductive layer. An end surface of the heat conduction member is exposed inside the mounting portion conductor layer on the surface of the laminated substrate by partitioning the mounting portion conductor layer.

According to a second aspect of the present invention, there is provided the multilayer circuit board according to the first aspect, wherein each of the plurality of heat conducting members is formed of a low-temperature fired ceramic forming the laminated substrate. It is characterized by being connected via an inner conductor layer disposed between the layers.

Further, the multilayer circuit board according to the third aspect of the present invention is the multilayer circuit board according to the second aspect,
Outside the region in which the plurality of heat conducting members are provided in the laminated substrate, a plurality of auxiliary heat conducting members are arranged so as to penetrate the low-temperature fired ceramic layer from the inner conductor layer to the back conductor layer. It is characterized by being provided.

Further, the multilayer circuit board according to a fourth aspect of the present invention is the multilayer circuit board according to the third aspect, wherein at least two or more inner conductor layers are provided, and The number of the auxiliary heat conductive member between the back heat conductive layer and the back heat conductive member is increased toward the back conductive layer side and outside the region where the auxiliary heat conductive member is provided. Is what you do.

According to the multilayer circuit board of the present invention, in order to conduct heat generated from the semiconductor element, the laminated board extends from a part of the mounting portion conductive layer on which the semiconductor element is mounted to an outer peripheral area of the mounting position of the semiconductor element. At least one of the plurality of heat conducting members disposed to penetrate and connect the mounting portion conductor layer and the back surface conductor layer is located outside the semiconductor element mounted on the mounting portion conductor layer. By exposing the end face inside the mounting part conductor layer on the surface of the laminated substrate, the heat conduction member disposed under the mounting part conductor layer with the end face of the heat conducting member as a mark. Since the position of the member can be grasped, for example, by using it as an image recognition mark when deciding the mounting position of the semiconductor element, a large number of heat conductive members arranged in the semiconductor element mounting portion can be directly under the semiconductor element. Accuracy, and so as to cause reproducibly arrangement, it is possible to mount the semiconductor element. As a result, heat generated from the semiconductor element can be efficiently conducted and radiated by the plurality of heat conducting members, so that the temperature rise of the semiconductor element can be suppressed as desired, and the semiconductor element inherently has an increased temperature. It is possible to provide a highly reliable multilayer circuit board that can sufficiently exhibit performance and sufficiently maintain the function as an electronic circuit module.

The operation and effect of the present invention can be sufficiently obtained if the number of the heat conducting members for exposing the end face is at least one. Since the angle correction can be performed more easily by using the end faces of the heat conducting members, it is a more preferable embodiment of the present invention. In this case, there is no particular limitation on the positional relationship of the heat conducting members exposing the end faces, and if the positional relationship is clear in advance, the mounting position of the semiconductor element can be accurately controlled.

Further, according to the multilayer circuit board of the second aspect of the present invention, each of the plurality of heat conducting members is connected via the inner conductor layer disposed between the low-temperature fired ceramic layers forming the laminated board. Therefore, the heat conduction by the plurality of heat conducting members can be more efficiently conducted through the inner conductor layer, and the heat generated from the semiconductor element can be more efficiently radiated.

Further, according to the multi-layer circuit board according to the third aspect of the present invention, in the multi-layer circuit board according to the second aspect, the plurality of auxiliary heat conductive members are provided with the plurality of heat conductive members. Since the low-temperature-fired ceramic layer is disposed outside the inner conductor layer and extends from the inner conductor layer to the back-surface conductor layer, the heat diffused into the low-temperature-fired ceramic layer around the heat conductive member is transferred to the auxiliary heat conductive member. As a result, the heat can be efficiently transmitted to the back conductor layer, so that the heat generated from the semiconductor element can be further efficiently radiated.

Further, according to the multilayer circuit board according to the fourth aspect of the present invention, in the multilayer circuit board according to the third aspect, at least two or more inner-layer conductor layers are provided and each inner-layer conductor layer is provided. The number of the auxiliary heat conducting members between the layer and the back conductor layer is increased toward the back conductor layer and toward the outside of the region where the auxiliary heat conducting member is provided, that is, Since the auxiliary heat conductive member is arranged stepwise or pyramid-shaped toward the back conductor layer side, the auxiliary heat conductive member is gradually diffused around the heat conductive member from the mounting portion of the semiconductor element toward the back surface of the laminated substrate. Since the heat generated from the semiconductor element that conducts through the low-temperature fired ceramic layer can be more efficiently transmitted to the back conductor layer, the heat generated from the semiconductor element can be more efficiently and stably radiated. It shall be, operations and functions of the semiconductor device becomes very stable and highly reliable multilayer circuit board.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a multilayer circuit board according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing the vicinity of a semiconductor element mounting portion showing one embodiment of the multilayer circuit board of the present invention, and FIG. 2 is a sectional view taken along line AA 'in FIG. In these figures, reference numeral 11 denotes a laminated substrate formed by laminating a plurality of low-temperature fired ceramic layers 12, on the surface of which a mounting portion conductor layer 14 on which a semiconductor element 13 is mounted on a part thereof, and a mounting portion conductor layer 14. Tier 14
A back surface conductor layer 15 is formed on the back surface opposite to. Although FIGS. 1 and 2 show an example in which the cavity 11a for mounting the semiconductor element 13 is formed on the upper surface of the laminated substrate 11, this cavity 11a is not always necessary, and A layer 14 is provided on the surface of the uppermost low-temperature fired ceramic layer 12 of the laminated substrate 11 to form a semiconductor device.
13 may be mounted on the outermost surface of the laminated substrate 11.

Reference numeral 16 denotes a heat conductive member, which extends from the portion of the mounting portion conductor layer 14 where the semiconductor element 13 is mounted to the outer peripheral region of the mounting position of the semiconductor element 13, penetrates the laminated substrate 11, and A plurality is provided so as to connect the heat generated from the semiconductor element 13 to the back conductor layer 15 so as to connect the back conductor layer 15 to the back conductor layer 15. Depending on the dimensions of the semiconductor element 13 to be mounted, the calorific value, the processing accuracy of the laminated substrate 11, and the like, the plurality of heat conductive members 16 may be, for example, in a lattice shape or a staggered shape so as to contribute to heat radiation most efficiently. , Are arranged with predetermined positional accuracy. The heat conducted to the back conductor layer 15 by the plurality of heat conducting members 16 is transmitted to a mother board, a radiating fin, or the like on which the multilayer circuit board is mounted, and is radiated.

In the multilayer circuit board according to the present invention, the end face of at least one heat conductive member 16 located outside the semiconductor element 13 mounted on the mounting portion conductor layer 14 of the heat conductive member 16 is mounted on the mounting portion. It is characterized in that it is separated from the conductor layer 14 and is exposed inside the mounting portion conductor layer 14 on the surface of the laminated substrate 11. In this embodiment, two semiconductor elements 13 are arranged substantially diagonally across the semiconductor element 13. An example is shown in which the end surfaces of the heat conducting members 16a and 16b are exposed.

Therefore, these heat conducting members 16a or 16b
The position of the plurality of heat conducting members 16 disposed under the mounting portion conductor layer 14 can be grasped by using the end surface of the semiconductor device 13 as a mark, and the heat conduction as an image recognition mark when determining the mounting position of the semiconductor element 13 can be understood. By using the end face of the member 16a or 16b, a large number of the heat conducting members 16 arranged on the semiconductor element mounting portion can be accurately arranged directly under the semiconductor element 13 with good reproducibility. The heat generated by the heat conduction member 16 can be efficiently conducted and radiated.

FIG. 2 shows a low-temperature fired ceramic layer as a multilayer circuit board according to a second aspect of the present invention.
An example is shown in which an inner conductor layer 17 is formed between layers 12, and a heat conductive member 16 is connected via the inner conductor layer 17. In the multilayer circuit board according to claim 1 of the present invention, the inner conductor layer 17 is not necessarily required, but even in such a case, the semiconductor element 13 can be accurately positioned with respect to the heat conducting member 16. It goes without saying that heat is efficiently dissipated by the heat conducting member 16. When the inner conductor layer 17 is provided, the heat conduction by the heat conducting member 16 can be performed more efficiently through the inner conductor layer 17.

Further, in the present embodiment, various conductive patterns 18 disposed on the surface or inside of the laminated substrate 11 are shown, while various mounted components mounted on the surface of the laminated substrate 11 are not shown. These are appropriately arranged and mounted according to the specifications of the multilayer circuit board.

Reference numeral 19 denotes a conductive connecting portion which also serves as heat radiation of the semiconductor element 13, and is made of brazing material, Au-Si, Au-Sn, Pb.
A high thermal conductivity material such as a metal bonding agent such as -Sn or a conductive resin paste such as Ag-epoxy is used. Then, each electrode of the semiconductor element 13 is electrically connected to circuit pattern wiring such as the mounting portion conductor layer 14 and the conductor pattern 18 by wire bonding or the like, and further, if necessary, the semiconductor element 13 is sealed with a molding resin or the like. Then, the desired electronic circuit module is obtained.

Next, another embodiment of the multilayer circuit board of the present invention will be described in detail with reference to FIGS.

FIG. 3 is a plan view showing the vicinity of a semiconductor element mounting portion showing another embodiment of the multilayer circuit board of the present invention, and FIG. 4 is a sectional view taken along line BB 'of FIG.

3 and 4, reference numeral 21 denotes a laminated substrate formed by laminating a plurality of low-temperature fired ceramic layers 22;
A mounting portion conductor layer 24 on which the semiconductor element 23 is mounted on a part thereof is formed on the front surface, and a back surface conductor layer 25 is formed on the back surface facing the mounting portion conductor layer 24. 3 and 4
Cavity 21 for mounting the semiconductor element 23
Although the example in which “a” is formed on the upper surface of the laminated substrate 21 is shown, the semiconductor element 23 may be mounted on the outermost surface of the laminated substrate 21 as described above.

Reference numeral 26 denotes a heat conducting member, which extends from a portion of the mounting portion conductor layer 24 on which the semiconductor element 23 is mounted to an outer peripheral region of the mounting position of the semiconductor element 23, penetrates the laminated substrate 21, and A plurality is provided so as to connect the heat generated from the semiconductor element 23 to the back conductor layer 25 so as to connect the back conductor layer 25 to the back conductor layer 25. Depending on the dimensions of the semiconductor element 23 to be mounted, the amount of heat generated, and the processing accuracy of the laminated substrate 21, the plurality of heat conductive members 26 may also be used, for example, in a lattice shape or a staggered shape so as to contribute to heat radiation most efficiently. , Are arranged with predetermined positional accuracy. The end surface of at least one heat conductive member 26 located outside the semiconductor element 23 mounted on the mounting portion conductor layer 24 of the heat conductive member 26 is separated from the mounting portion conductor layer 24 to form a surface of the laminated substrate 21. In the present embodiment, four heat conducting members 26a to 26c are arranged in a substantially square shape so as to surround the semiconductor element 23.
The end face of 26d is exposed.

Accordingly, the positions of the plurality of heat conductive members 26 disposed under the mounting portion conductor layer 24 can be grasped by using the end faces of the heat conductive members 26a to 26d as marks, and the mounting of the semiconductor element 23 can be grasped. By using the end surfaces of the heat conductive members 26a to 26d as image recognition marks when determining the position, the heat conductive members 26 provided in a large number on the semiconductor element mounting portion can be connected to the semiconductor element.
23 can be accurately and reproducibly disposed directly below the heat conduction member 26,
Thus, heat can be efficiently conducted and heat can be dissipated.

Further, in this embodiment, an inner conductor layer 27 is formed between the low-temperature fired ceramic layers 22, and a heat conducting member 26 is connected via the inner conductor layer 27.
A plurality of auxiliary heat conducting members 28 are disposed outside the region where the plurality of heat conducting members 26 are disposed from the inner conductor layer 27 to the back conductor layer 25.
The low temperature fired ceramic layer 22 is provided so as to pass through. As a result, the heat conduction by the heat conducting member 26 can be performed more efficiently via the inner conductor layer 27, and the low-temperature fired ceramic layer 22 around the heat conducting member 26 can be formed.
Since the heat diffused into the semiconductor element 23 can be efficiently conducted to the back conductor layer 25 by the auxiliary heat conducting member 28, the heat generated from the semiconductor element 23 can be radiated even more efficiently.

Furthermore, in the present embodiment, at least two or more inner conductor layers 27 are provided, and the number of auxiliary heat conducting members 28 between each inner conductor layer 27 and the back conductor layer 25 is determined by the number of back conductors. To the layer 25 side, and the auxiliary heat conducting member
It is arranged in a stepwise or pyramid-like manner outside the region where 28 are arranged. This allows
The heat generated from the semiconductor element 23 is conducted more efficiently through the low-temperature fired ceramic layer 22 so as to gradually diffuse from the mounting portion of the semiconductor element 23 toward the back surface of the laminated substrate 21 to the periphery of the heat conductive member 23. Since the heat can be conducted to the semiconductor device 25, heat generated from the semiconductor element 23 can be further efficiently and stably radiated.

The heat conducted to the back conductor layer 25 by the plurality of heat conducting members 16 and the auxiliary heat conducting members 28 is transmitted to a mother board, a radiating fin, and the like on which the multilayer circuit board is mounted and radiated. You.

In the present embodiment, various conductor patterns 29 are shown on the surface of or inside the laminated substrate 21. On the other hand, various mounted components mounted on the surface of the laminated substrate 21 are not shown. These are appropriately arranged and mounted according to the specifications of the multilayer circuit board.

Reference numeral 30 denotes a conductive connection portion which also serves as heat dissipation of the semiconductor element 23, and is made of the same high thermal conductivity material as the conductive connection portion 19 described above. Each electrode of the semiconductor element 23 is electrically connected to circuit pattern wiring such as the mounting portion conductor layer 24 and the conductor pattern 29 by wire bonding or the like, and the semiconductor element 23 is sealed with a molding resin or the like as necessary. Then, the desired electronic circuit module is obtained.

Each component in each of the above embodiments will be described according to a method of manufacturing a multilayer circuit board.

First, for example, SiO ₂ and Al ₂ O _3.
Glass powder 55% by weight consisting primarily of _{MgO · ZnO · B 2 O 3} · PbO, and Al ₂ O ₃ powder 45% by weight of the inorganic filler, the slurry was kneaded with binder plasticizer, and solvent I do.

The slurry is formed into a sheet by a doctor blade method to produce a green sheet for forming the low-temperature fired ceramic layers 12 and 22.

In predetermined green sheets, via holes as conductor patterns 18 and 29 for establishing electrical continuity between the low-temperature fired ceramic layers 12 and 22 and the heat conductive member 16 are provided.
-A through hole for forming a thermal via hole as 26 is provided by punching.

Next, a conductive paste made of a conductive material such as silver, gold, or copper is filled in the through holes of the green sheet by a screen printing method or the like. This conductive paste is, for example, a silver powder having a particle size of 0.5 to 5 μm, a low thermal expansion glass frit, ethyl cellulose as a binder, and 2,2,4-trimethyl-1,3-pentanediol monohydrate as a solvent. Isobutyrate is homogeneously kneaded.

Next, using the same conductive paste on the surface of a predetermined green sheet, desired mounting portion conductor layers 14, 24 and back surface conductor layers 15, 25, inner conductor layers 17, 27, conductor patterns 18, 29 Print. Here, the heat conduction members 16a, 16b, 26a to 26a to expose the end surfaces of the mounting portion conductor layers 13, 23 are provided.
The portion defined as d is printed in a pattern that does not form a conductor layer.

The conductive paste used as the material of these conductor layers is a material having a sag point of 700 instead of the low thermal expansion glass frit contained in the conductive paste for via holes.
A glass frit of ~ 850 ° C is used.
By using such a conductive paste, the sintering start temperature of the conductive paste and the sintering start temperature of the green sheet can be made close to each other, and the lamination of the low-temperature fired ceramic layers 12 and 22 without warpage or deformation can be achieved. Substrates 11 and 21 are obtained.

Next, in order to form the cavities 11a and 21a for mounting the semiconductor elements 13 and 23, a predetermined green sheet is punched by a mold so as to have a desired depth and area.

Next, after laminating the above green sheets in a predetermined order, integrating them by thermocompression bonding, firing in an oxidizing atmosphere at about 900 ° C. with a peak time of 30 minutes was performed. Is obtained.

Further, the semiconductor elements 13 and 23 are mounted on the conductive layer
Use the high thermal conductivity material described above for 14
Heat conducting members 16a and 16b with end faces exposed inside 14 and 24
The mounting position is controlled by using 26a to 26d, positioned, and bonded and mounted.

Finally, wire bonding is performed to electrically connect the electrodes of the semiconductor elements 13 and 23 with the circuit pattern wiring such as the conductor layers 14 and 24 and the conductor patterns 18 and 29. Forming a mold resin for resin sealing 23, and connecting the terminal electrodes for mounting electronic components and the terminal electrodes of the multilayer circuit board to a general surface mount type electronic component by using a solder paste and a reflow furnace. Similarly, by electrically connecting, a desired electronic circuit module including the multilayer circuit board of the present invention can be obtained.

According to the multilayer circuit board of the present invention,
The back conductor layers 15 and 25 are connected and bonded to the wiring conductors and radiating fins of the mother board on which the board is surface-mounted with a high heat conductive material such as solder, so that the heat generated from the semiconductor elements 13 and 23 can be efficiently used. Conducted and dissipated, the semiconductor element 13
・ Thermal destruction of 23 or a decrease in reliability can be prevented.

The present invention is not limited to the above embodiment, and various changes and improvements can be made without departing from the scope of the present invention. For example, the shape of the thermal via hole as the heat conducting member may be various shapes such as a square or an ellipse other than a circle, or may be a plate. Further, various shapes may be used to define the mounting portion conductor layer in order to expose the heat conductive member.

[0053]

As described above, according to the multilayer circuit board of the present invention, the end face of at least one of the plurality of heat conducting members located outside the semiconductor element is mounted on the surface of the laminated substrate. By separating and exposing the mounting portion conductor layer inside the portion conductor layer, the semiconductor device can be used as an image recognition mark for positioning when mounting the semiconductor element using the end surface of the heat conductive member as a mark. A multi-layer circuit board can be provided in which a large number of heat conducting members arranged in the element mounting portion can be arranged accurately and reproducibly immediately below the semiconductor element. As a result, heat generated from the semiconductor element can be efficiently conducted and radiated by the plurality of heat conducting members, so that the temperature rise of the semiconductor element can be suppressed as desired, and the semiconductor element inherently has an increased temperature. It was possible to provide a highly reliable multilayer circuit board capable of sufficiently exhibiting performance and sufficiently maintaining the function as an electronic circuit module.

According to the multilayer circuit board of the second aspect of the present invention, since each of the plurality of heat conductive members is connected via the inner conductor layer, in addition to the above, the heat conductive member is used. Heat conduction can be performed more efficiently, and a multilayer circuit board capable of more efficiently dissipating heat generated from a semiconductor element can be provided.

Further, according to the multilayer circuit board of the third aspect of the present invention, since a plurality of auxiliary heat conductive members are provided outside the area where the heat conductive member is provided, the heat conductive member has a plurality of auxiliary heat conductive members. Since the heat diffused into the surrounding low-temperature fired ceramic layer can be efficiently conducted to the backside conductor layer by the auxiliary heat conducting member, in addition to the above, the heat dissipation from the semiconductor element can be further efficiently dissipated. A circuit board could be provided.

Further, according to the multilayer circuit board of the fourth aspect of the present invention, the number of auxiliary heat conducting members between each inner conductor layer and the back conductor layer is increased toward the back conductor layer side, and Since it is arranged to be increased toward the outside of the area where the auxiliary heat conducting member is arranged, heat generated from the semiconductor element can be more efficiently conducted to the back conductor layer and radiated, In addition to the above, a highly reliable multilayer circuit board in which the operation and function of the semiconductor element are extremely stable can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a multilayer circuit board of the present invention.

FIG. 2 is a sectional view taken along line A-A 'of FIG.

FIG. 3 is a plan view showing another embodiment of the multilayer circuit board of the present invention.

FIG. 4 is a sectional view taken along line B-B ′ of FIG. 3;

FIG. 5 is a cross-sectional view showing a configuration of a conventional multilayer circuit board.

FIGS. 6A and 6B are plan views for explaining a positional shift between a semiconductor element and a thermal via hole.

[Explanation of symbols]

 11, 21 ... Laminated substrate 12, 22 ... Low temperature fired ceramic layer 13, 23 ... Semiconductor element 14, 24 ... Mounting part conductor layer 15, 25 ... Backside conductor layer 16, 26 ...・ Heat conduction members 17, 27 ・ ・ ・ Inner conductor layer 28 ・ ・ ・ ・ ・ ・ Auxiliary heat conduction members

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-63372 (JP, A) JP-A-7-321471 (JP, A) JP-A-6-77347 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H05K 3/46 H01L 23/12

Claims (4)

(57) [Claims] 1. A laminated substrate formed by laminating a plurality of low-temperature fired ceramic layers, a mounting portion conductive layer formed on a surface of the laminated substrate and partially mounting a semiconductor element, and the mounting portion conductive layer. A backside conductive layer formed on the backside of the opposing laminated substrate, and penetrating the laminated substrate from a part of the mounting portion conductive layer to an outer peripheral region of a mounting position of the semiconductor element to conduct heat generated from the semiconductor element. And a plurality of heat conducting members for connecting the mounting portion conductive layer and the back surface conductive layer, wherein the multilayered circuit board is provided outside the semiconductor element mounted on the mounting portion conductive layer. Wherein the end face of at least one of the heat conductive members located on the inner surface of the laminated substrate is exposed inside the mounting portion conductor layer on the surface of the laminated substrate while being partitioned from the mounting portion conductor layer. 2. The multilayer circuit board according to claim 1, wherein
A multilayer circuit board, wherein each of the plurality of heat conducting members is connected via an inner conductor layer disposed between low-temperature fired ceramic layers forming the laminated substrate. 3. The multilayer circuit board according to claim 2, wherein
Outside the region in which the plurality of heat conducting members are provided in the laminated substrate, a plurality of auxiliary heat conducting members are arranged so as to penetrate the low-temperature fired ceramic layer from the inner conductor layer to the back conductor layer. A multilayer circuit board characterized by being provided. 4. The multilayer circuit board according to claim 3, wherein
At least two or more inner conductor layers are arranged,
The number of the auxiliary heat conducting members between each inner conductor layer and the back conductor layer is increased toward the back conductor layer and toward the outside of the region where the auxiliary heat conducting member is provided. A multi-layer circuit board, comprising: