JP3956408B2 - Manufacturing method of multilayer wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer wiring board for mounting a semiconductor device used in an electronic device and the like, and a method for manufacturing the same. In particular, it has two or more multilayered conductor wiring layers on one side of a substrate to improve wiring density. The present invention relates to a multilayer wiring board having the above structure and a method for manufacturing the same.
[0002]
The multilayer wiring board referred to in the present invention is a circuit board of a type on which a semiconductor integrated circuit element (hereinafter referred to as a chip) is directly mounted / connected (a printed wiring board provided with a printed circuit, which is widely used). And a printed wiring board as an external circuit for connecting the semiconductor device with the chip mounted and connected to the lead frame.
[0003]
[Prior art]
In order to create a wiring board containing circuit patterns that cross each other on only one side, it is conventionally performed to obtain a multilayer wiring board and improve wiring density by alternately laminating conductor wiring layers and insulating layers. It is.
[0004]
In conventional printed wiring boards, after mounting components, fins are individually attached to components that generate a large amount of heat during operation.
[0005]
In addition, the conventional composite printed wiring board is formed by mounting a mounting component on the surface of the inner pattern layer in the printed wiring board manufacturing process and then forming a single printed wiring board by multi-layer adhesive pressing. Since the components are built in the printed wiring board, the heat dissipation is remarkably reduced and the circuit operation is adversely affected.
[0006]
Further, when a heat sink is used as a base substrate in a conventional multilayer wiring board, by alternately laminating insulating layers and conductor wiring layers on the heat sink, chips mounted on the multilayer wiring board and the heat sink The distance is made. For this reason, the heat radiating plate has been devised to be provided in the center of the multilayer wiring board. However, since the heat transfer direction is only in the horizontal direction with respect to the substrate, the parts that generate a large amount of heat are placed on the side of the multilayer wiring board. It was necessary to attach fins for heat dissipation.
[0007]
[Problems to be solved by the invention]
Since the conventional printed wiring board has to be provided with fins for heat radiation for each component, the component mounting cost is high and a lot of mounting work time is required.
[0008]
In the composite printed wiring board, since the components are mounted on the wiring board, it is not possible to attach fins for heat dissipation or the like, and there is a problem that the circuit operation is adversely affected by the heat generated by the components.
In addition, when a mounting method such as surface mounting, chip-on-board, or TAB is used, the amount of heat generated is about four times that of the conventional method, resulting in a problem of insufficient heat dissipation.
[0009]
Furthermore, in conventional multilayer wiring boards, insulating layers and conductor wiring layers are alternately stacked on the heat sink, so that the thickness of the insulating layer increases as the number of layers increases, and the multilayer wiring board is mounted on the multilayer wiring board. The distance between the chip and other components and the heat radiating plate is increased, and the heat dissipation is remarkably reduced. For this reason, a heat radiating plate has been devised in the center of the multilayer wiring board. However, since the heat transfer direction is only in the horizontal direction with respect to the board, heat is dissipated on the side of the multilayer wiring board for parts that generate a large amount of heat. Since it is necessary to attach fins for the purpose, the component mounting cost is high and a lot of mounting work time is required.
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a structure of a multilayer wiring board for efficiently releasing the heat generated in the multilayer wiring board to the outside and a method for manufacturing the same. There is a thing [0011]
[Means for Solving the Problems]
In order to solve the above problems in the present invention, on a metal substrate for the purpose of heat dissipation enhancement, and the multilayer wiring board and a conductor interconnect layer heat dissipation layer is characterized by being alternately laminated through an insulating layer It is a thing.
[0012]
Further , the present invention is a multilayer wiring board characterized in that a heat radiation pattern is provided on the conductor wiring layer surface.
[0013]
Further, the heat dissipation layer and the heat radiation pattern is electrically and thermally connected by a via to each other, it is ultimately connected to the metal substrate, in which so as to radiate through the metal substrate.
[0014]
According to a first aspect of the present invention, there is provided a method for manufacturing a multilayer wiring board, comprising the following steps (a) to (i).
(A) A step of forming a first insulating layer on a metal substrate.
(B) forming a via hole penetrating the first insulating layer, forming a conductor layer on the via hole and the first insulating layer, and forming a first conductor wiring layer;
(C) forming a second insulating layer and forming a via hole penetrating the first insulating layer and the second insulating layer;
(D) A step of forming a conductive layer on the second insulating layer and in the via hole, and patterning the conductive layer to form a first heat dissipation layer.
(E) forming a third insulating layer and forming a via hole penetrating the third insulating layer and a via hole penetrating the second insulating layer and the third insulating layer;
(F) A step of forming a conductor layer on the third insulating layer and in the via hole, and forming a second conductor wiring layer and a second heat radiation pattern.
(G) Forming a fourth insulating layer, forming a via hole penetrating the fourth insulating layer, forming a conductor layer on the fourth insulating layer and in the via hole, and patterning the conductor layer to form a second heat dissipation layer Process.
(H) forming a fifth insulating layer, forming a via hole penetrating the fifth insulating layer and a via hole penetrating the fourth and fifth insulating layers, and forming a conductor layer in the fifth insulating layer and the via hole; Forming a third conductor wiring layer and a third heat radiation pattern by patterning.
(I) A step of producing a multilayer wiring board by repeating the steps (c) to (f) as many times as necessary.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
A method for forming a multilayer wiring board according to the present invention is as follows.
FIG. 1 is a cross-sectional view showing a configuration of an embodiment of the multilayer wiring board of the present invention, and FIGS. 2A to 2H are cross-sectional views showing a manufacturing process of the embodiment of the multilayer wiring board of the present invention.
The basic structure of the multilayer wiring board of the present invention is that a heat dissipation layer is formed between the conductor wiring layer and the insulating layer, and a heat dissipation pattern is partially formed on the surface of the conductor wiring layer. And thermally connected, and finally connected to the metal substrate to dissipate heat.
[0016]
First, the first insulating layer 2 is formed on the metal substrate 1 (see FIG. 2A).
The metal substrate 1 can be used as long as it is conductive and has excellent thermal conductivity, and a copper plate is the most common.
As a method for forming the insulating layer, the resin solution can be applied using various means such as a roller coating method, a dip coating method, a spray coating method, a spinner coating method, a curtain coating method, and a screen printing method.
The material of the insulating layer is not particularly limited as long as it has electrical insulation used for a general multilayer wiring board. Benzocyclobutene (hereinafter referred to as BCB) is preferred from the standpoint of heat resistance and insulation.
[0017]
After forming a via hole in the first insulating layer 2, a conductor layer is formed, and patterning is performed to form a first conductor wiring layer 3. A part of the first conductor wiring layer is connected to a metal substrate through a via and grounded. They are connected (see FIG. 2B).
For the formation of via holes, machining methods such as drills, photolithography methods, and laser processing methods can be used. However, laser processing is not possible due to reasons such as fine processability, wide selection of insulating layer materials, and ease of control of the processing shape. It is common.
The conductor layer is formed by first forming a copper metal thin film conductor layer on the entire surface by any one of a vacuum deposition method, a sputtering method, and an electroless plating method, and a conductor layer and a via having a predetermined thickness by electrolytic copper plating. Form.
The conductor wiring layer is formed by patterning by a normal photolithography method.
[0018]
Next, after forming the second insulating layer 4, the via hole 5, and the conductor layer, the conductor layer is patterned to form the first heat radiation layer 6 (see FIGS. 2C and 2D). Here, the first heat dissipation layer 6 is electrically and thermally connected to the metal substrate 1 through the via 7.
[0019]
Next, a conductor layer is formed on the third insulating layer 8 and the via holes 9 and 10 and the entire surface by the above method, and then the conductor layer is patterned to form the second conductor wiring layer 11 and the second heat radiation pattern 12 ( (Refer FIG.2 (e) and (f)). Here, the second conductor wiring layer 11 and the second heat radiation pattern 12 are mixed on the same surface, but are electrically insulated. Further, the second conductor wiring layer 11 is electrically connected to the first conductor wiring layer 3 through a via 13, and the second heat radiation pattern 12 is electrically and thermally connected to the first heat radiation layer 6 through a via 14. The
[0020]
Similarly, after forming the fourth insulating layer 15 and the via hole, a conductor layer is formed on the entire surface and patterned to form the second heat dissipation layer 16 (see FIG. 2G).
[0021]
Similarly, after forming the fifth insulating layer 18 and the via hole, a conductor layer is formed on the entire surface, and patterned to form a third conductor wiring layer 19 and a third heat radiation pattern 20 (see FIG. 2H). .
Through the above series of steps, the multilayer wiring board of the present invention having three conductor wiring layers, two heat dissipation layers and a heat dissipation pattern is obtained. If more multilayer wiring boards are required, the steps (c) to (f) in FIG. 2 may be repeated as many times as necessary.
[0022]
As described above, in the multilayer wiring board having the heat dissipation layer and the heat dissipation pattern of the present invention, the heat dissipation layer and the heat dissipation pattern are connected to each other by vias at predetermined locations, and these are connected to the metal substrate. Therefore, heat dissipation is performed efficiently.
[0023]
【Example】
Embodiments of a multilayer wiring board according to the present invention will be described below with reference to the drawings. 2A to 2H show a manufacturing method of an embodiment of the multilayer wiring board.
[0024]
BCB (manufactured by Dow Chemical) resin solution was applied on a black metal substrate 1 having a thickness of about 400 μm by a spin coater, dried at 75 ° C. for 20 minutes, and then in nitrogen at 100 ° C. for 15 minutes. The first insulating layer 2 having a thickness of about 10 μm was formed by heating and curing at 150 ° C. for 15 minutes and 210 ° C. for 30 minutes (see FIG. 2A).
[0025]
Next, a via hole was formed in the first insulating layer 2 by irradiating a predetermined position with a laser beam of 0.5 J / cm ² using a KrF excimer laser processing machine. Further, a copper conductor thin film having a thickness of about 0.2 μm was formed on the first insulating layer 2 by sputtering, and a conductor layer having a thickness of about 10 μm was formed by electrolytic copper plating.
A negative liquid resist (PMER; manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the conductor layer with a dip coater, dried and cured to form a photosensitive layer, and is passed through a predetermined pattern mask to give about 500 mJ / cm ² . The resist pattern was formed by exposing with an exposure amount, developing with a dedicated developer, and heating and drying at 110 ° C. for 30 minutes. Further, the ferric chloride solution at 50 ° C. was spray-etched and then immersed in a 5% sodium hydroxide solution to peel off the resist pattern to form the first conductor wiring layer 3 (see FIG. 2B).
[0026]
Next, a BCB (Dow Chemical Co.) resin solution was applied with a spin coater and dried at 75 ° C. for 20 minutes, and then heated and cured in nitrogen at 100 ° C. for 15 minutes, 150 ° C. for 15 minutes, and 210 ° C. for 30 minutes. A second insulating layer 4 having a thickness of about 10 μm was formed. Further, using a KrF excimer laser processing machine, a laser beam of 0.5 J / cm ² was irradiated to a predetermined position to form a via hole 5 of 50 μmφ in the first insulating layer 2 and the second insulating layer 4 (FIG. 2 (c)).
[0027]
Next, a conductor layer having a thickness of about 10 μm was formed by the same method as that for forming the conductor layer, and the first heat dissipation layer 6 was formed by patterning using the same method as described above. Here, the first heat dissipation layer 6 is electrically and thermally connected to the metal substrate 1 through the via 7 (see FIG. 2D).
[0028]
Next, the third insulating layer 8 was formed by the same method as the second insulating layer 4 described above. Further, via holes 9 and 10 were formed by the same method as described above (see FIG. 2E).
[0029]
Next, a conductor layer having a thickness of about 10 μm was formed by the same method as that for forming the conductor layer, and the second conductor wiring layer 11 and the second heat radiation pattern 12 were formed by patterning by the same method as described above (FIG. 2). (Refer to (f)). Here, the second conductor wiring layer 11 is electrically connected to the first conductor wiring layer 3 through a via 13, and the second heat radiation pattern 12 is electrically and thermally connected to the first heat radiation layer 6 through a via 14. Is done.
[0030]
Next, the 4th insulating layer 15 and the via hole were formed by the method similar to said 2nd insulating layer. Further, a conductor layer having a thickness of about 10 μm was formed by the same method as that for forming the conductor layer, and the second heat radiation layer 16 was formed by patterning using the same method as described above (see FIG. 2G). Here, the second heat radiation layer 16 is electrically and thermally connected to the second heat radiation pattern 12 through the vias 17.
[0031]
Next, a fifth insulating layer 18 and a via hole were formed by the same method as that for the second insulating layer. Further, a conductor layer having a thickness of about 10 μm was formed by the same method as that for forming the conductor layer, and the third conductor wiring layer 19 and the third heat radiation pattern 20 were formed by patterning by the same method as described above (FIG. 2 ( h)). Here, the third conductor wiring layer 19 is electrically connected to the second conductor wiring layer 11 via the via 21, and the third heat radiation pattern 20 is electrically and thermally connected to the second heat radiation layer 6 via the via 22. Is done.
Through the above series of steps, the multilayer wiring board of the present invention having three conductor wiring layers, two heat radiation layers and a heat radiation pattern was obtained.
[0032]
【The invention's effect】
With the configuration of the multilayer wiring board of the present invention, it is possible to produce a circuit in which the heat generated in the chip flows from the heat radiation layer and the heat radiation pattern to the metal substrate through the via, and the heat radiation from the metal substrate. it can.
In addition, since it is not necessary to provide heat-dissipating fins, a multilayer wiring board capable of reducing the size of the substrate can be obtained.
Furthermore, since the heat dissipation layer is connected to the ground and the conductive pattern has a strip structure, there is no crosstalk and the electrical characteristics are improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a multilayer wiring board according to the present invention.
FIGS. 2A to 2H are process cross-sectional views illustrating a manufacturing method of an embodiment of a multilayer wiring board according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Metal substrate 2 ... 1st insulating layer 3 ... 1st conductor wiring layer 4 ... 2nd insulating layers 5, 9, 10 ... Via hole 6 ... 1st thermal radiation layer 7, 13, 14, 17, 21, 22... Via 8... Third insulating layer 11... Second conductor wiring layer 12... Second heat radiation pattern 15. ... Third conductor wiring layer 20 ... Third heat dissipation pattern

Claims (1)

The manufacturing method of the multilayer wiring board characterized by including the following processes.
(A) A step of forming a first insulating layer on a metal substrate.
(B) forming a via hole penetrating the first insulating layer, forming a conductor layer on the via hole and the first insulating layer, and forming a first conductor wiring layer;
(C) forming a second insulating layer and forming a via hole penetrating the first insulating layer and the second insulating layer;
(D) A step of forming a conductive layer on the second insulating layer and in the via hole, and patterning the conductive layer to form a first heat dissipation layer.
(E) forming a third insulating layer and forming a via hole penetrating the third insulating layer and a via hole penetrating the second insulating layer and the third insulating layer;
(F) A step of forming a conductor layer on the third insulating layer and in the via hole, and forming a second conductor wiring layer and a second heat radiation pattern.
(G) Forming a fourth insulating layer, forming a via hole penetrating the fourth insulating layer, forming a conductor layer on the fourth insulating layer and in the via hole, and patterning the conductor layer to form a second heat dissipation layer Process.
(H) forming a fifth insulating layer, forming a via hole penetrating the fifth insulating layer and a via hole penetrating the fourth and fifth insulating layers, and forming a conductor layer in the fifth insulating layer and the via hole; Forming a third conductor wiring layer and a third heat radiation pattern by patterning.
(I) A step of producing a multilayer wiring board by repeating the steps (c) to (f) as many times as necessary.

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