JPH06334346A - Pattern forming method of thick film - thin film hybrid multilayered wiring board - Google Patents

Abstract

PURPOSE:To prevent imperfect connection due to irregularity of shrinkage factor of a thick film wiring board part, and provide a pattern forming method of a high density thick film-thin film hybrid multilayered wiring board excellent in productivity and cost. CONSTITUTION:The title board is a multilayered wiring board corresponding with a module mounting an LSI, and consists of a thick film wiring board part 10 and a thin film wiring board part 20. A matching layer 30 for absorbing positional deviation of circuits is formed on the interface between the thick film wiring board part 10 and the thin film wiring board part 20. The surface of the thick film wiring board part 10 is divided into four blocks 40a-40d, in which the following are formed; alignment marks 50a-50d for block exposure to form matching pads 31a-31d of the matching layer by division exposure, and alignment marks 60 for collective exposure to form thin film viaholes 23a-23d by collective exposure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming technique for a thick-film / thin-film mixed multilayer wiring board, and particularly for a wiring board used for multilayer wiring and a module on which LSI is mounted, with a high density and a high manufacturing yield. The present invention relates to a technique effective when applied to a pattern forming method of a thick film / thin film mixed multilayer wiring board capable of improving reliability.

[0002]

2. Description of the Related Art In recent years, the technique of mounting an LSI chip on one ceramic wiring substrate in the manufacturing process of a multilayer wiring substrate is becoming a mainstream mounting technique for large-scale, high-speed digital systems such as large computers. The technological progress of the multilayer wiring board used in this technology is remarkable.

For example, at present, after forming a thick film wiring board portion made of ceramics or glass ceramics as an insulating layer and tungsten or molybdenum as a wiring conductor by a green sheet method, a thin film wiring board portion is formed on the upper surface by a thin film method. Examination of thick / thin film mixed multilayer wiring board to be formed,
Development is actively progressing.

One of the problems with this thick-film / thin-film hybrid multilayer wiring board is that there is a large variation in sintering shrinkage during the process of forming the thick-film wiring board portion. That is, since the thin film wiring board portion formed by the thin film method is generally formed by using the photolithography technique, the positional accuracy almost equal to the mask pattern to be used can be obtained, while the thick film wiring board portion side has the above contraction. The pattern position accuracy is extremely poor due to variations.

Therefore, the pattern of the thick film wiring board portion and the pattern of the thin film wiring board portion are misaligned at their joints, resulting in poor connection. Incidentally, at present, the dimensional tolerance from the central portion of the thick film wiring board portion to its peripheral portion is limited to about ± 0.5%.

For example, if the distance from the central portion to the peripheral portion is 50 mm, the peripheral portion will have a maximum displacement of ± 250 μm, and naturally this value becomes larger as the substrate becomes larger. Further, the shrinkage of the thick film wiring board portion often becomes non-uniform in the entire board due to non-uniform temperature distribution during sintering.

Therefore, as a technique for solving the problem of connection failure due to the variation in the shrinkage ratio of the thick film wiring board portion, Japanese Patent Laid-Open No. 58-73193 and Japanese Patent Laid-Open No. 31931/1983.
The techniques described in JP-A-101193 and JP-A-4-118990 are known.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 58-73193, as shown in FIG. 3, the thick film wiring board portion 1 is composed of a ground / power supply layer 2 and a thick film via hole 3 made of a sintered body. In its inner layer. The thick film via hole 3 is formed by embedding a tungsten paste in the alumina insulating layer 4, and the diameter thereof is set to a large diameter in consideration of the variation in the shrinkage rate of the thick film wiring board portion 1.

Further, a thin film via hole (not shown) is formed on the thick film wiring board portion 1 by a photolithography technique using a resist for the polyimide insulating layer 5,
Further, a wiring made of an aluminum conductor 6 is formed on the thin film via hole and the polyimide insulating layer 5. And, these polyimide insulating layer 5 and aluminum conductor 6
And are alternately formed to form the thin film wiring board portion 7.

In this thick-film / thin-film hybrid multilayer wiring board, by setting the diameter of the thick-film via hole 3 to a large diameter, it is possible to absorb the positional deviation due to the variation in the contraction rate of the thick-film wiring board portion 1. It is possible to prevent poor connection.
In this case, the amount of misalignment absorption is limited to about 1/2 of the pitch of the thick film via holes 3 of the thick film wiring board portion 1.

Further, in the techniques disclosed in Japanese Patent Laid-Open Nos. 3-101193 and 4-118990, the thick film via hole in the thick film wiring board portion and the thin film via hole in the thin film wiring board portion are formed by a matching layer formed by a thin film pad. A method of connecting and absorbing the positional deviation caused by the variation of the contraction rate of the thick film wiring board portion by this thin film pad is shown.

Specifically, there is a method of forming a mask of a thin film pad by measuring the position of a dummy via provided on the thick film wiring board portion (Japanese Patent Laid-Open No. 4-118990).
Similarly, it is a method (Japanese Patent Laid-Open No. 3-101193) of forming a thin film pad by an electron beam drawing method or a dot printer method.

[0013]

However, the above-mentioned conventional techniques have the following drawbacks.

(1). FIG. 3 of JP-A-58-73193
In the above example, the amount of misalignment absorption is limited to about 1/2 of the pitch of the via holes in the thick film wiring board portion, and high density and high yield of the thick film wiring board portion are hindered. .

(2). In the technique disclosed in Japanese Patent Laid-Open No. 3-101193, it is necessary to prepare various thin film photomasks in accordance with the contraction pattern of the thick film wiring board portion, so that the photomask management and the number of manufacturing steps are large. In addition to this, it is necessary to add a special process accompanied by an electron beam drawing apparatus using a vacuum, and the like, so that mass productivity is lacking.

(3). In the technique disclosed in Japanese Patent Laid-Open No. 4-118990, like the technique disclosed in Japanese Patent Laid-Open No. 3-101193,
Mass production is lacking because a thin film photomask is created for each substrate.

Therefore, in the conventional technique for manufacturing a thick-film / thin-film hybrid multilayer wiring board, there is an economical drawback in terms of manufacturing and production, which impedes the increase in density and yield of the multilayer wiring board. The improvement is desired.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, prevent connection failures due to variations in the shrinkage ratio of the thick film wiring board portion, and achieve high density and high mass productivity, which is economical. Another object of the present invention is to provide a pattern forming method for a thick / thin film mixed multilayer wiring board.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0020]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the pattern forming method of the thick film / thin film mixed multilayer wiring board of the present invention comprises a thick film wiring board portion and a thin film wiring board portion, and a thick film wiring circuit and a thin film wiring board of the thick film wiring board portion. A thick-film / thin-film hybrid multilayer wiring board in which a matching layer is provided at the interface with the thin-film wiring circuit in order to absorb misalignment between the circuits, and when the matching layer is formed after the thick-film wiring circuit is formed. , The surface of the thick film wiring board part is divided into small blocks, each of the blocks divided into these small blocks is exposed to form a matching layer, and then the thin film wiring circuit is formed by covering the entire surface of the thin film wiring board part. It is formed by batch exposure.

[0022]

According to the pattern forming method of the thick film / thin film mixed multilayer wiring board described above, the matching layer is formed for each small block, and the thin film wiring circuit is formed all over at once to form the thin film wiring circuit. Since the size of the previously formed matching layer can be sufficiently utilized, for example, when a circular matching pad originally installed so as to match the center of the via hole of the thick film wiring substrate is used as the matching layer, The misalignment that can be absorbed by this matching layer is about 1/2 of the pitch of the thick film via hole in the prior art, but is about 1 pitch of the via hole in the thick film wiring board portion in the present invention at the maximum. Can be

Further, since the matching layer is divided into blocks and formed in a small area, shrinkage which is not uniform in the entire substrate due to uneven temperature distribution during sintering is taken into consideration in each block. It is possible to form the matching layer corresponding to the displacement of the thick film via hole in the above step, the connection between the via hole of the thick film wiring board and the matching layer pattern becomes more reliable, and the yield can be increased.

Furthermore, since the formation of the thin film wiring circuit after the formation of the matching layer is performed by the collective exposure method on the entire surface of the substrate, the thin film wiring substrate portion can be formed on the entire surface of the substrate with substantially the positional accuracy of the mask pattern. .

As a result, it is possible to increase the density or increase the area of the board and module by increasing the density of the thick film via holes and wiring, and to prevent the connection failure between the thick film wiring circuit and the thin film wiring circuit, and to prevent the board and module from connecting. It is possible to achieve high reliability without hindering mass productivity.

In this case, in the present invention, after forming the thick film wiring substrate, the via hole position on the thick film wiring substrate is measured, and the alignment mark for exposure for each small block is provided for each block based on the data. 2 or more corresponding to each of the above, and two or more alignment marks for collectively exposing the entire surface of the substrate are formed. These two kinds of alignment marks have an important function at the time of exposure.

That is, the alignment mark for block exposure for forming the matching layer, the alignment mark for collective exposure for forming the thin film wiring circuit, the information on the position of the via hole on the thick film wiring substrate, And the information such as the size and position of the pattern of the thin film wiring board portion is all collected.

Thus, at the time of exposure for forming the matching layer and subsequent exposure of the via hole pattern of the thin film wiring substrate portion, the substrate and a predetermined photomask are simply aligned and exposed based on the respective alignment marks. so,
As a result, the connection between the via hole of the thick film wiring board and the matching layer, and the connection of the matching layer and the via hole of the thin film wiring board are secured, and the positional deviation due to the variation in the contraction rate of the thick film wiring board is prevented. It can be effectively prevented.

Further, based on the measurement data of the via hole position on the surface of the thick film wiring board portion, when the position of the alignment mark for block exposure formed for each block is calculated and determined, the subsequent batch exposure is performed. It is also possible to determine the alignment mark position for each block in consideration of the connection between the matching layer pattern and the via hole pattern of the thin film wiring board section. The connection with the via hole pattern becomes more reliable, and the yield can be improved.

[0030]

FIG. 1 is a sectional view showing a main part of a thick film / thin film mixed multilayer wiring board according to an embodiment of the present invention, and FIG. 2 is a plan view showing a thick film / thin film mixed multilayer wiring board according to this embodiment. Is.

First, the structure of the thick film / thin film mixed multilayer wiring board of this embodiment will be described with reference to FIG.

The thick-film / thin-film hybrid multilayer wiring board of this embodiment is a multilayer wiring board corresponding to a module for mounting an LSI, for example, and includes a thick-film wiring board portion 10 and a thin-film wiring board portion 2.
0, and a matching layer 30 for absorbing misalignment between the circuits is provided at the interface between the thick film wiring circuit of the thick film wiring board portion 10 and the thin film wiring circuit of the thin film wiring board portion 20. The thin film wiring board portion 20 is laminated on the wiring board portion 10 with a matching layer 30 interposed therebetween.

The thick film wiring board portion 10 is a thick film wiring board made of a ceramic portion 11 obtained by laminating and sintering a plurality of green sheets. A film-formed ground layer 12, a power supply layer 13,
A signal layer 14 is formed, which is a thick film via hole 15.
It is connected to the matching layer 30 or the land 16 on the back surface via.

The thin film wiring board portion 20 comprises a thin film wiring board on which a thin film insulating layer 21 and a thin film conductor 22 are laminated, and a matching layer 30 composed of a matching pad 31, and the matching pad 31 of the matching layer 30 is a thin film via hole. It is connected to the thin film conductor 22 of the thin film wiring board via 23.

The surface of the thick film wiring board portion 10 is shown in FIG.
Is divided into four blocks 40a to 40d, and the matching pads 31a to 31d are connected to the thick film via holes 15a to 15d of the blocks 40a to 40d, respectively.
31d is formed, and the matching pads 31a to 31 are formed.
thin film via holes 23a-23d so as to be connected to
Are formed.

Further, on the surface of the thick film wiring board portion 10,
Positioning marks 50a to 50d for block exposure for forming the matching pads 31a to 31d of the matching layer 30 by division exposure in the blocks 40a to 40d, respectively.
A collective exposure alignment mark 60 for collectively forming the thin film via holes 23a to 23d is formed.

Next, the operation of this embodiment will be described step by step in the procedure for forming this thick film / thin film hybrid multilayer substrate.

First, the thick film wiring board portion 10 as a base material.
Are prepared by a normal green sheet method, and based on standard shrinkage data at the time of sintering, the matching pads 31a to 3a are formed.
Photomask for forming 1d and thin film via hole 2
Photomasks for forming 3a to 23d are prepared in advance.

The blocks 40a-40d on the surface of the substrate
The division is assumed to be predetermined, and in this example, it is divided into 4 blocks. Further, the block exposure alignment marks 50a to 50 of the thick film wiring board portion 10 required at the time of exposure.
d. It is also assumed that the positional relationship between the collective exposure alignment mark 60 and the photomask pattern is predetermined.

First, as for the positions of the thick film via holes 15a to 15d on the surface of the thick film wiring board portion 10, the total number or the via holes at the end portions or the central portions of the blocks 40a to 40d are selected, for example, optical It is measured using a conventional method.

Further, the position data of the thick film via holes 15a to 15d obtained by the measurement is used for each block 40a.
The pad pattern positions of the photomask for forming the matching pads 31a to 31d are compared every 40 to 40d.

Then, in each of the blocks 40a to 40d, the thick film via holes 15a to 15d and the matching pads 31a to 3 are formed.
Block exposure alignment mark 50a for exposing alignment pads 31a to 31d so that 1d is connected.
.About.50d are formed on the surface of the thick film wiring board portion 10 in correspondence with the blocks 40a to 40d, for example, two by two, for example, by engraving with an excimer laser.

Further, each of the formed blocks 40a-4
The positions of the alignment pads 31a to 31d on the entire surface of the substrate are calculated from the positions of the block exposure alignment marks 50a to 50d for exposure of the alignment pads 31a to 31d for each 0d, and the position data and the thin film vias subsequent thereto are calculated. Hall 2
The pattern position data of the exposure photomasks 3a to 23d are compared.

Then, the matching pads 31a ...
A collective exposure alignment mark 60 for forming the thin film via holes 23a to 23d is formed on the surface of the thick film wiring board portion 10 by, for example, engraving with an excimer laser so that the 31d and the thin film via holes 23a to 23d are connected. Two
Form individually.

Subsequently, the thick film wiring board portion 10 is subjected to a pretreatment for removing an oxide film in order to ensure electrical conduction, and then a conductive metal for forming the matching pads 31a to 31d is formed on the entire surface. For example, aluminum is sputtered and the matching pads 31a to 31d of the matching layer 30 are formed by using a normal photolithography technique.

In this case, a predetermined photomask is used at the time of exposure, and the blocks and the photomask are aligned with the block exposure alignment marks 50a to 50d corresponding to each of the blocks 40a to 40d.
Separate exposure is performed for each.

Further, a thin film insulating layer 21, for example, a thermosetting film of polyimide resin is formed on the entire surface of the substrate, and thin film via holes 23a to 23d are formed in the thin film insulating layer 21 by using a normal photolithography technique.

In this case, a predetermined photomask is used at the time of exposure, and the substrate and the photomask are aligned with the collective exposure alignment mark 60 for forming the thin film via holes 23a to 23d, and the entire substrate is collectively exposed. .

The thin film via holes 23a-2a
Wiring is formed by a thin film conductor 22 such as aluminum on 3d and the thin film insulating layer 21, and the thin film insulating layer 21 and the thin film conductor 22 are alternately formed to form the thin film wiring substrate portion 20. A thick film / thin film mixed multilayer wiring board in which the thin film wiring board portion 20 is laminated on the thick film wiring board portion 10 is completed.

Therefore, according to the thick film / thin film mixed multilayer wiring board of the present embodiment, the block exposure alignment marks 50a to 50d are provided in each of the divided blocks 40a to 40d of the thick film wiring board portion 10. The alignment mark 60 for collective exposure is formed, and the combined exposure of the matching layer 30 and the collective exposure of the thin film wiring substrate section 20 are combined to connect the thick film via holes 15a to 15d to the matching pads 31a to 31d. The connection between the matching pads 31a to 31d and the thin film via holes 23a to 23d is secured, and a photomask is prepared for each substrate without using a special device such as an electron beam and a drawing device as in the past. Without
It is possible to prevent a connection failure due to the variation in the shrinkage ratio of the thick film wiring board unit 10.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the thick-film / thin-film hybrid multilayer wiring board of this embodiment, two block exposure alignment marks 50a to 50d are provided for each block 40a to 40d, and a collective exposure alignment mark 60 is provided. Although the case of forming two pieces has been described, the present invention is not limited to the above-mentioned embodiment, and is widely applicable as long as two or more pieces are taken into consideration in consideration of alignment accuracy during exposure.

The thick film wiring board portion 10 is not limited to ceramics obtained by stacking and sintering green sheets, but may be applied to a wiring board made of glass ceramics, for example.

In the above description, the case where the invention made by the present inventor is mainly applied to the multilayer wiring substrate corresponding to the module mounting the LSI, which is the field of use of the invention, is not limited to this. It can be widely applied to other wiring boards used for multilayer wiring.

[0055]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

(1) When the matching layer is formed after the thick film wiring circuit is formed, the surface of the thick film wiring substrate is divided into small blocks and each block divided into the small blocks is exposed. The matching layer is formed, and then the thin film wiring circuit is formed by collectively exposing the entire surface of the thin film wiring substrate portion,
Since the positional deviation that can be absorbed by the matching layer can be expanded and the matching layer can be formed corresponding to the via hole deviation in each block unit, the connection between the thick film wiring board portion and the matching layer can be further improved. As a result, the yield of the thick-film / thin-film hybrid multilayer wiring board can be increased.

(2) According to the above (1), the formation of the thin film wiring circuit after the formation of the matching layer should be performed on the entire surface of the thin film wiring substrate portion by the batch exposure method with substantially the mask pattern positional accuracy. Therefore, it is possible to improve the reliability of the multilayer wiring board and the module by preventing the connection failure of the thick film wiring board section, the matching layer, and the thin film wiring board section.

(3) By virtue of the above (1), the via holes and wirings of the thick film wiring board portion and the thin film wiring board portion can be formed with high density, so that the multi-layered wiring board and the module can be increased in density or increased in size. Area can be increased.

(4) Due to the above (1) to (3), it is possible to prevent the connection failure due to the variation in the shrinkage ratio of the thick film wiring board portion, without impairing the mass productivity and economically. It is possible to obtain a high-density thick / thin film mixed multilayer wiring board having high density.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a thick film / thin film mixed multilayer wiring board according to an embodiment of the present invention.

FIG. 2 is a plan view showing a thick film / thin film mixed multilayer wiring board of the present embodiment.

FIG. 3 is a cross-sectional view showing a main part of a thick film / thin film mixed multilayer wiring substrate which is an example of a conventional technique.

[Explanation of symbols]

 1 Thick Film Wiring Board Part 2 Ground / Power Layer 3 Thick Film Via Hole 4 Alumina Insulating Layer 5 Polyimide Insulating Layer 6 Aluminum Conductor 7 Thin Film Wiring Board Part 10 Thick Film Wiring Board Part 11 Ceramics Part 12 Ground Layer 13 Power Supply Layer 14 Signal Layer 15, 15a to 15d Thick film via hole 16 Land 20 Thin film wiring board part 21 Thin film insulating layer 22 Thin film conductor 23, 23a to 23d Thin film via hole 30 Matching layer 31, 31a to 31d Matching pad 40a to 40d Block 50a to 50d Block exposure Alignment mark 60 for batch exposure alignment mark

Claims (1)

[Claims] 1. A misalignment between each circuit at an interface between a thick film wiring circuit of the thick film wiring board portion and a thin film wiring circuit of the thin film wiring board portion, comprising a thick film wiring board portion and a thin film wiring board portion. A thick-film / thin-film hybrid multilayer wiring board provided with a matching layer for absorbing heat, wherein when the matching layer is formed after the thick-film wiring circuit is formed, the surface of the thick-film wiring board section is divided into small blocks. Then, the matching layer is formed by exposing each of the blocks divided into the small blocks, and then the thin film wiring circuit is formed by collectively exposing the entire surface of the thin film wiring substrate portion. A method for forming a pattern on a thick film / thin film hybrid multilayer wiring board.