JPH07142865A - Manufacture of ceramic multilayer board having cavity structure - Google Patents

Abstract

PURPOSE:To prevent the disconstinuity of the wiring and thus eliminate defective boards, by bonding together in advance laminated bodies having an opening, sandwiched between an upper metal plate and a lower metal plate, by pressing, and then bonding the resultant laminated bodies together with a laminated body having no opening by pressing. CONSTITUTION:Viaholes 2 are formed in a sheet 1, on which a wiring conductor layer 3 is in turn formed. Openings 4, 5 different in size are punched in the sheet 1. Sections containing an opening 4 of one size are laminated, and metal plates 11 having an opening of the same size are placed on the top and underside of the resultant laminated body 12; sections containing an opening 5 of the other size are laminated, and metal plates 11 having an opening of the same size are placed on the top and underside of the resultant laminated body 13. Similarly, sections of the sheet containing no opening are laminated, and metal plates 11' having no opening are placed on the top and underside of the resultant laminated body 14. Each of the laminated bodies 12, 13, 14 sandwiched between the metal plates 11, 11' is packaged in vacuum in a bag 8, and bonded by pressing using a medium 9. This eliminates steps. The laminated bodies 12, 13, 14 are taken out of the bags 8, and then laminated one another. The resultant laminated body 15 is packaged in vacuum in a bag 8, and bonded by pressing using the medium 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a via formed by filling a through-hole with a conductive paste and a plurality of sheets having wiring conductor layers formed by printing the conductive paste on the surface and laminated by pressure bonding. The present invention relates to a method for manufacturing a ceramic multilayer substrate formed by firing, and particularly to a method for manufacturing a ceramic multilayer substrate having a cavity structure formed for the purpose of mounting an IC or the like.

[0002]

2. Description of the Related Art FIG. 4 is a side sectional view showing a first conventional example of a method for manufacturing a ceramic multilayer substrate of this type.
The manufacturing process is shown in order in (2). First, a through hole is formed in a green sheet (hereinafter referred to as a sheet) 1 by punching or the like, and a conductive paste is filled in the through hole to form a via 2.

Thereafter, a conductive paste is formed as the wiring conductor layer 3 by screen printing or the like. Next, in order to form a cavity for the purpose of mounting an IC, etc., the sheet 1
Punching out openings 4 and openings 5 of different sizes,
The sheet 1 having the openings 4 and 5 and the sheet 6 having no openings are laminated.

The laminated body 7 is vacuum packaged in a bag 8 having nylon, polyethylene, or a suitable softness, and the medium 9 such as water or an inert gas is applied with uniform temperature and pressure from all directions and pressure-bonded. . A ceramic multilayer substrate having a cavity structure has been manufactured by firing the laminated body thus pressure-bonded.

FIG. 5 is a side sectional view showing a second conventional example, and the manufacturing steps are shown in order in (1) and (2). In this conventional example, in the step of vacuum-packing the laminate 7 and applying pressure thereto, a mold 10 having the same shape as the cavity shape is inserted into the cavity portion in order to adjust the shape of the cavity.

By doing so, the mold 10
The sheet was made to absorb the wiring conductor layer 3 of the cavity portion to prevent the step from being generated.

[0007]

However, according to the first prior art, when the laminated body is pressure-bonded, it is vacuum-packaged with a flexible bag and pressure is applied with a medium such as water or an inert gas. 6 shows the problem that when the thickness of the internal wiring conductor layer 3'is set to t as shown in the side sectional view of the main part, there is a step of t in the cavity, which hinders the wire bonding of the LSI. there were.

The second prior art is intended to compensate for the drawbacks of the first prior art. In this case, however, the problem is shown in FIG. The pressing force is often biased or becomes too strong due to misalignment or inaccuracy with the dimension of the step, causing disconnection A of the wiring conductor in many cases, and there is a problem that the function as a substrate is not fulfilled. It has not been resolved.

In view of the above problems, the present invention provides a method of absorbing a thickness of an internal wiring conductor layer by a sheet and obtaining a straight surface structure to prevent a step from occurring in a cavity, Furthermore, it eliminates the need to use a special mold for adjusting the shape inside the cavity, that is, prevents the disconnection of the wiring conductor, prevents the wire bonding due to the defective shape of the cavity, and the substrate due to the disconnection that occurs during use of the mold. It is an object of the present invention to eliminate defects and realize a substrate with high yield.

[0010]

In order to achieve the above object, the present invention is designed to compress a laminated sheet while vertically restricting the sheet surface from the vertical direction. That is, a via having a through hole filled with a conductive paste, a wiring conductor layer formed by printing a conductive paste on the surface, and a sheet having an opening for forming a cavity have no opening. In a method for manufacturing a ceramic multi-layer substrate having a cavity structure formed by stacking together with a sheet and press-bonding and firing, a laminated body in which sheets having an opening are stacked is sandwiched between metal plates from above and below and pre-pressed, and then the opening It is characterized in that it is laminated and pressure-bonded together with a laminated body in which sheets having no parts are laminated.

[0011]

According to the present invention by the above method, a cavity is formed for the purpose of mounting an IC on a sheet having a via formed by filling a through hole with a conductive paste and a wiring conductor layer formed by printing the conductive paste on the surface. In order to form, the opening is cut out, and the laminated body in which the sheets having this opening are laminated is sandwiched between the metal plates from above and below and the pressure is applied beforehand, the surface of the laminated body is regulated straight by the metal plate from the vertical direction. However, since the surface is compressed, the sheet absorbs the thickness of the internal wiring conductor layer, and a straight surface structure is obtained.

After that, a substrate having no step in the cavity portion can be obtained by laminating, press-bonding, and baking together with a laminated body in which sheets having no opening are laminated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a first embodiment of the present invention.
The manufacturing process is shown in order in (3). First, a through hole is provided in the sheet 1 by punching or the like, and a conductive paste is filled in the through hole to form the via 2. Then, a conductive paste is printed on the surface of the sheet 1 by screen printing or the like to form the wiring conductor layer 3.

In order to form a cavity in the sheet 1 for the purpose of mounting an IC or the like, the opening 4 and the opening 5 having different sizes are punched out. Next, the metal plates 11 having openings of the same size as the openings 4 and 5 are placed above and below the stacked bodies 12 and 13 in which the openings 4 and 5 are stacked. In this case, either the upper side or the lower side may not have an opening. Similarly, a metal plate 11 'having no opening is placed on the laminated body 14 in which sheets having no opening are laminated (FIG. 1 (1)).

The laminates 12, 13 and 14 with the metal plates 11 and 11 'installed on the upper and lower sides are individually vacuum-packaged by nylon, polyethylene or a bag 8 having an appropriate softness, which is then water or waterless. The medium 9 such as an active gas is applied with uniform temperature and pressure from all directions to perform pressure bonding (FIG. 1 (2)). The pressure at this time is usually lower than the pressure bonding pressure. This is to increase the adhesive force between the laminates that have been previously pressure-bonded at the time of pressure bonding for finishing later.

As a result, the laminated bodies 12, 13, 14 are surface-compressed from above and below while the surfaces are regulated straight by the metal plates 11, 11 ', so that the sheet absorbs the thickness of the internal wiring conductor layer 3'. However, the portions with and without the internal wiring conductor layer 3'have the same thickness, and the step is eliminated. Next, the respective laminated bodies 12, 13, 14 are taken out from the bag 8 and laminated, and the laminated body 15 is again vacuum-packaged by the bag 8 and press-bonded by the medium 9 by applying uniform temperature and pressure from all directions. (Fig. 1 (3)). The pressure at this time is usually the pressure bonding pressure.

The ceramic multilayer substrate having a cavity structure is completed by firing the laminated body 15 which is pressure bonded as described above. FIG. 2 is a side sectional view showing a second embodiment of the present invention, in which manufacturing steps are shown in order in (1) to (4). Similar to the first embodiment, the sheets having the openings 4 and 5 are laminated for each sheet having the openings, and the sheets having no openings are laminated to form the laminates 12, 13 and 14 (FIG. 2). (1)). Next, these laminated bodies 12, 13, 14
Are pressure-bonded by the axial pressure press machine 16 each having two facing metal plates 11 ″ at a pressure temperature and a value lower than the normal pressure bonding (FIG. 2 (2)).

As a result, the laminated bodies 12, 13, 14 are surface-compressed from above and below while the surface is regulated straight by the metal plate 11 ", so that the sheet absorbs the thickness of the internal wiring conductor layer 3 '. The portions with and without the internal wiring conductor layer 3'have the same thickness, and the step is eliminated.After performing the prior pressure bonding process of FIG. (3)), laminated sheet 1 after pressure bonding
After laminating 2, 13, and 14 to form a laminated body 15, vacuum packaging is performed by the bag 8 and pressure is applied uniformly by the medium 9 from all directions in the same manner as in the first embodiment (see FIG. 2 (4)). The ceramic multi-layer substrate having a cavity structure is completed by firing the laminated body which is pressure bonded as described above.

FIG. 3 is a side sectional view showing the operation of the present invention. In both the first and second embodiments, as shown in FIG. The sheet has a straight surface structure B that absorbs
Can be formed.

[0020]

As described above in detail, according to the present invention, the vias formed by filling the through holes with the conductive paste, the wiring conductor layers formed by printing the conductive paste on the surface, and the cavities are formed. In a method for manufacturing a ceramic multilayer substrate having a cavity structure, which is formed by laminating a sheet having an opening with a sheet having no opening, press-bonding and firing the laminated sheet, a laminated body obtained by laminating sheets having an opening is formed. Since it is sandwiched by metal plates from above and below and pressure-bonded first, and then laminated and pressure-bonded together with a laminated body in which sheets without openings are laminated, it is necessary to compress the surface of the laminated body while vertically regulating the sheet surface. Can and can

As a result, the sheet can absorb the thickness of the internal wiring conductor layer, and a straight surface structure can be obtained, which prevents a step from being formed in the cavity portion, and moreover the inner shape of the cavity is adjusted. It eliminates the need to use a special mold, that is, prevents the disconnection of the wiring conductor, eliminates wire bonding failure due to defective cavity shape, and substrate failure due to disconnection that occurs during use of the mold, resulting in high yield. The effect is to realize a substrate.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a second embodiment of the present invention.

FIG. 3 is a side cross-sectional view of an essential part showing the operation of the present invention.

FIG. 4 is a side sectional view showing a first conventional example.

FIG. 5 is a side sectional view showing a second conventional example.

FIG. 6 is a side sectional view of an essential part showing a problem of the first conventional example.

FIG. 7 is a side sectional view of an essential part showing a problem of a second conventional example.

[Explanation of symbols]

 1,6 sheet 2 via 3 wiring conductor layer 3'internal wiring conductor layer 4,5 opening 8 bag 9 medium 11, 11 ', 11 "metal plate 12, 13, 14, 15 laminated body 16 axial pressure press machine

Claims (1)

[Claims] 1. A sheet having an opening for forming a via, a via formed by filling a through hole with an electrically conductive paste, a wiring conductor layer formed by printing an electrically conductive paste on a surface, and an opening for forming a cavity. In a method of manufacturing a ceramic multilayer substrate having a cavity structure formed by laminating a sheet having no sheet and press-bonding and firing the sheet, a laminated body in which sheets having an opening are stacked is sandwiched between metal plates from above and below and pre-pressed, After that, a method for manufacturing a ceramic multilayer substrate having a cavity structure is characterized in that the sheet is laminated with a laminated body in which sheets having no openings are laminated and pressure-bonded.