JPS6239558B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a multilayer ceramic substrate with increased wiring density, and more specifically, the present invention relates to a method for manufacturing a multilayer ceramic substrate with increased wiring density. The present invention relates to a manufacturing method for easily manufacturing a multilayer ceramic substrate having high-density wiring.

Recently, multilayer ceramic substrates having circuit wiring not only on the surface layer but also on the intermediate layer have come to be widely used.

In such a multilayer wiring ceramic board, it is necessary to establish conduction between each wiring layer, but in this case, holes, so-called through holes, are made in the unfired ceramic board, and metal powder, binder, organic solvent, etc. are injected into the holes. It is being filled with a paste mixed with

However, today, the trend is toward downsizing substrates and increasing wiring density, and as a result, the spacing between through holes has become extremely close, and there is also a need to reduce the diameter of through holes. The current technology of creating a through hole and filling it with metal powder paste using a screen mask generally requires a through hole diameter of 0.3 mm or more, and if it is smaller than that, it is difficult to press fit the metal powder paste and there is no continuity. A defect occurs. Also, the distance between each through hole
0.6mm is the dimension required to drill a through hole with a diameter of 0.3mm; if it is smaller than that, it will be difficult to drill, cracks will occur between the holes, and unevenness will occur on the surface. This makes it difficult to print wiring.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and is a method for manufacturing a multilayer wiring ceramic board that is electrically connected to the wiring in each layer. , unfired ceramic plates are laminated and glued so that the printed lines are parallel, and then cut at right angles to the printed lines, with the cut surface as the main surface,
The present invention also provides a method for producing a high-density multilayer wiring ceramic substrate, which is characterized in that a wiring pattern is printed using metallized paste on the surface using the printed line cut portion as a conduction port, and the wiring patterns are laminated, bonded, and fired. be.

That is, the present invention is manufactured by a method that improves the conventional process of providing a through hole and filling it with metal powder paste to establish conduction as follows. This is a perspective view of a conductor made by forming a through hole and filling it with metal powder paste. It is a hole for deciding. Figures 2A, B, C, D, and E are perspective views showing the manufacturing process of the present invention. In Figure 2A, printed lines with metallized paste are applied to the conductive positions on five sheets, and the top and bottom surfaces are thickened. This is a perspective view of thick sheets arranged. In the figure, 11 is a thick sheet that is the same as the conduction interval of the conduction port 2, 12 is an unprinted thick sheet, 13 is a hole for determining the position, and 14 is a conduction position in the sheet 11. This is a printed line made of metallized paste.

FIG. 2B is a perspective view of FIG. 2A laminated and bonded, and in the figure, 14a is a printed edge by metallizing paste, 15 is a laminated end face with a printed edge, and E-I' is a cutting direction. Fig. 2C is a perspective view of Fig. 2B cut perpendicularly to the E-A' direction, in which 14a is the printed end that will become the conduction port, 16 is the cut surface that will be the main surface, and 17 is the position that determines the position. It is a hole. FIG. 2D is a perspective view showing circuit wiring on the four main surfaces 16 of FIG. 2C, and numeral 18 in the figure is circuit wiring made of metallized paste. FIG. 2E shows an unfired finished product obtained by laminating and bonding FIG. 2D and removing unnecessary portions of the end faces. Reference numeral 19 in the figure is a lead extraction printing section.

The above-described manufacturing method of the present invention can reliably manufacture through-holes with a diameter of 0.3 mm or less, which cannot be manufactured using conventional methods, and even when the distance between adjacent through-holes is 0.6 mm or less. There are no inconveniences such as cracks or crevices that occur during installation and poor conductivity that occurs because the metal powder paste is not reliably press-fitted into the hole.

With the manufacturing method of the present invention, it is possible to print products with a minimum dimension of 0.1 mm for printed lines serving as conductive holes and a minimum dimension of 0.2 mm for each conductive interval, and by increasing the number of laminated and bonded sheets, it is possible to print large and high-quality products. Multilayer ceramic substrates with dense and complex circuits can be manufactured.

Examples will be described below.

Example 1 Each conduction port has an equal interval of 0.3 mm in the vertical direction,
Manufactured with uniform width dimensions of 5.0mm in the horizontal direction.

To 100 parts of a mixed powder consisting of 96 parts by weight of alumina with an average particle size of 1.5μ and 4 parts by weight of a sintering aid such as magnesia, calcia, or silica with the same particle size, 6 parts of polyvinyl butyral resin as an organic binder and a plasticizer. 4 parts of dibutyl phthalate (codes D, B, P) are mixed with methyl ethyl ketone (codes M,
E, K) was used to make a slurry, and green sheets with thicknesses of 0.3 mm and 1.0 mm were produced using the doctor blade method.

Using that sheet, the vertical conduction spacing is 0.3
A green sheet having the same thickness dimension as mm was cut into the same external dimensions to obtain the sheet 11, holes 13 for determining the position were provided at the four corners, and five sheets were manufactured.
Two lower sheets 12 are manufactured by laminating and bonding five sheets each having the same external dimensions and a thickness of 1 mm, and holes 13 for determining the positions are provided at the four corners. Next, the sheet 11 has a horizontal conduction interval of 5.0 mm, a width of 0.3 mm, and a thickness of 0.3 mm.
Two printed lines 14 made of 0.02 mm metallized paste are mixed with 97% by weight of tungsten powder and 3% by weight of alumina powder (average particle size: 1μ), 5 parts by weight of ethyl cellulose as a binder, and butyl carbitol as an organic solvent. Screen printing is performed using a paste mixed with 30 parts by weight, and five sheets are printed, the same as the number of conductive pieces in the vertical direction.

A perspective view thereof is shown in FIG. 2A.

Next, using an adhesive device, five sheets are laminated on the 5 mm sheet 12 as the bottom layer with the printed lines 14 in the same direction, and the 5 mm sheet 12 as the top layer is placed on top of the 5 mm sheets 12 and placed in contact with each other. A perspective view thereof is shown in FIG. 2B.

Next, using a cutting machine, cut 4 pieces into 0.7 mm thick pieces in a direction perpendicular to the printed line of the metallized paste, that is, perpendicular to the direction of the arrows ``A'' and ``A'', excluding the end piece. Holes 17 are provided at the four corners of 16 to determine the position. A perspective view thereof is shown in FIG. 2C. Using the cut surface as the main surface 16, the printed cut portion 14a as the conductive hole, and screen printing the circuit wiring 18 using the same paste used to print the conductive metallized paste, respectively, to produce four sheets, and a perspective view of the same is shown in FIG. Shown in Figure 2D. These were laminated and bonded using an adhesive device, and the unnecessary portions at the four corners were cut off to obtain the desired product.

A perspective view thereof is shown in FIG. 2E. After removing the resin from the above product at a temperature of 200℃, the temperature is 1555℃.
The product was held in a hydrogen atmosphere for 1 hour and sintered to obtain the desired product.

Embodiment 2 There are 9 conduction ports in the vertical direction and 4 in the horizontal direction, for a total of 36, the two outer rows in the vertical direction are arranged on the same line in the horizontal direction, and the two inner rows in the vertical direction are arranged on the same line in the horizontal direction. Lined up on a line, the two outer rows and the two inner rows are not on the same line.
Another embodiment of the present invention shown in FIGS. 3A and B, in which the vertical conduction spacing is all 0.3 mm, the horizontal spacing between the two outer rows is 5 mm, and the spacing between the two inner rows is 4 mm. This will be explained using a perspective view.

Green sheets with thickness dimensions of 1.0 mm, 0.2 mm, and 0.1 mm were prepared using the same mixing ratio and preparation method as described in Example 1.
Manufactured using the doctor blade method. Cut this green sheet into the same external dimensions and have a thickness of 1.0 mm.
Ten sheets and nine each of 0.2 mm and 0.1 mm sheets are made, and holes 23 are provided at the four corners of the total number of sheets to determine the positions. On the above 0.2 mm thick sheet 21, two metalized wires 24 having a lateral conduction interval of 5 mm, a width of 0.1 mm and a thickness of 0.01 mm were screen printed using the tungsten paste used in Example 1, and 9
2 sheets with a thickness of 0.1mm in the same manner.
1a has a horizontal conduction interval of 4 mm and a width of 0.1 mm.
and line 24 made of metallized paste with a thickness of 0.01 mm.
Print 2 copies of a and make 9 copies.

Next, 5 sheets of 1 mm thickness were laminated and glued 22 from the bottom side, and the 0.2 mm sheet 2 printed above was placed on top of it.
1 with the printed surface 24 facing upward, and the 0.1 mm thick sheet 21a printed thereon is placed on the printed surface 24a.
21 with a thickness of 0.1 mm and 9 sheets of each sheet 21a with a thickness of 0.1 mm are stacked on top of it in the same manner as described above, and on top of that, a sheet 5 with a thickness of 1 mm is placed. The sheet 22 is laminated and bonded in the same manner as the bottom surface. A perspective view thereof is shown in FIG. 3A.

Next, using a cutting machine, cut 5 pieces to a thickness of 0.5 mm in the direction perpendicular to the metallized printing line, that is, in the direction of the arrows E-A', excluding the end piece. A hole 27 is provided to determine the position, and a perspective view thereof is shown in FIG. 3B. In the next step, in the same manner as in Example 1, the above-mentioned cut surface is used as the main surface 26, the printed cut portion 24 is used as a conductive hole, and a printed line is applied using metallized paste for circuit wiring, laminated and bonded, and the unnecessary parts on both sides are cut, resin After punching and sintering, the desired product was obtained.

Comparative Example In Figure 1 of the conventional method of forming through holes and filling them with metal paste to establish continuity, each through hole has a spacing of 0.5 mm and a through hole diameter of 0.2 mm. Although various viscosity changes were made and press-fitting into the through-hole was confirmed while checking with a magnifying glass, nothing satisfactory could be achieved. Therefore, for each through-hole with a spacing of 0.6 mm and a through-hole diameter of 0.3 mm, a total of 100 parts by weight of 49% by weight of tungsten, 49% by weight of molybdenum, and 2% by weight of alumina powder (average particle size of 1.5μ) is used.
The through-holes were then filled with a paste prepared by mixing 5 parts by weight of ethyl cellulose as a binder and 22 parts by weight of butyl carbitol as an organic solvent using a screen mask. The next steps of circuit wiring printing, adhesive lamination, cutting resin removal, and sintering were performed in the same manner as in Example 1 of the present invention, and a conventional product was obtained, but the main surface dimension was more than twice as large as that of the product of the present invention. Ta.

Actual use tests were conducted on the products manufactured in the above examples, and good results were obtained, no different from conventional products.In addition, in the above examples, the method of printing on green sheets, laminating, and bonding was used. As described above, only the top and bottom layers use green sheets,
It is also possible to manufacture the intermediate material by applying a paste of the same quality as the green sheet, printing on it, and repeating this process.

The manufacturing method of the present invention is suitable for manufacturing multilayer ceramic substrates with high wiring density, many conductive holes between layers, and extremely close spacing between conductive layers, and is suitable for the manufacturing method of multilayer ceramic substrates in which the wiring density is high and the wiring density is increased. This is a manufacturing method that meets the requirements. It can be used for ceramic chip carriers for electronic components, small transistor-based products, IC packages, motherboards, communication equipment, and other small and large products, so there are high expectations for the future.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional method in which through holes are made in a sheet cut by punching and filled with metal powder paste. Figure 2A is a perspective view of the present invention before lamination bonding with printed lines made of metallized paste provided at conductive positions, and Figure 2B is a perspective view of each sheet printed with the metalized paste of Figure 2A and the upper and lower layers without printing. Figure 2C is a perspective view of the sheets laminated and glued together, Figure 2C is a perspective view cut in the direction of the arrows E-A' in Figure 2B, and Figure 2D is a perspective view of Figure 2C with circuit wiring applied to the surface. , FIG. 2E is a perspective view in which the components shown in FIG. 2D are laminated with adhesive and unnecessary parts are removed. FIG. 3A is another embodiment of the present invention, and FIG. 3B is a perspective view of each sheet printed with metallizing paste and the upper and lower unprinted sheets laminated with adhesive, and FIG. ' is a perspective view cut in the direction of the arrow. 1, 11, 21, 21a... Sheet cut by punching, 2... Through hole filled with paste, 3, 13, 17, 23, 27...
...Position determining holes, 12, 22...Top and lower thick sheets, 14, 14a, 24, 24a...Printed portions serving as conduction ports, 15...Laminated end faces with exposed printed ends, 16, 26... ...Cut main surface, 18...
...Wiring circuit, 19...Lead extraction printing section.

Claims (1)

[Claims] 1. In a method for manufacturing a multilayer wiring ceramic board that is electrically connected to the wiring in each layer, parallel printed lines are formed using metallization paste on an unfired ceramic board, and the printed lines are made parallel to each other on the unfired ceramic board. are laminated and bonded, and then cut at right angles to the printed line, with the cut surface serving as the main surface and the cut portion of the printed line serving as a conductive hole, and printing a wiring pattern using metallized paste on the surface, A method for producing a high-density multilayer wiring ceramic substrate, which is characterized by laminating, adhering, and firing them.