JPH04211195A - Manufacture of ceramic multilayered wiring board - Google Patents

Abstract

PURPOSE:To prevent the positional deviation of a through hole at the time of piling up layers by performing the process for forming the through hole, etc., in a state where a carrier film is stuck to a green sheet. CONSTITUTION:Since the first process in which a through hole, etc., is formed through a green sheet cast on a carrier film 12 while the carrier film 12 is stuck to the green sheet 11 and the second process in which the carrier film 12 is removed after the green sheet 11 processed in the first process is piled up one by one and the piled up sheets 11 are adhered to each other by pressing are provided, the elongation of the green sheet is eliminated in each process and a ceramic multilayered wiring board which is free from positional deviation can be manufactured.

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ceramic multilayer wiring board. [0002]

[Prior Art] The conventional method for manufacturing ceramic multilayer wiring boards using the green sheet method involves casting ceramic slurry onto a casting film using a doctor blade method, drying it to form a ceramic green sheet, and then removing the green sheet from the casting film. The process involved peeling it off, cutting it into pieces that corresponded to the size of the board, punching holes for alignment on each piece, printing conductor paste, forming through holes, filling vias, laminating, and then firing. . [0003]

[Problems to be Solved by the Invention] In this conventional method of manufacturing a ceramic multilayer wiring board, a ceramic slurry is cast to form a green sheet, and then the green sheet is peeled off from the casting film and subjected to subsequent processes. Therefore, the green sheet is easily deformed during handling during each process of forming through holes, embedding conductive paste in the through holes, and printing conductive patterns, or due to poor storage conditions of the green sheet, and when laminating through holes, the green sheet is easily deformed. There was a drawback that positional deviation occurred. [0004]

[Means for Solving the Problems] The method for manufacturing a ceramic multilayer wiring board of the present invention includes forming through holes in a ceramic green sheet cast on a carrier film, embedding a conductor paste in the through holes, and applying a conductor to the surface of the green sheet. A first step in which each step of pattern printing is performed with the carrier film attached to the green sheet, and the green sheets with the carrier film that have been subjected to the first step are laminated and pressed one by one, and then the carrier film is peeled off. and a second step. [0005]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. [0006] FIG. 1 shows a green sheet 11 cast onto a carrier film 12 by a doctor blade method. The thickness of the green sheet 11 at this time is approximately 100 μm, and the thickness of the carrier film 12 is approximately 10 μm.
It is 0 μm. The thickness of the carrier film 12 can be changed depending on the width of the green sheet 11 to be cast. In other words, when casting with a wide width (width)
300 mm), depending on the tension at which the film is wound, it is best to use a carrier film with a thickness of about 100 μm to prevent the film from becoming wavy. Carrier films are usually made of polyester and have excellent thermal stability and mechanical strength, making them suitable for holding soft green sheets. [0007] FIG. 2 is a cross-sectional view of the cast green sheet 11 cut together with the carrier film 12, with alignment holes 21 formed at the four corners. The holes for alignment can be of any shape, but if the green sheet is large, a hole of 5 mm in diameter should be placed at each corner as shown in the diagram.
Drilling multiple holes of about 100 mL is effective in reducing misalignment. All subsequent steps are performed using this positioning hole as a reference. [0008] FIG. 3 is a cross-sectional view of a green sheet 11 in which through holes 31 are formed together with the carrier film 12. At this time, the diameter of the through hole 31 is 0.00 mm when the hole is connected to the signal wiring within the board. 1~
The diameter is 0.2 mm, and when used for power supply to an LSI mounted on the surface of the substrate, the diameter is 0.2 to 0.3 mm.

Next, FIG. 4 is a cross-sectional view of a green sheet 11 in which through-holes are formed, with conductive paste 41 embedded in the holes. Gold, silver, silver-palladium, tungsten, molybdenum, or the like is used as the conductive paste 41, and is embedded in the through-hole portion by screen printing using a metal mask. Paste accuracy is 300~
It is 500 kcps.

Next, as shown in FIG.
Conductor pattern 51 for signal wiring and power wiring on the surface of 1
is formed by printing. The conductive paste material used is the same as that used for the through-hole portion, and the accuracy is 100 to 250 kcps. Pattern formation is performed by screen printing, and a screen mesh size of 325 meshes is used at this time. In this way, a signal wiring pattern with a minimum line width of about 100 μm and a thickness of 12 μm (after drying) is printed. [0011] Figure 65 Figure 7 shows the T/H formation as described above,
The sheets with embedded conductor paste and printed conductor patterns are stacked one by one using pins 65 for positioning.
4 to form a green sheet laminate 73. At this time, it is necessary to place several green sheets that will become the substrate base 72 at the bottom. This sheet has no electrical meaning at all and is only needed to laminate the green sheet on top of it. The green sheet of the substrate base 72 is vacuum-adsorbed through a hole at the bottom of the lower mold so that it does not shift inside the mold. Next, the green sheet 11 with the pattern formed thereon is laminated in the opposite direction with the carrier film 12 attached, and the laminated mold (periphery) 6
2. Laminated mold (upper part) 63 and laminated mold (lower part 3) 6
4, heat and press lightly and remove the carrier film 12 (Fig. 6). At this time, the carrier film 12 side and the front side of the green sheets 11 are alternately laminated. The temperature of this thermocompression bonding was 80° C. and the pressure was 70 kg/cm 2 . After the green sheets are laminated in this manner, they are again bonded by thermocompression using the lamination molds 62, 63, and 64. At this time, the temperature was 110°C and the pressure was 180 kg/cm2. As a result, the green sheets are unified to form a ceramic green sheet laminate (FIG. 7). [0012] The substrate base 72 is obtained by removing the binder from the ceramic green sheet laminate 73 and firing it to form a ceramic sintered body, which is then removed by grinding to expose the circuit surface. [0013] In this example, alignment holes 21 are formed in the four corners of the ceramic green sheet cast on the carrier film, and the subsequent steps are performed using these alignment holes. In addition to this, it is also conceivable to create a structure in which a green sheet with a carrier film is attached to a frame 81 for positioning and handling, as shown in FIG. FIG. 9 is a cross-sectional view of FIG. 8. The material of the frame 81 may be metal or engineering plastic with small deformation, and the alignment of the green sheets can be performed by providing alignment holes or grooves in the frame 81 or by adjusting the outer shape of the frame 81. Furthermore, another method for alignment is to form alignment marks on the surface of the green sheet in advance, and to perform alignment in each step by optically recognizing the marks. [0014]

[Effects of the Invention] As explained above, the present invention eliminates elongation of the green sheet during the process by performing each process with the carrier film attached to the green sheet at the time of green sheet casting. This has the effect of making it possible to create a multilayer wiring board.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of another embodiment of the invention.

FIG. 9 is a longitudinal sectional view of another embodiment of the invention.

[Explanation of symbols]

11 Green sheet 12 Carrier film 21 Positioning hole 31 Through hole 41 Conductor paste 51 Conductor pattern 62 Laminated mold (periphery) 63 Laminated mold (upper part) 64 Laminated mold (lower part) 65 Positioning pin 71 Multilayer wiring layer 72 Board base 73 Laminated body 81 frames

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Claims (1)

[Claims] 1. A method for manufacturing a ceramic substrate using a green sheet method, which includes forming a through hole in a ceramic green sheet cast on a carrier film, embedding conductive paste in the through hole, and printing a conductive pattern on the surface of the green sheet. a first step in which each step is performed with the carrier film attached;
1 green sheet with carrier film subjected to the process of
1. A method for manufacturing a ceramic multilayer wiring board, comprising the steps of sequentially laminating and press-bonding the boards one by one, and then peeling off the carrier film.