JPH0575264A - Manufacture of glass ceramic multilayer circuit board - Google Patents

Abstract

PURPOSE:To prevent the generation of the recess of a through-hole by simultaneously grinding a glass ceramic multilayer circuit board, an external shape of which is cut completely, and the dresser of a grinding wheel in the quantity of notch in a trace quantity and to a specified thickness and lapping both sides through a free abrasive grain system. CONSTITUTION:The surface of a glass ceramic multilayer circuit board 1, an external shape of which is cut completely, is ground in a grinding process. When the glass ceramic multilayer circuit board 1 is set to a grinding table 2, green carbon 3 as a dresser for the dressing of a grinding wheel 4 is disposed on the side of the multilayer circuit board 1, and the grinding wheel 4 is rotated in the direction C while moving the grinding table 2 in the direction B. The quantity of notch of the grinding wheel 4 to the green carbon 3 and the multilayer circuit board 1 at that time is represented by 4mum per one stroke. Both sides of the glass ceramic multilayer circuit board 1 the surface of which is grounded completely are lapped through a free abrasive grain system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a glass-ceramic multilayer wiring board, and more particularly to a method for manufacturing a glass-ceramic multilayer wiring board manufactured by a green sheet method using a silver-based conductor as an inner layer conductor.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a state in the vicinity of a through hole after heat treatment in an example of a conventional method for manufacturing a glass-ceramic multilayer wiring board.

A conventional method for manufacturing a glass-ceramic multilayer wiring board manufactured by the green sheet method is to improve the deteriorated layer on the surface by preventing the generation of microcracks in the grinding of the surface after firing the substrate. Therefore, an alumina substrate having a melting point higher than that of glass ceramics is used as a setter, and the ground glass ceramic multilayer wiring substrate is placed on this alumina substrate and heat-treated at about 800 to 900 ° C. in the atmosphere to obtain glass. Work is carried out in which the glass component in the ceramic is raised to form a glass layer again on the surface of the substrate.

That is, in the glass-ceramic multilayer wiring board, both the front and back surfaces of the board are ground by a diamond wheel of a surface grinder so that the board has a predetermined thickness. At this time, microcracks are generated in the glass layer formed on the surface of the glass-ceramic multilayer wiring board due to stress during grinding. The microcracks are generally formed to a depth of 4 to 5 times the surface roughness after grinding, not only lowering the mechanical strength of the glass ceramic multilayer wiring substrate itself, but also I / It also reduces the adhesion strength of the O pin. Therefore, it is necessary to improve the generation state of microcracks, and as a means for this, the heat treatment as described above is performed to re-form the glass layer.

However, in the case of a glass-ceramic multilayer wiring board using a silver-based conductor as the conductor of the inner layer, as shown in FIG.
In a temperature range of ℃ or more, a phenomenon occurs in which silver in the through holes 19 exposed on the surface of the substrate evaporates. For this reason,
A recess 11 having a depth of 10 and several μm is generated in a portion of the through hole 19 which is continuous with the surface of the glass ceramic 10. That is, in the method for manufacturing a ceramic multilayer wiring board using a silver-based conductor as the inner layer conductor, if heat treatment is performed to improve the surface where microcracks are generated by grinding, microcracks are improved, but The recesses 11 are formed in the holes 19, which causes various problems when an organic insulating layer is formed in a later step.

[0006]

As described above, when the conventional method for manufacturing a glass-ceramic multilayer wiring board is applied to a ceramic multilayer wiring board in which a silver-based conductor is used as the inner-layer conductor, through-holes are not formed. It has a defect that a dent is generated and a pinhole is generated when an organic insulating layer is formed in a later step, or the adhesion strength is lowered when an I / O pin is brazed to the back surface.

[0007]

A method for manufacturing a glass-ceramic multilayer wiring board according to the present invention is a glass-ceramic multilayer wiring board in which a silver-based conductor is used as an inner layer conductor to form a glass-ceramic multilayer wiring board by a green sheet method. In the method of manufacturing a substrate, a glass ceramic multilayer wiring substrate and a grinding wheel formed by laminating green sheets that have been formed into a through-hole and metallized, thermocompression-bonded and fired, and then cut the outer shape Of the glass ceramic multilayer wiring board to remove the surface-altered layer by lapping the front and back surfaces of the glass-ceramic multilayer wiring board.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a process diagram showing an embodiment of the present invention, FIG. 2 is a sectional view showing a ground state of the multilayer wiring board in the embodiment of FIG. 1, and FIG. 3 is a multilayer wiring board in the embodiment of FIG. FIG. 5 is a cross-sectional view showing a lapping state, FIG. 5 is a perspective view showing a through hole formation state in the embodiment of FIG. 1, and FIG.
FIG. 7 is a perspective view showing a state of forming via fill in the embodiment of FIG. 7, and FIG. 7 is a perspective view showing a state of stacking green sheets in the embodiment of FIG.

As shown in FIG. 1, the method for manufacturing the glass-ceramic multilayer wiring board of this embodiment comprises a film forming step 21 for forming a green sheet and a through hole forming step 22 for forming a through hole in the formed green sheet. A metallizing step 23 for forming a via-fill and a wiring pattern on the green sheet having the through holes, a laminating step 24 for laminating the green sheet on which the via-fill and wiring patterns are formed, and a thermocompression-bonding step for thermocompression-bonding the laminated green sheets. 25, a firing step 26 for firing the thermocompression-bonded green sheet, a cutting step 27 for cutting the outer shape of the fired green sheet into a glass-ceramic multilayer wiring board, and a surface of the glass-ceramic multilayer wiring board for which the outer shape is cut. Grinding process 28 for grinding and glass whose surface is ground And a lapping step 29 of wrapping La mix multilayer wiring board.

The film forming step 21 is a step of forming a green sheet having a predetermined thickness on a carrier film by a doctor blade method. The through hole forming step 22 is
As shown in FIG. 5, this is a step of forming holes through the green sheet 13 using the punch 12 at a predetermined pitch to form the through holes 9. In the metallizing step 23, as shown in FIG. 6, the screen 14 is placed on the green sheet 13,
Further, a silver paste 15 is placed on the screen 14 as a conductive paste, and the squeegee 16 is moved in parallel in the direction of arrow A while applying an appropriate pressure to the silver paste 1 in the through hole 9 (see FIG. 5).
5 is filled to form a through-hole 17 that is via-filled. Similarly, the wiring pattern 18 (see FIG. 7) is also metalized and formed by screen printing. The laminating step 24 is a step of laminating the plurality of green sheets 13 formed as described above in a mold, as shown in FIG. 7. The laminated green sheets are thermocompression bonded in a thermocompression bonding step 25, baked in a baking step 26, and cut in a cutting step 2.
At 7, the outer shape is cut and finished into a predetermined shape to obtain a glass-ceramic multilayer wiring board.

The surface of the glass-ceramic multilayer wiring board whose outer shape has been cut is ground in a grinding step 28. This surface grinding process destroys the glass layer formed on the surface of the board during firing, and thus a large number of micro-chips are formed. It is in a state where cracks have occurred. Moreover, since the silver-based conductor is used as the conductor of the inner layer, the grinding wheel is easily clogged during this surface grinding process.If the grinding wheel is clogged, stress will be applied to the substrate during grinding. As a result, the surface of the substrate is deeply altered.

When the surface of the substrate is ground in the grinding step 28, it is necessary to suppress the surface roughness of the substrate after grinding to 0.3 μm or less. This makes it possible to keep the depth of the surface-altered layer due to grinding as shallow as possible. Therefore, as shown in FIG. 2, the glass ceramic multilayer wiring board (multilayer wiring board) 1 is attached to the grinding table 2
When set to, the green carbon 3 which is the dressing dresser for the grinding wheel 4 is arranged beside the multilayer wiring board 1, and the grinding table 4 is rotated in the direction of arrow C while moving the grinding table 2 in the direction of arrow B. Let At this time, the cutting amount of the grinding wheel 4 with respect to the green carbon 3 and the multilayer wiring board 1 is about 4 μm per stroke. As a result, clogging of the grinding wheel 4 can be prevented, and the multilayer wiring board 1 can be ground to a predetermined thickness while reducing the load on the multilayer wiring board 1.

In the lapping step 29, the glass ceramic multilayer wiring substrate which has been subjected to the surface grinding is subjected to lapping by the free abrasive grain method on both front and back surfaces thereof to remove the surface-altered layer. The wrapping process is
This is performed as shown in FIG. That is, the multilayer wiring board 1 whose surface has been ground is placed on the resin-based surface plate 5, and the diamond paste 7 and the lubricant 8 are intermittently sprayed from the nozzle 6. At this time, the resin-based surface plate 5 is rotated to diffuse the diamond paste 7 and the lubricant 8 between the multilayer wiring board 1 and the resin-based surface plate 5. Further, the multilayer wiring board 1 is pressed from above (arrow D). By performing the lapping process in this manner, the multilayer wiring board 1
Is capable of removing the surface-altered layer while suppressing the formation of microcracks in the glass part that connects the alumina particles, avoiding thermal stress as in the past, and eliminating cracks and evaporation of the conductor paste. Therefore, a highly reliable multilayer wiring board can be completed.

[0015]

As described above, according to the method for manufacturing a glass-ceramic multilayer wiring board of the present invention, the glass-ceramic multilayer wiring board whose outer shape has been cut and the dresser of the grinding wheel are ground simultaneously with a very small amount of cut. To a predetermined thickness, and then, by lapping the front and back surfaces by the loose abrasive grain method to remove the surface-altered layer, microcracks on the surface can be improved without heat treatment. It is possible to prevent the occurrence of dents in the holes, and thus to prevent pin holes from being formed when the organic insulating layer is formed in the subsequent process, and to reduce the adhesion strength when I / O pins are brazed to the back surface. There is an effect that it can be prevented, and a highly reliable multilayer wiring board can be obtained.

[Brief description of drawings]

FIG. 1 is a process chart showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a ground state of a multilayer wiring board in the embodiment of FIG.

FIG. 3 is a cross-sectional view showing a lapping state of the multilayer wiring board in the embodiment of FIG.

FIG. 4 is a perspective view showing a state near a through hole after heat treatment in an example of a conventional method for manufacturing a glass-ceramic multilayer wiring board.

5 is a perspective view showing a through hole formation state in the embodiment of FIG. 1. FIG.

FIG. 6 is a perspective view showing a via fill formation state in the embodiment of FIG. 1;

FIG. 7 is a perspective view showing a state in which green sheets are laminated in the embodiment of FIG.

[Explanation of symbols]

1 Glass Ceramics Multilayer Wiring Board (Multilayer Wiring Board) 2 Grinding Table 3 Green Carbon 4 Grinding Wheel 5 Resin Surface Plate 6 Nozzle 7 Diamond Paste 8 Lubricant 9 Through Hole 10 Glass Ceramics 11 Recess 12 Punch 13 Green Sheet 14 Screen 15 Silver Paste 16 Squeegee 17 Via-filled through hole 18 Wiring pattern 19 Through hole 21 Film forming step 22 Through hole forming step 23 Metallizing step 24 Laminating step 25 Thermocompression bonding step 26 Firing step 27 Cutting step 28 Grinding step 29 Lapping step

Claims (2)

[Claims] 1. A method for manufacturing a glass-ceramic multilayer wiring board, which comprises forming a glass-ceramic multilayer wiring board by a green sheet method using a silver-based conductor as an inner-layer conductor, and forming a through hole to form a through hole for metallization. After laminating the green sheets that have been subjected to the above procedure, thermocompression-bonding and firing, and then cutting the outer shape, the glass-ceramic multilayer wiring substrate and the dresser of the grinding wheel are ground at the same time with a minute amount of cut, and the predetermined thickness is obtained. A method of manufacturing a glass-ceramics multilayer wiring board, comprising lapping the front and back surfaces of the glass-ceramics multilayer wiring board to remove the surface-altered layer. 2. A method for manufacturing a glass-ceramic multilayer wiring board, which comprises forming a glass-ceramic multilayer wiring board by a green sheet method using a silver-based conductor as an inner-layer conductor, and forming a through-hole to form a through hole for metallization. The glass ceramic multilayer wiring substrate and the dresser of the grinding wheel which are formed by laminating the green sheets subjected to
Grinding with a minute amount of cut of about 4 μm per stroke to a predetermined thickness, and then lapping the front and back surfaces of the glass-ceramic multilayer wiring board by a loose abrasive grain method to remove the surface-altered layer. A method of manufacturing a glass-ceramic multilayer wiring board, comprising: