JPH04124071A - Ceramic circuit board and its production - Google Patents

Abstract

PURPOSE:To prevent the generation of cracks by applying a wiring material comprising a specific metal to a ceramic substrate and into openings, press- sealing the ceramic substrate and the wiring material and calcining the combina tion. CONSTITUTION:A green sheet comprising a ceramic substrate material 1 such as Al2O3 or AlN is prepared, punched and laminated. Viaholes (openings) 3 having prescribed diameters are formed in the prepared substrate. After the formation of the viaholes 3, a wiring material 2 comprising a metal melting at the calcination temperature of the ceramic substrate material 1, such as Cu, Au, Ag, Al, Ni, Pd, Pt, Ag-Pt alloy or W-Cu alloy in the case of the Al2O3 substrate is wired on the ceramic substrate material 1 and in the viaholes. The wired substrate 1 is nipped with plates comprising the same material as the ceramic substrate material from both the sides of the substrate 1, press- sealed under a pressure of approximately 30-100MPa, heated in a N2 atmosphere for defatting, and subsequently calcined at a prescribed temperature to provide a ceramic circuit substrate free from cracks.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a ceramic circuit board and a method for manufacturing the same, and particularly to a multilayer ceramic circuit board provided with a wiring material having low electrical resistance and strong adhesion to the board, to increase the electrical resistance value. The purpose of the present invention is to provide a ceramic circuit board and a method for manufacturing the same that improves the consistency of the firing shrinkage rate between the board and the conductor and prevents cranking, and that the present invention is made of a ceramic circuit board and a metal that melts at the firing temperature of the ceramic board. and a wiring material (2) made of a metal that melts at the firing temperature of the ceramic substrate material (2) on the ceramic substrate material (1) and in the opening (3) provided in the ceramic substrate material (1). The ceramic substrate material on which the wiring material (2) is formed is pressurized, sealed, and fired.

[Industrial application field]

The present invention relates to a ceramic circuit board and a method for manufacturing the same,
In particular, the present invention relates to a multilayer ceramic circuit board provided with a wiring material having low electrical resistance and strong adhesion to the substrate.

As computer systems become faster in recent years, multilayer ceramic circuit boards are required. A technique for forming circuit wiring is a necessary technique for producing a multilayer ceramic circuit board. As a wiring material for ceramic substrates, it is required to have low electrical resistance and strong adhesion to the substrate, and as a conductor for vias to connect layers, it is necessary to bond the substrate and conductor to prevent cracks between the substrate and the conductor. It is necessary to match the firing shrinkage rate.

[Prior Art] Currently, it is said that the conductor material of a ceramic circuit board is a metal that is sintered at the firing temperature of the circuit board through simultaneous firing. However, since the shrinkage modes of the ceramic and metal during the firing process do not match, a difference in shrinkage occurs between the substrate and the conductor. Therefore, a crank is formed between the board and the conductor, reducing the adhesion between the board and the conductor, causing poor conduction.

As shown in FIG. 3, a conventional method for manufacturing a ceramic substrate uses a metal that starts sintering at the firing temperature of the ceramic substrate 1, and adds powder of the same composition as the ceramic substrate into the conductor to form the substrate 1- There is a method for preventing cracks by alleviating the shrinkage rate difference between the vias 3 during the firing process. However, in this method, an insulator is mixed into the conductor in order to increase the adhesion between the substrate and the conductor, resulting in an increase in electrical resistance. Furthermore, low resistance metals such as Cu and Au have melting points of 1200°C.
Ceramink fired at a high temperature of 1600°C or higher (
II2N, Ap2os), the conductor melts and becomes spherical. Therefore, since the conductors that can be used in high-temperature fired ceramics are limited to W, Mo, etc., it is difficult to reduce the resistance of the conductor and adjust the firing shrinkage rate.

[Problem to be solved by the invention]

Accordingly, an object of the present invention is to provide a ceramic circuit board and a method for manufacturing the same, which prevent cranking by improving the consistency of firing shrinkage between the board and the conductor without increasing the electrical resistance value.

Furthermore, the present invention provides high-temperature fired ceramics (A7!N, Al2
An object of the present invention is to provide a ceramic circuit board in which the resistance of a conductor used in ZO3) is reduced, and a method for manufacturing the same.

[Means to solve the problem]

According to the present invention, the above problem can be solved by a ceramic substrate (1),
The problem is solved by a ceramic circuit board characterized by having a wiring material (2) made of metal that melts at the firing temperature of the ceramic circuit board (1).

Ceramic substrates used in the present invention include glass-ceramic composites, alumina (A1.z(h), magnesia (
Preferred are MgO), zirconia (ZrO□), or aluminum nitride (A f N).

In addition, when the ceramic substrate is a glass ceramic composite substrate, the wiring material may be copper (Cu), gold (Au), aluminum, Cu, Au, Ag, or 8!
An alloy containing W, Mo, Ni, Pd, or pt as a main component is preferable.

In addition, when the ceramic substrate is used as an alumina substrate, wiring materials such as Cu, Au, Af, Ni, Pd, Pt, or alloys with W or Mo whose main components are Cu, Au, Ag, Al, Ni, Pd, or pt are used. is preferred.

Furthermore, it is 80% as a wiring material when the ceramic substrate is a magnesia substrate or a zirconia substrate.

Pd, PL, or an alloy containing Au, Ag, Pd, or PL as a main component is preferable.

In addition, when the ceramic substrate is an aluminum nitride substrate, wiring materials such as Cu, Au, Af, Ni, and Pd can be used.
.

Pt or Cu, Au, Ag, Al, Ni, P
An alloy containing d or pt as a main component and W or Mo is preferable.

In the present invention, it is preferable that the wiring material is sealed and fired within the ceramic, and that the circuit wiring is formed of wire.

Furthermore, the above problem can be solved by the ceramic substrate material (1) according to the present invention.
an opening (
3) is characterized by applying a wiring material (2) made of a metal that melts at the firing temperature of the ceramic substrate material, pressurizing and sealing the ceramic substrate material on which the wiring material (2) has been formed, and firing it. The problem is solved by a method of manufacturing a ceramic circuit board.

In the present invention, it is preferable that the wiring material has a wire shape, and the above pressure-sealing treatment is different from the ceramic substrate material.
``It is preferable to sandwich the ceramic substrate material from above and below using the same material.

The pressurizing pressure is preferably about 30 MPa to 100 MPa.

(Function) According to the present invention, cranking between the substrate and the conductor can be prevented by using a metal that melts at the ceramic firing temperature as the wiring material, wiring with wire, and sealing it inside the ceramic. Since the conductor is sealed within the substrate, spherical deformation of the conductor does not occur even if the conductor is fired at a high temperature (1600'C or higher).

Therefore, low-resistance metal wiring can be applied to ceramic (Ml!N, 1203) fired in a high temperature range (1600''C or higher).

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a perspective view of a green sheet (ceramic substrate material) according to the present invention, in which conductor wires 2 are wired and vias are formed with the conductor wires, and a partially enlarged view of A, and FIG. 2(a) and (b) is a sectional view showing a laminate in which a via-forming green sheet is sealed with a solid green sheet, and a partially enlarged view of B.

In the present invention, an alumina substrate is used as the ceramic substrate 1, and Cu, Au, etc., which melt at the firing temperature of the alumina substrate (green sheet) (approximately 1600''C), are used as the wires 2 and the via material 3a.

As shown in FIG. 2, a ceramic substrate material in which wiring material is provided on a green sheet is sandwiched vertically by sealing ceramics 6 of the same quality, and further pressurized through a laminated mold 7. 4 is Delami.

Example 1 A green sheet (density 1.60 g/cffl, thickness 30
0 tna) was prepared by the doctor blade method. This green sheet was punched out to have an opening of 90 mm, and a set of 6 sheets were laminated (60°C, 5 MPa). As shown in FIG. 4, ten pier holes 3 having a diameter of 250 μm were formed in the laminate using a drill. Next, commercially available conductor wire 2 (φ250
, 1111). After forming the vias, wiring was applied to the laminate using commercially available conductor wires (φ250 diameter). After wiring, the top and bottom of the laminate were sandwiched between four green sheets of the same quality as above, and laminated (60℃, 50?1Pa).
The sample was degreased at 800°C for 5 hours in No. 2, and fired under the conditions shown in Table 3, Item a. Table 4 shows the volume resistivity of the wiring after firing and the presence or absence of wrinkles between the substrate and the via.

Example 2 Green sheet 1 (density 1.70 g/d, thickness 300 mm) having the composition shown in Table 1 No. b was produced by a doctor blade method. This green sheet was punched out into a hole of 90Il111 and laminated (60°C, 5MPa) into a set of 6 sheets.

As shown in FIG. 4, ten pier holes 3 of φ250p were formed in the laminate using a drill. Next, commercially available conductor wire 2 (φ250) shown in Table 2 was filled.

After forming the vias, a commercially available conductor wire (φ250IzII
1) was used for wiring. After wiring, the top and bottom of the laminate are
Sandwiched and laminated with green sheets of the same quality as above (60
℃, 50MPa) and wet N, 800℃ in 25
It was degreased at 100 m and then fired under the conditions shown in Table 3 bb.

Table 4 shows the volume resistivity of the wiring after firing and the presence or absence of cracks between the substrate and vias.

Example 3 Green sheet 1 having the composition shown in Table 1 (density 1
．． 60 g/d, thickness 300 Inn) was produced by the doctor blade method. This green sheet was punched out to have an opening of 90 mm, and a set of 6 sheets were laminated (60°C, 5 MPa).

As shown in FIG. 4, ten pier holes 3 of ≠250 tna were formed in the laminate using a drill. Next, commercially available conductor wire 2 (φ250p#A) shown in Table 2 was filled.

After forming the vias, wiring was applied to the laminate using commercially available conductor wires (φ250.m). After wiring, the top and bottom of the laminate were sandwiched between four green sheets of the same quality as above and laminated (60°C,
50 MPa), degreased in the air at 800°C for 5 hours, and fired under the conditions of N[lC in Table 3. Table 4 shows the volume resistivity of the wiring after firing and the presence or absence of cracks between the substrate and vias.

Example 4 Green sheet 1 having the composition shown in Table 1 Nαd (density 1
．． 60g/cd, thickness 300B) was produced by the doctor blade method. This green sheet was punched out to a width of 90m,
A set of 6 sheets was laminated (60″C, 5 MPa).

As shown in FIG. 4, ten pier holes 3 having a diameter of 250 mm were formed in the laminate using a drill. Next, commercially available conductor wire 2 (φ250μ) shown in Table 2 was filled.

After forming the vias, the laminate was wired using commercially available conductor wires (φ250μ). After wiring, the top and bottom of the laminate were sandwiched between four green sheets of the same quality as above and laminated (60℃, 5
0 MPa), degreased in the air at 800° C. for 5 hours, and fired under the conditions shown in Table 3 Nl1d. Table 4 shows the volume resistivity of the wiring after firing and the presence or absence of a crank between the substrate and the via. Further, Table 5 shows the results of samples with Cu wiring.

Example 5 Green sheet 1 (density 1.70 g/d, thickness 300 mm) having the composition shown in Table 1 No. e was produced by a doctor blade method. This green sheet was punched out to a width of 90 mm and laminated (60°C, 5 MPa) into a set of 6 sheets.

As shown in FIG. 4, ten pier holes 3 having a diameter of 250 nm were formed in the laminate using a drill. Next, a commercially available conductor wire 2 (φ250I!In) shown in Table 2 was filled.

After forming the vias, wiring was applied to the laminate using commercially available conductor wires (φ25On). After wiring, the top and bottom of the laminate were sandwiched between four green sheets of the same quality as above and laminated (60°C, 50°C).
0 MPa), degreased in N2 at 800°C for 5 hours,
Firing was performed under the conditions of Nαe in Table 3. Table 5 shows the volume resistivity of the wiring after firing and the presence or absence of cracks between the substrate and vias.

Comparative Example 1 A green sheet having the composition shown in Table 1 No. e (density 1.7 og/cffl, thickness 30011v) was produced by a doctor blade method. This green sheet was punched out to a diameter of 90 mm, and 6 sheets were laminated at 1&[1] (60°C, 5MPa)
I did it.

As shown in FIG. 4, ten pier holes 3 having a diameter of 250 mm were formed in the laminate using a drill. Next, filling was performed with commercially available W paste. After forming the vias, a metal mask was used on the laminate to form wiring 2 (width 3004) using commercially available W paste. After wiring, the top and bottom of the laminate were sandwiched between four green sheets of the same quality as above and laminated (60°C, 50MPa), degreased in N2 at 800°C for 5 hours, and fired under the conditions shown in Table 5. Ta. Volume resistivity of wiring and substrate after firing
Table 5 shows the presence or absence of cranks between vias.

Comparative Example 2 Green sheet 1 having the composition shown in Table 1 Nne (density 1
．． 70 g/d, thickness 300 an) was produced by the doctor blade method. This green sheet was punched out to have an opening of 90 mm, and a set of 6 sheets were laminated (60°C, 5 MPa).

As shown in FIG. 4, ten pier holes 3 each having a diameter of 250 mm were formed in the laminate using a drill. Next, filling was performed with commercially available copper paste. After forming the vias, a metal mask was used on the laminate, and wiring 2 (width 300 mm) was formed using commercially available copper paste. After wiring, the top and bottom of the laminate were sandwiched between four green sheets of the same quality as above and laminated (60°C, 50MPa), degreased at 800''C in N2 for 5 hours, and fired under the conditions shown in Table 5. Volume resistivity of wiring and substrate after firing
Table 5 shows the presence or absence of cranks between vias.

Comparative Example 3 Green sheet 1 (density 1.70 g/cd, thickness 3001 na) having the composition shown in Table 1 Nthe was produced by a doctor blade method. This green sheet is 90++ m
The sheets were punched out and laminated (60''C, 5MPa) in a set of 6 sheets.

As shown in FIG. 4, ten pier holes 3 having a diameter of 250 mm were formed in the laminate using a drill. Next, a commercially available conductor wire 2 (φ250p) shown in Table 2 was filled.

After forming the vias, wiring was applied to the laminate using commercially available conductor wires (φ25On). After wiring, the wiring surface of the laminate was covered with four green sheets of the same quality as above and laminated (60°C, 50°C).
MPa), degreased at 800"C in N2 for 5 hours, and fired under the conditions shown in Table 5. Table 4 shows the volume resistivity of the wiring after firing and the presence or absence of wrinkles between the substrate and vias. .

Table 1: Green sheet composition Table 2: Combination of substrate and conductor O: Good combination, 2 bad combinations: Table 5 Comparison [Effects of the invention] As explained above, according to the present invention, cracks occurring between the substrate and the conductor can be prevented. In addition, the high temperature range (1
600°C or higher) fired ceramics (AffiN, A
pzox) can be provided with low resistance metal wiring. In addition, these effects greatly contribute to the high performance, versatility, and yield improvement of ceramic circuit boards.

[Brief explanation of the drawing]

Fig. 1 is a perspective view and a partially enlarged view of a green sheet according to the present invention, in which conductor wires are wired and vias are formed with the conductor wires, and Fig. 2 (a) and (b) are solid green sheets. FIGS. 3(a) and 3(b) are a perspective view and a partially enlarged view of a ceramic circuit board (conventional), and FIGS. The figure shows an embodiment of the present invention. 1... Ceramic substrate material (green sheet), 2...
・Wire (wiring conductor), 3... Via (wiring conductor), 3a... Via material (wiring material), 4... Delami, 6
... Sealing ceramics (before firing), 7... Laminated mold. 3... Via (wiring material) 3a... Via material 4... Delami 6... Ceramic for sealing Embodiment Fig. 2 Conventional example Fig. 3 Embodiment Fig. 4

Claims (1)

[Claims] 1. Ceramic substrate (1) and the ceramic substrate (1)
A ceramic circuit board comprising a wiring material (2) made of a metal that melts at a firing temperature of . 2. Apply a wiring material (2) made of a metal that melts at the firing temperature of the ceramic substrate material to the opening (3) provided on the ceramic substrate material and the ceramic substrate (1), and apply the wiring material (2) Pressure is applied to the ceramic substrate material that has been formed.
A method for manufacturing a ceramic circuit board, characterized by sealing and firing. 3. The method according to claim 2, wherein the wiring material has a wire shape. 4. The method according to claim 2, wherein the pressurizing and sealing treatment is performed by sandwiching the ceramic substrate material from above and below using a material that is substantially the same as the ceramic substrate material.