JPH0444393A - Manufacture of multilayer ceramic circuit board - Google Patents

Abstract

PURPOSE:To contrive to generate hardly a warpage in the title board and to contrive the improvement of the thermal shock resistance of the board by a method wherein a conductive cementing material consists of a conductive paste containing a resin composition as a binder and/or a solder material and an insulative bonding agent is constituted of an organic bonding agent. CONSTITUTION:With an organic bonding agent 4 consisting of an SiO2 particle- containing thermosetting epoxy resin composition applied on the surface of a ceramic substrate 1' except parts 2'a for intersubstrate continuity use of a circuit 2' on the surface of the substrate 1' by a screen printing method, a conductive paste 5 containing a resin composition as a binder is applied on the parts 2'a as a conductive cementing material using a dispenser. A ceramic substrate 1 is superposed on the substrate 1' in such a way that parts 2a for intersubstrate continuity use face the parts 2'a via the paste 5 and the substrates 1 and 1' are pressed and heated. Whereupon, the bonding agent 4 and the paste 5 are hardened, the parts 2a and 2'a are jointed to each other and a multilayer ceramic circuit board is completed. A prescribed interval is held between the ceramic substrates 1 and 1' SiO2 particles and short circuit between a circuit 2 on the surface of the substrate 1 and the circuit 2' is reliably prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a ceramic multilayer wiring board in which a plurality of ceramic substrates are laminated and bonded.

[Conventional technology and problems]

In recent years, as electronic devices have become smaller and lighter, there has been a strong demand for higher density wiring boards used to implement electronic circuits. Ceramic wiring boards are no exception.
Multi-layering is being considered and proposed for higher density.

For example, there is a method of stacking and firing ceramic green sheets that are printed with conductor paste in a circuit pattern before a ceramic substrate, but this method has problems such as being prone to cracking or warping during firing.

Therefore, in order to solve the problem of cracking and warping mentioned above, we obtained a plurality of ceramic substrates that were processed into substrates and circuits instead of using green sheets, and used them to heat the conductive parts between the substrates in the circuit at a high temperature (approximately 800 degrees Celsius). ) There is a method in which the two parts are placed facing each other through a treated conductive bonding material and the other parts are overlapped through an insulating adhesive made of a glass composition, and then heated under pressure (Ono et al.; Electronic Materials 1988). However, even with this method, it is difficult to say that the problem of warping has been sufficiently improved;
There is a problem that the thermal shock resistance of the bonded portion between the ceramic substrates is insufficient.

[Problem to be solved by the invention]

In view of the above circumstances, it is an object of the present invention to provide a method for obtaining a ceramic multilayer wiring board that is less likely to warp and has excellent thermal shock resistance at bonded portions between ceramic substrates.

[Means to solve the problem]

In order to solve the above-mentioned problem, in the method for manufacturing a ceramic multilayer wiring board according to the present invention, the parts for inter-board conduction in the circuit face each other via a conductive bonding material, and the other parts are arranged via an insulating adhesive. The conductive bonding material is made of a conductive paste and/or solder material using a resin composition as a binder, and the insulating adhesive material is made of an organic adhesive. That's what I do.

The circuit-formed ceramic substrate used in this invention is as follows:
Examples include those in which a metal layer (for example, a copper layer) is formed on a ceramic substrate by a plating method such as electroless plating or a vapor deposition method such as sputtering, and then patterned using photolithography technology to provide a circuit. Another option is to print a conductive paste in a predetermined pattern and fire it, but the former method of forming a metal layer and patterning allows for the formation of finer circuits, and has the advantage that the electrical resistance of the circuit itself is lower. . The ceramic substrate may be further mounted with a resistive element or a semiconductor element to form a HIC (high frit IC). Further, the thickness of the ceramic substrate is usually about 0.3 to 1 nm.

In the present invention, as the conductive bonding material, a conductive paste having a resin composition (for example, a thermosetting resin composition such as an epoxy resin composition) as a binder and a solder material are used alone or in combination. In the case of a conductive paste, it is applied to a predetermined position on the surface of the ceramic substrate using a screen printing method or the like. In the case of solder materials, solder paste (a cream-like mixture of solder powder and vehicle) is applied to a predetermined position on the surface of a ceramic board using a screen printing method, or it is applied to a predetermined position on the surface of a ceramic substrate using a solder bath.
There are methods such as attaching it to a predetermined position on the surface of a ceramic substrate by f-dipping.

Examples of the organic adhesive used as the insulating adhesive in this invention include thermosetting resin compositions such as epoxy resin compositions, solder resists, and the like.

Note that it is preferable that a filler is mixed into the insulating adhesive in order to adjust the distance between the substrates.

Specifically, ceramic particles (for example, 5iOz particles, A1.O, particles) having a particle size of about 20 to 100 microns are made to account for about 5 to 50vo1% of 100vo1% of the insulating adhesive.

Heat treatment is usually carried out at a temperature of 200°C or less for conductive pastes and 250°C or less for solder materials, and
．． Applying a pressure of about 1 to 1 kg/aJ Next, an example of the flow of manufacturing will be explained with reference to the drawings.

First, a ceramic board with a circuit including through holes,
Prepare as follows.

96% of through holes (diameter 0.3 to 0.5 m) are clear.
Alumina substrate (thickness 0-5 wm, W 10 cm,
Two pieces of horizontal 10 (J) are immersed in an 85% phosphoric acid bath at about 270 to 330°C for 3 to 10 minutes to roughen the surface. Next, the normal thickness is applied by electroless copper plating to cover the substrate surface including the inside of the through hole with a 10 μm thick layer of f1, using normal photolithography technology as shown in Figure 1 (al). Then, !PlFi is patterned to form a circuit 2.2' including through holes.In this case, it is fully possible to set the minimum line width and minimum distance between lines in the circuit to about 50n.

After this, as shown in FIG. 1 t8), the ceramic substrate 1
．． A resistive element 3.3' is provided at 1' to obtain a ceramic substrate 1.1' with a circuit including through holes. Resistance element 3.
For the formation of 3′, il! A conventional N2 fired resistor paste or an organic resistor paste is used.

Subsequently, as shown in FIG. 1 (bl), SiO□ particle-containing thermosetting epoxy was applied to the surface of the ceramic substrate 1', except for the inter-substrate conduction portion (conduction electrode) 2'a of the circuit 2'. An organic (insulating) adhesive 4 made of a resin composition is applied by a screen printing method, and a conductive part 2 between the substrates is applied.
A conductive paste 5 having a resin composition as a binder is applied as a conductive bonding material to 'a by a dispenser.

Then, the ceramic substrate 1.1' is connected to the inter-board conduction portion 2.
a and 2'a are stacked so as to face each other with the conductive paste 5 interposed therebetween, and then, for example, 150
Heat under pressure at ℃. Then, organic adhesive 4
And the conductive paste 5 is hardened and the inter-board conductive portion 2a
, 2'a are combined, and a ceramic multilayer wiring board is completed as shown in Figure 1 (C1).The ceramic substrate 1.1' is maintained at a predetermined distance by 5iO=particles, and short circuits are reliably prevented. When using a solder material as a conductive bonding material, it is recommended that the organic adhesive is first cured under pressure and heat, and then heat treated at a temperature higher than the solder melting temperature (no pressure is sufficient). Make it.

Of course, the invention is not limited to the above example.

For example, the roughening treatment on the substrate surface may be omitted.

Furthermore, although the number of laminated ceramic substrates is two, there is no limit to the number of laminated substrates, and it goes without saying that the number of laminated ceramic substrates may be as many as three, four, and so on. Furthermore, the inter-board conduction portion of the circuit 2 on the surface of the ceramic substrate 1 (
The organic (insulating) adhesive 4 is also applied to the part other than the conductive electrode 2a, and the conductive paste 5 is also applied to the inter-board conductive part 2a, so that both adhesive surfaces are conductive. A bonding material or an organic adhesive may also be used.

[For production]

In the method for manufacturing a ceramic multilayer wiring board according to the present invention, the conductive bonding material includes a conductive paste and/or a solder material whose binder is a resin composition that requires a low heat treatment temperature, and a conductive paste and/or a solder material that requires a low heat treatment temperature. Since the laminated bonding between the substrates is performed using a low-temperature organic insulating adhesive and heat treatment at a lower temperature than conventional methods, warping is less likely to occur.
Since the organic adhesive together with the conductive bonding material firmly bonds the substrates, and the glass composition does not directly bond the substrates, the thermal shock resistance of the bonded portion between the substrates is improved. Direct bonding using a glass composition is weak because the glass portion is likely to crack due to thermal shock applied in subsequent processing steps.

〔Example〕

The present invention will be explained in detail below. This invention is not limited to the following embodiments.

Example 1 - 96% alumina substrate (thickness 0.5 m, length 10 aa, width 10 c11) with open holes for through holes (diameter 0.3 m) 2
The sheet is immersed in an 85% phosphoric acid bath at 300° C. for 5 minutes to roughen the surface. Next, using a high-speed electroless copper plating method, the surface of the substrate including the inside of the through hole was coated to a thickness of 10. n copper layer and pattern the copper layer using conventional photolithography techniques to form a circuit including through holes. In this case, the minimum line width and minimum line distance in the circuit is 50n.
degree'. Thereafter, a normal N2 firing type resistor paste was applied to the ceramic substrate and fired to provide a resistor element.

Next, Al with a particle size of 30 nm was applied to the surface of one ceramic substrate, excluding the inter-board conduction portion (conduction electrode) in the circuit.
An organic (insulating) adhesive made of a thermosetting epoxy resin composition containing 30νo1% of -0a particles is applied by screen printing, and a copper (conductive ) Apply the paste with a dispenser, stack two ceramic substrates so that the conductive parts between the substrates face each other with the copper paste in between, and heat under pressure at a temperature of 150°C in a N atmosphere. Then, the organic adhesive and copper paste harden, and the inter-board conductive parts are bonded together, completing the ceramic multilayer wiring board.

Example 2 A ceramic multilayer wiring board was obtained in the same manner as in Example 1, except that a commercially available solder resist containing no filler was used as the organic adhesive.

Example 3 - Using a solder paste instead of a copper (conductive) paste, the epoxy resin composition was first cured by pressure heating at a temperature of 150° C. in an N2 atmosphere, and then a solder flow furnace was used to cure the epoxy resin composition. A ceramic multilayer wiring board was obtained in the same manner as in Example 1, except that heat treatment was performed in an N8 atmosphere at a temperature of 230° C. at which the solder paste melts to ensure conduction between the substrates.

Example 4 A copper layer was formed by sputtering without surface roughening treatment, and 5iO8 particles with a particle size of 50 nm were
0voj! A ceramic multilayer wiring board was obtained in the same manner as in Example 1, except that an organic (insulating) adhesive made of a thermosetting epoxy resin composition containing 10% was used.

Example 5 A ceramic multilayer wiring board was obtained in the same manner as in Example 4, except that an aluminum nitride substrate (thickness: 0.635 mm, length: 51 cm, width: 5 C1 l) was used.

-Comparative Example 1~ A high-temperature firing type conductive bonding material made of copper powder, glass powder, and vehicle was used as the conductive bonding material, a glass composition paste was used as the insulating adhesive, and N! Medium, 900
A ceramic multilayer wiring board was obtained in the same manner as in Example 1, except that the substrates were heated under pressure at a temperature of .degree. C. and the substrates were directly bonded through an insulating layer made of a glass composition.

The ceramic multilayer wiring boards of Examples 1 to 5 had sufficient electrical continuity and adhesion between substrates, and no abnormal short circuits occurred.

The ceramic multilayer wiring board of Comparative Example 1 had greater warpage than that of Example 3, and the thermal shock resistance of the bonded portion between the boards was low.

〔Effect of the invention〕

As described above, in the method for manufacturing a ceramic multilayer wiring board according to the present invention, the heat treatment temperature during lamination bonding of ceramic substrates is lower than that in the past, so warping is less likely to occur, and an organic adhesive is used in addition to a conductive bonding material. Since the adhesion between the substrates is reliable and there is no need to directly bond the ceramic substrates with a glass composition, the thermal shock characteristics of the bonded portion between the substrates can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view for explaining steps in carrying out an example of the method for manufacturing a ceramic multilayer wiring board of the present invention. ■, 1'... Ceramic substrate 2 on which a circuit is formed.
2'...Circuit 2a, 2'a...Part for conduction between boards 4...Organic insulating adhesive 5...Conductive paste agent Patent attorney Takehiko Matsumoto Procedural amendment (View 7) August 1990 / θ "- 1,19 Ushi no J Shiroku Patent Application No. 2-153563 2, Title of Invention Method for Manufacturing Ceramic Multilayer Wiring Board 3, Relationship with the Amendment Person Case Patent Applicant Address 1048 Kadoma, Kadoma City, Osaka Name (583) Representative Matsushita Electric Works Co., Ltd. (1 m Toshio Miyoshi 4, Agent 6, Specification subject to amendment 7, Contents of amendment ■ Specification page 4 Line 10 says "0.3~1",
Correct it to "0.1~1". ■ On page 5 of the specification, lines 13 to 15, it says “In the case of solder material...
··multiply. "In the case of solder material, the temperature is 400℃.
It is carried out at the following temperature and a pressure of about 0.1 to 1 kg/- is applied. In addition, high-temperature solder material with a melting point (liquidus temperature) higher than the solder reflow temperature is used to prevent the solder between the boards from flowing out during the solder reflow process that is performed to mount components such as semiconductor elements after forming the multilayer board. It is preferable to use ” he corrected. ■ Insert the following text between lines 15 and 16 on page 11 of the specification. “Example 6 - Instead of copper (conductive) paste, commercially available liquidus temperature 240
Using a high-temperature solder paste having a temperature of 150°C, first heat and pressurize the epoxy resin in an N2 atmosphere at a temperature of 150°C to harden the epoxy resin, then use a solder flow furnace to heat the solder paste at a temperature of 280°C, which melts the solder paste, in an N2 atmosphere. A ceramic multilayer wiring board was obtained in the same manner as in Example 1, except that heat treatment was performed to ensure conduction between the substrates. ”

Claims (1)

[Claims] 1 A plurality of ceramic substrates on which circuits are formed are stacked so that the parts for inter-board conduction in the circuits face each other via a conductive bonding material, and other parts are placed via an insulating adhesive, and heated. In the method for manufacturing a ceramic multilayer wiring board, the conductive bonding material is made of a conductive paste and/or a solder material using a resin composition as a binder, and the insulating adhesive is made of an organic adhesive. A method for manufacturing a ceramic multilayer wiring board characterized by: