JPS6150395A - Method of producing ceramic multilayer circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method of manufacturing a ceramic multilayer circuit board.

(Prior Art) Conventional ceramic multilayer circuit boards are manufactured by printing a conductive paste on a pre-sintered ceramic substrate, printing an insulating paste on it, repeating it multiple times to form a multilayer circuit, and then
It was manufactured by firing.

(Problems to be Solved by the Invention) However, this method has the disadvantage that the thermal expansion coefficient of the pre-sintered ceramic substrate is different from the firing yield of the insulating paste, which causes peeling and cracking of the insulating layer. Ta.

A method called Ceramic Green Note was attempted to compensate for this drawback, but this method also had the drawback of peeling and cranking when the insulating layer on the conductor circuit was sintered.

The object of the present invention is to provide a method for manufacturing a ceramic multilayer circuit board free of such drawbacks.

(Means for solving the problem) The present inventors focused on the fact that peeling of the insulating layer and cracks that occur in the insulating layer are caused by firing shrinkage, thermal shock resistance, and chemical resistance of the insulating layer, and conducted various studies. As a result, when the ceramic powder constituting the insulating paste contained 5 to 30% by weight of zirconia and 35 to 6.0% by weight of flux in place of the conventionally used insulating paste, it was found that the conductor It has been discovered that a ceramic multilayer circuit board can be manufactured without peeling or cracking of the insulating layer on the circuit.

The present invention is a method of manufacturing a ceramic multilayer circuit board by printing a conductive paste and a ceramic insulating paste multiple times on a green sheet and firing them simultaneously, in which zirconia is added to the ceramic powder constituting the insulating paste. ~
The present invention relates to a method for manufacturing a ceramic multilayer circuit board containing 30% by weight and 3.5 to 6.0% by weight of flux.

The main component of the ceramic powder used in the present invention is not particularly limited, but it is preferable to use alumina. Although there is no restriction on the particle size of zirconia, it is preferable to use a particle size that is equal to or smaller than the main component of the ceramic powder used. Furthermore, the green sheet used in the present invention is subject to no restrictions such as thickness, material 7, etc.
−, <l−O#*, EIJJla e,! There are no restrictions on '.

In the present invention, it is necessary to contain 5 to 30 ZS, preferably 10 to 20 ZS, of zirconia in the ceramic powder constituting the insulating paste.

If the amount is less than 5M, the thermal shock properties will be poor.

If it exceeds % by weight, the sintering temperature will be high and it will be expensive.

In addition, slack is 3.5 to 6.0 in ceramic powder.
It is necessary to contain 40 to 5.0% by weight of the weight, and if it is less than 3.5% by weight, the sinterability will be poor, and if it exceeds 9.6.0% by weight, the shrinkage rate will be low. 1 Mechanical strength and thermal shock properties deteriorate.

In addition to the above-mentioned composition, inorganic substances such as copierite and mullite may be added to the ceramic powder of the present invention, if necessary.

(Example) The present invention will be explained below using examples.

Example High purity alumina with an average particle size of 2 μm (alumina purity 1i99)
．． 5% or more) 96 parts by weight of flux (talc 87.5
4 parts by weight of a melt of 115 parts by weight of dolomite and 115 parts by weight of dolomite were added and mixed uniformly to obtain a raw material powder.

4 parts by weight of phthalate ester as a plasticizer, 20 parts by weight of furinol and 50 parts by weight of trichlorethylene as a solvent were added to this raw material powder 1007JC as a binder, and then milled in a ball mill for 50 hours. After uniformly mixing to form a ceramic slip, a green sheet with a thickness of 0.8 mm was obtained by tape casting.

Separately from the above, zirconia with an average particle size of 1.8 μm and the above 7 lux are blended into high purity alumina (alumina purity 99.5- or higher) with an average particle size of 2 μm in the ratio shown in Table 1,
The mixture was uniformly mixed to obtain ceramic powder Nnl~8.

Next, 8 parts by weight of polyvinyl butyral resin as a binder, 4 parts by weight of phthalate ester as a plasticizer, and 30 parts by weight of terpine oil as a solvent were added to 100 parts by weight of this ceramic powder round 1 to 11k18, and the mixture was processed in a sieving machine. Mix uniformly for 5 hours to make insulation paste N111~N11
I got 8.

Next, after forming a through hole with a diameter of 0.3 nm in the green sheet, this through hole was filled with a commercially available tungsten (W) conductive paste, and the same W as described above was added to each of the front and back sides of the green sheet. A circuit is formed by printing conductive paste, and on top of that, the above-mentioned insulating pastes 1 to 8 are printed to a thickness of 70±1011 m, and this process is repeated 4 times on the front side and 4 times on the back side to form an 8-layer multilayer circuit. Then, a metallized terminal was printed on the outermost side. after that.

The ceramic multilayer circuit board of the present invention was obtained by firing at 1500° C. for 1 hour in a weakly reducing atmosphere.

As a result of observing the external appearance of this ceramic multilayer circuit board, it was found that there was no peeling of the insulating layer or occurrence of cracks in those in which the insulating layer was formed using the insulating paste of Nch 3 to Nch 6 shown in Table 2.

Also, after connecting lead terminals to this ceramic multilayer circuit board with silver solder, it was heated at 150°C for 10 minutes.

No cracks occurred in the insulating layer even after repeated thermal shock for 10 minutes at -195°C 10 times.

On the other hand, in the case where the insulating layer was formed using the Nnl insulating paste, cracks occurred after firing, and in the case where the insulating layer was formed using the NQ2 insulating paste, microcracks occurred after the lead terminals were soldered with silver. The insulation pastes of Takinu 7 and N118 were insufficiently sintered at a temperature of 1500°C.

(Effects of the Invention) The present invention contains 5 to 30% by weight of zirconia and 3.5% of flux in the ceramic powder constituting the insulating paste.
Since the content is 6.0% by weight, the thermal shock resistance of the insulating layer is improved, and a ceramic multilayer circuit board can be manufactured without peeling or cracking of the insulating layer on the conductor circuit.

Claims (1)

[Claims] 1. In a method of manufacturing a ceramic multilayer circuit board by printing a conductive paste and a ceramic insulating paste multiple times on a ceramic green sheet and firing them simultaneously, zirconia is added to the ceramic powder constituting the insulating paste. 30% by weight and 3.5 to 6.0% by weight of flux.