JPS61136965A - Manufacture of ceramic substrate for thin membrane - 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 (Field of Industrial Application) The present invention relates to a method for manufacturing a ceramic substrate for thin film with improved mass productivity.

(Prior art) Ceramic substrates for forming electronic circuits are generally smooth on both sides when they are in the form of green sheets, so when multiple sheets formed into a substrate shape are directly stacked and fired in a furnace, each sheet will overlap with the other. If it adheres, it will be difficult to peel it off after firing. For this reason, conventionally, for example, as shown in FIG. 2, bedding powder 12-- is interposed between each board 11--, or as shown in FIG. 23 and then baked. However, in the former case, the surface of the green sheet is easily scratched by the bedding powder.
In the latter case, the number of sheets to be fired is limited, making it unsuitable for mass production.

Therefore, as a result of intensive research, the inventors of the present invention found that by creating unevenness on the back side of the guaranteed surface of the green sheet, that is, increasing the surface roughness, even if a plurality of green sheets were directly stacked in a multi-tiered manner and fired, the board It was found that they did not adhere to each other and that no scratches occurred on the warranty surface.

Therefore, the present invention can directly stack a plurality of green sheets cut into thin shapes in a multi-tiered manner as a ceramic substrate for a thin film, and can be easily peeled off after firing without causing any damage to the guaranteed surface. It is an object of the present invention to provide a method for manufacturing a thin film ceramic substrate that can significantly improve mass productivity.

[Kα
A method for manufacturing a ceramic substrate for thin film is provided, which comprises firing a green sheet having a surface roughness of 3 μwt Ra or more.

In fact, ceramic green sheets are obtained by coating a slurry on a release material using the tape casting method and drying it during transportation, but the surface roughness formed on the back side of the green sheet corresponds to this. The slurry can be obtained by coating the slurry on a release material that already has a surface roughness. After the drying process, the green sheets having such surface roughness on one side are die-cut into the desired shape of a ceramic vine substrate for thin films, and are directly placed in a furnace with the guaranteed side A facing up, as shown in Figure 1. They are stacked alternately and fired with the rougher side B facing down. At this time, the above surface roughness is 0.3
If the pan Ra is less than -, there is no difference from the case where the layer is smooth, but when a plurality of these layers are directly laminated and fired, most of the layers will be adhered and it will be difficult to separate them. Surface roughness is preferably 07-2.
5μ scraps are suitable.

In addition, if the purity of the ceramic powder is less than 97.0%, impurities such as glass components (CaO, MgO, S'rOs)
etc.), and a reaction occurs between the laminated substrates during firing, causing the substrates to adhere to each other in the same way as above. The purity of the ceramic powder used is preferably 99.0% or higher.

(Example) AlgOa, ZrOs, Si, aN+ and Ba having respective purity shown in Table 1 as ceramic powder
Ti03 was used. Appropriate sintering aids, binders, dispersants, solvents, plasticizers, etc. were added to each of these powders, and mixed in a ball mill for 20 to 40 hours. The resulting slurry is shown in Table 1. A thickness of 25 mm is achieved by applying tape casting onto house materials with different surface roughness.
Got a green sheet from the mill.

These green sheets were cut into a size of 115 x 14 Off to obtain green sheets for ceramic substrates for thin films. Thereafter, the obtained green sheets were directly stacked one on top of the other with the guaranteed side facing up and the rougher back side facing down, without using any dusting powder, and fired. . Obtained samples 1-3
Regarding the samples of No. 4, those in which 8 or more of the 5 layers were adhered during firing were evaluated with an X mark, those with less than 8 sheets adhered with a Δ mark, and those with 0 sheets adhered with a Q mark. In addition, the condition of the substrate surface is that all 6 boards are glued together and the substrates cannot be peeled off, and the board is "unable to peel", and although it can be peeled off, the substrate is partially reacting, and particles come off during peeling, causing the substrate to peel off. Those in which the smoothness of the guarantee surface was impaired were marked as "inter-warranty damage," and those in which all six sheets could be peeled off without damage to the guarantee surface were marked as "good."

As is clear from the examples above, high-purity ceramic powder with a purity of 97.0% or more is made into green sheets, and the back side of the obtained green sheet has a surface roughness of α8βm or more. Samples 2-6.8-18.16, 16, 18-2 were fired by stacking multiple sheets directly.
0, 22, 28, 26-27, 29.30.82-34
could be easily peeled off without any damage to the warranty surface. On the other hand, sample 1.7 was made by directly stacking and firing a plurality of green sheet-like substrates made of ceramic powder with a purity of less than 970% and having less than α3μ debris on the back side of the guaranteed side of the green sheet.
14.17.81.24.28 and 81 cannot be peeled off at all, or even if peeled off, the substrates partially react with each other, causing particles to come off during peeling, and the smoothness of the guaranteed surface is impaired. damaged or damaged.

As described above, according to the present invention, it is possible to directly stack and fire a plurality of green sheets created as ceramic substrates for thin films in a multi-tiered manner, which significantly improves mass productivity when firing this type of ceramic substrate. can be improved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a stacked state during firing with a green sheet according to an embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams showing a stacked state during conventional firing. In the figure, l indicates the substrate and A indicates the guaranteed surface, respectively.

Claims (1)

[Claims] (1) A method for manufacturing a ceramic substrate for thin film having a guarantee surface for circuit formation on the surface, which is obtained from high-purity ceramic powder with a purity of 97.0% or more, and has 0.0% on the back side of the guarantee surface.
A method for manufacturing a ceramic substrate for a thin film, comprising firing a green sheet having a surface roughness of 3 μmRa or more.