JPH0429588Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a method of re-firing a ceramic substrate on which an integrated circuit is mounted to correct the deformation of the substrate, such as warpage, due to firing. This invention relates to a jig for straightening ceramic firing plates used when straightening warps by heating at high temperatures.

[Conventional technology]

Generally, when an integrated circuit chip is mounted and sealed on an insulating ceramic substrate made of alumina or barium titanate powder, etc., the ceramic substrate contains conductive Mo, which connects to the electrodes inside the integrated circuit chip. A metallization pattern is usually applied using W paste. In this way, the ceramic substrate provided with the metallized pattern is mounted on a base plate and fired at a temperature in the range of about 1200 to 1600°C. Figure 2a shows the firing furnace at this time, Figure 2b
The figure below shows an example of the use of the bottom plate. When firing the board, in order to prevent the metallized pattern from welding to the bottom plate, Jikosho
A molybdenum base plate 41 with a roughened surface as shown in Japanese Patent No. 56-19408 is used. A molybdenum plate is used as the bottom plate, and this molybdenum plate is heated to the maximum height (as defined in JIS B 0601) by, for example, spraying with abrasive grains, knurling, or milling. Rmax) is 20 μm or more, and has a roughened conductive paste contact surface. This bottom plate 41 was extremely effective in preventing welding of the metallized pattern.

[Problem that the invention attempts to solve]

However, the manufactured ceramic substrate 20
During firing, the surface of the ceramic substrate warps due to differences in density and shrinkage rate of each part specific to the ceramic substrate.

Further, the above-mentioned bottom plate 41 is made of ceramic substrate 20.
Due to its own weight, due to repeated high-temperature firing such as
Warping gradually occurs, and accordingly, the ceramic substrate 20 mounted on the bottom plate 41 frequently warps. Warping of the ceramic substrate 20 due to such various causes causes problems such as mounting an integrated circuit chip on the substrate 20 in another manufacturing process and making it impossible to bond an integrated circuit mount afterwards. The permissible standard is that the height must be 10 to 50 μm or less per inch of length.

Ceramic substrates with such warpage are treated as non-standard products, resulting in an increase in manufacturing costs.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a ceramic substrate straightening jig suitable for re-firing and straightening a ceramic substrate that has warped due to firing without damaging the metallized pattern. do.

[Means for solving problems]

According to the present invention, in a straightening jig for straightening a substrate that is deformed due to firing, the tool includes a support plate that supports the substrate, and is used in combination with the support plate to press the substrate on the support plate. A jig for straightening a ceramic substrate is provided, the support plate and the weight plate having a roughened surface and made of a material selected from the group of Mo and Mo alloys. It will be done.

[Effect]

The operation of the substrate straightening jig according to the present invention will be described.

A substrate warped by firing, such as ceramic, is mounted on the roughened surface of the support plate,
A weight plate is placed on top of this substrate so that its roughened surface is in contact with the substrate. When this straightening jig is used in a high-temperature firing furnace, the substrate is softened and the warp of the substrate is corrected by the weight of the weight plate. The contact surface of this plate with the substrate is finished with a moderate roughness (Rmax is 3 μm or more and does not exceed 20 μm), so it is possible to prevent local differences in the amount of heat supplied to the substrate and local loads. Does not cause scratches or cracks due to concentration of

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the substrate straightening jig of the present invention.

In this example, a warped substrate 20, in this case a ceramic substrate, is mounted on a support plate 10, and a weight plate 30 is further stacked thereon. As a result, the substrate 20 is
It is in a state where it is pressed by 0. This substrate has metallized pattern parts 21 and 22 on both sides, and these metallized patterns 21 and 22
The surfaces 11 and 31 of the support plate 10 and the weight plate 30 are in contact with each other.

The illustrated surfaces 11 and 31 of the support plate 10 and the weight plate 30 are roughened as shown in the partially enlarged view.
This was done by spraying Metsuyu's white alundum abrasive grains with liquid homing. As a surface roughening method other than this surface roughening, for example, a method of spraying abrasive grains such as dry sandblasting, a method of knurling, a method of milling, etc. may be used.

According to experiments, all the warpage of the ceramic substrate 20 held between the jigs 10 and 30 was corrected by firing at about 1600°C. The surface roughness of the jigs 10 and 30 at this time is JIS B 0610
Maximum height (Rmax) is 5μm or more and 20μm
This is a range that does not exceed. For comparison, if a ceramic substrate with the above warp is fired using a jig with a roughened surface larger than this range, that is, Rmax is larger than 20 μm, the substrate will soften and metallize. Damage to patterns 21 and 22 occurred. Also, for further comparison, Rmax is 3μm
When using a jig with a smaller roughened surface,
The metallized patterns 21 and 22 were welded to the surface of each plate. From the above, the roughening process performed on the board straightening jig is 20 μm when Rmax is 3 μm or more.
It is desirable to do this within a range that does not exceed m. Also,
It was confirmed that a substrate straightening jig having an Rmax of 5 to 15 μm and having a roughened surface is most desirable. Furthermore, although the above-mentioned example was applied to straighten a ceramic substrate, the present invention is not limited to ceramic substrates, but can also be applied to substrates that are deformed by firing, such as magnetic materials.

[Effect of idea]

As described above, in the present invention, a ceramic substrate that has warped due to firing is held in a jig consisting of a pair of roughened plates and re-fired. Welding, damage, and damage to the metallized pattern formed on the surface of the ceramic substrate.
Warpage in ceramic substrates can be corrected without damage such as cracks.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view of a substrate straightening jig according to an embodiment of the present invention, FIG. 2a is a partially cutaway sectional view showing a conventional firing furnace for ceramics, and FIG. 2b
1 is a diagram showing an example of the use of a conventional ceramic floor plate.

Claims (1)

[Scope of utility model registration request] A straightening jig for straightening a substrate that is deformed by firing, comprising a support plate that supports the substrate, and a weight plate that is used in combination with the support plate and presses the substrate. The maximum height (Rmax) of the support plate and the weight plate is 3 μm.
A substrate straightening jig characterized in that the surface is roughened within a range not exceeding 20 μm and is made of a material selected from the group of Mo and Mo alloys.