JPH0331485A - Enameled substrate and thermal head or circuit parts using the same - Google Patents

Abstract

PURPOSE:To improve the surface smoothness of an enameled substrate for a thermal head by forming a glass film contg. filler made of fine particles of glass having a higher softening point than the glass of the glass film on a metal substrate. CONSTITUTION:Fine particles of glass having a higher softening point than the glass of a glass film formed on a metal substrate is added as a filler to glass powder. They are mixed with an org. solvent and a binder and milled in a ball mill to prepare paste. A metal sheet such as a stainless steel sheet is coated with the paste and dried to form an enameled substrate. When the electrically conductive circuit of a thermal head is formed on the enameled substrate, dispersion in resistance can be reduced.

Description

[Detailed Description of the Invention] Industrial Field of Application Companion of the Invention Circuit board Enamel board used for thermal head board etc. and thermal spatula K using the same Conventional technology related to circuit parts Conventional enamel board is made of stainless steel. Powder of amorphous glass or crystallized glass is applied to a metal substrate such as a steel plate for coating by a method such as printing, spraying, dip, etc., and then fired. However, the surface roughness is still large compared to the conventional enamel substrate (or alumina glaze substrate), and the surface roughness of the enamel substrate is 0.15 to 0.3 μm. When forming a conductive circuit for a thermal head consisting of a resistor or the like, there is a large variation in the resistance value.

In order to reduce the surface roughness of the substrate, the inventors have made various attempts on enamel substrates using amorphous glass as the glass frit. As a result, the surface roughness can be reduced by increasing the firing temperature. I found out that it can be done, but
On the other hand, even though a glass film was formed in a predetermined area on a metal substrate, the surface tension of the glass was negative.
A problem arises in that the area of the glass film after firing becomes small.The purpose of the present invention is to solve the problems of the prior art. A glass film containing a filler is formed, and the filler is glass fine particles having a softening point higher than the softening point of the glass of the glass film. When a glass with a low softening point flows during firing, a filler with a high softening point suppresses the surface tension of the glass with a low softening point. (Examples below &- Examples of the present invention will be described with reference to the drawings. Example 1 As shown in the figure, jQ 350 mesh under glass (commercial example: CGW8445) powder with a softening point of 714°C As filler 2, 20% of 350 mesh under glass (commercial example: CGWO317) powder with a softening point of 870°C was added and milled with an organic melt binder in a ball mill for 5 hours to make a paste. It was applied onto a 2 mm stainless steel plate, dried, and baked at 950°C for 10 minutes to obtain an enamel substrate on which the glass film 3 was formed. The thickness of the glass film 3 was 0.0511.
& The size was 110 x 90. On top of the glass film created in this way, a thermal head having a cross section as shown in the figure was fabricated as a prototype. 4 is an electric plate 5 is a heating resistor, and 6 is an overcoat layer. Amo〈Example 2〉 As shown in the figure, the softening point of 1350 mesh under is 74.
Glass (commercial example: HOYAZnCl) powder at 3℃
350 mesh under glass with a softening point of 870°C (commercial example: CGWO317) powder 2 added at 20% was milled with an organic salt binder in a ball mill for 5 hours to make a paste. It was applied onto a steel plate and dried at 950℃ for 10 minutes.
The rest is Example 1.
A thermal head was prototyped in the same manner as 9. Comparative Example 1.2
〉 An enamel substrate was obtained without adding filler in Example 1.2. At this time, the area of the glass film after firing was the same as that of Example 1.
In Example 2, the shrinkage was 8x, so we did not want to make a prototype thermal head, so Comparative Example 3> As an example of a conventional enamel substrate, there is a document (Am.

Ceratrr, Soc, 62.683 (1983
)) Amorphous glass (composition: 5ioe
-45w tX+ Bt 0r-14w tX+ Na
g O-19w tX+KeO-5wt pallet, Li*0
-4vtX, Cab-3vt%, Ale's -1
0wt measure (softening point 535℃) was used, and the firing temperature was set to 60℃.
An enamel substrate was obtained at 0°C.The Ra of the substrate after firing was 0.3 μm, which was not much different from that of a conventional enamel substrate.After that, a thermal head was prototyped in the same manner as above, and Examples 1 and 2 and Comparative Example 3 were obtained. , center line average roughness RL on the substrate surface, resistance value variation of the heating resistor of the thermal head, thermal efficiency of the thermal head (OD = 1.0
The power consumption per dot when Effects of the invention confirmed to be obtained As is clear from the above description, the present invention J, t is a glass containing glass fine particles having a softening point higher than the softening point of the glass of the glass film as a filler on a metal substrate. By forming an enamel substrate by forming a film, it is possible to obtain an enamel substrate with improved surface smoothness, and when used as a thermal head, it is possible to reduce variation in resistance value.

[Brief explanation of drawings]

The figure is a cross-sectional view of a thermal head using an enamel substrate according to an embodiment of the present invention.
...Filler, 3...Glass style 4...Electric [5...
・Heating resistance 6...Overcoat layer.

Claims (3)

[Claims] (1) An enamel substrate formed by forming a glass film containing a filler on a metal substrate, characterized in that the filler is glass fine particles having a softening point higher than the softening point of the glass of the glass film. enamel board (2) A thermal head characterized by using the enamel substrate according to claim 1. (3) A circuit component characterized by using the enamel substrate according to claim 1.