JPS5811112B2 - substrate - Google Patents

Description

[Detailed description of the invention] The present invention relates to a substrate using a metal base.

Substrates made of metals such as nickel-iron alloys are used for substrates used in wiring boards and surface heaters because of their advantages in terms of heat dissipation and mechanical strength. In order to achieve this, a glass layer is formed as an insulating layer on the main surface of the substrate, and wiring members are formed on this glass layer.

Therefore, when forming a glass layer on the main surface of a metal substrate, from the viewpoint of bonding strength, it is necessary to perform oxidation treatment on the main surface of the substrate to form an oxidized layer, and then form the glass layer through this oxidized layer. Therefore, it is necessary to increase the bonding strength of the glass layers.

That is, the glass layer bites into the uneven portion of the oxide layer and can be firmly bonded.

For example, when forming a wiring member such as a heat generating resistor by a thin film method (since firing is not required), a glass layer made of molten glass is formed.

However, when molten glass is applied onto the oxide layer on the main surface of the substrate, the uneven portions of the oxide layer directly affect the surface of the glass layer, causing uneven portions on the surface of the glass layer and making it not smooth.

This poses a problem in the formation of wiring members on the surface of the glass layer and in contact with other objects, and therefore, conventional substrates using metal substrates have low practical value.

The present invention has been made in view of the above-mentioned circumstances, and provides a substrate using a metal base, which has a smooth glass layer surface and has an increased withstand voltage, thereby increasing its practical value.

That is, the substrate of the present invention includes a metal base having an oxide layer formed on the main surface, a crystallized glass layer formed on the main surface of the metal base, and a molten glass layer formed on the crystallized glass layer. It is characterized by:

The present invention will be explained below.

In the figure, reference numeral 1 denotes a metal base, and the metal base 1 is made of a metal having a thermal expansion coefficient similar to that of glass, such as iron-nickel alloy, iron-chromium, iron-nickel-cobalt, or iron-nickel-chromium.

The thickness of the metal base 1 is 0.1 to 2.0 mm. The main surface of the metal base 1 is subjected to oxidation treatment to form an oxide layer 2.

For example, oxidation treatment is performed by heating at a temperature of 800 to 1200°C in the air, or by heating at a temperature of 800 to 1200°C in a warm hydrogen atmosphere.
There are methods such as heating.

A crystallized glass layer 3 is formed on the main surface of the metal base 1 with an oxide layer 2 interposed therebetween.

This crystallized glass layer 3 is made of Al2O3, S10□, B2O
It is made of glass such as 3°PbO, TiO2, etc., and is formed to a thickness of 10 to 30 μm by a thick film method (printing method) and then fired at a temperature of 800 to 900°C.

The crystallized glass layer 3 has a certain thickness and the surface (oxidized layer 2
The f-plane is smooth (without being affected by the oxidation layer 2), and the crystals on the f-plane combine with the oxide layer 2 and are firmly bonded.

A molten glass layer 4 is formed on the surface of the crystallized glass layer 3.

This molten glass layer 4 is made of Al2O3,5i02. B2O3
, PbO, etc., and is formed to a thickness of 30 to 100μ by the thick film method and then heated to a temperature of 800 to 900C.
It was fired in

Since the molten glass layer 4 is formed with a constant thickness on the smooth surface of the crystallized glass layer 3, its surface is also smooth.

Note that a wiring member is formed on the surface of the molten glass layer 4 by, for example, a thin film method, if necessary.

Thus, in the substrate configured in this way, a crystallized glass layer 3 having a smooth surface is formed on the oxide layer 2 on the main surface of the metal base 1, and a molten glass layer 4 is formed on this crystallized glass layer 3.
The surface of the molten glass layer 4 is not affected by the oxide layer 2 and becomes smooth.

Therefore, a wiring member can be formed satisfactorily on the surface of the molten glass layer 4, and the surface will not be damaged due to contact with other objects.

Further, when forming the molten glass layer 4, a part of the molten glass penetrates into the crystal gaps of the crystalline glass layer 3 and is solidified integrally by firing, so that the crystallized glass layer 3 and the molten glass layer 4 are integrated. The withstand voltage in the overall thickness direction increases.

With only the molten glass layer 4, the withstand voltage is low, and by adding the crystallized glass layer 3 to the molten glass layer 4, the withstand voltage can be increased.

Therefore, by smoothing the surface of the glass layer and increasing the withstand voltage of the glass layer, the practical value of a substrate using a metal base can be increased.

This board can be used as it is without forming any wiring members, or it can be used as a wiring board for thermal heads, sheet heaters, etc. by forming wiring members such as conductors and resistors on the molten glass layer depending on the application. can be used.

Next, examples will be described.

An oxide layer is formed on the main surface of a metal substrate with a thickness of 0.75μ made of an iron-18% nickel alloy, and an oxide layer with a thickness of 20μ is formed on the main surface.
A layer of crystallized glass having a thickness of μ was formed, and a molten glass layer having a thickness of 70 μ was formed on this crystallized glass layer.

The surface of the molten glass layer was extremely smooth, and the overall withstand voltage was IKV or more/100μ, which was very large.

[Brief explanation of drawings]

The figure is a sectional view showing an embodiment of the substrate of the present invention. 1...Metal base, 2...Oxide layer, 3.
...Crystallized glass layer, 4... Molten glass layer.

Claims (1)

[Claims] 1. Consisting of a gold layer substrate with an oxide layer formed on the main surface, a crystallized glass layer formed on the main surface of the gold layer substrate, and a molten glass layer formed on the crystallized glass layer. board.