JPS5820719B2 - Brazing alloy for ferrite bonding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filler alloy for bonding ceramics, and more particularly to a braze alloy for bonding ferrite with good water resistance.

Glass can be used to bond ceramics together.

However, when bonding ceramics to metals, metalloids, etc., thermosetting resins have traditionally been used as adhesives because glass cannot cope with the differences in thermal expansion coefficients and there are no other suitable bonding methods. It has been.

However, commonly used thermosetting resin adhesives have the disadvantage that their strength against mechanical impact is low, and their temperature-strength characteristics rapidly decrease at temperatures above about 80°C.

For this reason, for example, when assembling an ultrasonic cleaning device, if a ferrite vibrator is bonded to a metal diaphragm with a thermosetting resin adhesive, it may be used continuously for a long period of time, or the adhesive surface may The defect that the vibrator sometimes peeled off and fell off the diaphragm was observed.

In recent years, it has been discovered that when molten or semi-molten solder is vibrated on ceramics and then solidified, the solder firmly adheres to the ceramics, and soldering to glass or ceramics has been proposed as a method. It was done.

(Japanese Patent Publication No. 48-12850) According to this method, the drawbacks of adhesion using resin adhesives can be overcome, and it is expected that the reliability of adhesion will be greatly improved.

Subsequently, various solder compositions (hereinafter referred to as braze alloys) with improved adhesive properties were proposed.

A typical brazing alloy is a Pb-8n-Zn alloy (for example, Japanese Patent Publication No. 48-847 and Japanese Patent Publication No. 45-1739).

This alloy is characterized in that zinc is added to conventional PB-8N solder to improve wettability to oxides and improve adhesive strength.

However, even when using this Pb-8n-Zn alloy with a ferrite resonator attached to the diaphragm, the resonator may occasionally fall off after long-term use.
There was a need to further improve the adhesion of the 8n-Zn alloy.

In response to such requests, the present inventor has already developed tin 1-10 weight ratio, zinc 0.5-5 weight ratio, germanium 0.1-1.
We have developed a brazing alloy consisting of 5 parts by weight and the balance being lead.

This brazing alloy has significantly improved adhesive strength compared to the Pb-8n-Zn alloy, completely eliminating the problem of peeling and falling off at the adhesive interface between the ceramic and the brazing alloy.

However, it must be taken into account that articles bonded with braze alloys such as those described above will be used in a high humidity environment.

That is, it is required that the adhesive strength between the ceramic and the brazing alloy does not decrease under high humidity.

The present invention aims to improve the water resistance of the already developed Pb-Sn-Zn-Ge alloy.

In order to achieve this objective, the present inventor conducted further research and found that the water resistance was significantly improved by adding a small amount of copper, thereby achieving the present invention.

That is, the brazing alloy of the present invention has a weight ratio of 1-io of tin and 0.5 of zinc.
~5% by weight, germanium 0.1-1.5% by weight, copper 0
．． 05 to 0.5 by weight, the balance being lead.

The composition of the Pb-8n-Zn-Ge alloy that is the base material of the present invention is determined to be in a molten or semi-molten state at about 300 to 350°C so that it has sufficient strength when used at 80 to 100°C. There is.

That is, too much tin would lower the melting point of the brazing alloy, so it was set at 1 to 10% by weight, and too much zinc would cause hardening to be too high, so it was set at 0.5 to 5% by weight.

Germanium is a component to increase adhesive strength and has a content of 0.1 to 1.
5 Weighers are required.

The brazing alloy of the present invention is such a basic alloy with 0.05 copper added.
~0.5% by weight was added.

Copper is not preferable because its water resistance is hardly improved when the weight is 0.05 weight, and when the weight is 0.5 weight or more, the adhesive force decreases.

The preferred amount of copper added is 0.1 to 0.3% by weight.

Lead makes up the balance with tin, zinc, germanium, and copper.

The brazing alloy of the present invention may contain one or both of aluminum and antimony at a weight ratio of 0.2 or less.

These ingredients tend to slightly improve adhesion and water resistance.

The above pb-8n Zn Ge- containing approximately 0.05 weight factor of aluminum and antimony each.
The Cu alloy had good adhesive strength and water resistance.

Such a brazing alloy is obtained by weighing, mixing, and melting each component, and can be molded into an appropriate shape for practical use.

For example, if the alloy is formed into a rod or thread shape by extrusion, rolling, wire drawing, etc., it can be applied to any bonding surface using a soldering iron.If the shape of the bonding surface is flat and constant, rolling the alloy It can also be used by forming it into a plate shape and punching it into a desired shape.

Examples are shown below.

Example: 4 x 1 ferrite vibrator with adhesive surface of 2 cm x 4 cm
It was adhered to a strip-shaped SUS plate of 0C1n x 2-thickness, and a splitting test was conducted under various conditions.

For bonding, first preheat the ferrite vibrator to 300 to 350°C, and melt the bar-shaped brazing alloy with a weight ratio of 91 lead, 5 tin, 3 zinc, 0.8 germanium, and 0.2 copper with a soldering iron. The solder alloy was applied to the adhesive surface of the ferrite, and while the soldering iron was in a molten state, ultrasonic vibrations were applied to a soldering iron, and the soldering iron was then allowed to cool to adhere to the adhesive surface of the ferrite.

For comparison, lead: 91.2, tin: 5, zinc: 3, germanium: 0
．． 8. Similar samples were prepared using brazing alloys of various weights.

These ferrite vibrators coated with the brazing alloy were then adhered to the SUS plate using solder of 40% lead and 60% tin, and the resulting samples were subjected to a splitting test.

In the splitting test, the ferrite vibrator 1 is clamped and fixed between the fixing metal fittings 2 as shown in the figure, and the metal fitting attached to one end of the SUS plate 3 is pulled upward using a tensile testing machine (not shown).
This is to measure the tensile force at the time of 0% tearing.

If the sample did not split at 100 kg, it was held for 60 seconds.

The splitting test was conducted at room temperature after immersion in oil at room temperature of 100°C and in hot water for 10 hours.

For samples that had split, the state of peeling was observed.

The test was performed on 10 samples each.

The results are shown in the table. Example of the present invention after immersion in hot water at room temperature 100°C Strength No splitting 90
~9 out of 100, no split, no dispute
Comparative example of cohesive failure Strength No splitting 90 to 100 9'10 to 100
9 peeling state cohesive failure
In the 1/2 to 1/3 interfacial peeling table, cohesive failure is yield failure of the brazing alloy layer 4 itself.

Also, interfacial peeling refers to peeling at the interface between the ferrite vibrator 1 and the brazing alloy layer 4, and peeling at the interface between 1/1/2 and 1/3 is 1/2 to 1/3 of the total adhesive area. means that it has been exposed.

The results show that the brazing alloy containing copper does not crack even after being immersed in hot water, and there is almost no decrease in adhesive strength.

Therefore, the brazing alloy of the present invention can maintain high adhesive strength even in a high humidity environment and is extremely reliable.

[Brief explanation of drawings]

FIG. 1 is a front view of the splitting test apparatus used in the example. FIG. 2 is a side view of FIG. 1. DESCRIPTION OF SYMBOLS 1... Ferrite vibrator, 2... Fixing metal fittings, 3... SUS plate, 4... Brazing alloy layer.

Claims (1)

[Claims] 1 A wax consisting of 1 to 10 parts by weight of tin, 0.5 to 5 parts by weight of zinc, 0 to 1.5 parts by weight of germanium, 0.05 to 0.5 parts by weight of copper, and the balance lead. alloy. 2 Tin 1-10 weight, zinc 0.5-5 weight, germanium o, i-1.5 weight, copper 0.05-0.5 weight, one or both of aluminum and antimony 0.2 weight Below, a brazing alloy consisting of the balance being lead.