JPS60214410A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To eliminate a process having high difficulty and to attain ease of positioning by bringing a surface of a low melting point glass of a protection base to which the low melting point glass is weleded into contact with a thin film structure provided to other base, heating and bonding them at a temperature over the softening point of the welded low melting point glass. CONSTITUTION:It is desirable to select the low melting point glass 9 having a thermal expansion coefficient near to that of a background base 7 and a protection base 6 in order to avoid generation of cracks. The probability of generation of cracks is high when the difference is >=+ or -10X10<-7>/ deg.C. Further, the bonding temperature of <=600 deg.C from the standpoint of the deterioration of the magnetic characteristic of a ''Permalloy'' being a part of material of the thin film structure 8 and the low melting point glass of <=600 deg.C is desired as the working point. As the welding method of the low melting point glass 9 to the protection base 6, the welding by the screen print method is most practical. Further, the melting point higher than the work point of the low melting point glass 9 by 50-200 deg.C is used in order to attain the extraction of air bubbles in the low melting point glass 9 and the smoothing of the surface of the low melting point glass 9 after welding.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a thin film magnetic head used for recording data in computers and the like.

Conventional structure and its problems Thin-film magnetic heads for tape use
A substrate (single crystal ferrite, glass, etc.) is bonded onto the thin film component. Conventionally, organic adhesives have been mainly used to bond thin film components and protective substrates due to their ease of production. However, bonding the protective substrate with an organic adhesive has poor durability, and the rate of peeling and displacement of the protective substrate is high, resulting in problems with product reliability. Therefore, in some thin film magnetic heads that require high durability and high reliability, as shown in FIG. A method has been devised and implemented in which the thin film component 3 and the protective substrate 1 are bonded by sandwiching the thin plates 4 of the glass and heating the glass to a temperature higher than the softening point of the low melting point glass.

Although it was extremely difficult to cut low-melting point glass into thin sheets or polish both sides, it was discovered that the low-melting point glass adhesive layer had lower wear resistance against tape sliding than the substrate material. Considering this, it is desirable to make the thin plate of low melting point glass as thin as possible, and in order to prevent the low melting point glass adhesive layer from containing air bubbles, it is necessary to polish both sides into a flat shape. Therefore, according to the above-mentioned manufacturing method in which the thin plate 4 of low melting point glass is polished on both sides between the thin film component 3 and the protective substrate 1, the durability is high.

Although a highly reliable product was obtained, processing of low melting point glass and protective substrate 1. There is a problem in the alignment of the thin film component 3 on the thin 4° substrate 2 made of low melting point glass, which makes manufacturing difficult and expensive, and only thin film magnetic heads have been manufactured using this method. In addition, in the thin-film magnetic head manufactured by this method, there is a limit to the processing thickness of the thin plate of low-melting glass.
There was a large amount of protrusion of the glass, so it was necessary to make the wiring pattern 5 longer. Increasing the length of the wiring pattern 6 has long been a cause of an increase in resistance value and an increase in pattern defects such as pattern breakage and short circuits.

OBJECTS OF THE INVENTION The present invention provides a method of manufacturing a thin film magnetic head that eliminates the above-mentioned manufacturing difficulties.

Composition of the invention The present invention uses a sputtering method and a frit precipitation method (DG method).

The surface of the low melting point glass layer side of the protective substrate, on which low melting point glass has been fused in advance to an arbitrary thickness by screen printing or the like, is brought into contact with a thin film component provided on another substrate, and the This is a method of bonding by heating to a temperature higher than the softening point of the fused low melting point glass.

According to this method, highly difficult steps such as cutting the low-melting point glass into thin sheets and polishing both sides are eliminated, and since the low-melting point glass layer is fused to the protective substrate, it can be placed on another substrate. Positioning with the provided thin film component becomes easy, and workability is significantly improved.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The magnetoresistive effect has a three-layer structure in which the base substrate 7 is made of soda-lime glass (melting point M, P, = 720°C, thermal expansion coefficient α-93×10 /′C), and the highest step difference in the thin film component 8 is 3 μm. A type magnetic head (MR head) was formed, and a protective substrate 6 on which a low melting point glass 9 was fused was adhered. The protective substrate 6 was made of glass of the same quality as the base substrate 7. The low melting point glass 9 is desirably selected to have a coefficient of thermal expansion similar to that of the underlying substrate 7 and the protective substrate 6 in order to prevent cracks from occurring after bonding. The difference is ±10×10−
If the temperature is 77° C. or higher, there is a high probability that cracks will occur in the low melting point glass adhesive layer. In addition, the adhesion temperature is desirably 600'C or less in view of the deterioration of the magnetic properties of permalloy, which is a part of the material of the thin film component 8. If this temperature is exceeded, the rate of defects in the permalloy magnetic properties increases.

Therefore, the softening point of the low melting point glass 9 to be fused to the protective substrate 6 is limited to 600°C or less, and in reality, considering the thinning of the low melting point glass adhesive layer, the working point of the low melting point glass is 600'C or less. is desirable. Methods for fusing the low melting point glass 9 to the protective substrate 6 include sputtering, frit precipitation (DG method), screen printing, etc., but fusing by screen printing is the most practical as it has fewer problems. It is.

In addition, the fusing temperature is approximately 60 to 200"C higher than the working point of the low melting point glass 9 in order to extrude air bubbles in the low melting point glass 9 and smoothing the surface of the low melting point glass 9 after fusing. It is desirable to do this, and good adhesion was obtained during use.It is desirable that the thickness of the fusion bonding of the low melting point glass 9 to the protective board 6 is made thin, but at least the maximum thickness of the thin film component 8 to be combined is It is necessary to have a thickness equal to or greater than the step difference.If this thickness is not met, many air bubbles will be included in the low melting point glass layer after bonding.

In this embodiment, the thermal expansion coefficient is 94 x 10'/'C1 working point 64 on the soda lime glass protective substrate 7.
Frits made of low melting point glass at 3°C are 3-10 μm thick by precipitation method (DG method), and 30-50 μm thick by screen printing method.
It was fused to a thickness of μm.

The baking temperature is 600 to 650' because the surface condition of the fused low-melting glass 9 is good and there is almost no deformation of the soda lime glass that is the underlying protective substrate 6.
I went with C. Low melting point glass 9 produced by these above-mentioned methods
The protective substrate 6, which is fused to various thicknesses, is brought into contact with the thin film component 8 formed on the base substrate 7, and is heated in a nitrogen atmosphere for 5 minutes.
Bonding was carried out at 60'C and held for 10 minutes. All of the thin film magnetic heads fabricated by these methods have high durability, with no peeling or displacement of the protective plate 6 even after being left in a harsh environment (temperature 60'C, relative humidity 95%) for i ooo hours. It was highly reliable.

Furthermore, as an example, a thin film multilayer node having a nine-layer structure in which the base substrate 7 is made of Mn-Zn-ferrite (thermal expansion coefficient α-12o×1o-'/l) and the highest level difference of the thin-film component 8 is about 10 μm. A pattern was provided, and a protective substrate 6 on which a low melting point glass 9 was fused was adhered. The protective substrate 6 is made of Mn-Zn-ferrite, which is the same as the base substrate 7, and has a thermal expansion coefficient α=126×10-7/l and a low melting point Galanuf lift with a working point of 548°C and a temperature of 650 to 760°C by screen printing. It was fused to a thickness of 20 to 30 μm at the firing temperature. The protective substrate 6 produced in this way was combined with the thin film component 8, and
0' (, adhesion was performed by holding for 10 minutes.

Even in the thin film multihead produced by this method, the high step region of the thin film component 8 was completely filled with low melting point glass, and the head was highly durable and reliable. Further, the amount of protrusion of the low melting point glass onto the wiring pattern 10 can be easily reduced by reducing the thickness of the low melting point glass 9 to be fused, and the wiring pattern 10 can be shortened. Ta. In a thin film multihead with extremely narrow wiring patterns and pattern intervals, by shortening the length of the wiring pattern 10, the occurrence of defects such as disconnections and shorts between lines can be significantly reduced.

Effects of the Invention As described above, the present invention applies the surface of the low melting point glass layer side of a protective substrate, on which low melting point glass is fused to an arbitrary thickness, to a thin film component provided on another substrate. This is a method of bonding by heating to a temperature above the softening point of the low melting point glass that has been brought into contact and fused. According to this method, difficult and dusty processes such as cutting the low melting point glass into thin sheets and polishing both sides can be done. deleted,
Furthermore, since the low melting point glass layer is fused to the protective substrate, alignment with the thin film component provided on another substrate is easy and workability can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is an exploded view showing a conventional thin film multihead, and FIG. 2 is a perspective view showing the present invention. 6...Protective substrate, 7... Base substrate,
8... Thin film component, 9... Low melting point glass, 10... Wiring pattern.

Claims (1)

[Claims] (1) One substrate on which a glass layer has been formed in advance,
The glass layer is brought into contact with the other substrate having the thin film head component so as to face the thin film head component, and the glass layer is softened by heating to bond and integrate the two. A method for manufacturing a thin film magnetic head. (-A method for manufacturing a thin film magnetic head according to claim 1, characterized in that the glass layer of one substrate has a softening point of 600° C. or less. (3) The glass layer fused to one substrate. A method for manufacturing a thin film magnetic head according to claim 1, characterized in that the thickness is greater than or equal to the thickest thickness of the thin film component provided on the other substrate. (41 glass layers are screen printed. 2. A method of manufacturing a thin film magnetic head according to claim 1, wherein the thin film magnetic head is formed by a method.