JPS63249915A - Glass joining method - Google Patents

Abstract

PURPOSE:To provide a glass joining method to eliminate holes in glass and to decrease glass cracks at the time of working by executing joining in a high-pressure inert gaseous atmosphere under heating and a heat treatment in order to remove remaining strain (stress). CONSTITUTION:High melting nonmagnetic films 11 consisting of SiO2, etc., are formed by a vapor deposition or sputtering method on the surfaces intended to be joined of magnetic ferrite cores 9, 11 and thereafter, low melting glass films 12 for improving joint strength are formed on the films. The cores are then assembled by bringing the surfaces to be intended of said cores into contact with each other and pressing the cores by means of a jig 14 from both sides and inserting a gap reinforcing glass rod 14 having the same working temp. as the working temp. for welding to the low melting glass or the lower temp. into the groove part 13 of the magnetic ferrite core 9. This assembly is heated up by a hot isostatic press (HIP) up to the working temp. at which the low melting glass and the gap reinforcing glass are welded; in addition, the assembly is joined under >=20atm. isostatic pressure exerted thereto. The assembly is subjected to the heat treatment in order to remove the strain of the joined members. The holes to be generated in the glass and the glass cracks generated at the time of working after the joining are thereby decreased and the mass productivity and yield are improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a member formed by bonding magnetic ferrites or magnetic ferrite and non-magnetic ceramics, and particularly to a member bonded with glass such as a magnetic head. This relates to a joining method.

[Conventional technology]

At present, there is a magnetic head for a magnetic recording/reproducing device in which a plurality of polycrystals or single crystals are integrated, for example, magnetic ferrites or magnetic ferrites and non-magnetic ceramics are bonded together with glass. Generally, glass bonding of ceramic parts constituting a magnetic head is carried out by the steps shown in Fig. 1, a), b), and c).

In other words, 5
After forming the high melting point nonmagnetic film 3 such as i02, the surfaces to be joined are brought together and pressed with a jig, and then the gap reinforcing glass rod 5 made of low melting point glass is inserted into the groove 4 of the magnetic ferrite core 1. . Then, the reinforcing glass and magnetic ferrite are heated to a working temperature at which they are fused and bonded.

However, the gas used in forming the film is contained in the film, and this creates pores in the glass during heat bonding. Furthermore, the gas (air) that is sucked in when the glass flows in creates pores. There is a drawback. As an example of solving these drawbacks (1), JP-A-58
No. 130426 and Japanese Patent Application Laid-open No. 153222/1987, which proposed a method of performing hot isostatic pressing (HIP) after joining and preventing gas from entering the gap. 2), Tokuko Sho 61-1675
In Publication No. 2, after joining only by heating in a HIP furnace,
A method of reheating and applying pressure has been proposed, and JP-A-61-53134 proposes a method of applying pressure near the softening point of the glass used. However, the above methods (1) and (2+) require double labor and are not suitable for mass production.In addition, as a result of detailed study by the present inventors, the method (3), near the softening point of glass, The flow is very poor, and sometimes there is no flow at all, resulting in a poor yield.This is especially noticeable when the glass inflow length is long.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned drawbacks of the prior art, provides a glass bonding method that simultaneously fuses the glass in the gap portion and the reinforcement portion, and eliminates holes in the glass, and also provides a glass bonding method that eliminates the problem of glass bonding during processing of bonded members. The purpose of this study is to provide a method for reducing this.

[Means for solving problems]

Therefore, in order to achieve the above object, the present inventors performed a bonding method in which the bonding was performed in a high-pressure inert gas atmosphere while heating, and heat-treated the bonded members to remove residual strain (stress). This is what we offer.

That is, as shown in FIG. 2, the magnetic ferrite I core 9
, 10 is coated with a high melting point non-magnetic film 11 such as 5iOz.
After forming by vapor deposition or sputtering, a low melting point glass film 12 is formed on the film to improve bonding strength. Next, the surfaces of both cores to be joined are brought into contact, and after pressing from both sides with a jig 14, a gap reinforcing glass rod 14 whose working temperature is the same or lower than that of the low melting point glass is inserted into the groove 13 of the magnetic ferrite core 9. Insert and assemble. Next, this assembled product is heated by hot isostatic pressing (HIP) to a working temperature at which the low melting point glass and gear reinforcing glass are fused together, and a hydrostatic pressure of 20 atmospheres or more is applied to join them. This paper proposes that heat treatment be applied to remove the strain on the glass parts, thereby reducing glass cracks that occur during processing.

The reason why a low melting point glass film is formed on top of the high melting point nonmagnetic film such as 5i02 is that a high melting point nonmagnetic film alone has low bonding strength, whereas a low melting point glass film alone has a high reaction rate with the magnetic ferrite. This is because the gap accuracy is large and the gap accuracy is deteriorated. Further, the above-mentioned formation of both films may be performed on the entire surface of the magnetic ferrite core 9 shown in FIG. 2 to be bonded.

In addition, the bonding temperature in HIP is determined by the flow condition of the glass, especially the inflow condition of the gap reinforcing glass, and the working temperature for fusion by normal heat treatment is good, and the viscosity η of the glass is 10'~10'~
A temperature of 102 poise is best. Also, the pressure at that time is
Pressurization may be started already when the heating temperature in HIP is 100° C. or lower, and it is only necessary that the pressure at the working temperature finally reaches 20 atm or higher. This is because many pores remain in the glass below 20 atmospheres. Furthermore, if the applied pressure is increased too much, cracks will occur in the bonded members, so it is desirable that the applied pressure be up to about 1,500 atmospheres.・Also, cracks during processing can be reduced if the heat treatment temperature for removing strain from parts joined by HIP is around the strain point of the glass used (viscosity η is 10Iff/3 poise) or higher. I found out. However, if the temperature is raised too much, the glass will loosen and cause gap fluctuations, so it is desirable that the temperature range be from around the strain point to around the softening point.

〔Example〕

Hereinafter, the present invention will be explained in detail as it is applied to the magnetic head chip manufacturing process described as an example above.

Example 1 The magnetic ferrite cores 9 and 10 in FIG. 2 are MnO,
After processing a groove 13 into which a gap reinforcing glass rod is inserted into one side of the Mn-Zn ferrite (thermal expansion coefficient 108 x 10-'/"c) made of ZnO and FezOz, the core 9 is
．． A Sing film 11 with a thickness of 0.5 μm was formed on the surface to be bonded of No. 10 by sputtering. Furthermore, the softening point on the above film is 675.
°C low melting point glass film (thermal expansion coefficient 82x 10-'/
"c) 12 was formed by a 0.1 μm sputtering method. Next, the surfaces to be bonded of both members on which the film was formed were brought into contact, and 7!20
3 After pressing with a jig 14 at a pressure of 2 kg/'cd, a gap reinforcing glass rod 15 with a softening point of 635°C is inserted into the groove.
Insert and assemble. Next, attach the above assembly to A (1203
After placing it in a crucible and setting it in a hot isostatic press (HIP), the temperature was raised to 300°C/Hr in a static atmosphere, and the IHr was maintained at 850°C, the temperature at which the glass melts, to 300°C/llr.
It was cooled down. At this time, the pressure cover turns at a heating temperature of 100
A pressure of about 50 atm was already applied at 0.degree. C., and then the pressure was increased as the temperature rose until it reached 200 atm at the working temperature, and the pressurization was continued until the cooling temperature reached 300.degree.

Next, the glass bonded product was heat-treated in a N2 atmosphere at a temperature increase/decrease rate of 200° C./Hr, a holding temperature of 400 to 700° C., and a holding time of IHr.

The dimensions of each core are core 9, length 30 fins, width 3 width 61 graves.

The thickness is 2 mm, and the core 10 has a length of 30**, a width of 5+n, and a thickness of l+n. The obtained sample was divided into 30 pieces in the longitudinal direction of 30++ m, mirror finished, and the presence or absence of pores in the glass and glass cracks after processing was examined. In addition, bonding was performed using normal heat treatment and comparison was made with the bonded product described above. The results are shown in Table 1.

As is clear from the above, it is known that pores can be almost eliminated in both the gap part and the reinforced glass part by HIP processing bonding, and it is known that glass cracks that occur during processing can be reduced by using heat treatment in combination. The temperature at which the heat treatment is effective is from around the strain point of the glass to around the softening point at which the gap does not change.

Example 2 The sample used in Example 1 was subjected to HIP treatment at a bonding temperature of 850°C.
The final pressure was set in the range of 10 to 1,500 atmospheres. The obtained sample was divided into 30 parts in the longitudinal direction of 30 fins, mirror finished, and the presence or absence of holes was examined. The results are shown in Table 2.

0 As is clear from Table 2 and above, it is known that if a pressure of 20 atmospheres or more is applied during HIP bonding, the number of pores in the glass can be significantly reduced.

Example 3 The sample, the pressure pattern during HIP, and the final pressure were the same as in Example 1, and the heating temperature and glass flow condition were investigated. The results are shown in Table 3.

As is clear from Table 3 and above, it is known that the heating temperature during HIP process bonding needs to be approximately the same as the working temperature for fusion in normal heating.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the occurrence of pores in glass and glass cracks that occur during processing after bonding, and to improve mass production and yield, which have been disadvantageous in the past. Its industrial effects are extremely large in terms of manufacturing parts that require high reliability.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic diagrams of the process of bonding the glass to the magnet. 1.2, 9.10...Magnetic ferrite core 3.11.
. . . High melting point nonmagnetic film 12 . . . Low melting point glass film 4. 13 . . . Groove 5 into which the gap reinforcing glass rod is inserted.
15...Gap reinforcing glass rod 6.16...Front gap part 7.17...Pasoku cassow part 8.18...Gap reinforcing glass part 14...Press jig Figure 1 Procedure correction band Patent Office Dear Director, Ward 1, Indication of the case Patent Application No. 84092 of 1984 2, Name of the invention Glass bonding method 3, Relationship with the person making the amendment Patent applicant Office 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Title (508) Hitachi Metals Co., Ltd. The "Detailed Description of the Invention" column of the specification is amended as follows. Correct the description. 2. In the 4th line of the same page of the same book, "The yield is poor due to some cases."
In some cases, there may be a shortage of glass. ” is corrected. 3. In the same book, page 5, line 6, "14" is corrected to "15". 4. In the same book, page 6, line 18, "up to around the softening point" is corrected to "up to the working temperature at which glass melts or below."that's all

Claims (1)

[Claims] In the manufacture of a magnetic head in which polycrystals of the same or different types, single crystals, or polycrystals and single crystals are joined by interposing glass between the members and fusing the glass, the magnetic head of the member is After forming a groove in which a gap reinforcing glass rod is inserted into at least one side of the gap, Si is applied to both or one of the surfaces to be joined to the members.
A first step of forming a high melting point non-magnetic film such as O_2 and further forming a low melting point glass film on the film, and after bringing the film-formed member joining surface into contact and pressing with a jig from both sides, a second step of inserting into the groove a gap reinforcing glass rod whose working temperature is the same or lower than that of the low melting point glass film to form an assembled product; and a working temperature at which the low melting point glass and the gap reinforcing glass are fused together. a third step in which the glass is bonded by heating the glass to a temperature of 200 psi and applying a hydrostatic pressure of 20 atmospheres or more, and a fourth step in which the glass bonding member is heat treated to reduce the occurrence of glass cracks during processing.
1. A glass bonding method comprising the steps of 1st, 2nd, 3rd, and 4th steps in sequence.