Method and manufacturing a hybrid type magnetic head slider using a thin film coil

A method of manufacturing a hybrid type magnetic head slider using a thin film coil in which a number of cores can be manufactured in the sane condition, and improvement and uniformity in yield and performance can be expected. A conductor pattern forming a plurality of thin film coils (2b) and a magnetic material (magnetic cores 2a) passing in the thin film coils are formed on a nonmagnetic base (1) by means of spattering or the like, and grooves (15) for bonding a plurality of ferrite made head cores (13) are formed on a different nonmagnetic base (14). The ferrite made head cores, which are bonded by glass thin films with a fixed gap, are bonded after polished into the outer dimension fitted to the grooves. A thin film coil stick (4) having the thin film coils formed thereon and a head core base (16) having the head cores bonded thereto are combined and bonded together to form a magnetic head slider bond bar (20), which is then cut and subjected to a polishing, whereby a magnetic head slider is completed reducing manual work.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a method of manufacturing a hybrid type magnetic 
head slider using thin a film coil which is used in hard disc drives and 
floppy disc drives used as auxiliary recording devices for a computer. 
2. Description of the Prior Art 
A composite type magnetic lead conventionally used in an auxiliary 
recording device for a computer has a structure as shown in FIG. 8, 
wherein an electromagnetic converting coil 38 was wound round either one 
or both of legs of a core through a winding window 37 disposed on a slider 
side surface. In accordance with the improvement in recording density per 
unit surface and volume, the manufacture of a lightweight and small-sized 
slider has come to be in great demand. However, the dimension of the 
winding window was also minimized with the downsizing of the slider, and 
the manual winding as in the past has gotton close to limits of its 
availability in aspects of yield and productivity. Therefore, it was 
proposed to reduce the manual winding work by forming the coil portion by 
the thin film manufacturing technique as employed in the manufacture of a 
semiconductor, and sticking the coil chip onto the slider side surface, as 
shown in Japanese Patent Laid-Open Nos. 5-128426, 5-242447, and 7-6316. In 
FIG. 8, denoted at 33 is a slider, 34 is a rail, 35 is a ferrite core, and 
36 is a read-write gap. 
However, since a photoresist; used as an insulating film in a coil 
manufacturing process is deformed or deteriorated when continuously heated 
at a high temperature, for example, a temperature of 270.degree. C. or 
more, glass, bonding process of 450.degree.C. or more which was 
conventionally used in adhesion of cores could not be adopted. When a 
polymer adhesive such as epoxy resin was used instead of a glass bond, the 
adhesion interface was likely to be worn or corroded because the slider 
was exposed to the surface opposed to or slid on a medium, and this had a 
problem in the reliability of the slider. Further, a conventional 
manufacturing method comprising adhering cores to the slider side surface 
while positioning them one by one was limited in aspects of yield and 
productivity. 
SUMMARY OF THE INVENTION 
This invention has been attained in order to solve the problems described 
above, and its object is to provide a method of manufacturing a hybrid 
type magnetic head slider using a thin film coil in which a number of 
cores can be manufactured in the same condition, and improvement and 
uniformity in yield and performance can be expected. To attain this 
object, this invention provides a method of manufacturing a hybrid type 
magnetic head slider using a thin film coil which comprises a second 
process of manufacturing a bar-like thin film coil stick formed on 
nonmagnetic ceramics having a pair or more of coil magnetic cores and 
coils for a magnetic head slider and a bar-like nonmagnetic ceramic head 
core base having a pair or more of ferrite made head cores; a third 
process of combining and bonding the thin film coil stick and the head 
core stick together; a fourth process of polishing the rail surface of the 
resulting bonded slider bond bar, thereby adjusting track width and gap 
depth; and a fifth process of cutting the slider bond bar, thereby forming 
individual sliders, and also provides a method of manufacturing a hybrid 
type magnetic head slider using thin film coils which further comprises, 
in addition to the above processes, a process of polishing the air inlet 
end and air outlet end sides of the rail surface of the slider to provide 
inclinations, or a process of performing a blending work for removing the 
acute angle portion of the edge portion of the slider rail.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of this invention are further described in detail 
every process in reference to the drawings. 
FIG. 1 (A) to FIG. 1 (D) show the first process of a first embodiment of 
this invention. In FIG. 1 (A), a number of thin film coil elements 2 
containing magnetic cores are formed on one surface of a nonmagnetic base 
1. In this embodiment, zirconia (Z.sub.r O.sub.2) was used as the 
nonmagnetic base 1, but calcium titanate (CaTiO.sub.3), ALTIC (AlTiC), or 
alumina (Al.sub.2 O.sub.3) materials may be also used. The dimensions of 
the base were set to a diameter of 3 inches and a thickness of 0.8 mm. 
Although the base may have a square form, the unit cost of parts can be 
reduced by the above dimensions since the number of elements to be taken 
per unit area increases as the surface area becomes larger. 
In this connection, about 2500 pieces of pico-size sliders can be taken 
from the 3-inch-diameter base used in this embodiment. Although the 
cutting margin is reduced in the following process as the base is thinner, 
leading to reduction in manhour, the thickness is preferably set to about 
0.8 mm-1 mm because the base, when thinned, warps in the formation of 
elements or in the polishing, leading to reduction in working precision. 
In FIG. 1 (B) and (C), cutting grooves 12 are formed in the base 1 by a 
grinder or dicer to form thin film coil sticks 4. In this case, the 
cutting is performed so as to expose magnetic cores 2a, and the exposed 
surface is smoothed by polishing as occasion demands. Denoted at 2b is a 
thin film, coil, and 2c is a terminal. In FIG. 1 (D), a notch 5 is formed 
by a grinder on the opposite side to the surface having thin film elements 
of the thin film coil stick 4 formed thereon. 
FIG. 2 (E) to FIG. 3 (M) show the second process of the first embodiment. 
In FIG. 2 (E), thin films 7a and 7a' of iron series having high magnetic 
permeability are formed by means of spattering on the surfaces of two 
ferrite made ferrite bases 6 and 6' having grooves 6a and 6'a cut therein, 
respectively. Further, glass films 7 and 7' forming adhesives for gap 
formation and glass bonding are formed thereon by the same spattering 
method. In FIG. 2 (F), the ferrite bases 6 and 6' are put one over 
another, and then glass-bonded together at about 500-600.degree. C. to 
form a bond bar 8. Denoted at 9 is a reinforcing glass for filling the 
grooves 6a, 6'a, and 10 is an apex. Denoted at 11 is a composition plane. 
In FIG. 2 (G) to (H), the bond bar 8 is cut in the cutting portions 12 by 
a grinder or dicer to form core sticks 13. In FIG. 2 (I), stick 
positioning grooves 15 are worked in a separately prepared nonmagnetic 
base 14, and glass thin films for glass bonding, which are not shown in 
the drawing, are formed on the worked surfaces by means of spattering. As 
for such glass thin films, those having a thickness of about 2000-3000 
angstroms and a softening point of about 400.degree. C. are selected. The 
reliability of the glass can be enhanced by increasing the content of 
silicon oxide in the glass. 
In FIG. 2 (J), the core sticks 13 are arranged in the grooves 15 of the 
nonmagnetic base 14 having the glass thin films formed on the surfaces 
thereof, and temporarily fixed thereto by an instant adhesive or the like 
with the positions of the apexes 10 of the sticks being mutually lined up. 
Thereafter, the glass thin films are fused in an electric furnace, whereby 
the core sticks 13 are bonded to the nonmagnetic base 14 to form a head 
core base 16. The core sticks cut from the same bond bar 8 are used 
herein, whereby a stick in which the apexes 10 of the head cores are 
horizontally lined up can be formed in a cutting process described later, 
and the yield can be increased in a process of adjusting the track width 
and gap depth. In FIG. 3 (K) to (L), cutting portions 12' are cut along 
the longitudinal direction of the head core base 16. In this case, 
triangular grooves 12" are preliminarily cut on the apex side of the head 
cores prior to the cutting, whereby the apex side of the head cores can be 
tapered with an angle of about 60 , which facilitates the working of track 
width described later. In FIG. 3 (M), a notched portion 19 is worked by a 
grinder in the part of the nonmagnetic body having the cores of the head 
core base 16 adhered thereto. This working is performed so as to expose 
the side surfaces of the core sticks 13 to the notched portion 19. 
FIG. 4 (N) shows the third process of the first embodiment. The head core 
base 16 and the thin film coil stick 4 formed in the first process are 
bonded together by epoxy resin or the like with the surface of a cut notch 
5 and the surface of the notched portion 19 shown in FIG. 3 (M) being 
fitted to each other, whereby a slider bond bar 20 is formed. In order to 
protect the insulating resist film used in the thin film coil portion, the 
bonding is performed at a temperature not more than 270.degree.C. 
FIG. 4 (O) shows the fourth process of the first embodiment. The height of 
a rail 22 is uniformed, and the rail surface side of the slider bond bar 
20 is polished to adjust track width 23 and gap depth 24. 
FIG. 5 (P) to FIG. 5 (Q) show the fifth process of the first embodiment. 
The slider bond bar 20 is cut in positions of 25 to form individual 
sliders 26. 
FIG. 5 (R) shows the sixth process of the first embodiment. The air inlet 
side 27-A and air outlet side 27-B of the rail surface 22 are subjected to 
tapers 27-a, 27-b by lapping. 
FIG. 5 (S) shows the seventh process of the first embodiment. The corner 
portion of the rail surface opposed to a medium of the slider is removed 
by an abrasive tape, and blended 28A-28B. 
FIGS. 6A-6C show a second embodiment of this invention. In this embodiment, 
the thin film coil stick 4 having the thin film coil elements formed 
thereon in the first embodiment is notched in the portion 5, and worked 
into a thin plate form (FIG. 6 (A)), notched portions 5" and 5"" are 
formed on the nonmagnetic body portion of the head core base 16 having the 
ferrite cores bonded thereto (FIG. 6 (B')), and the thin film coil stick 4 
and the head core body 16 are mutually adhered in the composition plane 11 
at a low temperature by the use of epoxy resin or the like (FIG. 6 (C)). 
It is cut in the same position as the portions 25 in FIG. 5 (P) to form 
sliders. 
FIG. 7 shows a third embodiment of this invention. In this embodiment, the 
thin film coil stick 4 having the thin film coil elements formed thereon 
in the first embodiment is notched in the portion of 5 to expose the 
magnetic cores 2a to the notched surface (FIG. 7 (A)), the notched portion 
5 is formed on the nonmagnetic body portion of the head core base 16 
having the ferrite cores bonded thereto, and the thin film coil stick 4 
and the head core base 16 are adhered together at a low temperature in the 
composition plane 11 by the use of epoxy resin or the like as shown in 
FIG. 7 (C). 
According to this invention, since fine ferrite cores which were 
individually stuck in the past can be stuck to a nonmagnetic base in the 
form of a stick to prevent the breakage of the cores, improvement in yield 
can be expected, and further, since a number of sliders can be worked in 
the same condition, improvement in working precision, reduction in 
manhour, and uniformity of performance can be also expected. The adhesive 
layer exposed to the slider surface opposed to a medium consists of only 
glass, which improves the reliability.