JPH0349004A - Manufacture of multiple magnetic head and integral grinder used in manufacturing - Google Patents

Abstract

PURPOSE:To manufacture a multiple chip head with high yield by forming a pair by selecting a chip of prescribed shape and size out of plural chips, sticking it on the same base member as a multiple chip, and integrally grinding the tape sliding plane of the multiple chip. CONSTITUTION:Pairing that the chip of prescribed shape and size is selected and collected out of the plural chips is performed. Next, each paired chip is stuck on a common base member after paying consideration for integral grinding as a multiple chip. Then, it is confirmed to whether or not the prescribed shape and size are formed by performing inspection for sticking. The multiple chip head 1 is connected with a screw on a grinding drum 15. The tape sliding plane 21 of the grinding drum 15 is ground at this part. A coil is wound across each chip head after integral grinding is performed, and electrostatic characteristic inspection as the multiple magnetic head is performed. Then, RF envelop inspection whether or not a ratio of output to noise and the output are stabilized at every head is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to the manufacture of multiple magnetic heads, which have recently been frequently used for high-density recording and reproduction in VTRs that record and reproduce high-definition images. The present invention relates to a method and an integral polishing device used therein, and more specifically, it relates to a method for polishing a tape sliding surface of a multiple chip head (a plurality of head chips attached to the same base member) constituting a multiple magnetic head. This relates to a polishing finish that is finished by integral polishing.

[Conventional technology]

Regarding the general polishing finish of the tape sliding surface of conventional Helad chips, as described in Japanese Utility Model Application No. 63-29213, the tape is pasted on the base of a single head attached to a rotating plate in a polishing cylinder. There is a method of polishing the tape sliding surface of a single tip with lapping tape, a method of polishing the sliding surface of a single head tip attached to a swinging jig by cutting it into a rotating grindstone, and a method of polishing the sliding surface of a single tip attached to a rotating jig. A method and apparatus have been proposed for polishing the sliding surface by cutting a chip attached to the outer periphery with a rotating grindstone.

Regarding the method of slight polishing, which is used to improve the clogging of the tape sliding surface of a video head attached to a rotating cylinder using wrapping tape, there are commercially available cassette tapes for cleaning heads of home VTRs. , a method using this is known.

[Problem to be solved by the invention]

The above-mentioned conventional technology uses a single chip in the middle of assembly,
Alternatively, the present invention relates to a method of polishing a single chip, and does not relate to an integral polishing finish of a multiple Herad chip formed by pasting a plurality of chips close to each other on a single base. When assembling multiple head chips, it is easily possible to use chips for each head that have been individually polished using the prior art described above.

However, in a multi-chip head, when the polishing process is completed, the surface shape of the tape sliding surface is slightly different for each head that makes up the multi-chip head, and the shape should be slightly different. If you try to make and assemble each chip head individually, you will have to attach each chip individually to a polishing jig, polish it, then peel it off from the polishing jig and attach it to a common base for each chip head. It is necessary to repeat the processing assembly process and handling,
In addition, the pairing process of selecting the required number of chips with the desired shape and dimensions from among the multiple chips that are to become the head and assembling multiple chips (pairs) becomes complicated. There is also a high probability of making a mistake when attaching the chip head to a common base. If even one head in a multi-chip head produced by such a problem is defective, the multi-chip head itself becomes a defective product, which causes great damage.

Furthermore, although it is not a defective product, multiple chip heads that are individually polished and reattached and assembled require several hours of break-in before the contact between each head and the tape becomes normal after mounting on the VTR rotating drum. Without operation, it is difficult to ensure that each head that makes up the multi-chip head has sufficient output, and as a result, the yield of good products in chip processing, head assembly, VTR rotating drum mounting, etc. is poor. However, there was a problem in that only a multi-chip head with low reliability could be manufactured.

It is an object of the present invention to solve the problems of the prior art as described above, and to apply (
In other words, it is possible to manufacture a high-quality multi-chip head in which the output of each head is sufficiently uniform (within several tens of minutes of running), or in other words, there is little variation in the output between heads regarding the finishing of the sliding surface. An object of the present invention is to provide a method for manufacturing a multi-magnetic metal and an integrated polishing device used therein.

Means to solve problem C] In order to achieve the above object, the present invention is carried out as follows.

First, the desired shape and dimensions of the tape sliding surface of each head are determined from the output of each head after the multi-chip head is mounted on a VTR.

Next, we performed the assembly work of multiple chip heads, including assembly work such as machining, pairing, pasting, polishing, etc., and inspection on the premise of integral polishing of multiple chip heads (simultaneous finishing of the tape sliding surface of each head). Create a procedure (flowchart). Then, a polishing drum devised to obtain the desired dimensional accuracy of the finished shape and dimensions of the tape sliding surface of each head by integral polishing, and an integral polishing device capable of inspecting the finished state before, during and after polishing are manufactured.

Furthermore, we will clarify the relationship between dimensions for chip selection (pairing) and attachment to enable integrated polishing.

The multi-chip head completed using this assembly procedure and method is mounted on a VTR, and the output of each head is inspected to confirm and correct the appropriate values for chip processing, pairing, pasting, and integrated polishing, resulting in high quality. Multiple magnetic heads can be manufactured with significantly improved yield.

[Effect]

The desired shape of the tape sliding surface for each head of the multi-chip head is such that it can produce sufficient output when the multi-chip head is mounted on a VTR rotating drum and touches the magnetic tape. In order to achieve such a shape, it is better to polish all the chip heads together with polishing tape than to polish each head individually. This is advantageous in that it is easy to obtain a tape sliding surface shape.

Furthermore, by controlling the conditions of integral polishing, it is possible to easily obtain slightly different tape sliding surface shapes between each head.

In addition, as for the assembly procedure, it is difficult to perform additional machining or polishing on a chip-by-chip basis without using other jigs, and polishing multiple chips at the same time requires fewer polishing times than polishing each chip individually. Since it does not need to be replaced, there is less damage and defects, making it easier to obtain good quality products.

If a practical multi-head can be obtained by integral polishing,
The assembly process 11IN, which involves chip processing, chip attachment to the pairing 1 common base member, and integral polishing, can be said to be a rational process (procedure). In order to make integrated polishing possible, measures can be taken to obtain the desired dimensional accuracy (for example, by changing the diameter of the polishing drum to V).
Before and after polishing work (such as using a material with a diameter equal to or larger than the TR rotating drum, adding tape guides or protrusions to the polishing drum, and using polishing tape with low amphoteric properties) It is also necessary to create an integrated polishing device for multiple chip heads that can measure (using a microscope camera, a monitor, and a printer) the polishing state of each part of the tape sliding surface of each part of the head along the way.

As a result of these measurements, you can check the finish condition of the tape sliding surface before and after polishing, and check if there are any defects such as chip cracks or chips.
By doing so, it is possible to take measures and improve the reliability of processing.

Furthermore, since integral polishing is possible, the relevant dimensions for each head during chip pairing and attachment can be clarified by making a prototype using the above-mentioned integral polishing apparatus.

In the post-process, the finished product of the multi-chip head, which has been wound around each head and tested for static characteristics, is mounted on the rotating drum of a VTR, and the output is inspected and changes in the shape of the sliding surface are confirmed, and the chips are paired, pasted, and integrated. Confirmation and correction of appropriate polishing values (head evaluation)
By doing so, it is possible to obtain high-quality multiple magnetic heads with significantly improved yield.

〔Example] The present invention will now be described in detail with reference to the drawings.

FIG. 2 is a front view of the quadruple chip head. In the same figure, 1 is a quadruple chip head, 2 is a base member, 2A~
2D is a finger-like part of the base member 2, 3 is a helad tip (four pieces a, b, c, and d are shown), and 4 is a helad tip 3 glued to the finger-like tip of the base member 2. adhesive, is.

FIG. 2A shows the finger-shaped portion 2A of the base member 2 in FIG.
It is an enlarged front view of one Herad chip 3 adhered to the tip part of. In FIG. 2A, 5 is the tape sliding surface of the groove 3, 6 is the gap for the magnetic head, 7 is the apex of the sliding surface 5, and 8 is the gap line.

FIG. 2B is a side view of one Herad tip 3 shown in FIG. 2A. In FIG. 2B, it will be well understood that the head chip 3 is bonded to the tip of the finger-shaped portion 2A of the base member 2 with an adhesive 4.

Figure 2C shows the four Herad chips a and b in Figure 2.
, c and d are front views seen from the tape sliding surface. Although each of the head chips a, b, c, and d is bonded to the tips of the finger-like parts 2A to 2D, they are not all located at the same height, but are different from each other. It will be recognized that it is arranged and glued together with the

Now, as seen in Figure 2, Figures 2A to 2C, ・1
The serial chip head 1 is made by selecting four head chips with desired dimensions and shapes from among a large number of head chips cut out from a pounding block according to well-known video head manufacturing procedures.
They are simply selected individually and adhered to the tips of the four finger-shaped parts 2A to 2D of the base member 2 with adhesive 4, and cannot be used as a four-wire magnetic hend as is.

In other words, unless the tape sliding surfaces of each of the four Herad chips a, b, c, and d are well polished in advance so that each sliding surface makes good contact with the magnetic tape, each head chip will not be polished. Since sufficient output cannot be obtained from the windings, the quadruple chip head 1 is useless as a quadruple magnetic head.

Therefore, there are shapes and dimensions before polishing and shapes and dimensions after polishing. In these figures, the symbols with an O suffix indicate the initial values (dimensions before polishing), and the ones with 0 indicate the initial values (dimensions before polishing). Symbols without symbols indicate dimensions after polishing.

In Fig. 2, if the reference radius is R, XO is given for each head chip, and is the initial value of the protrusion step from the reference radius R after pasting, X is the value of the protrusion step after polishing, and YO is the value of the protrusion step after polishing. Y is the initial value of the gap distance between adjacent head chips after attachment, and Y is the value after polishing.

Similarly, in FIG. 2A, RXO is the initial value of the sliding surface radius after chip pairing, RX is its value after polishing, and GdO is the initial value of the gap depth after chip pairing, Gd is the value after polishing, α0 is the initial value of the displacement amount of the vertex 7 of the sliding surface 5 after pasting, and α is the value after polishing. In FIG. 2B, RYO is the side surface The initial value of the radius of the sliding surface after chip pairing, R
Y is the value after polishing.

In Figure 2C, G2 is the gap length (this does not change before and after polishing), θO is the initial value of the azimuth angle after chip pairing, θ is its value after attachment, and HO is the track height of the chip pair. The initial value after the ring, H is the value after attachment, and TW is the trunk width (this does not change before and after polishing).

Using the four-chip head as an example, we have explained the shape and dimensions of the multi-chip head, and the multiple chip head cannot be made into a multi-chip magnetic head as it is, and the tape sliding surface of the chip head needs to be polished. You must have understood that there are certain things.

FIG. 1 is a flowchart showing a method for manufacturing a multiple magnetic head as an embodiment of the present invention.

As seen in the figure, the method for manufacturing a multiple magnetic head as an embodiment of the present invention consists of steps S1 to S13. Each step will be explained below.

First, assuming that a quadruple magnetic head is to be manufactured, in step S1, the desired finishing dimensions of the tape sliding surface and other details are determined for each head a, b, c, and d in accordance with the required head performance. The desired finishing dimensions of the tape sliding surface and other dimensions include gap length G2, trunk width TW, and azimuth angle θ.
, track height H1 sliding surface radius RX, sliding surface radius RY seen from the side, gap depth Cd, protrusion level difference quantity α, etc.

Next, in step S2, chip processing is performed to obtain a head chip, that is, a bonding block is created according to a well-known procedure for manufacturing a video head, and a number of head chips are cut out from the block.

In step S3, from among the large number of head chips cut out in step S2, each head is selected to have the required dimensions and shape according to the dimensions of the chip itself, and conditions that take into consideration attachment to the base member and polishing. Sort the chips. The process of performing this sorting and collecting chips with the required dimensions and shape is called pairing.The dimensions of each paired chip remain at their initial values (azimuth angle θ0, track height HO, gap depth Gd01) Surface radius RX
The radius of the sliding surface viewed from the O1 side is RYO).

However, since the gap length GE and track width TW are not related to the polishing of the sliding surface, they also become the values after polishing.

Next, in step S4, each of the paired chips is attached to a common base member as a multiple chip in consideration of integral polishing. At that time, the protrusion level difference X, the gap distance Y between adjacent head chips, the positional deviation amount α of the apex of the sliding surface, etc. will be distorted depending on the attachment position when each chip is attached to a common base member. Because it's easy,
Paste while doing the @ tone. After pasting, each head chip is set to an initial value XO1α0, and the initial value YO of the gap distance between each head chip becomes an approximate final finished dimension (value after polishing) Y.

Since these quantities do not exist in a single Herad chip itself, these quantities can only be determined by attaching multiple chips to a common base member.

Next, the process moves to step S5, and a pasting test is performed.

Here, for the azimuth angle, the initial value θ0 after chip pairing becomes approximately the final value θ after polishing due to pasting.Similarly, the track height also changes to the initial value HO after chip pairing due to pasting. becomes approximately the final value (final finished dimension) H after polishing. Therefore, at the stage of pasting, the large amounts of Y, TW, and θ1 H become the final finished dimensions.

Kono stage Teha, initial values RXO, RYO, XO.

α0 and final finished dimensions Y, TW, θ, H
It is checked whether the size is within a predetermined size range, and if not, the result is NG (No Good) and the process returns to step S2. This pasting inspection also includes an appearance inspection.

Next, in step S6, the multi-chip head after the pasting test is attached to the polishing drum. FIG. 3 shows this installation situation.

FIG. 3 shows that the multiple chip head l is mounted on the polishing drum 15.
It shows how they are screwed together by means not shown. 21 is the outer peripheral surface of the polishing drum 15, and 25 is a cutout hole. Here, the amount of protrusion AO by which the sliding surface 5 of the chip head protrudes outward from the outer peripheral surface 21 of the polishing drum 15 is determined. Please note that the polishing equipment including the polishing drum is described below.

Returning to FIG. 1, the process moves to step S7.

Here, AO and RXO are inspected before polishing.

RYO, αO2δ0 (CdO), and XO are measured and inspected. Here, δO is the required polishing 9N (initial value), and when polishing is actually performed, the gap depth Cd at that time can be calculated backward from the polishing amount δ.

Next, the process moves to step S8, in which the multiple chips are polished in one piece using a polishing device. At this time, various quantities of RX, RY, α, δ (Gd), and X are measured before, during, and after polishing.
Performing integral polishing while inspecting 0 Next, the process moves to step S9 and a post-polishing inspection is performed.

If the polishing result is insufficient, the process returns to step S8 and re-polishing is performed, and if the polishing result is obviously poor, the original step S2. S3. Return to S4 etc.

After the integral polishing is completed, in step S10, winding is applied to each chip head, and the process proceeds to step S11, where static characteristics testing (inductance,
Measurement of resistance R1 impedance Z1 quality factor Q) is performed, and if it passes, the process moves to step 312 and is mounted on the rotating drum of the VTR.

Then, in step 313, an output test, an output-to-noise ratio (C/N), and an RF envelope test are performed for each head to determine whether the output is stable. The test results are used for chip pairing in step S3,
The appropriate values for pasting in step S4 and integral polishing in step S8 are used to confirm whether they were appropriate (head evaluation) and are fed back to the next manufacturing stage.

As explained above, if integrated polishing of multiple chip heads is possible, chip processing and pairing are possible.

It is possible to put together an extremely rational process of pasting and integral polishing. In addition, the head evaluation results can be adjusted by correcting the pairing of the chips, correcting the attachment position of each chip, and modifying the polishing conditions without changing the processed shape and dimensions of the chips.
The shape of the tape sliding surface can be easily and subtly modified. Therefore, even with multiple chip heads, the output of each head is good without the need for a break-in operation after the VTR drum is actually installed.
It is possible to obtain a product with little variation between heads. In addition, since the number of times each chip is handled before it is pasted multiple times is small, there are fewer chip breakage accidents.

If integrated polishing is possible in the middle of assembling a multi-chip head in this way, it can be said that the manufacturing process connected to chimbling, pairing, pasting, and integrated polishing is an extremely rational assembly process. The dimensional relationship before and after integral polishing will be described later.

FIG. 4 is a plan view showing an embodiment of an integrated polishing apparatus for a multi-chip head used in the above-described method for manufacturing a multi-chip magnetic head, and FIG. 5 is a side view of the same.

In these -, 10 is an integrated polishing device, 11 is a frame,
12 is a vertical slider, 13 is a small DC motor, 14 is a shaft, 15 is a polishing drum, 16 is a cam, 17 is a small DC motor, 18 is a polishing tape, 19 is an electromagnetic brake, 20 is a supply reel, 22 is a DC motor, 23 is a take-up reel, 24
is a guide roller, 26 is an XY stage, 27 is a Z stage, 28 is a plate, 29 is a two-beam objective lens, 3o is a microscope, 31 is a camera, 32 is a monitor, 33 is a printer, 34
is a stay, 35 is a linear sensor, 36 is a mounting base, 37
is a counter.

The previously explained FIG. 3 shows the polishing drum 1 in FIG.
5 is an enlarged view showing details of the situation in which the multi-chip head 1 is attached to the multi-chip head 5. FIG.

Referring again to FIGS. 3 to 5. A polishing drum 15 is attached to the shaft 14 of a small DC motor 13 that can perform forward/reverse rotation and braking positioning via a vertical slider 12 attached to a frame 11. The vertical slider 12 is moved up and down and its position is determined by a small DC motor 17 capable of positioning by braking the rotation of the cam 16. A small DC motor 17 is attached to the frame 11. The polishing tape 18 is attached to the frame 11
A supply reel 20 attached to an electromagnetic brake 19 attached to the lower part of the frame 1
Winding device attached to the DC motor 22 attached to the bottom of 1.
23. During this time, the polishing tape 18 is guided by a guide roller 24.

The feeding speed and tape tension of the polishing tape 18 are determined by the set voltages of the DC motor 22 and the electromagnetic brake 19. In addition, the forward and reverse rotations of the sliding surface RX of the polishing drum 15 to prevent one-sided slipping and the vertical movement and positioning of the sliding surface radius RY to prevent one-sided slipping can be performed by rotational braking and positioning of the C motors 13 and 17. Determined by the set voltage. In addition, there are timers (not shown) for the total polishing time, forward rotation, reverse rotation time, switching, etc., polishing start and emergency stop buttons (not shown), and start/stop buttons for forward/reverse rotation and vertical movement of the polishing drum 15 ( Polishing work (not shown) and positioning for inspection (indexing) can be done by wet cultivation (not shown).

FIG. 3 shows an enlarged view of the polishing drum 15. The tape sliding surface 5 of the quadruple tip head 1 is attached to the cutout hole 25 of the polishing drum 15 so as to protrude from the outer peripheral surface 21 by a dimension AO. Similarly, a four-speed chip head 1 or a balance weight (not shown) is attached to the target position to perform simultaneous polishing or to balance the rotational movement of the polishing drum 15.

Also, each of the four chip heads 1 (a, b).

Frame 1 is used for inspecting the finished shape of the tape sliding surface 5 in c and d).
A microscope 30 with a two-beam objective lens 29 is mounted on a plate 28 mounted on an XY stage 26 and a Z stage 27 mounted on
and attach camera 31. The image captured by the camera 31 is then displayed on a television monitor 32 as a superimposed image of the object and interference fringes showing the unevenness of the object. Furthermore printer 3
3. Document the images.

Further, the amount of movement of the mount 36 of the microscope 30 in the X-axis direction is detected by an X-axis near sensor 35 provided on a stay 34 mounted on the frame 11', and is displayed on a counter 37.

In this way, each head (a,
b, c, d,) sliding surface 5 is the TV monitor 3
2, the polishing amount δ is due to the X-axis fine movement of the XY stage 26.
This is confirmed by the display change on the counter 37 when the light beam objective lens 29 is focused. The normal line of the polishing drum 15 and the origin are aligned with the Y-axis stage of the XY stage 26,
On the Z stage 27, each head of the 41-series chip head 1 (
It can be slightly moved according to the dimensions of each track height H of a, b, c, and d).

Of course, during measurement, the polishing operation is temporarily stopped, the head is moved and positioned in front of the objective lens 29 while watching the television monitor 32, and the polishing tape 18 is moved to the outer peripheral surface 21 of the polishing drum 15.
It is necessary to remove each tape sliding surface 5 of the quadruple tip head 1 to expose it.

The dimensions that change greatly on the tape sliding surface 5 of each head of the multi-chip head 1 due to integral polishing are Gd, X,
These are various quantities of α, RX, and RY.

Hereinafter, the dimensional relationship during chip pairing in step S3 in FIG. 1, at the time of pasting in step S4, and after integral polishing in step S9 will be clarified.

FIG. 6 is an explanatory diagram showing the dimensions of the four-channel knob head attached to the polishing drum 15 before and after polishing. As seen in the figure, the end 1 is attached to the quadruple chip so as to protrude from the outer circumferential surface 21 by a dimension AO, and it is finished by integral polishing, and the amount of polishing of the end a head is set to δa.

If the amount of polishing of the center b head is δb, the relational expression between the initial protruding step XO at the time of attachment and the protruding step X after polishing is expressed by the following equation.

XO−δb−δa + X −−(1
) When XO=O, X=δa−δb ・−・−(
2).

In addition, the initial gap depths Gd0a and Gd0b of the a-head and b-head of the chip, and the gap depth G after polishing.
The relational expression between da and Gdb is Gd0b=Gdb+δb (
3) GdOa-Gda+δa --(
4) Also, the formula (4) - (3) is Gd0a-Gd0b+Gda-Gd b+δa-δb
......(5), and this (5
) Substituting formula (1) into formula gives Gd0a-Gd0b+Xd
a-Gd b+X-Xo (6) In the above equation (6), the gap depth G after chip finishing
If d a 'i G d b, then Gd0a! ;Gd
0b+X−Xo --(6a) Above (6a)
Initial protrusion step XO with formula! = iO, then the following (6b
) formula is obtained.

Gd0a=caob+x=cctob+δa-δb・・
...(6b) That is, as shown in the above equation (1), the initial protrusion step XO at the time of pasting is the desired protrusion step X and the grinding 19ffiδ at the time of integral polishing.
It is determined by the difference between a and δb, and as shown in equation (6a) above, the desired gap depth, for example, G d a ! If =i G d b, then if one initial gap depth Gdob is determined,
The other one, Gd0a, is determined, and it becomes possible to pair the initial gap depth GdO of the chip and to determine the size of the initial protruding step XO at the time of pasting. Since it is a quadruple chip head, the C head can be considered to have the same size as the B head, and the d head can be considered to have the same size as the A head.

FIG. 7 shows the time vs. polishing amount characteristics of each head of the 4-chip head during integral polishing. In other words, the 4-chip head 1 attached with the initial protrusion level difference X0=O is applied to the outer circumferential surface 2 of the polishing drum 15. This is a characteristic diagram of the changes in grinding II of each head a, b, c, and d over time when the heads are mounted so as to protrude by the dimension AO'. Position head a.

The amount of polishing (δaζδd)〉(δ
bζδC).

If the difference in polishing amount per unit polishing time between the inner head and the outer head is known in advance, the pairing and pasting work can be carried out according to (1) 2 to (6) above.
This is possible with the formula That is, for example, by integrally polishing multiple chip heads in which X0≈0 at the time of attachment, the protrusion step X between the heads after polishing is determined over time. Furthermore, if the protruding IAO is large, for example, after polishing the protruding IAO, the protruding step X between the heads will increase in proportion to the protruding amount (
In FIG. 7, it can be seen that X for AO'' is larger than X for AO'.

This shows that if a certain protrusion step X between heads is allowed, it is possible to polish by increasing the protrusion ff1Ao when finishing in a short time, and it is also possible to increase the protrusion step X or finishing gap Gd over time. If you want to finish with high precision, you can consider polishing with a smaller protrusion amount AO. Further, when the desired protrusion level difference X is large, if a material with a large initial protrusion level difference XO at the time of attachment is used, the polishing time is short and the desired finish can be achieved with less polishing lff1δ. As can be seen in (6a) 2 above, by varying the initial protruding step XO, the selection range of the initial gap depth Gd0a of head a with respect to the initial gap depth Gdob of head b is expanded, and the pairing rate is also improved. It is possible.

Next, check the sliding surface radius RX of each head by integral polishing.

The finishing status of RY will be described. The shapes of RX and RY are determined by interference fringes (interference rings) produced by a three-beam objective lens.

First, the sliding surface radius RY of each head is a flat surface (RYO''!=,
oo). When this is finished with Ikkenreki, RY can be achieved by running the abrasive tape. As for the polishing conditions, a material with low rigidity is used as the polishing tape 18 (the tape is a polyester film with a width of 1 inch and a thickness of 16 to 6 μm), and the amount of protrusion of the sliding surface 5 from the outer peripheral surface 21 of the polishing drum 15 is AO.
is the range of allowable conditions for the protruding step X between heads (AO#50
~500μm), and the protrusion step X and sliding surface radius RX
The tension of the polishing tape 18 is within the range of allowable conditions (50~
By selecting each condition of 300g), the sliding surface radius RY#1. O
~2.5mm items were made, heads a, b, and c.

There is also little variation between d. If the RY is made a little smaller than the desired RY in practical use, the desired RY can be obtained by adapting to the magnetic tape immediately after the VTR drum is mounted and operated.

The polishing conditions for the sliding surface RX include tape rigidity.

The protrusion amount AO is the same as that of the sliding surface RY, but the tension of the polishing tape should be as low as possible within a range that allows for the deviation of the apex of RYO from the center of the track width TW. The sliding surface radius RX is determined by selecting these polishing conditions and the initial sliding surface radius RXO during chip processing.
Determined by , each head a.

b, c, d all RX'i1.5RXO~3.5RX
You can make things with O. Desired RX in practical use:=i2R
Initial sliding surface radius RX0≒(RX
/2) to (RX/3) and if the chip is processed at a constant radius, there is no need to pair each head separately.

Finally, we will discuss the finishing status of the apex misalignment α, the apex misalignment α which is the biggest technical problem unique to the integrated polishing of multi-chip heads, and the technique for reducing the size of the protruding step X between the heads mentioned earlier.

In other words, as shown in Fig. 7, the polishing drum 1 during integral polishing
Unless the amount of protrusion AO of the sliding surface 5 from the outer circumferential surface 21 of the head is about 1.5 times or more than that when the rotating drum of the VTR is attached, the polishing time of the head will be long and the finished shape will not be good. However, if the protruding IAO is made larger, the central head (b) becomes larger than necessary.

C) The grinding 111ffi of both ends of the head (a, d) becomes larger, X becomes larger, RX also becomes deformed, and it is difficult to match the apex deviation α.

In order to solve these problems, the diameter of the polishing drum should be made 0.8 to 2.4 times the diameter of the VTR mounting drum.

FIG. 8 shows a schematic view of the external shape of the multi-chip head 1 before and after polishing, in which the diameter of the polishing drum 15 is made equal to the diameter DI of the VTR mounting drum, and the initial inter-head protrusion level difference X0≈0 is made.

The gap line 7 of each chip 3 in the series is approximately the same as the polishing drum 15.
It is attached facing the center point P (exact details will be explained later)
Therefore, if multiple chip heads 1 with an initial head-to-head protrusion level difference X0≈0 are attached to the polishing drum 15 having the same diameter as the diameter D1 of the VTR mounting drum, protruding from the outer peripheral surface 21 by the dimension AO, the end head a and the center The vertices 7a and 7b of the tape sliding surface 5 of the head b of the section touch at the same radius R, which is approximately half the diameter D1 of the polishing drum, and intersect at the center P of the polishing drum 15.

When polishing is carried out in one piece in this state, as shown by the broken line, the polishing amount δa of the end head a is larger than the polishing amount δb of the head b in the center, and the protruding step X is as shown in equation (2) above. Become. Furthermore, the trajectory of the polishing tape 18 before and after polishing also changes suddenly.

In a pairing that requires a large amount of polishing δb on the tip 3 of head b, the tip 3 of head a will be further removed as shown in FIG. For this reason, when multiple heads are mounted on the mounting drum of a VTR, head a tends to have poor contact with the magnetic tape.
If the desired protrusion step Xζ is 0.5 to 1 μm when the diameter is the same as the TR mounting drum diameter, only when chip pairing is limited to the polishing amount δb of the central head b within the range of δb - 0.5 to 2 μm. It becomes effective.

FIG. 9 shows a schematic diagram of the external shape of the multi-chip head 1 before and after polishing when the polishing drum diameter D2 is approximately twice the VTR mounting drum diameter. The conditions for attaching multiple heads are the same as those shown in FIG.

The initial protrusion level difference X0 of the multi-chip head 1 is approximately 0, and the vertices 7a and 7b of the sliding surfaces 5 of each head a, b, etc. intersect at the same radius R and protrude from the outer periphery 21 of the polishing drum 15 by a dimension AO. If the polishing amount δb of the head b in the center is the same, the polishing amount δa of the end head a is smaller than that shown in FIG. 8 before and after installation and integral polishing, and the protruding step X thereof is also small. Further, there is little change in the locus of the polishing tape 18 before and after polishing.

This means that by increasing the drum diameter, even if the protrusion 1iAO from the outer circumferential surface 21 is increased, the protrusion step X and the sliding surface radius RY can be made smaller, and the pairing of chips with a large polishing amount δb of the head 5 can be made smaller. It means that it is possible.

Furthermore, by increasing the diameter of the grinding drum, it is possible to prevent the sliding surface radius RX of the end head a from deforming and to reduce the apex deviation α immediately after grinding and during practical use.

This will be explained below. FIGS. 10A and 10B show the chip plane and sliding surface before and after integral polishing of Radar a to the end where the apex shift and the sliding surface radius RX are severely deformed.

FIG. 10A shows chip 3 of end head a of a multi-chip head.
The gap line 8 is pasted in the direction of the center line of the VTRTR rotating drum, and the protrusion amount A is applied to the small-diameter polishing drum shown in FIG.
The outlines before and after mounting and polishing are shown with O.The broken line shows the shape after polishing.After polishing, the 41 and 42 side of RX on the sliding surface is 4
One side is heavily cut. Also, even if the sliding surface 5 is made with apex deviation α0≒O when pasted, the apex will move as seen on the sliding surface 5' after polishing, and the deviation of the apex of RX of the sliding surface with the gap 6 will occur. can be shifted by α.

Therefore, as shown in FIG. 10B, the gap line 8 is shifted by βl in the attitude of the chip 3, the initial apex deviation α0 is shifted, and the apex deviation α after bonding and integral polishing is α! = io. However, since the polishing conditions are the same as those shown in FIG. 10A using a small-diameter polishing drum, 41 on the RX of the sliding surface after polishing is shaved more than the 42 side. This phenomenon can be alleviated by increasing the diameter of the polishing drum.

That is, the diameter may be increased (approximately twice) as shown in FIG.

Figure 11 shows the apex deviation α after polishing in such a case.
The chip plane and sliding surface before and after integral polishing of RAD a are shown to the end where the radius RX of the sliding surface is severely deformed. The broken line indicates after polishing.

As seen in Figure 11, when the diameter of the polishing drum is increased, the difference in the amount of wear between the 41 side and 42 side of the sliding surface RX after integral polishing becomes smaller, and the deformation of the 41 case is also reduced. Therefore, the attitude β2 of the chip 3 at the time of attachment can be made smaller than that β1 in Fig. 10B, and the setting of the initial apex deviation αO at the time of attachment is also small, reducing the chipping on the 41 side of RX of the sliding surface after polishing. The apex deviation after polishing can easily be αζ0.

In this way, it is possible to prevent the RXO shape of the end heads of the multiple heads from collapsing and create a desired apex deviation α.

Figure 12 shows the results for large and small polishing drum diameters.
Grinding of the end heads (a, d) of the continuous tip head F! It can be seen that when the diameter of the polishing drum, which shows the relationship between the j amount δ and the apex deviation α, is increased, the apex deviation α becomes smaller by about half compared to the polishing amount δ, as described above. In this way, the diameter of the polishing drum is set to V
By making it (0.8 to 2.4 times) the diameter of the TR mounting drum,
Since the RXO shape deformation of both end heads a and d during integral polishing can be reduced, the initial protrusion amount AO can be increased, and even if the polishing amount δ of the center head (b, c) is increased, the RY
It is possible to create a multi-chip head with a small X value.

In addition, as a measure to prevent the sliding surfaces RX of the heads at both ends from being chipped due to integral polishing of the multiple heads, the plan shown in FIGS. 13 and 14 can also be considered. In this proposal, instead of increasing the drum diameter as shown in FIG. 9 as an improvement on FIG. 8, another obstacle is intentionally provided to lift the retainer.

In FIG. 13, tape guides 45 and 46 are attached to both ends of the quadruple tip hand 1 attached to the polishing drum 15 to prevent one side of the RX of the sliding surfaces of heads a and d from being scraped during integral polishing. FIG. 13A is a bottom view of the main part in FIG. 13.

In addition, in FIG. 14, a four-chip head 1 is attached to a polishing drum 15, and protrusions 47 are provided on both sides of the notched hole portion 25 to prevent one side of the RX of the sliding surfaces of heads a and d from being scraped during integral polishing. This is what I did. FIG. 14A is a bottom view of the main part in FIG. 14.

According to this embodiment, a practical tape sliding surface shape slightly different for each head can be obtained by integrally polishing the multiple chip heads with an abrasive tape during assembly. By polishing multiple chips at the same time, you can expect to reduce the number of polishing times and reduce damage and breakage accidents by handling individual chips. In addition, there is no need to process the initial RXO on the sliding surface of the chip for each head, which facilitates chip pairing and prevents erroneous pasting when it is created for each head.

By enlarging the diameter of the polishing drum, attaching a tape guide, or providing a protrusion on the polishing drum, it is possible to prevent one side of the RX on the tape sliding surfaces of the heads at both ends of the multi-chip head from being scraped. In addition, by creating an integrated polishing device that can control the polishing conditions and inspect the shape of the sliding surface of each head during the polishing process, we can perform dimension inspections during polishing, judge pass/fail, chip pairing, and attach. By clarifying the relationship between the conditions and the integral polishing results, the finished dimensions of the tape sliding surface of each head can be improved.

Therefore, it is possible to obtain a high-quality, high-yield multi-chip head in which the output of each head is better than that of an actual device on a VTR drum, and there is little variation in the output between heads regarding the sliding surface finish.

〔Effect of the invention〕

According to the present invention, (1) When assembling a multi-chip head, by performing an integral polishing finish using an abrasive tape, it is possible to obtain a practical tape sliding surface shape that is slightly different for each head.

■By polishing each chip at the same time, the number of times of polishing and chip handling can be reduced compared to handling each chip individually, thereby reducing damage to and breakage of the chips.

■There is no need to individually process the initial RXO on the sliding surface of each chip, making it easy to pair the chips, and preventing erroneous pasting when making them individually.

■By increasing the diameter of the polishing drum, it is possible to reduce one-sided scraping of the RX on the sliding surfaces of the heads at both ends of the multi-chip head. This can also be done by adding tape guides or protrusions to the drum.

■-Dimensions related to chip pairing and attachment during integral polishing (
By clarifying α, X, RX, RY, Cd, it is possible to construct a rational multiple chip head assembly system.

■In order to achieve the advantages of ■～■ above, an integrated polishing device equipped with adjustable polishing conditions and inspection means during polishing expands the range in which chips can be paired and improves the finished shape of the sliding surface. Since a stable product can be obtained and the polishing result data can be easily fed back, multi-chip heads can be manufactured with high quality and significantly improved yield.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an embodiment of the method for manufacturing a multiple magnetic head of the present invention, FIG. 2 is a front view of a four-chip head, FIG. 2A is an enlarged front view of the main parts in FIG. 2, and FIG. 2B 2C is an enlarged front view of other important parts in FIG. 2, FIG. 3 is an enlarged view of important parts of the polishing drum, and FIG. 4 is an embodiment of the integrated polishing apparatus of the present invention. A plan view showing
Fig. 5 is a side view of the same, Fig. 6 is an explanatory diagram of the dimensional relationship before and after polishing of the multiple chip head, Fig. 7 is a characteristic diagram showing the time vs. polishing amount characteristics of each chip head during integral polishing, and Fig. 8 , FIG. 9 is a schematic diagram of the external shape of the chip head before and after integral polishing in the polishing drum, FIGS. 10A and 10B are explanatory diagrams showing the plane and sliding surface of the chip before and after integral polishing, respectively, and FIG. 11 12 is an explanatory diagram showing the plane and sliding surface of the chip before and after integral polishing, FIG. 12 is a characteristic diagram showing the relationship between polishing amount and apex slippage, and FIG. 13 is another embodiment of the integral polishing apparatus of the present invention. A plan view showing an example, FIG. 13A is an enlarged bottom view of the main parts thereof, FIG. 14 is a plan view showing another embodiment of the integrated polishing apparatus of the present invention, FIG. 14A is an enlarged bottom view of the main parts, It is. Explanation of symbols

Claims (1)

[Claims] 1. A pairing process in which a required number of chips having a desired shape and dimensions are selected from among a plurality of chips to become a head, and the required number of chips are formed into pairs; and a required number of chips formed in pairs. A multiple chip attaching process in which multiple chips are attached to the same base member, and an integral polishing process in which the tape sliding surfaces of the multiple chips attached to the same member are then integrally polished. A method for manufacturing a multiple magnetic head characterized by: 2. A chip head, which is made by pasting chips on the same base member, is attached to the polishing drum, and the polishing tape fed out from the supply reel is wound onto a take-up reel via the polishing drum, thereby making the chips attached to the polishing drum. A polishing device for polishing a head, which includes a microscope disposed near the polishing drum, a camera for taking an image obtained by the microscope, and means for monitoring the output of the camera, and a microscope for monitoring each of the chip heads during polishing. A polishing device characterized in that the polishing status of a head can be observed. 3. A multi-chip head made up of multiple chips attached to the same base member is attached to the polishing drum, and the polishing tape fed out from the supply reel is wound onto a take-up reel via the polishing drum. In an integrated polishing device that integrally polishes multiple chip heads attached to
An integrated polishing apparatus characterized in that the diameter of the polishing drum is equal to or larger than the diameter of a VTR mounting drum on which the multi-chip head is mounted after polishing. 4. A multi-chip head made up of multiple chips attached to the same base member is attached to the polishing drum, and the polishing tape fed from the supply reel is wound onto a take-up reel via the polishing drum. In an integrated polishing device that integrally polishes multiple chip heads attached to
A traveling tape guide means is attached to the polishing drum for lifting the traveling polishing tape at the entrance and exit sides of the multiple chip head to be polished and polishing the multiple chip head. An integrated polishing device characterized by: 5. In the method for manufacturing a multi-magnetic head according to claim 1, in the pairing step, the initial gap depth of the central chip constituting the multi-chip is Gd0b, and the initial gap depth of the end-side chips is Gd0b. is Cd0a, and when they are Gdb and Gda after integral polishing, Gd0
A multi-magnetic head characterized in that when the value of either a or Gd0b is determined in advance, the other is determined according to the relational expression: Gd0a≒Gd0b+Gda-Gdb+X-X0 (where, X is the protruding step and X0 is its initial value). manufacturing method. 6. In the method for manufacturing a multi-magnetic head according to claim 5, when the amount of polishing of the central chip after integral polishing of the multiple chips is δb, and the amount of polishing of the end-side chips is δa,
A method for manufacturing a multi-magnetic head, characterized in that the values of δa and δb are determined in advance, and the initial value X0 is determined from a desired protrusion step X according to the relational expression: X0≈δb−δa+X. 7. In the method for manufacturing a multi-magnetic head according to claim 5, the initial protrusion amount A0 of the head sliding surface of the multi-chip from the outer peripheral surface of the polishing drum used for integral polishing is 50 μm or more.
By making a variable selection in the range of 500 μm, varying the polishing time, and making the initial value X0 of the head protrusion step variable, the initial chip gap depth Gd0 can be adjusted while keeping the desired protrusion step X constant. A method for manufacturing a multiple magnetic head, characterized in that the pairing range is expanded. 8. The method for manufacturing a multi-magnetic head according to claim 1, in which the plurality of chips are to be paired with each other in the pairing step, and the initial sliding surface radius of the chips during chip processing is set to RX0; When it is designated as RX after integral polishing, the initial sliding surface radius RX0 of the chip is processed so that it falls within the range of RX0≒(RX/2) to (RX/3), and a multi-chip is constructed. 1. A method of manufacturing a multiple magnetic head, characterized in that a plurality of chips are shared as objects to be paired with each other for each chip. 9. In the method for manufacturing a multi-magnetic head according to claim 1, in the integral polishing step, even if the radius RY0 of the initial sliding surface of the chip is unprocessed and flat (RY0≒∞),
As the polishing tape, a material with low rigidity such as a polyester film having a width of 1 inch and a thickness of 16 to 6 μm is used, and the tension of the polishing tape is increased or decreased in inverse proportion to the initial protrusion amount A0 (50 to 500 μm) during integral polishing. 300-50
g) A method for manufacturing a multi-magnetic head, characterized in that by doing so, it is possible to finish the heads of each chip constituting the multi-chip so that the sliding surface radius RY0≈1.0 to 2.5 mm. 10. In the method for manufacturing a multi-magnetic head according to claim 1, in the pasting step, the attitude (gap line) of the chip is shifted by β in advance, and the initial apex deviation of the sliding surface is shifted by α0 in advance. A method for manufacturing a multiple magnetic head, characterized in that it is possible to finish the apex deviation α after bonding and integral polishing so that α≈0.