JPH03161264A - Working method for video head by wire saw and wire saw working device - Google Patents

Abstract

PURPOSE:To drastically increase the dimensional accuracy of the head height and to omit or drastically curtail the adjusting work of the head position at the assembly stage thereafter, by performing the relative alignment of the track tip part of a video head and a working wire with <=+ or -1mum accuracy. CONSTITUTION:The relative position of a traveling wire 1 and the track tip part of a video head 3 is detected by a detection means 5. The relative alignment of the track tip part of the video head 3 and the working wire 1 is performed with the accuracy in <=+ or -1mum by a positioning means 10 based on this detection value. The accuracy of head height dimension can thus be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire saw processing method and apparatus for processing magnetic heads of magnetic recording devices such as VTRs. [Conventional technology] In conventional wire saw machining, first, a dummy sample is trial-machined, and after it is taken out of the machine, the difference between the actual machining position and the target machining position is measured, and the difference is calculated. It was common practice to set the workpiece (bonding block) on a device (wire saw) at the position to be cancelled.

[Problem to be solved by the invention]

The above conventional technology requires trial machining and measurement of the machining position every time the type of workpiece changes, resulting in low productivity.
Furthermore, even if the products are of the same type, if there is an error in setting the workpiece to the device, the machining position changes, resulting in a problem in that the machining position accuracy decreases.

The purpose of the present invention is to improve processing dimensional accuracy and productivity by aligning the workpiece (bonding block: a block-shaped component consisting of several video heads of several chips) with the wire and then processing it with a wire saw. An object of the present invention is to provide an improved method and apparatus.

[Means to solve the problem]

In order to achieve the above purpose, a means for detecting the relative position of the running wire and the workpiece, and a positioning means for adjusting the position of the workpiece based on the detected value are provided. I decided to process objects by pressing them against a moving wire. That is, the present invention is a video head processing method using a wire saw, which is characterized in that the relative positioning of the track tip of the video head and the processing wire is performed with an accuracy of ±μm or less, and the head height dimension is improved. .

The present invention also provides means for detecting the relative position of the wire and the workpiece in a wire saw processing device that cuts or grooves the part by pressing the part against a traveling wire, and a means for detecting the relative position of the wire and the workpiece, and a position of the workpiece based on the detected value. This wire saw processing apparatus is characterized in that it is provided with a positioning means for adjusting the position of the workpiece, and processes the workpiece after aligning the position of the workpiece with respect to the wire.

The present invention also provides a method for detecting the relative position of the wire and the workpieces above and below the wire in a wire saw processing device that simultaneously cuts or grooves parts placed above and below a traveling wire by pressing the parts against the wire. This wire saw processing apparatus is characterized in that it is provided with a means for adjusting the position of the workpiece and a positioning means for independently adjusting the position of the workpiece, and processes the workpiece after aligning the position of the workpiece with respect to the wire based on the detected value.

[Effect]

A wire saw processing device generally processes a workpiece by pressing a workpiece against a traveling wire from below to above. First, the workpiece is brought under the wire to a position where it does not come into contact with the workpiece. Next, a small detection unit (for example, an optical R microscope) for detecting the positions of the wire and the workpiece is set above the wire, and the relative positions of the two are detected.

The workpiece is set on a moving stage (for example, a position adjustment stage in the X, Y directions and rotational direction within a plane) provided on a lift mechanism that presses the workpiece against the wire.

The above-mentioned detection unit can simultaneously observe both the running wire and the workpiece as images. First, by determining the average center position of the wire as it runs, Find the center position of. next,
A predetermined position from the center position is displayed on the monitor screen with a cursor or the like. Therefore, it was decided to move the position adjustment stage described above to align a specific reference position of the workpiece with the cursor position, and then press the workpiece against the wire for processing.

〔Example〕

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings. FIG. 1 is a diagram showing a schematic structure of a wire saw processing apparatus according to the present invention. The wire saw processing device causes a wire to reciprocate horizontally with respect to a workpiece 3 (hereinafter referred to as a bonding block) via a wire bobbin 2,
Zlli on wire 1 running through bonding block 3
By pressing using the moving mechanism 4, cutting or grooving is performed. In this embodiment, an optical microscope 5 (including an imaging TV camera 6) for detecting the relative position between the wire 1 and the bonding block 3 is provided above the wire 1, and the image taken by the optical microscope 5 is captured by the TV camera 6. An image processing device 9 and a TV camera 6 detect the center of the wire 1 and the processing position of the bonding block 3 from this image.
An image monitor 7 that displays images obtained from the cursor, etc.
, a stage 8 and a stage control device IO for correcting the position of the bonding block 3 in the X, Y and rotational directions, and a wire saw control device 11 for controlling the wire bobbin 2, the Z moving mechanism 4, and the like.

Generally, the running of wire 1 in wire saw processing equipment is as follows:
The vehicle travels back and forth by repeatedly traveling in the forward direction (direction a in FIG. 1) and stopping, then traveling in the opposite direction (direction b in FIG. 1) and then stopping.

FIG. 8 is a diagram showing a schematic configuration of an embodiment of the optical microscope 5. As shown in FIG. The optical microscope 5 epi-illuminates the wire 1 and the bonding block 3 with white light introduced through the optical fiber cable 37 and the condenser lens 51, and magnifies the bright field image of the wire 1 with the objective lens 38 and the relay lens 39. , TV. An image is formed on the camera 6.

FIGS. 2 to 4 are diagrams for explaining the process of cutting and separating a plurality of video head chips using the wire saw processing apparatus. That is, the bonding block 3 is a block-shaped component in which two types of head components 3a and 3b are bonded together via an insulating layer 19. This bonding block 3 is cut and separated into a plurality of video head chips using a wire saw.

The optical microscope 5 has a wire 1 and a bonding block 3.
is enlarged and displayed on the monitor 7 as a monitor image as shown in FIG. The image processing device 9 processes a signal waveform captured in a detection range 13 of the wire 1 (a position perpendicular to the wire 1) determined within a detection image 12 detected by the optical microscope 5 as shown in FIG. and its signal level) 14 (shown in FIG. 3), find the center position of the wire 1. This signal waveform (shown in Figure 4(a)) is
By epi-illuminating the wire 1, the signal level at the center of the wire is high and the wire has a simple shape, and the center position X of the waveform can be easily calculated using a threshold method or the like. Note that the wire position before the wire is running (when stationary) and while the wire is running changes due to a position offset when the wire is replaced in the wire bobbin 2, vibration of the wire itself, or the like. An example of a monitor screen of the running wire 1 is shown in FIG. 9(.). The wire moves in the vertical direction of the screen '#J (1, la, 1b) to repeat running and stopping, and also to reverse and reverse the running direction.The signal waveform in this state is shown in Figure 9 (b). (14
．． 14a, 14b), and the center positions of the wires are XO, Xa, and Xb, respectively. FIG. 10 shows the change in the center position +IX of the wire 1 at this time. Assuming the time it takes for the TV camera 6 to take in an image and perform image processing, the wire center position changes regularly with a period W as shown in 54, and a large amount of change e occurs by about 10 μm. In the video head chip, as shown in FIG. 2 (Q), the dimension between the end surface of the bonding block 3 and the end surface of the track 20 (referred to as head height: h') is set with high precision, for example,
Since it is necessary to control it to within ±5μm,
As shown in Figure 0, if the center position changes with each detection, it becomes impossible to achieve the target. Therefore, the time t for capturing an image with the TV camera 6 and performing image processing is
The average value of the center position is determined so that the time is longer than the vibration period W of . As shown in Figure 11,
Waveform 14 detected at time t when an image is captured by the TV camera 6 and image processing is performed. 14a and 14b are detected for a period longer than the vibration period W of the wire 1, and the respective detected waveforms are combined to form a waveform 55. Wire 1 at this time
FIG. 12 shows changes in the center position X. When detected with a time T longer than the period W, the result is 55, and the maximum change me
is approximately 2 μm, making it possible to achieve the target.

Therefore, it was decided to detect the center position lx of the wire using the method described above while the wire was running, similar to wire saw processing.

The method of aligning the end face of the bonding block 3 and the end face of the track 20 is as shown in FIG. 2(b).
A cursor (height cursor) 22 indicating the position of the tip of the track 20 of the bonding block 3 is displayed on the monitor 7 with respect to the center position X (indicated by a cursor 21). The distance h between both cursors (shown in Figure 4(b)) is
If the diameter of the wire 1 is d, it is determined by d/2+h'. Note that the position of the height cursor 22 changes every time h' changes depending on the type of bonding block 3, so the track height h' for the type is determined by the image processing device 9.
Register in advance. Next, the bonding block 3 is moved in the X, Y and rotational directions using the stage 8 and its control device 10 shown in FIG. 1, and as shown in FIG.
As shown, align the leading end of the track 20 with the cursor 22. This operation (shown in FIG. 4 (Q)) can be performed manually while observing the screen of the monitor 7. Alternatively, the leading end of the track 20 may be
For example, there is a method in which the bonding block 3 is automatically aligned by detecting it by image processing (as described in Japanese Patent Publication No. 59-23467).

After the above alignment, the bonding block 3 is pressed against the traveling wire 1 and processed based on a command from the wire saw control device l1. (Showed in FIG. 4(d)) FIG. 5 shows another embodiment of the present invention. The embodiment shown in FIG. 1 shows a case where there is only one bonding block 3, but this embodiment shows a case where a plurality of bonding blocks 3 are processed simultaneously with a wire saw. First, each bonding block 3 is
In advance, they are arranged on the alignment jig 23 shown in FIG. 5 at a constant arrangement angle θ and so that the track positions shown in FIG. 2 are on the same line, and fixed with adhesive banks 1 or the like.

Note that the present invention does not specify this alignment method.

In order to simultaneously process a plurality of arranged bonding blocks 3 with high precision using a plurality of wires 1 as shown in the arrow view of FIG. The relative position between the head section at the center position and the wire 1 is measured using a twin-lens optical microscope 1i [24 (the same applies to two single-lens microscopes), that is,
Left and right TV cameras 25. After aligning the wire 1 and the end surface of the track 20 using the method explained in FIGS. 2 and 8 to 12 based on the image taken in step 26,
I decided to machine it with a wire saw. In this method, in advance,
Since mutual alignment errors between the plurality of aligned bonding blocks 3 affect processing accuracy, more precise alignment is important than with a single bonding block 3. For example, in order to achieve the dimensional accuracy of the head height of ±5 μm or less, the alignment error between the track end surfaces of the wire 1 and the bonding block 3 must be ±1 μm or less. In addition, in this method, it is relatively easy to obtain an image detection resolution of about 0.5 μm by using the optical microscope 24 and the image processing device 9, and furthermore, it is relatively easy to obtain an image detection resolution of about 0.5 μm by using the optical microscope 24 and the image processing device 9. There is no particular problem in terms of mechanism or control when adjusting the position with .

FIG. 6 shows another embodiment of the invention. FIG. 6(a) is a diagram showing a state in which the lower bonding block 31 and the wire 1 are aligned before the upper bonding block 30 is set. FIG. 6(b) shows the lower bonding block 31.
FIG. 3 is a diagram showing a state in which the upper bonding block 30 and the wire 1 are aligned with each other when the upper bonding block 30 and the wire 1 are moved downward. Figure 6(c)
misses the detection unit, and the upper and lower bonding blocks 3
0. 31 is a diagram showing a state in which wire processing is performed on wires 31 at the same time.

That is, in FIGS. 1 and 5, a wire saw was used to process the wire 1 by pressing the bonding block 3 against the wire from below, whereas in this embodiment, the wire 1 was processed in the vertical direction ( It is based on a wire saw device (specifically described in Japanese Patent Publication No. 7901/1983) which presses bonding blocks 3 provided on both sides of the wire 1 so as to face the wire 1 for processing.

In this embodiment, an upper bonding block 30, a lower bonding block 3l, an upper stage 32 and a lower stage 33 for positioning in the X, Y, and rotational directions are arranged above and below the wire 1, respectively. It is provided on top of 35. Further, an optical microscope 36 for detecting the position of the wire 1 and the bonding block 3 is installed so as to be retractable during wire saw processing.

FIG. 7 shows the configuration of one embodiment of this microscope (detection unit) 36. This involves epi-illuminating the wire and the bonding block 3 with white light introduced through the optical fiber cable 37 and the illumination lens 51, and transmitting the magnified image using the objective lens 38 and the relay lens 39.
V camera 25. This is a microscope that focuses an image on 26. As shown in FIG. 6, this optical system needs to be installed in the gap between the upper stage 32 and the wire 1. Therefore, the objective lens 38 is placed horizontally, and the detection optical axis is directed downward at the tip of the objective lens 38. By arranging the bending mirror 40', the entire optical system is made thinner. In addition, a mirror 41 that bends the detection optical axis upward is placed next to this mirror 40, and by sliding both of them in the left and right directions and switching the detection optical axis up and down, the microscope 36 can be moved both upward and downward without reversing. This made it possible to detect

Below, a method of aligning the wire 1 and the bonding block 3 using this simultaneous upper and lower processing method will be explained.

First, move the upper Z movement mechanism 34 to the upper end, set the optical microscope 36 above the wire 1, and align the wire 1 and the lower bonding block 31 by the method described in FIG. This is done using the lower stage 33. However, wire sawing is not performed at this point. next,
The microscope 36 is temporarily retracted, the lower Z mechanism 35 is moved to the lower end, and the upper bonding block 30 is brought closer to the wire 1. Next, the microscope 36 is installed below the wire 1, and as shown in FIG. is performed on the upper stage 32. As described above, the upper and lower bonding blocks 30. After completing the alignment of ZIH 31, the microscope 36 is evacuated and the upper and lower ZIH
Movement mechanism 34. Wire saw processing is performed using 35.

〔Effect of the invention〕

According to the present invention, the dimensional accuracy of the head height (height) of a VTR head chip, etc. can be significantly improved compared to the conventional one (for example, from conventional ±10 μm to less than a few μm). The head position adjustment work can be omitted or significantly reduced. Further, since the present invention can simultaneously process a plurality of heads with the above-mentioned accuracy, it is expected that in addition to the above-mentioned effects, yield and productivity will be improved.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a wire saw device showing an embodiment of the present invention, Fig. 2 is a view showing a monitor image illustrating a method of aligning a wire and a bonding block in the present invention, and Fig. 3 is a diagram showing wire detection. FIG. 4 is a flowchart showing the process of aligning the wire and bonding block; FIG. 5 is a configuration diagram of a wire saw device showing another embodiment of the present invention; FIG. An explanatory diagram showing another embodiment of the wire saw processing method, FIG. 7 is a perspective view of the structure of an embodiment of the detection unit of the present invention, and FIG. 8 is a structure of one embodiment of the detection unit of the present invention. figure,
Figure 9 shows the monitor image of the vibrating wire and the detected signal waveform at that time, Figure 10 shows the change in the wire center position when detected in Figure 9, and Figure 11 shows the vibration of the wire. FIG. 12 is a diagram showing a monitor image of the wire and the detected signal waveform at that time when considering the following. FIG. 12 is a diagram showing a change in the wire center position when detected in FIG. 1...Wire, 2...Wire bobbin,
3... Z heel movement mechanism, 4... Workpiece (bonding block), 5...
Optical microscope, 6... TV camera, 7... Monitor 5, 8... Stage, 9... Image processing device, 10... Stage control device, 11... Wire saw control device. 1st Figure 1 - Wire 2 - Wire hole bobbin 3 - Z. %rua,t; night shift+---ne Aotl mouthwork. Object (Bo'〉TeknigbuO,,,ku) 5... Ikkou Civil Nod 4 Mosquito Fighter J-TV Force Mela 7--Monitor 8-Stacy' 2 Figure 5 Figure b 7th Brother 7 26 Mu 6 Figure 10 First

Claims (1)

[Claims] 1. A video head using a wire saw, characterized in that the relative positioning of the track tip of the video head and the processing wire is performed with an accuracy of ±1 μm or less to improve the dimensional accuracy of the head height. Processing method. 2. In a wire saw processing device that presses a part against a traveling wire to cut or groove the part, a means for detecting the relative position of the wire and the workpiece, and adjusting the position of the workpiece based on this detected value. Provide positioning means,
A wire saw processing device that processes the workpiece after aligning the position of the workpiece with respect to the wire. 3. In a wire saw processing device that simultaneously cuts or grooves parts placed above and below a traveling wire by pressing them against the wire, means for detecting the relative position of the wire and the workpieces above and below the wire; A wire saw processing apparatus characterized in that a positioning means for independently adjusting the position of a workpiece is provided, and the workpiece is machined after aligning the position of the workpiece with respect to the wire based on the detected value. 4. The wire saw processing apparatus according to claim 2 or 3, wherein the wire saw processing apparatus determines the center position of the wire, and then positions a specific part of the workpiece at a predetermined distance from the center position. 5. The wire saw processing according to claim 2 or 3, wherein the means for detecting the relative position of the wire and the workpiece comprises an optical microscope using an imaging device and a device for processing the image. Device. 6. The wire saw processing apparatus according to claim 5, wherein the means for processing the image of the wire detects the image over a period of time longer than the vibration period of the wire and calculates the average value of the center position. 7. Claim 3, wherein the means for detecting the relative position of the wire and the workpiece includes an optical microscope capable of detecting both the upper and lower directions by switching the detection optical axis.
The wire saw processing device described. 8. The position of the wire and the workpiece can be simultaneously detected from above the stationary or running wire by providing the position detection means inside the wire support roller. Wire saw processing equipment. 9. A claim characterized in that by providing the position detection means inside and outside of the wire support roller, the positions of both the wire and the workpiece can be simultaneously detected from above and below the stationary or running wire. The wire saw processing device according to item 3.