JPH0552135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a linear stepping motor, and more particularly to a method for manufacturing a small linear stepping motor with improved processing accuracy.

[Conventional technology]

Conventionally, in the manufacturing method of this type of small linear step pink motor, the teeth at the tip of the yoke containing the excitation coil were formed by processing with a grindstone, and the teeth at the tip of the yoke and the comb-like teeth opposite to the teeth at the tip of the yoke were formed by grinding. The base was formed by half etching, and the processing accuracy was ±10 μm and ±20 μm, respectively, according to these methods. However, as mounting becomes more compact, the positioning accuracy of small linear stepping motors is required to be even higher, and conventional methods are no longer able to satisfy this requirement.

Therefore, by wire electrical discharge machining the teeth at the tip of the yoke having the excitation coil, improvements have been made such that the pitch accuracy of the teeth is less than ±5 μm and the shape accuracy is less than ±1 μm. In addition, the base facing the teeth of this yoke is separated into a thin plate with comb teeth and the base, and the thin plate with comb teeth is formed by full etching to eliminate the comb-like pitch.
It is now possible to form with a precision of 3 μm or less and a shape accuracy of ±0.5 μm or less. Further, by diffusion bonding the thin plate having the comb teeth to the base, it is possible to ensure the bonding.

[Problem that the invention seeks to solve]

In the conventional manufacturing method for linear stepping motors described above, pitch accuracy and shape accuracy can be greatly improved by separating the thin plate with comb teeth from the base and forming the comb teeth by full etching. . However, when diffusion bonding is performed using a thin plate with high-precision comb teeth as a base, there is a drawback that elongation of several tens of micrometers occurs in the pitch direction.
Although it was possible to improve the accuracy of each by separating the thin plate having the comb teeth and the base, there is a drawback that the accuracy deteriorates at the stage of diffusion bonding.

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a method for manufacturing a small linear stepping motor with good positioning accuracy, in which the base and the comb-like thin plate are diffusion bonded while maintaining high precision. be.

[Means for Solving the Problems] The method for manufacturing a linear stepping motor of the present invention comprises stacking a comb-like thin plate facing the teeth of a yoke with a small gap and a base on the comb-like thin plate. , by overlapping the comb-like thin plate and the base, and further using two thermocompression jigs having teeth in the same direction and pitch as the comb teeth of the comb-like thin plate, and narrower than the width of the comb teeth. The comb-shaped thin plate and the base are sandwiched from above and below and diffusion bonded.

[Effect]

In the diffusion bonding of the comb-like thin plate and the base, the present invention does not press the entire surface of the comb-like thin plate in order to suppress the elongation of the comb-like thin plate. Partial diffusion bonding is performed using a thermocompression bonding jig with teeth narrower than the width. As a result, the comb teeth of the comb-like thin plate tend to partially widen slightly in the direction of the comb teeth of the thin plate, but the dimension in the pitch-to-pitch direction is not affected. Therefore, although the accuracy in the comb tooth direction does not need to be high, the need for extremely high accuracy in the feeding direction, that is, the longitudinal direction of the comb tooth-shaped thin plate is satisfied.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIGS. 1a, b, and c are exploded perspective views of one embodiment of the present invention, and FIG. 2 is a perspective view of a thermocompression bonding jig used for diffusion bonding of this embodiment.

This embodiment consists of a yoke 1, a permanent magnet 2, an excitation coil 3, a comb-shaped thin plate 4, comb teeth 5, and a base 6. In addition, during the diffusion bonding of this embodiment, thermocompression bonding jigs 7, 7' and small pitch teeth are used. 8,8' is used.

The teeth at the tip of the yoke 1 are formed by wire electrical discharge machining, and a permanent magnet 2 is fixed to the center thereof. The excitation coil 3 is inserted into the toothed portion of the yoke 1. The comb tooth-like thin plate 4 is a silicon steel plate with a thickness of several tens of micrometers, and the comb teeth 5 are processed by full etching. By processing this comb tooth-like thin plate 4 by full etching, it is possible to form the comb teeth 5 with a pitch accuracy of 5 μm or less and a shape accuracy of ±1 μm.
The base 6 is integrated by overlapping the comb-like thin plates 4 and diffusion bonding them. Second
As shown in the figure, the thermocompression bonding jigs 7 and 7' are provided with small pitch teeth 8 and 8' at the same pitch in the same direction as the comb teeth 5 of the comb-shaped thin plate 4.

In performing diffusion bonding with this embodiment having such a configuration, the comb tooth-like thin plate 4 and the base 6 are superimposed, and the comb tooth 5 and the small pitch tooth shapes 8, 8'
After positioning and clamping from above and below with thermocompression bonding jigs 7 and 7', apply pressure of 2 to 4 kg/mm ² and heating temperature.
The comb-shaped thin plate 4 and the base 6 are bonded under bonding conditions of 400 to 700° C. and a heating time of 1 to 2 hours.

〔Effect of the invention〕

As explained above, the present invention uses a thermocompression bonding jig provided with teeth in the same direction and pitch as the comb teeth, by thermocompression bonding the comb tooth-shaped thin plate and the base.
Although the dimension in the direction of the comb teeth may be slightly longer,
The dimension in the direction perpendicular to the comb teeth, that is, in the direction between the pitches, hardly increases. This is because the comb-like thin plate is pressed only partially, and although there is a slight elongation, it has the effect of minimizing the effect on pitch errors.

That is, as an actual measurement result, since the elongation as a whole could be suppressed to a few microns or less, the error per pitch is less than a submicron, and there is no problem in use. As a result,
The positioning accuracy according to the present invention was able to ensure ±5 μm.

[Brief explanation of drawings]

FIGS. 1a, b, and c are exploded perspective views of one embodiment of the present invention, and FIG. 2 is a perspective view of a thermocompression bonding jig used for diffusion bonding of this embodiment. DESCRIPTION OF SYMBOLS 1...Yoke, 2...Permanent magnet, 3...Exciting coil, 4...Comb tooth-shaped thin plate, 5...Comb tooth, 6...
...Base, 7,7'...Thermocompression bonding jig, 8,8'...
Small pit teeth.

Claims (1)

[Claims] 1. A method for manufacturing a linear stepping motor comprising a comb-shaped thin plate facing the teeth of a yoke with a minute gap and a base stacked on the comb-shaped thin plate, wherein the comb-shaped thin plate and the base are stacked. Further, the comb-shaped thin plate and the base are sandwiched from above and below by two thermocompression jigs having teeth in the same direction and pitch as the comb teeth of the comb-shaped thin plate and narrower than the width of the comb teeth. A method for manufacturing a linear stepping motor, characterized in that the motor is manufactured by diffusion bonding.