1. A method of fabrication of a semiconductor device, comprising the steps of:
die bonding of a plurality of semiconductor chips on a substrate;
forming a target mark in the substrate, the target mark corresponding to the semiconductor chips;
forming of a first insulation film on said substrate, wherein a top surface and at least a portion of side surfaces of said plurality of semiconductor chips are incrusted in said first insulation film;
forming a second insulation film directly on and contacting the first insulation film, the minimum height of a top surface of the second insulation film exceeding the maximum height of a top surface of the first insulation film;
grinding flat the second insulation film;
forming a third insulation film directly on and contacting the flatly ground second insulation film;
forming of a connection hole reaching a semiconductor chip of said plurality of semiconductor chips though said first insulation film, said second insulation film, and said third insulation film; and
forming of wiring on said third insulation film, wherein said wiring is connected to said semiconductor chip through said connection hole.
2. The method of fabrication of a semiconductor device according to claim 1, further comprising the steps of:
forming of an upper layer insulation film on said third insulation film, wherein said upper layer insulation film covers said wiring;
forming of a connection hole reaching said wiring, on said upper layer insulation film; and
forming of an electrode on said upper layer insulation film, wherein said electrode is connected to said wiring through said connection hole.
3. The method of fabrication of a semiconductor device according to claim 1, wherein said substrate is a silicon wafer.
4. The method of fabrication of a semiconductor device according to claim 1, wherein
said die bonding of said plurality of semiconductor chips on said substrate comprises die bonding of each said semiconductor chips on said substrate, wherein each said semiconductor chip is set so as to float on an adhesive resin applied on said substrate.
5. The method of fabrication of a semiconductor device according to claim 1, wherein
after said step of forming said wiring, said substrate is removed from said semiconductor chip and said insulation film.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An encoder comprising:
a disk disposed rotatably about a rotating axis and including a first track and a second track in which a first optical rotating grating and a second optical rotating grating are formed, respectively; and
a first detector and a second detector disposed so as to face the first track and the second track, including a first fixed grating constructing a first diffraction interference optical system together with the first rotating grating and a second fixed grating constructing a second diffraction interference optical system together with the second rotating grating, respectively, and configured to detect a first detection signal and a second detection signal from the first diffraction interference optical system and the second diffraction interference optical system, respectively,
at least one of the first rotating grating and the second rotating grating includes a plurality of curved slits in a curved shape, and
an absolute value of the disk is obtained based on a difference in the number of slits between the first rotating grating and the second rotating grating.
2. The encoder according to claim 1, wherein:
the difference in the number of slits between the first rotating grating and the second rotating grating is one.
3. The encoder according to claim 1, wherein:
the curved slits are formed along curved lines formed by curving a plurality of radial lines extending from the rotating axis in radial directions of the disk toward circumferential directions at curve degrees determined in advance, respectively.
4. The encoder according to claim 1, wherein:
the curved slits are formed within an angle range exceeding 0 degrees and less than 360 degrees with the rotating axis as a center.
5. The encoder according to claim 1, further comprising a position data generating portion configured to generate first position data representing an absolute position of the disk during one rotation and second position data having a resolution higher than that of the first position data based on the first detection signal and the second detection signal, and to specify the absolute position of the disk with a resolution higher than that of the first position data based on the first position data and the second position data.
6. The encoder according to claim 5, wherein:
the first rotating grating and the second rotating grating includes a first curved slit and a second curved slit, respectively, and curve degrees of the first curved slit and the second curved slit are set respectively in the manner that pitches of the first curved slit and the second curved slit are substantially equal.
7. The encoder according to claim 6, wherein:
a first gap between the first rotating grating and the first fixed grating and a second gap between the second rotating grating and the second fixed grating are substantially equal in size.
8. The encoder according to claim 6, wherein:
the first curved slits are curved in a circumferential direction opposite to the direction in which the second curved slits are curved.
9. The encoder according to claim 6, wherein:
the first curved slit and the second curved slit are reflection slits, respectively, and
the first fixed grating and the second fixed grating are disposed on the same surface side of the disk, respectively.
10. The encoder according to claim 9, wherein:
the disk further includes a third track on the outermost periphery, in which a third optical rotating grating is formed and which is configured to determine a maximum resolution of the encoder,
a plurality of radial lines extending in a radial direction at angular intervals determined in advance with the rotating axis as a center is set in the disk, and
the third rotating grating includes radial slits extending along the radial lines.
11. The encoder according to claim 10, wherein:
pitches of the radial slits and the first and second curved slits are substantially equal.
12. The encoder according to claim 10, wherein:
slits being included in the first fixed grating and the second fixed grating are substantially parallel to tangents of curved lines along which the first curved slit and the second curved slit curve, respectively.
13. A servomotor comprising:
a motor configured to rotate a rotary shaft; and
an encoder configured to measure an absolute position of the rotary shaft;
the encoder comprising:
a disk disposed rotatably about a rotating axis of the rotary shaft and including a first track and a second track in which a first optical rotating grating and a second optical rotating grating are formed, respectively; and
a first detector and a second detector disposed so as to face the first track and the second track, including a first fixed grating constructing a first diffraction interference optical system together with the first rotating grating and a second fixed grating constructing a second diffraction interference optical system together with the second rotating grating, respectively, and configured to detect a first detection signal and a second detection signal from the first diffraction interference optical system and the second diffraction interference optical system, respectively,
at least one of the first rotating grating and the second rotating grating includes a plurality of curved slits in a curved shape, and
an absolute value of the disk is obtained based on a difference in the number of slits between the first rotating grating and the second rotating grating.
14. A motor unit comprising:
a motor configured to rotate a rotary shaft;
an encoder configured to measure a position of the rotary shaft; and
a controller configured to control rotation of the motor based on the position detected by the encoder;
the encoder comprising:
a disk disposed rotatably about a rotating axis of the rotary shaft and including a first track and a second track in which a first optical rotating grating and a second optical rotating grating are formed, respectively; and
a first detector and a second detector disposed so as to face the first track and the second track, including a first fixed grating constructing a first diffraction interference optical system together with the first rotating grating and a second fixed grating constructing a second diffraction interference optical system together with the second rotating grating, respectively, and configured to detect a first detection signal and a second detection signal from the first diffraction interference optical system and the second diffraction interference optical system, respectively,
at least one of the first rotating grating and the second rotating grating includes a plurality of curved slits in a curved shape, and
an absolute value of the disk is obtained based on a difference in the number of slits between the first rotating grating and the second rotating grating.