1. An adhesive composition for a wafer processing film, the composition comprising:
an acrylic polymer; and
a photosensitive gas generating agent,
wherein the photosensitive gas generating agent comprises an ester of 2-diazonaphtolsulfonic acid; and
wherein the photosensitive gas generating agent comprises at least one selected from the group consisting of novolac 2-diazo-1-naphthol-5-sulfonate, 2,3,4-trihydroxy benzophenone 2-diazo-1-naphthol-5-sulfonate, and 2,3,4,4\u2032-tetrahydroxy benzophenone 2-diazo-1-naphthol-5-sulfonate.
2. The adhesive composition according to claim 1, wherein the acrylic polymer has a glass transition temperature of \u221250\xb0 C. to 15\xb0 C.
3. The adhesive composition according to claim 1, wherein the acrylic polymer has a weight average molecular weight of 50,000 to 1,000,000.
4. The adhesive composition according to claim 1, wherein the acrylic polymer comprises:
90 parts by weight to 99.9 parts by weight of a (meth)acrylic acid ester monomer; and
0.1 part by weight to 10 parts by weight of a copolymerizable monomer having a crosslinkable functional group, in a polymerized form.
5. The adhesive composition according to claim 4, wherein the crosslinkable functional group comprises a hydroxyl group, a carboxyl group, an amide group, a glycidyl group, or an isocyanate group.
6. The adhesive composition according to claim 1, wherein the photosensitive gas generating agent is present in an amount of 0.5 parts by weight to 30 parts by weight based on 100 parts by weight of the acrylic polymer.
7. The adhesive composition according to claim 1, further comprising:
a polyfunctional crosslinking agent.
8. A wafer processing film, comprising:
a substrate; and
an adhesive layer formed on one or both sides of the substrate and comprising an acrylic polymer and a photosensitive gas generating agent,
wherein the photosensitive gas generating agent comprises an ester of 2-diazonaphtholsulfonic acid; and
wherein the photosensitive gas generating agent comprises at least one selected from the group consisting of novolac 2-diazo-1-naphthol-5-sulfonate, 2,3,4-trihydroxy benzophenone 2-diazo-1-naphthol-5-sulfonate, and 2,3,4,4\u2032-tetrahydroxy benzophenone 2-diazo-1-naphthol-5-sulfonate.
9. The wafer processing film according to claim 8, wherein the substrate has a thickness of 10 \u03bcm to 500 \u03bcm.
10. The wafer processing film according to claim 8, wherein the adhesive layer has a thickness of 0.5 \u03bcm to 50 \u03bcm.
11. The wafer processing film according to claim 8, further comprising:
a release film formed on the adhesive layer.
12. A method of processing a semiconductor wafer, comprising:
attaching the wafer processing film according to claim 8 to a semiconductor wafer;
processing the semiconductor wafer to which the wafer processing film is attached; and
irradiating the wafer processing film with ultraviolet light.
13. The method according to claim 12, wherein the processing the semiconductor wafer comprises a dicing process or a back-grinding process.
14. The method according to claim 12, wherein the irradiating the wafer processing film with ultraviolet light is performed by radiating ultraviolet light at a wavelength of 200 nm to 400 nm and a light intensity of 5 mWcm2 to 200 mWcm2 for 5 seconds to 60 seconds.
15. The method according to claim 12, further comprising:
delaminating the semiconductor wafer from the wafer processing film after the ultraviolet light radiation.
16. The wafer processing film according to claim 8, wherein the adhesive layer has a gel content of 80% to 99%,
wherein the gel content is a value obtained by the following Expression 1:
Gel content (%)=BA\xd7100,\u2003\u2003Expression 1
where
A is a mass of a cured adhesive composition, and
B is a dry mass of undissolved powder collected after curing the adhesive composition and 48 hours at room temperature after depositing the adhesive composition.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A magnetic sensor comprising:
a plurality of sensor units each including a magnetic detector and a magnetic field developing means for applying a bias magnetic field to the magnetic detector; and
means for driving and controlling the bias magnetic field developing means in the plurality of sensor units;
the drivecontrol means monitoring an output from the magnetic detector in one of the plurality of sensor units, and driving and controlling the bias magnetic field developing means in the plurality of sensor units for the monitored magnetic detector to provide a constant output.
2. The magnetic sensor as set forth in claim 1, wherein the bias magnetic field developing means includes a bias coil wound on the magnetic detector; and
the drivecontrol means drives and controls the bias magnetic field developing means by adjusting a current supplied to the bias coil.
3. The magnetic sensor as set in claim 1, wherein the magnetic detector includes a core unit made of a high permeability material, and a sensor coil wound on the core unit and driven with a high frequency, to detect an external magnetic field on the basis of a change of the sensor coil impedance which is changed due to the external magnetic field.
4. A position transducer including:
a magnetic field developing means for developing a magnetic field whose strength and direction are changed correspondingly to a position of the magnetic field developing means;
a plurality of sensor units each including a magnetic detector and a bias magnetic field developing means for applying a bias magnetic field to the magnetic detectors and movable relatively to the magnetic field developing means;
means for driving and controlling the bias magnetic field developing means in each of the sensor units; and
means for detecting a moved position of each of the plurality of sensor units relative to the magnetic field developing means on the basis of an output from the magnetic detector in each of the plurality of sensor units;
the drivecontrol means monitoring the output from the magnetic detector in one of the plurality of sensor units, and driving and controlling the bias magnetic field developing means in each of the plurality of sensor units for the monitored magnetic detector to provide a constant output.