Patent Application
20080176021
1. Field of the invention
The present invention relates to an inner lining structure for photoresistant collecting devices, and more especially to an inner lining structure for photoresistant collecting devices in photoresistant coaters.
2. Description of the prior art
At present, the photoresistant coating used in a wafer is produced via a rotating photoresistant coater. The photoresistant coater drops moderate liquid photoresistant with a high viscosity on the center of the top surface of a wafer and turns the wafer at a high speed. Due to the centrifugal force created by the turning of the wafer, the photoresistant expands outwards quickly and uniformly adheres to the surface of the wafer. Excess photoresistant is meanwhile thrown off the surface of the wafer and drained away via a photoresistant collecting device mounted on the photoresistant coater. However, the excess photoresistant is easily scattered around and needs to be removed by drawing air out of the device.
The coater has a sucking plate and sucks the wafer on the sucking plate. The sucking plate connects with a turnable axis at a bottom thereof which rotate the wafer at a high speed. The photoresistant collecting device has an inner lining mounted under the sucking plate.
As shown in
When the sucking plate operates at a lower rotating speed, the excess photoresistant thrown off by the wafer has a drip shape. However, when the sucking plate operates at a higher rotating speed, the photoresistant has a filament shape, such as cotton candy, and a weak vacuum is created under the sucking plate to form negative pressure. At the same time, the lighter photoresistant filaments produce a restoring force to themselves after being thrown out and breaking. As such, the photoresistant filaments easily adhere to the bottom of the wafer under the influence of the negative pressure under the sucking plate and the restoring force.
The prior art inner lining structure has shortcomings as described below:
1. The distance between the inner lining and a top surface of the sucking plate is too large, so that the photoresistant filaments are easily sprayed back on the bottom of the wafer, even if an iron ring is mounted between the inner lining and the sucking plate;
2. The step of the inner lining is too high, so that the photoresistant filaments easily remain on the bottom of the wafer under the guidance of airflow caused by suction.
Hence, the inventors of the present invention believe that the shortcomings described above are able to be improved upon and suggest the present invention which is of a reasonable design and is an effective improvement based on deep research and thought.
An object of the present invention is to provide an inner lining structure for photoresistant collecting devices to ensure that excess photoresistant filaments don't remain on the bottom of a wafer when the wafer is being spun at a high speed in the process of being coated with photoresistant.
Another object of the present invention is to provide an inner lining structure for photoresistant collecting devices which adjusts the height and level of the inner lining so the present invention can be applied to different products or types of devices.
To achieve the above-mentioned object, an inner lining structure for photoresistant collecting devices in accordance with the present invention is disclosed. The inner lining structure for photoresistant collecting devices includes a body having a periphery which is a circular arced surface that gradually shrinks in size as it gets higher, a receiving groove formed by concaving the top of the body downwards, which has an upper end shaped like an opening; and a through-hole arranged in a center of the body and penetrates a bottom surface of the receiving groove and a bottom of the body.
The efficacy of the present invention is as follows: the present invention reduces the distance between the top surface of the sucking plate and the upper flange of the inner lining so that it is difficult for the photoresistant filaments to remain on the bottom of the wafer; and the present invention includes adjustable screws that can be used to adjust the height and the level of the inner lining so that the present invention can be applied to different products.
To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings related to the present invention. However, the drawings are only to be used as references and explanations, and not to limit the present invention.
Please refer to
The body 10 is slightly shaped like a disc, the periphery of which is a circular arced surface 13 that gradually shrinks in size as it gets higher. The body 10 has two thread holes 11 formed in the circular arced surface 13. The two thread holes 11 are symmetrically formed at two sides of the body 11 for engaging with the two handles 50. The body 10 further has another circular arced surface 14 concaving inwards on a bottom thereof.
The receiving groove 20 is shaped like a circle and formed by concaving a top of the body 10 downwards. The receiving groove 20 is inside the body 10 and has an upper end shaped like an opening.
The connecting pole 30 is shaped like a short column and protrudes downwards from a center of the circular arced surface 14 on the bottom of the body 10. The connecting pole 30 has a cut groove 31 shaped like a ring and is formed in a bottom surface near a fringe thereof The cut groove 31 extends upwards from the bottom surface of the connecting pole 30 in the connecting pole 30 for a predetermined depth.
The through-hole 40 is shaped like a circle at a center inside the body 10. The through-hole 40 penetrates a bottom surface of the receiving groove 20 and the bottom surface of the connecting pole 30 for engaging with a turnable axis 200 (as show in
The two handles 50 both have screw threads 51 on bottoms thereof and are fixed on the body 10 via the engagements of the screw threads 51 and the two thread holes 11 of the body 10, thereby the two handles 50 are protrudently mounted on the top of the body 10, which is convenient for a user to hold the body 10.
Please prefer to
Please prefer to
The body 10 is arranged under the sucking plate 100. Because the inner diameter of the receiving groove 20 is greater than that of the sucking plate 100, the sucking plate 100 can be received in the receiving groove 20 and a top surface of the sucking plate 100 slightly protrudes from and closes to an upper flange of the body 10. A wafer 300 is placed on the top surface of the sucking plate 100. The sucking plate 100 sucks and fixes the wafer 300 on the top by means of suction in order that the wafer 300 can synchronously turn with the sucking plate 100. The turnable axis 200 extends from the bottom of the body 100 into the receiving groove 20 through the through-hole 40 and connects with a bottom of the sucking plate 100. The turnable axis 200 can rotate the sucking plate 100 for the photoresistant coating process.
During the photoresistant coating process, after being thrown off, excess photoresistant on the wafer 300 flows along an inner wall of the photoresistant collecting device into the bottom of the photoresistant collecting device. At the same time, the photoresistant collecting device draws air out and induces the photoresistant via a suction hole (not shown) in a bottom thereof to drain the photoresistant from a draining hole (not shown).
Accordingly, the present invention adopts the body with a circular arced surface structure instead of a step-shaped surface structure, reduces the outer diameter of the body 10 and increases the thickness of the body 10 (increases the height of prior iron rings), thereby the photoresis filaments easily attach themselves to the circular arced surface 13 of the body 10 under the guidance of airflow caused by suction. Furthermore, the present invention has a receiving groove 20 receiving the sucking plate 100, so that the sucking plate 100 can be embedded in the receiving groove 20 and the distance between the top surface of sucking plate 100 and the upper flange of the body 10 is reduced. Thereby, even if the wafer 300 is operating at a high speed, it is difficult for the photoresis filaments to enter the space between the sucking plate 100 and the body 10 and the photoresis filaments cannot adhere to the bottom of the wafer 300.
Additionally, three adjusting screws 60 are mounted on the bottom of the body 10 to adjust the height and the level of the inner lining structure. This ensures that the interval between the surface of the sucking plate 100 and the upper flange of the body 10 can be adjusted so that the present invention can be applied to different products.
What is disclosed above is only the preferred embodiment of the present invention and it is therefore not intended that the present invention be limited to the particular embodiments disclosed. It will be understood by those skilled in the art that various equivalent changes may be made depending on the specification and the drawings of present invention without departing from the scope of the present invention.
