US20070068846A1

US20070068846A1 - Wafer packing

Info

Publication number: US20070068846A1
Application number: US11/162,950
Authority: US
Inventors: Huang-Ting Hsiao
Original assignee: United Microelectronics Corp
Current assignee: United Microelectronics Corp
Priority date: 2005-09-29
Filing date: 2005-09-29
Publication date: 2007-03-29

Abstract

The present invention provides a wafer packing. The wafer packing includes a box, at least two sponges, at least two hollow support pads, and a plurality of wafers. The sponges are put on a bottom and under a lid of the box, the hollow support pads are put between sponges, and each wafer is put between adjacent hollow support pads touching a non-complete wafer area of each wafer.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to wafer packing, and more particularly, to wafer packing that avoids wafer pollution and saves space.
2. Description of the Prior Art
The manufacturing of semiconductor wafers includes many complex processes. Processes for forming transistors or other devices on semiconductor wafers and processes for packaging wafers are usually undertaken by different manufacturers, or performed in different factories. When a wafer manufacturer ships the wafers to a packager, the wafers are stored in cartons or wafer transfer apparatuses, for delivery to the packager.
Please refer to FIG. 1 that is schematic diagram of wafer packing according to prior art. A wafer packing 10 includes a cassette 12 for depositing a plurality of wafers 14, and utilizes a interleaf 16 between adjacent wafers 14 for separating the wafers 14. The function of the interleaf 16 is to prevent damage to the wafers 14 from other wafers 14 touching them, rubbing, shaking, and crashing during shipment. Furthermore, the prior art uses a plurality of sponges 18 put on a bottom 20 and under a lid 22 of the cassette 12, for protecting the wafers 14 from touching the cassette 12. Generally, first, the sponge 18 is set on the bottom 22 of the cassette 12, and then the interleafs 16 and the wafers 14 are alternately stacked onto the sponge 18. Another interleaf 16 is put on each wafer 14 and another wafer 14 is put on each interleaf 16. When the cassette 12 has about ten of the wafers 14, another interleaf 16 and sponge 18 are put on the top wafer 14 and then the cover 22 is affixed on the sponge 18, meaning a batch of wafers are securely loaded into the packing 10. Finally, a quantity of wafer packing 10 is stored in a carton of one of various sizes. However, the interleaf 16 directly contacts a surface of the wafer 14, so the surface of the wafer 14 may become polluted and scraped. Therefore, another method of wafer packing has been developed.
Please refer to FIG. 2 that is schematic diagram of wafer packing according to another prior art. As shown in FIG. 2, U.S. Pat. No. 6,581,264 issued to Ohori et al. discloses a wafer packing of a front opening shipping box (FOSB). The FOSB wafer packing 30 comprises a cassette 32 having a plurality of support grooves 36, and each support groove 36 forms a groove (not shown) to hold a wafer. The wafers 34 are put in the grove for separating and fixing each wafer 36 in place. The cassette 32 also comprises many additional structures that are not illustrated. As above-mentioned, in order to avoid interleafs polluting wafers, the FOSB wafer packing 30 was developed, but utilizing FOSB wafer packing 30 to pack 12 inch wafers for shipment is disadvantageous to costs. Due to the structure of the support grooves 36 and the cassette 32, a volume of a batch of wafer packing 30 is very huge, and the number of wafer packings 30 in a carton is decreased so that the shipping cost is increased. Therefore, for solving problems with pollution and volume, a factory developed another form of wafer packing.
Please refer to FIG. 3 that is schematic diagram of wafer packing 50 according to another prior art. As shown in FIG. 3, US Patent Application Publication 2004/0149623 discloses a wafer packing 50. The wafer packing 50 includes a cassette 52, and a sponge 58, wafers 54, and pads 56 for separating wafers 54 and are put into the cassette 52 in a manner similar to that used putting the wafers 14 and the interleafs 16 into the cassette 12 in FIG. 1. Moreover, the structure of the pad 56 includes a top surface 60, a first recessed portion 62, and a second recessed portion 64. When the wafer 54 is put on the first recessed portion 62 of the pad 62, the top surface 60 and the first recessed portion 62 form a ladder-like structure for fixing the wafer and preventing the wafer 54 from sliding. The second recessed portion 64 is for depositing solders 66 or other devices of the wafer 54. The depth of the second recessed portion 64 is greater than or equal to the height of the solders 66 of the wafer 54. Although the solder 66 or others devices of the wafer 54 are detached from the pad 56, a top surface of the wafers 54 still touches the pad 56. In addition, the pad 56 needs the ladder structure of the top surface 60 and the first recessed portion 62 to fix the wafers 54 in place, and needs the second recessed portion 64 to deposit the solders 66 of the wafer 54. If the wafer 54 is not fixed to the first recessed portion 62 and the second recessed portion 64, the wafer 54 may break. Therefore, this prior art wafer packing 50 utilizes the pad 56 to prevent damage to the solders 66 of a bottom of the wafers 54 and others devices, but the first recessed portion 62 of the pad 56 might lock the wafers 54 while the wafers 54 is took out.

SUMMARY OF THE INVENTION

It is therefore a primary objective of the claimed invention to provide a wafer packing to solve the above-mentioned problems.
According to the claimed invention, the present invention provides a wafer packing. The wafer packing includes a box, at least two sponges, at least two hollow support pads, and a plurality of wafers. The sponges are deposited on a bottom and under a lid of the box, the hollow support pads are deposited on and between the sponges, and each wafer is deposited on and between two adjacent hollow support pads that contact a non-complete wafer area of each wafer edge.
The present invention utilizes hollow support pads inserted between each wafer in the wafer packing, in order to separate stacked wafers. The present invention can avoid the pollution and scraping of the wafers from the wafers touching with interleafs, and decreases the volume of wafer packing, reducing shipping costs. Furthermore, the present invention can prevent the damage from shaking of the wafers during shipment.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 to FIG. 3 are schematic diagrams of a wafer packing according to prior art.
FIG. 4 is a schematic diagram of a wafer packing according to the present invention.
FIG. 5 to FIG. 10 are schematic diagram of the hollow support pad according present invention.

DETAILED DESCRIPTION

Please refer to FIG. 4 that is a schematic diagram of a wafer packing 70 according to the present invention. The wafer packing 70 includes a cassette 72, at least two sponges 78, and a plurality of hollow support pads 76 for depositing a plurality of wafers 74. First, at least one of the sponges 78 is put on a bottom of the cassette 72, and at least one hollow support pad 76 and a wafer 74 are alternately put on the sponges 78. Other hollow support pads 76 and other wafers 74 are continuously and repeatedly stacked in alternation on the bottom wafer 74 until the cassette is filled with 25 wafers 74, although this quantity is not limiting as other quantities are equally possible. Then, a lid 82 of the cassette 72 covers and completes the batch of wafer packing 70. A quantity of wafer packings 70 is stored in a carton (not shown) for shipment. In addition, the hollow support pads 76 touch a non-complete wafer area of the wafers 74, so the complete wafer area of the wafers 74 cannot be polluted and/or scrapped by touching the hollow support pads 76.
Also, please refer to FIG. 5 through FIG. 10, which are schematic diagrams of the hollow support pad 76 according present invention. The hollow support pads 76 can be many structures, such as a rounded pad like an O-ring, a C-shape pad, near rounded pad, and at least two arc pads. As shown in FIG. 5 to FIG. 7, the hollow support pad 76 is rounded pad, and an internal periphery (FIG. 5) or external periphery (FIG. 6) of the rounded hollow support pad 76 can be toothlike in shape, can have two toothlike peripheries (FIG. 7), or two smooth peripheries. As shown in FIG. 8, the hollow support pad 76 can be a C-shape pad with an angle 94 of the C-shape hollow support pad 76 greater than 180 degrees. The shape of the support pad should supports the wafer uniformly, but the structure of the support pad is not limited to the above-mentioned shape.
The materials of the hollow support pads 76 can be plastic, an electrical conductor, or magnetic materials, having a width ((external diameter of the pad—internal diameter of the pad) divided by 2) greater than 3 mm, and a thickness greater than 1 mm. Besides, as shown in FIG. 9 and FIG. 10, the hollow support pad 76 can be two or three pieces of arc magnetic materials. It can be noted that the hollow support pad 76 can be a mixture of the above-mentioned structures, but the above-mentioned structures do not limit the shape of the hollow support pad 76. On the other hand, the hollow support pad 76 can be a rounded or tube-like pad, but the rounded pad has at least one raised portion touching the non-complete wafer area of the wafer 74.
The present invention utilizes the hollow support pads 76 to separate wafers 74. The complete wafer area of wafers 74 does not touch the hollow support pads 76, so the surface of the wafers 74 does not get polluted and scraped by touching the hollow support pads 76. Moreover, the present invention wafer packing 70 stacks the wafers 74, and uses the cassette 72 to fix and prevent movement of the wafers 74, so the diameter of the hollow support pads 76 is the same size as the wafers 74. Therefore, we can use the original cassette 72, without a need to change the width or height of the cassette. The present invention can effectively decrease the volume of wafer packing 70 by holding more wafers 74 in a single cassette while not decreasing the quantity of wafer packings 70 in a carton, and therefore decreases shipping costs.
To sum up, when related to the wafer packing of prior art, the present invention utilizes hollow support pads in the wafer packing and can be applied to ship 12″ wafers and thin wafers. Not only can the present invention avoid the polluting and scraping of the wafer from the wafer touching an interleaf, but it also decreases the volume problem of the FOSB wafer packing when the hollow support pads separate the wafers. In addition, the pads of prior art cannot solve the volume, pollution, and abrasion problems at which the present invention is directed. The present invention can eliminate the above-mentioned problems, and further decrease shipping costs.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.

Claims

1. A wafer packing, the wafer packing comprising:

a cassette;

at least two sponges, the sponges respectively put on a bottom and under a lid of the cassette;

a plurality of hollow support pads, the hollow support pads put between the sponges on the bottom and under the lid of the cassette;

a plurality of wafers arranged in alternation with the plurality of hollow support pads, a non-complete wafer area of the each wafer touching adjacent hollow support pads.

2. The wafer packing of claim 1 wherein the hollow support pads are rounded pads, C-shaped pads, near rounded pads, and at least two arc pads.

3. The wafer packing of claim 2 wherein an angle of the C-shaped is larger than 180 degree.

4. The wafer packing of claim 2 wherein at least one of peripheries of the hollow support pads is toothlike in shape.

5. The wafer packing of claim 1 wherein a material of the hollow support pads is a plastic material, an electrically conducting material, or a magnetic material.

6. The wafer packing of claim 1 wherein a thickness of the hollow support pads is greater than 1 mm.

7. The wafer packing of claim 1 wherein a width of the hollow support pads is greater than 3 mm.