APPARATUS FOR USE IN THE MANUFACTURE OF SEMI-CONDUCTOR DEVICES
United States Patent 3667661
When a semi-conductor slice is subjected to a manufacturing process to convert it to a plurality of semi-conductor components, it is then necessary to separate the semi-conductor components. The invention provides apparatus for doing this in which a pair of resilient diaphragms are used to sandwich the wafer, the diaphragms then being distended to crack the slice along previously scribed lines.
US Patent References:
METHOD OF DICING SEMICONDUCTOR WAFERS
Bielen et al. - April 1970 - 3507426
Method for dicing semiconductor material
Kalvelage et al. - May 1965 - 3182873
APPARATUS AND METHOD FOR SEPARATING A SEMICONDUCTOR WAFER
Litant et al. - February 1970 - 3493155
METHOD OF DICING SEMICONDUCTOR WAFERS
Bielen et al. - April 1970 - 3507426
Method for dicing semiconductor material
Kalvelage et al. - May 1965 - 3182873
APPARATUS AND METHOD FOR SEPARATING A SEMICONDUCTOR WAFER
Litant et al. - February 1970 - 3493155
Application Number:
05/026734
Publication Date:
06/06/1972
Filing Date:
04/08/1970
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
225/96.500
International Classes:
H01L21/301; B26F3/00
Field of Search:
225/2,96.5
Primary Examiner:
Yost, Frank T.
Claims:
Having thus described my invention what I claims as new and desire to secure by Letters Patent is
1. Apparatus for cracking a previously scribed semi-conductor slice, including a first resilient diaphragm upon which, in use, a scribed semi-conductor slice is supported, a second resilient diaphragm engageable with the surface of the slice remote from said first diaphragm to maintain the slice in engagement with the first diaphragm and means for distending the diaphragms into a domed configuration so as to crack the slice along the scribed lines, the relative thicknesses of the first and second diaphragms being such that the neutral plane of the laminated unit constituted by the first and second diaphragms and the semi-conductor slice occurs in one of the first and second diaphragms.
2. Apparatus as claimed in claim 1 including a body having therein a recess closed by the second diaphragm, the diaphragms being distended into said recess by application of a force to the first diaphragm.
3. Apparatus as claimed in claim 2 in which the recess is of generally domed configuration with its radius of curvature greater towards the periphery of the recess than at the center of the recess.
4. Apparatus as claimed in claim 1 in which the first diaphragm is thicker than the second diaphragm so that during cracking the neutral plane of the laminated unit constituted by the diaphragms and slice occurs in the first diaphragm.
5. A method of cracking a previously scribed semi-conductor slice including the steps of trapping the slice between a pair of resilient diaphragms and distending the diaphragms to a domed configuration to crack the slice along the scribed lines the relative thicknesses of the two diaphragms being such that the neutral plane of the laminated unit constituted by the two diaphragms and the slice occurs, during distention of the laminated units, in one of the diaphragms, and the scribed semi-conductor slice being positioned between the diaphragms in such a manner that its scribed surface is outermost during the distention of the diaphragms.
1. Apparatus for cracking a previously scribed semi-conductor slice, including a first resilient diaphragm upon which, in use, a scribed semi-conductor slice is supported, a second resilient diaphragm engageable with the surface of the slice remote from said first diaphragm to maintain the slice in engagement with the first diaphragm and means for distending the diaphragms into a domed configuration so as to crack the slice along the scribed lines, the relative thicknesses of the first and second diaphragms being such that the neutral plane of the laminated unit constituted by the first and second diaphragms and the semi-conductor slice occurs in one of the first and second diaphragms.
2. Apparatus as claimed in claim 1 including a body having therein a recess closed by the second diaphragm, the diaphragms being distended into said recess by application of a force to the first diaphragm.
3. Apparatus as claimed in claim 2 in which the recess is of generally domed configuration with its radius of curvature greater towards the periphery of the recess than at the center of the recess.
4. Apparatus as claimed in claim 1 in which the first diaphragm is thicker than the second diaphragm so that during cracking the neutral plane of the laminated unit constituted by the diaphragms and slice occurs in the first diaphragm.
5. A method of cracking a previously scribed semi-conductor slice including the steps of trapping the slice between a pair of resilient diaphragms and distending the diaphragms to a domed configuration to crack the slice along the scribed lines the relative thicknesses of the two diaphragms being such that the neutral plane of the laminated unit constituted by the two diaphragms and the slice occurs, during distention of the laminated units, in one of the diaphragms, and the scribed semi-conductor slice being positioned between the diaphragms in such a manner that its scribed surface is outermost during the distention of the diaphragms.
Description:
This invention relates to apparatus for, and a method of cracking a semi-conductor slice, which has previously been scribed, to divide the slice into a plurality of semi-conductor components.
Apparatus according to the invention includes a first resilient diaphragm upon which, in use, a scribed semi-conductor slice is supported, a second resilient diaphragm engageable with the surface of the slice remote from said first diaphragm to maintain the slice in engagement with the first diaphragm and means for distending the diaphragms into a domed configuration so as to crack the slice along the scribed lines.
The invention further resides in a method of cracking a previously scribed semi-conductor slice including the steps of trapping the slice between a pair of resilient diaphragms and distending the diaphragms to a domed configuration to crack the slice along the scribed lines.
The accompanying drawing is a fragmentary diagrammatic sectional view of apparatus according to one example of the invention.
The apparatus for cracking previously scribed semi-conductor slices includes a base 11 including a chamber 12 closed at one end by a rubber diaphragm 13. The apparatus further includes a movable platen 14 which is movable towards and away from the base 11, and which is provided, in its face presented to the diaphragm 13, with a recess 15. The recess 15 is closed by a second rubber diaphragm 16 which is movable with the movable platen 14. Means (not shown) is provided for pumping air into the chamber 11, and since the chamber 11 is closed by the diaphragm 13, then when the air pressure within the chamber 12 increases the diaphragm 13 will be distended towards the movable platen 14 and will assume a domed configuration.
A slice 17 of silicon which has been treated to produce therein a P-N junction is scribed on its upper surface to divide the slice into a plurality of rectangular P-N wafers each of which will constitute a diode. In order to crack the slice 17 along the scribed lines to separate the P-N wafers from one another, the slice 17 is placed on the diaphragm 13 with its scribed surface uppermost. The movable platen 14 is then moved into engagement with the base 11 so that the diaphragm 16 traps the slice 17 in position on the diaphragm 13. Air is then admitted into the chamber 12 under pressure, thereby causing the diaphragm 13 to be distended towards the movable platen 14. Since the diaphragm 16 traps the slice 17 in facial contact with the diaphragm 13, then as the diaphragm 13 assumes its domed configuration, the slice 17 and the diaphragm 16 will also assume a domed configuration, and in so doing the slice 17 becomes cracked along the scribed lines. In order for a clean fracture to be produced along the scribed lines, it is desirable that the slice 17 is subject to tensile bending stresses only, and not to shear stresses. For this reason the diaphragm 13 is made thicker than the diaphragm 16 so that the neutral plane of the laminated unit constituted by the diaphragm 13, the slice 17 and the diaphragm 16, during distension thereof, occurs in the diaphragm 13.
If the diaphragm 13 were permitted to distend normally under the action of air pressure in the chamber 12, then the amount of movement of the slice 17 at its edges would be less than that at the center of the slice and unless the slice was of considerably smaller diameter than the diameter of the diaphragm 13 then the cracking of the slice at the periphery thereof might produce wafers with damaged edges. In order to ensure satisfactory cracking at the periphery of the slice 17, the base of the recess 15 in the movable platen is so shaped that its radius of curvature is greater towards the periphery of the recess than at the center of the recess. Thus, when the diaphragm 13 is distended, the periphery of the distended portion of the diaphragm 16 engages the base of the recess 15, so that the peripheral portion of the diaphragm 16 and therefore the slice 17 and the diaphragm 13, follow the shape of the peripheral portion of the base of the recess 15.
When the slice has been cracked, the pressure in the chamber 12 is reduced to atmospheric pressure so that the diaphragms 13, 16 return to their original positions. The movable platen 14 is then moved away from the base 11 to expose the cracked wafers which are removed from the diaphragm 13 in any convenient manner.
It will be appreciated that the apparatus and procedure described above can be used to crack any form of scribed semi-conductor slice. Moreover, the cracked wafers could be of shapes other than rectangular, for example triangular or rhombic. Furthermore, although compressed air is used to power the apparatus as described above, both other gases and liquids could be used.
Apparatus according to the invention includes a first resilient diaphragm upon which, in use, a scribed semi-conductor slice is supported, a second resilient diaphragm engageable with the surface of the slice remote from said first diaphragm to maintain the slice in engagement with the first diaphragm and means for distending the diaphragms into a domed configuration so as to crack the slice along the scribed lines.
The invention further resides in a method of cracking a previously scribed semi-conductor slice including the steps of trapping the slice between a pair of resilient diaphragms and distending the diaphragms to a domed configuration to crack the slice along the scribed lines.
The accompanying drawing is a fragmentary diagrammatic sectional view of apparatus according to one example of the invention.
The apparatus for cracking previously scribed semi-conductor slices includes a base 11 including a chamber 12 closed at one end by a rubber diaphragm 13. The apparatus further includes a movable platen 14 which is movable towards and away from the base 11, and which is provided, in its face presented to the diaphragm 13, with a recess 15. The recess 15 is closed by a second rubber diaphragm 16 which is movable with the movable platen 14. Means (not shown) is provided for pumping air into the chamber 11, and since the chamber 11 is closed by the diaphragm 13, then when the air pressure within the chamber 12 increases the diaphragm 13 will be distended towards the movable platen 14 and will assume a domed configuration.
A slice 17 of silicon which has been treated to produce therein a P-N junction is scribed on its upper surface to divide the slice into a plurality of rectangular P-N wafers each of which will constitute a diode. In order to crack the slice 17 along the scribed lines to separate the P-N wafers from one another, the slice 17 is placed on the diaphragm 13 with its scribed surface uppermost. The movable platen 14 is then moved into engagement with the base 11 so that the diaphragm 16 traps the slice 17 in position on the diaphragm 13. Air is then admitted into the chamber 12 under pressure, thereby causing the diaphragm 13 to be distended towards the movable platen 14. Since the diaphragm 16 traps the slice 17 in facial contact with the diaphragm 13, then as the diaphragm 13 assumes its domed configuration, the slice 17 and the diaphragm 16 will also assume a domed configuration, and in so doing the slice 17 becomes cracked along the scribed lines. In order for a clean fracture to be produced along the scribed lines, it is desirable that the slice 17 is subject to tensile bending stresses only, and not to shear stresses. For this reason the diaphragm 13 is made thicker than the diaphragm 16 so that the neutral plane of the laminated unit constituted by the diaphragm 13, the slice 17 and the diaphragm 16, during distension thereof, occurs in the diaphragm 13.
If the diaphragm 13 were permitted to distend normally under the action of air pressure in the chamber 12, then the amount of movement of the slice 17 at its edges would be less than that at the center of the slice and unless the slice was of considerably smaller diameter than the diameter of the diaphragm 13 then the cracking of the slice at the periphery thereof might produce wafers with damaged edges. In order to ensure satisfactory cracking at the periphery of the slice 17, the base of the recess 15 in the movable platen is so shaped that its radius of curvature is greater towards the periphery of the recess than at the center of the recess. Thus, when the diaphragm 13 is distended, the periphery of the distended portion of the diaphragm 16 engages the base of the recess 15, so that the peripheral portion of the diaphragm 16 and therefore the slice 17 and the diaphragm 13, follow the shape of the peripheral portion of the base of the recess 15.
When the slice has been cracked, the pressure in the chamber 12 is reduced to atmospheric pressure so that the diaphragms 13, 16 return to their original positions. The movable platen 14 is then moved away from the base 11 to expose the cracked wafers which are removed from the diaphragm 13 in any convenient manner.
It will be appreciated that the apparatus and procedure described above can be used to crack any form of scribed semi-conductor slice. Moreover, the cracked wafers could be of shapes other than rectangular, for example triangular or rhombic. Furthermore, although compressed air is used to power the apparatus as described above, both other gases and liquids could be used.