EP 1 912 250 B12510152025303540455055DescriptionBACKGROUND OF THE INVENTION(1) Field of the Invention[0001] The present invention relates to an adhesivetape cutting method for joining a supporting adhesivetape to a ring frame and a semiconductor wafer such thatthe ring frame holds the semiconductor wafer, and thencutting the adhesive tape in such a manner that a cutterblade travels along a contour of the ring frame, and anadhesive tape joining apparatus using the same. In par-ticular, the present invention relates to a technique forcutting and joining an adhesive tape along and to a ringframe with good accuracy.(2) Description of the Related Art[0002] A semiconductor wafer (hereinafter, simply re-ferred to as a "wafer") having a front face on which apattern is formed is made thinner in thickness by backgrinding. The wafer subjected to the back grinding istransported to a mount apparatus. In the mount appara-tus, the wafer is joined to and held by a ring frame througha supporting adhesive tape. Herein, a disc-shaped cutterblade capable of rotating freely is pressed against thestrip-shaped adhesive tape joined to the ring frame andthe wafer positioned at a center of the ring frame; thus,the adhesive tape is cut along a contour of the ring frame(refer to JP-A 62-174940).[0003] It is considered herein that the adhesive tapeis cut in the conventional manner. In the case where theadhesive tape is cut by the cutter blade, first, a cuttingedge of the cutter blade penetrates through the adhesivetape. Thereafter, the cutter blade travels in a state thatthe cutting edge thereof is pressed against a tape joinedside of the ring frame. Consequently, a notched grooveis formed on the tape joined side of the ring frame dueto the contact with the cutter blade.[0004] The ring frame for holding the wafer is collectedfor reuse after being subjected to processing such asdicing. In a case that such a ring frame is reused, if anadhesive tape joined to the ring frame is cut by the cutterblade, the sharp cutting edge of the cutter blade is fittedinto the notched groove formed on the surface of the ringframe, so that the cutter blade travels on a pathway whichis different from a preset traveling pathway. This causesa problem of a cutting failure that the adhesive tape can-not be cut along the contour of the ring frame because acutting start position does not correspond with a cuttingend position.[0005] In addition, when the cutter blade is fitted intothe notched groove, the cutting edge thereof is suscep-tible to wear. Consequently, a service life of the cutterblade becomes short, and the cutter blade must be ex-changed frequently. That is, there is a problem of dete-rioration in workability.[0006] From document EP 1 320 121 A2 a semicon-ductor wafer transport method and apparatus have be-come known. For cutting a supporting adhesive tapethrough which a ring frame holds a semiconductor wafer,a cutting mechanism with a conventionally shaped cutterblade is used. A similar method and apparatus is knownfrom document US 2006/0068524 A1.[0007] From document EP 1 339 095 A2 a method ofcutting a protective tape and a protective tape applyingapparatus have become known. These also use a cuttingmechanism for cutting a supporting adhesive tapethrough which a ring frame holds a semiconductor wafer.The cutting mechanism uses a conventionally shapedcutter blade having a sharp cutting edge.SUMMARY OF THE INVENTION[0008] An object of the present invention is to providean adhesive tape cutting method according to claim 1capable of cutting a supporting adhesive tape, which al-lows a ring frame to hold a semiconductor wafer, withgood accuracy while improving the workability, and anadhesive tape joining apparatus according to claim 5 us-ing the same.[0009] In order to accomplish the aforementioned ob-ject, the present invention adopts the following configu-ration:[0010] A method for cutting a supporting adhesive tapethrough which a ring frame holds a semiconductor wafer,the method comprising the step of: cutting a supportingadhesive tape along a contour of a ring frame in such amanner that the supporting adhesive tape is stuck witha cutter blade having a flat plane obtained by forming asharp cutting edge into a wedge shape.[0011] With this method according to the present in-vention, even when the cutting edge of the cutter bladepenetrates through the adhesive tape upon cutting of theadhesive tape, a contact area of the cutting edge of thecutter blade with respect to the ring frame is enlarged.Therefore, the cutting edge is not fitted into a notchedgroove formed on the ring frame. Accordingly, the cutterblade travels on a preset traveling pathway, so that acutting start position corresponds with a cutting end po-sition. As a result, there occurs no cutting failure.[0012] Moreover, the cutting edge of the cutter bladeis not fitted into the notched groove, and therefore doesnot receive unnecessary frictional resistance. As a result,the service life of the cutter blade can be prolonged. Thus,a frequency of exchange of the cutter blade can be re-duced, so that workability can be improved.[0013] Further, even when the cutter blade cuts theadhesive tape in such a state that the cutting edge thereofcomes into contact with the ring frame, the flat planeformed at the cutting edge of the cutter blade preventsformation of a notched groove on the ring frame. Accord-ingly, the ring frame can be used repeatedly.[0014] In the present invention, the adhesive tape maybe cut in a state that the flat plane formed at the cutting1 2
