Patent Application
20160271835
1. Field of the Invention
The present invention relates to a cutting apparatus for cutting a workpiece such as a chip size package (CSP) substrate obtained by packaging semiconductor chips.
2. Description of the Related Art
In a semiconductor device fabrication process, a plurality of crossing division lines called streets are formed on the front side of a substantially disk-shaped semiconductor wafer to thereby define a plurality of separate regions where a plurality of circuits (devices) such as ICs and LSIs are formed. The semiconductor wafer thus having the devices is cut along the division lines to thereby obtain individual semiconductor chips. These semiconductor chips are packaged to be widely used in electric equipment such as mobile phones and personal computers.
A further reduction in size and weight of such electric equipment is desired and there has been developed a packaging technique capable of reducing the size of a semiconductor device package, called chip size package (CSP). As one of the CSP techniques, a packaging technique called quad flat non-lead package (QFN) has been put into practical use. This packaging technique called QFN is such that a plurality of semiconductor chips are arranged like a matrix on a metal plate such as a copper plate so as to be partitioned by a plurality of streets, the metal plate having a plurality of connection terminals corresponding to the connection terminals of the semiconductor chips. Further, the semiconductor chips are molded with resin from the back side to thereby form a resin portion for integrating the metal plate and the semiconductor chips, thus forming a CSP substrate. This CSP substrate is cut along the streets to obtain the individual chip size packages (CSPs) divided from each other.
In general, cutting of the CSP substrate is performed by a cutting apparatus. This cutting apparatus includes a holding table for holding a workpiece, cutting means having a cutting blade for cutting the workpiece held on the holding table, cutting water supplying means for supplying a cutting water to a cutting area where the workpiece is cut by the cutting blade, feeding means for moving the holding table in a feeding direction, a first bellows connected at one end thereof to one end of the holding table in the feeding direction for covering the feeding means, a second bellows connected at one end thereof to the other end of the holding table in the feeding direction for covering the feeding means, a pair of drain channels provided along both sides of the first and second bellows so as to extend in the feeding direction, for receiving the cutting water used in cutting the workpiece, and a scrap receptacle provided at the downstream ends of the drain channels and the first bellows for receiving scraps generated from the workpiece in cutting the workpiece as well as the cutting water containing cutting dust, whereby cutting is not hindered by the scraps of the CSP substrate (see Japanese Patent Laid-Open No. 2004-186361, for example).
However, when the scraps generated from the workpiece in cutting the workpiece falls into the drain channels from the first bellows and they are accumulated in the drain channels, there arises a problem such that the cutting water may stay in the drain channels and finally overflow from the drain channels to contaminate the inside of the cutting apparatus.
It is therefore an object of the present invention to provide a cutting apparatus which can prevent that the scraps generated from the workpiece in cutting the workpiece and scattered onto the first bellows may fall into the drain channels provided on both sides of the first bellows.
In accordance with an aspect of the present invention, there is provided a cutting apparatus including a holding table for holding a workpiece, cutting means having a cutting blade for cutting the workpiece held on the holding table, cutting water supplying means for supplying a cutting water to a cutting area where the workpiece is cut by the cutting blade, feeding means for moving the holding table in a feeding direction, indexing means for moving the cutting means in an indexing direction perpendicular to the feeding direction, a first bellows connected at one end thereof to one end of the holding table in the feeding direction, the first bellows having an upper wall and opposite side walls adapted to be expanded and contracted for covering the feeding means, a second bellows connected at one end thereof to the other end of the holding table in the feeding direction, the second bellows having an upper wall and opposite side walls adapted to be expanded and contracted for covering the feeding means, a pair of drain channels provided on both sides of the first and second bellows in the indexing direction for receiving the cutting water supplied to the cutting area by the cutting water supplying means in cutting the workpiece, a scrap receptacle provided at the other end of the first bellows in the feeding direction for receiving scraps generated from the workpiece in cutting the workpiece, and a pair of fall prevention plates provided along the pair of drain channels for preventing that the scraps scattered onto the upper wall of the first bellows in cutting the workpiece may fall into the drain channels.
Preferably, the fall prevention plates are formed of fluororesin.
The cutting apparatus of the present invention includes the pair of fall prevention plates provided along the pair of drain channels for preventing that the scraps scattered onto the upper wall of the first bellows in cutting the workpiece may fall into the drain channels. Accordingly, the scraps scattered above the drain channels in cutting the workpiece with the cutting blade can be received by the fall prevention plates. Further, the scraps scattered onto the upper wall of the first bellows and moved toward the drain channels can be received by the fall prevention plates. That is, all of the scraps thus scattered can be prevented from falling into the drain channels by the provision of the fall prevention plates, so that it is possible to solve the problem that the cutting water may stay in the drain channels due to the accumulation of the scraps in the drain channels, and as a result the cutting water may overflow from the drain channels to contaminate the inside of the cutting apparatus.
The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing a preferred embodiment of the invention.
A preferred embodiment of the cutting apparatus according to the present invention will now be described in detail with reference to the attached drawings.
The cutting apparatus 2 shown in
The cutting apparatus 2 further includes imaging means (imaging unit) 45 for imaging the surface of the workpiece held on the holding table 3 to detect an area to be cut by the cutting blade 43. The imaging means 45 includes an optical system such as a microscope and an imaging device (CCD). An image signal obtained by the imaging means 45 is sent to control means (controller) (not shown).
Referring to
Each of the plural protective plate members 514 is formed of synthetic resin such as polyester or metal such as aluminum alloy. As shown in
Each of the plural protective film members 515 provided between the plural protective plate members 514 and the bellows member 511 is formed of a flexible material such as polyurethane elastomer. Each protective film member 515 has substantially the same length as the length La of each protective plate member 514 in the Y direction. Each protective film member 515 is mounted in such a manner that one side edge of each protective film member 515 in the X direction is bonded to the lower surface (back side) of the corresponding protective plate member 514 at its central portion in the X direction and that the other side edge of each protective film member 515 is bonded to the corresponding ridge of the bellows member 511 on which its adjacent protective plate member 514 (the adjacent protective plate member 514 on the left side of each protective plate member 514 as viewed in
As similar to the first bellows 51, the second bellows 52 is composed of a bellows member 521 adapted to be expanded and contracted and a pair of connecting members 522 and 523 mounted on both ends of the bellows member 521 in the X direction. However, the second bellows 52 has no protective plate members and no protective film members. The bellows member 521 is formed from a foldable sheet member like a cloth so as to have a plurality of alternate ridges and grooves. The bellows member 521 has an upper wall 521a and a pair of opposite side walls 521b connected to the upper wall 521a. Each of the connecting members 522 and 523 may be formed from a metal plate. The second bellows 52 configured above is mounted in such a manner that the connecting member 522 is connected to the other end surface of the holding table 3 and the connecting member 523 is connected to another stationary member (not shown).
Referring again to
Referring again to
Referring again to
The operation of the cutting apparatus 2 according to the preferred embodiment will now be described. FIG. 5A is a perspective view of a package substrate 10 as a workpiece to be cut by the cutting apparatus 2, and
In dividing the package substrate 10 into the individual packaged devices (chip size packages) 113 by using the cutting apparatus 2, the package substrate 10 is first placed on the vacuum chuck 32 of the holding table 3 of the cutting apparatus 2. Thereafter, the suction means (not shown) is operated to hold the package substrate 10 on the vacuum chuck 32 of the holding table 3 under suction (package substrate holding step).
After performing the package substrate holding step, the X moving means (not shown) is operated to move the holding table 3 holding the package substrate 10 to a position directly below the imaging means 45. In the condition where the holding table 3 is positioned directly below the imaging means 45, an alignment operation is performed by the imaging means 45 and the control means (not shown) to detect a subject area of the package substrate 10 to be cut. More specifically, the imaging means 45 and the control means (not shown) perform image processing such as pattern matching for making the alignment between the cutting blade 43 and the first division lines 111 extending in the first direction on the front side of the package substrate 10, thus performing the alignment for the first division lines 111. Similarly, the alignment is performed for the second division lines 112 extending in the second direction perpendicular to the first direction on the front side of the package substrate 10.
After performing the alignment for detecting the first and second division lines 111 and 112 of the package substrate 10 held on the holding table 3, the holding table 3 is moved to a cutting position where the package substrate 10 is cut by the cutting blade 43. That is, as shown in
After performing the first cutting step, the holding table 3 is rotated 90 degrees to make the second division lines 112 of the package substrate 10 held on the vacuum chuck 32 of the holding table 3 parallel to the X direction. In this condition, the package substrate 10 is cut along all of the second division lines 112 in a manner similar to that of the first cutting step (second cutting step). Also in performing the second cutting step, the cutting water supplying means (not shown) is operated to supply the cutting water from the cutting water nozzle 44 to the cutting area where the package substrate 10 is cut by the cutting blade 43.
In performing the first and second cutting steps, the cutting water supplied from the cutting water nozzle 44 to the cutting area where the package substrate 10 is cut by the cutting blade 43 and the cutting dust generated by the cutting are scattered onto the plural protective plate members 514 covering the upper surface of the bellows member 511 of the first bellows 51 and then allow to fall into the drain channels 66 and 67. The cutting water containing the cutting dust is then allowed to flow into the scrap receiving means 7. Further, the scraps 10a and 10b generated from the package substrate 10 in cutting it by using the cutting blade 43 are also scattered onto the protective plate members 514. The scraps 10a and 10b are also scattered above the drain channels 66 and 67 provided on both sides of the protective plate members 514 in the Y direction.
However, since the fall prevention plates 8 are provided to prevent that the scraps 10a and 10b scattered onto the protective plate members 514 may fall into the drain channels 66 and 67, the scraps 10a and 10b can be received by the fall preventing portions 81 of the fall prevention plates 8. Further, the scraps 10a and 10b scattered above the drain channels 66 and 67 can also be received by the fall preventing portions 81 of the fall prevention plates 8. Accordingly, all of the scraps 10a and 10b thus scattered can be prevented from falling into the drain channels 66 and 67, so that it is possible to solve the problem that the cutting water may stay in the drain channels 66 and 67 due to the accumulation of the scraps 10a and 10b in the drain channels 66 and 67, and as a result the cutting water may overflow from the drain channels 66 and 67 to contaminate the inside of the cutting apparatus 2.
The scraps 10a and 10b received by the fall preventing portions 81 of the fall prevention plates 8 are forced toward the scrap receiving means 7 to fall into the scrap receiving means 7. At this time, since the fall prevention plates 8 are formed of fluororesin superior in lubricity, the scraps 10a and 10b can be easily moved along the fall preventing portions 81. The scraps 10a and 10b that have fallen into the scrap receiving means 7 are received (entrapped) by the net 72 provided near the bottom of the scrap receiving means 7 and then accumulated on the net 72. The scraps 10a and 10b scattered onto the protective plate members 514 are also forced into the scrap receiving means 7 by the movement of the holding table 3 and the protective plate members 514. On the other hand, the cutting water containing the cutting dust that has fallen into the scrap receiving means 7 is allowed to pass through the net 72 and then discharged through the drain duct 73.
The present invention is not limited to the details of the above described preferred embodiment. The scope of the invention is defined by the appended claims and all changes and modifications as fall within the equivalence of the scope of the claims are therefore to be embraced by the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-054771 | Mar 2015 | JP | national |
