STRASBAUGH CONFIDENTIAL INFORMATION
4
Help For Some Robot/Prealigner Errors
Two problems with the robot and/or prealigner had not been correctable within the 7AF software, requiring exit
to DOS or cycling power. They can now be fixed by selecting the prealigner icon in the Inputs/Outputs menu
under Machine Maintenance.
If a wafer fails to align, producing a 1084 error status, you can now clear that status. There is a new selection
under the prealigner icon, called Align. You can try again to align this wafer or you can try a different wafer. A
successful alignment will set the good status 1004. To align a wafer, first place it onto the prealigner, then turn
on the vacuum, and then select Align. Watch the status displayed near the top center of the screen. It may
require two aligns to set the good status. Turn off the vacuum and remove the wafer when alignment has been
successful. (Note: The wafer must be the same shape and diameter as the one that just failed. Do not try a
round align to fix a failed square align.)
If a serial communications error occurs for the robot and/or prealigner, producing a status that begins with 9
instead of 1, you can now clear that status. There is a new selection under the prealigner icon, called Clear
Comm Err. Press that to clear the error for both robot and prealigner. Watch the status displayed near the top
of the screen.
New Option for High/Low Areas on the Wafer
There is a new option that provides help with wafers having uneven surfaces. If this Approach Option is chosen,
the following actions take place at the start of the approach to the wafer.
The work chuck speed is set to 20 rpm for several seconds. During this time, the probe takes many readings
around the surface of the wafer. The highest “peak” seen in these readings is used as the wafer thickness when
computing how far it is safe to drop the grind wheel at high speed. The lowest “valley” seen in these readings is
used as the wafer thickness when computing recipe targets for delta grind.
This option can prevent a high speed crash of the grind wheel into a warped wafer, mainly in fine grind.
The cost of this option is a decrease in throughput, as the chuck is slowed to 20 rpm, held at that speed while
taking probe readings, and then accelerated to the recipe speed. The longest of these three steps is the middle
one, so the cost will be less if the 7AF has a fast computer. It was tested on a Pentium 133 MHz, where the
total delay was about ten seconds, with half of that in the middle step.
To set this option, use Machine Variable 97, formerly called Raise Probe Before Dwell, and now called Probe
Options. It uses individual digits in the same method as described earlier in this document for some other
machine variables. Allowed values are:
0 Raise Probe After Dwell (The original behavior of the 7AF.)
1 Raise Probe Before Dwell (The change formerly made by setting variable 97 to non-zero.)
10 Raise Probe After Dwell; Approach Option ON
11 Raise Probe Before Dwell; Approach Option ON
Series 100 Robot Macros Updated
There is a new set of macros v2_06.mac for the Series 100 robot. This adds features that have been available
previously for Series 212 only. The new features are:
1. Slow flip of the robot end effector is allowed. It no longer times out.
2. GET will make several small steps down at the work chucks and spin station as it seeks the wafer.
3. A new macro RWS reports the currently selected wafer diameter.
4. The optional delay in GET’s stroke up (introduced in software version 5.00) is available.
5. There is an optional change allowing GET 4-inch wafers on center.
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