Sitemap Contact Disclaimer 

High precision fully automatic wafer grinding machine with two spindles and cassette-to-cassette operation.

Application

Fully automatic grinding of semiconductor wafers up to 300 mm diameter.
Thin grinding down to 100 µm final thickness.

Spindles

The machine is equipped with two independent spindles (ball bearing: up to 4.000rpm, air bearing up to 6.000rpm). One Spindle position can be equipped with a TWIN SPINDLE.

Fine downfeed

Each spindle is mounted on an independent slide. All parameters of each spindle is programmable independently.
Minimum infeed step is 0.1 µm.

Rotary table

The air-bearing CNC indexing table transports the wafer between roughing, finishing and loading / unloading stations. The three rotary chucks are built into the table. Each vacuum chuck (all ceramic chucks) is mounted on a high-precision spindle.

Handling

The machine is equiped with one wafer handling with

• high speed robot
• wafer transport system
• centering station
• wafer cleaning unit
• up to four cassettes.

In-Process gaging

In-process thickness gaging is utilized to measure wafer thickness during grinding by using contact probes (differential measurement principle).

Since the control always knows the actual wafer thickness and wheel position, it can stop the infeed, when the required wafer thickness is reached. In this way, the optimum in thickness accuracy can be achieved.

Thus thermal influences and tool wear have no significant effects.

Wafer size	3 inch bis 300 mm
Spindles
Speed	100 - 4000 min-1 (ball bearing) / 100 - 6000min-1 (air bearing)
Output	4 kW
Grinding wheels	250 mm Diamond
Fine Infeed
Speed	0,001 - 50 mm/min
Min. step	0,1 µm
Resolution	0,1 µm
In-Process-Gaging
Range	0-1200 µm
Resolution	0,06 µm
Accuracy	0,1 µm
Rotary table
Number of chucks	3
Type of chucks	Porous ceramics
Speed	0 - 600 min-1
Throughput	50 Wafer/h (dep. on process)
Accuracy
TTV	<2 µm
Variation	<2µm
Surface quality	Rmax = <0,01 µm (dep. on process)
Power connection	20 kW
Weight	6500 kg
Space	3914 x 2530 mm