Hi,
I checked the archives to see if the questions that I pose have
already been discussed on the forum. I could find complete answers.

I have a silicon wafer with a pattern of SU-8 on it. I pour PDMS on it
and peel it off and then heat it and then bond it.

1) PDMS is mixed in the ratio 10:1 as given in the data sheet of dow
corning. I degas it by means of a vacuum pump for about an hour and
then do a visual inspection to make sure there are no bubbles.

2)I take the si wafer which has the patterned su-8 on it and and clean
it with a blast of N2.

3) I usually use about 20ml : 2ml of the sylgard 184 kit and when put
on the si wafer of 4.inch diameter, will give me a pdms layer, which
is about 3 mm thick. However, the pattern of su-8 on the wafer is just
a 100 micron thick.

4) i use glass slides provided by corning and their dimensions are
75mm x 50 mm. I clean the slide with di water and then dry it with N2
and heat it in an oven for about 45 mins at 65 degrees.

5) I heat the pdms for about 7-8 min on a hot plate.

6) I then peel the pdms from the wafer and then cut it to the size
that of glass slide and put it in the plasma cleaner provided by yield
engineering systems. i use oxygen plasma at 1 torr for 1 mins at 25w

7) i then bring the pdms layer and the glass slide in contact and put
it in the oven at 65 degrees, overnight.

My questions:

1) The product data sheet says that it has to be heated at 85 degrees
for 45 mins..is it in an oven or hot plate? does the amount of time i
heat has a significant impact on bonding

2) where exactly can i find the parameters for plasma cleaning?

3)is there a solvent that i can use to make sure that pdms doesn't
stick to the wafer when peeling

4) when i follow the procedure described above, the pdms comes apart
fromt the glass slide, if i try to peel it right after i bring those
in contact.

Sorry for sending out a long mail. I just wanted to get the facts
cleared. Hope to hear from you guys soon.

Thanks a bunch,
Vishwa