[mems-talk] Su 8 thickness

[Oakes Garrett]

Hi,

When I do double coats of SU-8 to 100 or 150 µm I simply perform the same coat sequence twice.  Thicker double coats may require changes to the first bake process.  Excessive heat seems to begin crosslinking SU-8 at the wafer but that shouldn't be the case here. 

Best Regards,
Garrett Oakes

EV Group 
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-----Original Message-----
From: jiang Liudi [mailto:ldjiang at hotmail.com] 
Sent: Thursday, August 07, 2008 12:27 AM
To: General MEMS discussion
Subject: Re: [mems-talk] Su 8 thickness

Hi,
Many thanks for kind suggestions. 
 
I think double coat could be the solution. could you further suggest procedures of double layers in terms of baking, expose and PEB?According according to the data sheet, 1700rpm should get almost 140um thickness. is it common for half the thickness, compared with the sheet?
 
thanks again.