The following is based soley on my experience of Soldermask Processing, please feel free to correct any inaccuracies. We currently process Soldermask using P52 with 91h and aqueous systems, Taiyo,Carapace etc.. The main differance is the base chemistry, Probimer 52 is epoxy based where Taiyo, Tamura etc. are aqueous based. Yes, P52 is normally curtain coated, it also requires specific chemistry for developing (4-Butyrolacetone) which is a one part solvent which can be recliamed to reduce costs. Aqueous systems can use a sodium carbonate solution which is much cheaper. P52 has a "very" long exposure time up to 60 sec on 7kW ORC units, again aqueous systems require a lesser exposure time period on a 5kW lamp. Holding fine webs is also harder using P52, typically you will have to start adjusting exposure time v dev speed to achieve less than 6 thou webs. Taiyo will process 4 thou with only an increase in exposure time. Cure time for P52 is approx. 2 hours @ 150degC. Taiyo cures @ 150degC for 1 hour. So why use P52? On the plus side assembly shops are usually happy with the finish due to the resilient (hardness of 6+) and very matt finish (low to non existant solderballing). The electrical breakdown voltage is typically higher than 3kV which customers producing High volatge boards like. Aqueous systems are about 0.5 to 2 kV in my experience. One other point is cost, our experience shows that P52 can be more expensive per sq foot than an aqueous system. If you are looking to intrduce P52, then I would recommend 52CSM as the solvent carrier is less toxic and finer webs are easier to attain. If you require further info please email direct. Mark Gillan Process Engineer Prestwick Circuits Ltd. Scotland UK. [log in to unmask] ---------- From: pacrim To: TechNet Subject: [TN] Properties of Probimer 52 Soldermas Date: 29 May 1998 07:27 I am trying to determine the differences between Probimer-52 and other soldermasks (Tamura, Taiyo, etc.). I understand that application techniques differ, as Probimer requires a curtain coating process, while the others can be sprayed, etc. Are there significant differences between Probimer-52 and others? If so, what are they? Is one better then the other? I am trying to make an argument for the changing to a more conventional S/M and any feedback would be greatly appreciated. Thanks for all of your help in advance. Best Regards ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################