Hi Pankaj:
Preheating the boards in an oven and taking them out of the oven and into the wave solder, fluxing the top side with a spray bottle, slowing the belt speed, and definitely raising the wave height all will help to have better penetration. If you get too many bridges, a second pass at a lower wave height will remove them.
As far as rework, it can be done if the board is placed on a heating plate and kept at about 270 deg F. while it is being soldered after it is preheated in an oven.
Regards,
Ramon
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Karnwal, Pankaj
Sent: Monday, August 16, 2004 2:24 AM
To: [log in to unmask]
Subject: [TN] Vertical fill up of 3.2mm thick PCB.
Dear Tecnetters " Hi "
we have a PCB of 12 layers with thickness of 3.2mm.
Problems we are facing are
1.Solder doesn't come top side and as the thickness is more than pre
established components lead lengths ,like DIP's IC,connectors pins , it is
mandatory for us that a fully wetted solder is visible from primary side.
2.Many of the components are on the ground plane , so if any rework is
required we could not do so by soldering iron ( we tried weller 150 watts
iron with temp. 450 deg. C , but we could not remove an electrolytic cap.)
3.What IPC tells about the power connector lead protrusion and the top side
solder fill up for the same. As the IPC 610B states in components
installation 3.5.3.1/note: that lead protrusion may not be visible in more
than 2.3mm thick boards.How we interrelate it with soldering 4.1/vertical
fill of soldering 75 % in this case.
4.We are using AC by pass connector "PICH47F400A1" with recommended PCB
hole dia 2.1mm for lead dia 1.6mm , Is it enough for 3.2mm thick PCB too.
Any body have the soldering experience of 3.2mm thickness PCB. what
parameters ( wave height/ pre heater temp ) of wave soldering M/c matter in
this case .Is chip wave is useful , Pls. share your exp. it will be highly
appreciated.
Thanks
BR
Pankaj Karnwal
Jr. Engineer QA
Barco Electronics System (P) Ltd.
Plot no. A- 4 & 5, Sector- 5
G.B Nagar, Noida - 201301
India
Tel .+91-120-2421651-660 Ext.211
Fax.+91-120-2421691
WWW.barco.com
mailto:[log in to unmask]
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