We have used this technology for assembly of PTHs on PWAs that are otherwise mostly SMD (e.g. for PTH connectors). Typically the paste is applied using a syringe and the PWA reflowed in vapor phase. Another option is the use of solder preforms (most solder vendors make preforms, Indium Corp. seems to have quite a few formats to choose from). Interestingly enough, vapor phase was initially invented and used for soldering large motherboards (PTH) and the SMD applications came later. Some cautions re reflow soldering of PTH devices: * Many PTH devices aren't meant to see the temperatures associated with reflow assembly (e.g. dwells for 30-90 seconds above 360F with a "top end" of 420F) * The "cleanability" of rosin fluxes decreases with increasing reflow time (i.e. the process that removes an RMA flux after wave solder may not be adequate after vapor phase). Hope this helps. Jim Maguire Principal Engineer, E/E M&P Boeing Defense & Space Group [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Paste in hole Author: [log in to unmask] at esdigate Date: 8/16/95 1:28 PM Hi, We are interested in assembly alternatives for components requiring wave soldering. The option of "paste in hole" was suggested. Does anyone have any experience in using "paste in hole" instead of conventional wave soldering for assembly of through hole components such as PGAs or connectors? Any related information, e.g. published papers, reference, or standards for this manufacturing technique will help. Thanks in advance. Tom Chung