Description

<style>.e_editor{font:14px/24px Roboto,Helvetica,Tahoma,Arial,'Microsoft YaHei','b8bf53';}.e_editor div,e_editor p,e_editor td,e_editor th,e_editor li{font-weight:inherit;font-size:inherit;font-style:inherit;font-family:inherit;}.e_editor ul{margin:-10px 0 20px;}.e_editor li{padding:5px 0;}.e_table{width:96%;border-collapse:collapse;empty-cells:show;}.e_table th,.e_table td{padding:5px;border:2px solid #eee;}.e_img{padding:10px 0;text-align:center;}.e_p{line-height:20px;padding:0 0 20px;text-indent:0em;}</style> <div class="e_editor"> <div class="e_p"> Is anyone out there aware of any standard or even a section of a standard that specifically addresses design guidelines for two-sided assemblies, particularly one that focuses on different processes? </div> <div class="e_p"> I'm being asked to produce information from said standards, and I have no recollection of the existance of anything of the kind. Specifically, we're looking for guidelines for design to optimize a glue/wave bottom side process AND the same for a reflow/selective wave (with pallet) process. Currently the boards are designed with all pth on the top and all smt on the bottom, but that may change depending on what we find and can convince engineering to do. </div> <div class="e_p"> Again, I doubt the existance of such but pointers to anything close would be appreciated. And yes, I tried the obligatory archive search but combinations of dfm, bottom-side, two-sided, circuit side, produced nothing of any value in this context. </div> <div class="e_p"> Secondly, I'm looking for any information re: any relationships between overall pcb size and smt reliability. We're trying to decide if we should reduce the size of some boards to avoid potential failures derived both from rough handling during assembly and mechanical stresses in the use environment. </div> <div class="e_p"> If it's not already apparent, we don't do testing here to find this stuff out for ourselves. We just hope someone else has and has written a paper publishing the results so we don't have to. </div> </div>