The termination exhibits a gap of less than two (2) insulated wire diameters (<2d) between the end of the insulation and the first point of contact of the conductor to the termination/pad.Īdhesives may be used to temporarily hold discrete components in position during wave or reflow soldering. The contour of the conductor shall not be obscured at the termination end of the insulation. The insulation shall not be imbedded in the solder joint. and shall be mechanically restrained.Ĭomponents weighing in excess of 7 g (0.25 oz.) total, or 3.5 gm (0.12 oz.) per lead, shall be mechanically secured to the mounting surface by at least 4 evenly spaced bonds, when no other mechancial support is used. Parts which dissipate heat in quantities of 1 Watt or greater, or in quantities sufficient to damage the laminate shall be mounted with sufficient standoff The fillet completely wets all elements of the connection and is concave. The solder joint surfaces are smooth, nonporous and undisturbed, with a finish varying from satin to bright. The fillet completely wets all elements to the periphery of the connection and is concave. The solder joint surface is smooth, nonporous and undisturbed, with a finish varying from satin to bright. Populated plated through holes (PTH) should exhibit a vertical solder fill of 100%, with a fully formed fillet on the solder side, and evidence of 100% wetting on the component side lead, barrel and pad. Solder fillets are smooth and shiny with concave profiles. Component leads exhibit proper bend radii and stress relief. Component and board markings are clear and legible. While discretes are rapidly being displaced by the smaller-form surface mount technology (SMT) package, the discrete component is still widely in use, especially in extreme environmental applications where the SMT device will not perform reliability and/or is unavailable.Ĭomponents are installed per engineering documentation and are parallel to, and in contact with, the board surface. THROUGH-HOLE SOLDERING GENERAL REQUIREMENTS THROUGH-HOLE SOLDERINGĭiscrete components are the backbone of the electronics world, consisting of individually packaged, leaded devices, highly integrated circuits (IC), interconnects, terminators, switches, etc.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |