Through-Hole Connectors Going Strong
SMD inductors are a common culprit for TMI failures – if a HP 34401A croaks, checking input coils is a great idea. Nevertheless, engineers keep using SMD parts in this area. An interesting question is how developers think about SMD connectors.
Having analysed search trends for both SMD and THT connector searches, the trend is clear – throughhole comes out on top.
This is valid all over the block. A “conventional” candidate would be the USB3145-30-1-A by GCT; it implements traditional USB, but comes with a neat twist of being rectangular. This means that insertion forces do not bend the connector – removal can, of course, strain the solder joints.
Of course, the automotive market and its high vibration and high reliability demands come with their own caveats. While SMD usually is better for cars as the lower mass lowers stress cracking, connectors such as the DT13-08PA are THT as they can dissipate connection and disconnection stresses more efficiently.
Finally, friends of odd connectors can feast their eyes on the nf2d-b-2 by Neutrik. It is an RCA connector which has to be soldered in; an interesting approach which was used to great success on systems such as the SolarTron 7150. Mechanical mounting must then be done with a set of screws, as seen in the figure.
…Physical and electrical positioning are two different problems
THT and SMD connectors usually do not give one another much in terms of price. The extra price for the drill holes usually is insignificant, PCB layouts can even become smaller in one plane. However, word on the street has it that reflow soldering machines gravely dislike headers and similar elements – touching base with your manufacturing partner is very recommended.
While engineering usually is not a black and white subject matter, the voice of the people seems clear when connectors are concerned. Going THT might increase prices slightly; the increased reliability makes it worth your while most of the time…