Ken F. I assume the joint is in tension and not in shear when you say verticle upward pull. However, some background first on your choices: When you use heavy gold plating, which is anything over 0.3 microns, with solders that have a good amount of tin, such as Sn63, you are very subject to bittle fracture. NASA in the mid 1960's reported the problem with the formation of AuSn4 intermetallic which caused failure even with through-hole printed boards that were plated with 2-3 microns of gold over copper or over nickel. There have been numerous very good reports and information published on the subject since that time. Most of these indicate that there should be no more than 4% gold in the joint, but when you are soldering, the method may leave more than the maximum percentage at some portions of the interface or in localized areas, grain boundaries etc. Therefore, heavy gold platings with tin-based solder are to be avoided. This avoidance of heavy gold platings applies to leads, pins, lands regardless of the underplating such as nickel, palladium or NI/Pd. Therefore, you are left with your other choice of tin plating over copper plating. Your suggested tin plating of at 200-300 microns (0.008 -012 inch) thick is not a realistic tin plating thickness, suggest 6 to 12 microns if the tin plating is alloyed completely with the solder during soldering. (Pure tin platings/coatings on leads or surfaces tend form whiskers later when in operation). Suggest you use a tin-lead plating/coating on the pin over the copper plating instead of the tin. If you have restrictions on lead in the plating process, you can also use 3-6 microns of nickel followed by 0.1-0.2 microns of gold or the same with 0.1-0.2 microns of Pd between the nickel and gold, the platings should be electrolytic (galvanic) until the brittle fracture problems associated with the electroless platings is sorted out. Many of the SMT electronic components used today have a nickel plating with an overplate of palladium on the leads. My experience is that they solder well and form a good reliable joint. I am not sure if the Pd/Ni plated alloy would be any advantage over the other combinations, but have heard that it is better to solder to than nickel without a thin gold overplate. As to strength, since you are using a bare copper land, you will not increase the strength by switching to one of the more exotic and costly platings. Hope this has some value to you. Phil Hinton ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################