How to increase lifetime of electronic products (THT components): investigation and results Soldering process platforms for THT components Delta Wave 6748 Present status for technology 6747 Inertec ERSA Svetlana Andersen 06-05-2014 Soldering methods Svetlana Andersen Present status for technology Soldering of THT components Soldering platforms: • Wave soldering (one side SMD, same side THT). Full nitrogen (ERSA) machine operates with less maintenance and less tin consumption compared to Soltec. No limitation in quantity of product variants. • Selective soldering Soltec (2 sides SMD, one side THT). 6748 machine is used for module alignment and soldering at the same time. Limited to 4 possible products. 6747 machine is used for hign volume, low mix production set up. Limited to 2 possible products. • Selective soldering Inertec (2 sides SMD, 1 side THT). Machine is used for soldering and accurate alignment of modules. Change over between products is not complicated, but the technology is rather expensive because of wear of tools. 06-05-2014 Svetlana Andersen Test on representative products 5 Barrel fil, clinch-angle & hole size Other findings: •Simulation •Test Hulstørrelse er vigtigere end clinchning Solder joint and Cycling Experience, 2007-04-27 JOJ 6 Simulation findings Solder fill is very important Solder fill is much more important than clinch angle Ranked order of importance: 1. Solder Fill 2. Size of hole 3. Solder Clinch Angle joint and Cycling Experience, 2007-04-27 JOJ 7 Weak point candidates 8 What can impact flow-through (solder filling): - Lack of adequate heat transfer up the lead and barrel. Both the barrel and the lead must reach soldering temperature throughout the PWB thickness, or solder flow up the barrel will be halted. Problems can be caused by lack of lead protrusion, too many ground plane connections to the PTH or insufficient thermal relief on ground connections, too low solder temperature or too-short contact time. - Slow or absent wetting. Both the lead surface and the hole wall must be made wettable by a flux in order for a capillary force to be generated that will cause the solder to flow up the hole. Wetting problems can be caused by poorly-solderable surface finishes, lack of flux penetration, or improper pre-heat (either too-aggressive or insufficient), or contamination of hole walls or leads. Proces parameters and output Noise factors Variation in raw material Process variation (e.g. temperature, nozzle size, comp.placement inside the hole) ... Factors Flux material(??) Flux amount Borehole design Diameter Solder surface quality (solderability) Dimention of solder thermals Cu thickness Output Filling degree How to measure? How to lower variation? Selective soldering: Saver on the existing solder plate Control parameter Solder temperature Contact time Preheating temperature/time Temperature measurements Temperature in nozzles (Saver 3ph) No significant difference in temperature – no influence of nozzle size Preliminary test with solder filling in wave soldering process (test board used) Picture of the test PCB PCB manufactured with following parameters: - Cu in outerlayer (track 1+4) - Cu in innerlayer (track 2+3) - Cu in all 4 layers (track 1+2+3+4) - Full flood in all layers - thermal 0,4mm long in all layers - thermal 1mm long in all layers movement direction Test results with pcb layout Solder direction standard (9 PCB) 120 Solder filling % 100 80 Track layer 1+2+3+4 60 Full flood Thermal 0,4/1,0 40 Thermal 1,0/1,0 20 0 0,8 0,9 1 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9 2 2,1 2,2 2,3 Solder direction changed 180 degr. (4 PCB) 120 100 Solder filling % Process parameters: 1 reflow Wave soldering conveyor speed 110cm/min Tin temp. 270oC Preheating :280-200-200 flus: KOKI JS-EU-01 PCB nr.: 6-14 80 Track layer 1+2+3+4 60 Full flood Thermal 0,4/1,0 40 Thermal 1,0/1,0 20 0 0,8 0,9 1 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9 2 2,1 2,2 2,3 Test resultater Ref 3ph 11-30600372 11-30600393 11-30701632 11-30701630 11-30701599 11-30701573 SaVer Reference Print (til HMY layout) HMY Trial Layout C2.1 C2.2 C13.1 Barrel fill <75% (but >50%) C13.2 C16.1 C16.2 C19.1 Barrel fill <100% (but >75%) C19.2 C201.1 C201.2 C202.1 C202.2 C203.1 C203.2 C204.1 C204.2 C206.1 C206.2 C207.1 C207.2 C208.1 C208.2 C209.1 C209.2 C210.1 C210.2 C211.1 Find a difference Possible solution Contacting top layer and innerlayers by side of solder hole with via holes 1 Selective soldering optimisation Begge 2 løsninger Indføres i DG om lodning 2 There should be thin connection between solder pad and solder thieve.