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Wave Cassettes and Heat convection

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#46664

Wave Cassettes and Heat convection | 15 January, 2007

We use Alpha EF-2202 low-VOC No-Clean flux Selective wave soldering cassettes Bottom pre-heating wave soldering machine

We have one component that will not solder properly: http://www.epcos.com/web/generator/Web/Sections/ProductCatalog/Capacitors/Ultracapacitors/PDF/PDF__OverviewTypes,property=Data__en.pdf;/PDF_OverviewTypes.pdf leaded single cell

There is a few inner layers of copper surrounding the holes for this and one ground layer is attached all around the holes, so cheat convection is the main problem here, however we also use the wave machine for non-wave cassette PCB so having a separate pre-heated conveyer speed is not possible, we have even slowed down the flux spray below the recommended conveyer speed to add more flux, without luck. THE COMPONENT WILL NOT SODLER TO THE TOPSIDE. The connection issue causes problems with the delay in testing for the charging of the component and measuring. Other factories who produce this product don�t have this issue. Also our wave soldering machine is over 10 years old. :-( Any ideas guys? How can I fix it? I tried dipping the comp. legs into flux but it doesn�t help.

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#46669

Wave Cassettes and Heat convection | 15 January, 2007

Questions are: * Does the component take solder when you dip it in the solder pot to test the solderability of the leads? * Can you get full barrel fill when wave soldering a bare board? * Is your flux reaching the top of the board through the hole barrels? * Are you considering that IPC-A-610 does not require complete barrel fill?

We're not so sure that adding more flux is the proper approach when using no clean fluxes. It is the proper approach with OA fluxes. You might be better off with more heat.

Search the fine SMTnet Archives for more on hole fill.

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#46674

Wave Cassettes and Heat convection | 15 January, 2007

So others can solder the same board and part but you can't. Dipping the legs in flux doesn't help. Then it's either your pre-heat or wave. Measure your pre-heat and compare to others or flux mfger. Do you have chip wave or something like an Omega wave found on them Electrovert machines?

Also, what is a "selective wave solder cassette"? Are you running boards thru a wave solder machine just for the pre-heat and then selective soldering? If so, it probably is you preheat.

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#46696

Wave Cassettes and Heat convection | 16 January, 2007

Answers: The component does take solder, no problem We get a full barrel fill with an empty PCB but only on one of the holes, the other hole has so much copper around it. The flux reached the top of the PCB when I tested the empty PCB. The IPC-A-610 rule doesn�t help the loading of the component during testing if the solder joint is not full to the topside, or so testing department tells me.

I assume that the problem lies with the heat convection, do you believe that a partially connected ground layer would help enough to solder the legs better as the whole ground layer is connected to one leg. With 4 tracks attached to the hole? Any ideas is better than arguing with the quality manager, as he told me my flux dipping idea was stupid. :(

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#46697

Wave Cassettes and Heat convection | 16 January, 2007

I cant touch the pre-heat as it would affect all other products or so i am told by the Qaulity manager. Maybe they think i am Mickey Mouse and the pcb�s jump around the factory like a scene from Fantasia :) if this was only the truth.

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#46703

Wave Cassettes and Heat convection | 16 January, 2007

Your Quality Manager won't let you make changes, yet you get blammed for process problems? First, you need a change in management.

Second, if you can't change set pre-heat temps, change the conveyor speed. Slow it down and see if your joints look better.

Three, http://www.pinenose.com/waldisworexm.html

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#46705

Wave Cassettes and Heat convection | 16 January, 2007

we worked out that the wave soldering cassettes Duratstone material takes alomst 35 degree away from the surface of the pcb, and the speed is already too slow it should be over 1.0 - 1.8 meters a minute but its now already 82 cm a minute, in order to compensate for the temperature drop we would have to add almost 1 minute of extra time in the pre-heat, so it looks like we need a new wave soldering machine with pre-heat top and bottom. but thanks for the answers guys. NOTICE FOR EVERYONE ALWAYS GET TOP+BOTTOM PRE-HEAT WAVE MACHINE

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