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Selective wave selection

Yngwie

#19343

Selective wave selection | 1 April, 2002

Anyone with selective wave experience ? I'm buying the Selective Wave machine and trying to workout the comparison matrix. Can someone tell me what criteria should I look at when listing down the matrix ?...things like, min clearance to the high profile components, deep access capability, speeds, max board size, point/drag soldering, dip soldering etc. Anything that you guys could think of, pls share them with me.

thanks

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#19359

Selective wave selection | 1 April, 2002

Selective soldering machines are a good way to "finish automation", if the design of the PCB is conducive to the application with just a few components to solder.

Your points are good. A decision matrix for selecting a machine might also include: * Maintenance costs (ie, periodic maintenance requirements, replacement parts cost, etc) * Fixture costs (ie, chimneys, pallets, etc) * Repeatability of the process * Set-up and change over time * Flux application and control, because over- and excess-spray can be very detrimental to cleanliness and obtaining hole fill is important. * Solder level (ie, measurement, indication, etc) * Nitrogen consumption and ppm levels, if running no-clean flux * PCB recognition (ie, fiducial, hard-stop, etc) * Preheating profile adjustment and control (ie, ramp rate, peak temperature, dwell, etc) * Warped PCB damage avoidance. * Ease of programming. Properly, with offline programming that is generated from CIM software [eg, CIMBridge, CircuitCAM, etc] to avoid teaching from Gerbers or entry by hand.

Other points are: * Also, be wary of the promise of very tight spacing capabilities. For instance, a supplier might rightly claim the ability to solder through-hole leads within 0.020" of a nearby SMT component. While accurate, this may be possible only with a 0.150" clearance on the other side of the through-hole lead and maybe use the lead to wick the solder to the hole. Er, cute stuff like thet. * Some machines require peculiar fixturing for each PCB design that further increases the cost of the machine. * Selective soldering machines are very limiting, but are a good option for a very specific application or PCB design. * Consider evaluating chimney versus programmable / conveyored machines separately. * Consider evaluating selective soldering machines versus pallets for the same application. Typically if the PCB has 10-15 components (which is a lot) and the release quantity is GT 100, the cost justification for a selective soldering machine might be very difficult.

Finally, we have discussed these machines on SMTnet in the past, for instance http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=4586&#Message17907& Search the fine SMTnet Archives for additional background.

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Yngwie

#19416

Selective wave selection | 6 April, 2002

Dave, thanx for your input. Its really helps.

Just need some clarifications on : 1) Consider evaluating chimney versus programmable / conveyored machines separately.

Question: is there any disadvantages of the programmble/conveyored vs chimney ?

2) Consider evaluating selective soldering machines versus pallets for the same application. Typically if the PCB has 10-15 components (which is a lot) and the release quantity is GT 100, the cost justification for a selective soldering machine might be very difficult.

Question: whatdo you mean by GT100?

cheers.. yngwie

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#19418

Selective wave selection | 6 April, 2002

Sorry for being unclear.

Question: is there any disadvantages of the programmble/conveyored vs chimney ? Answer: No, not really. They are just machines that operate differently to do the same job, in most cases.

Question: whatdo you mean by GT100? Answer: Greater Than 100. In part, this goes back the ~$200k cost of a slow machine.

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Alex K.

#19427

Selective wave selection | 8 April, 2002

Hi!!

I've looked at few of those. Look very nice and neat, can place and solder vurtually any shape and size....

BUT you need feeders for parts.. and they are not cheap.. I think if you have just a few desighs you can try to justify it, but if you run high mix/low volume, don't even think about it.

I couldn't justify one even with more than 15min/PCB improvement.

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wf

#19533

Selective wave selection | 16 April, 2002

Have you considered point-to-point selective soldering using microflame ? If we look at the excellent points that Dave made.... The clearance required for the microflame is minimal, no tooling plate is required - only to fixture the parts and the pallet (the flame position and angle are programmable), Because it is completely progammable, different products can be run at any time by selecting the appropriate program, and new programs are easy to create. Maintenance, cleaning, warm-up, safety, are all pluses for the microflame and can help with justification.

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