Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Vacuum Reflow Oven

Views: 4156

#80340

Vacuum Reflow Oven | 3 May, 2018

Can anyone advise on the approximate cost of a reflow oven with vacuum? Just looking for a ballpark number to see if it feasible for us.

reply »

#80342

Vacuum Reflow Oven | 3 May, 2018

Also, are there any other industry practices for void reduction? I read that Nitrogen helps.

reply »


dwl

#80344

Vacuum Reflow Oven | 3 May, 2018

Solder paste selection can have a huge impact on size and quantity of voids. Talk to a few suppliers and ask for their recommendation on low voiding formulas. Pick a few of your top candidates and then perform a DOE to see who has the best result.

Stencil design is another big contributor, especially for large areas like thermal pads on QFNs and DPAKS. some sort of window pane aperture is typical, although people have had success with other patterns. The key is to find a balance between providing enough solder coverage but allowing channels for the flux to outgas and not get trapped in the molten solder.

Finally, voids aren't necessary a bad thing and are quite common. They only present an issue if the reduced solder volume interferes with the thermal or electrical properties of the solder joint.

If you can give us some background on your problem, we can give more targeted advice

reply »

#80354

Vacuum Reflow Oven | 6 May, 2018

Thanks for the feedback. I was looking into solder pastes and saw some advertised specifically for low voiding by Indium and another supplier.

This is customer driven - requesting voids in the single digit percent for components with thermal pads for efficient heat dissipation.

reply »

#80389

Vacuum Reflow Oven | 11 May, 2018

Rehm Thermal Systems (Germany)offer in process vacuum reflow in convection ovens and vapor phase pending what makes sense - volumes of PCB per hour needed. There are other vendors getting into this of course.

Can only get single digit void free joints with asssiatnce, anti void pastes will gte some way with good DFM,Stencil and reflow profile, but < 10% would be tough ask without machine assistance in reflow process.

reply »

#80612

Vacuum Reflow Oven | 26 June, 2018

Minami vacuum reflow is easy to maintain air tightness, and oxygen can be reduced to 50ppm or less by filling N2 gas. And generation of oxide film can be suppressed, and production in low oxygen environment is possible. In addition to the air tightness, vacuum void-less function is equipped in the reflow zone. Air bubbles (voids) in BGA and CSP, which basically could not be reduced in the past, can be eliminated by sucking in the vacuum chamber, and uniform bumps without voids can be formed. We need more details of the target boards to run and its component including the solder paste to use as this is customize machine. Texas Instrument already qualified minami vacuum reflow and now in production mode.

reply »

reflow oven profiler

Reflow Oven