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Heller 1088 Reflow Oven Conveyor Adjust

Dreamsniper

#18473

Heller 1088 Reflow Oven Conveyor Adjust | 18 December, 2001

Hi, Forgive me for my stupidity. Has anyone moved the fixed side of the Heller's Edge hold conveyor by 50mm ? I need infos on how they did it. This is because of the high delta T that we are getting from our oven which is between 20 to 20 deg. C from center of the board to the edge which is the fix edge of the conveyor. If we are going to move the fix conveyor by 50 to 70mm towards the center of the oven we will only have a delta T of 5 to 7 degrees. I noticed that we need the 2 lead screws from both front and rear of the oven to be machined. But i'm not sure what will be the next step as we have no time to stop the line due to our current tight turn around time. If anyone has done this with the same machine, please help. Our oven comes without the edge hold system and was installed as part of a retro-fit.

Thanks in advance. armin

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#18478

Heller 1088 Reflow Oven Conveyor Adjust | 18 December, 2001

This sounds goofy. That is too much side-to-side del T, even for a 1088. Something is wacked with the machine.

Contact Mark Peo at Heller. Search the fine SMTnet Archives for his contacts. He's a good guy.

Alternately, how much do you like pallets?

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Dreamsniper

#18480

Heller 1088 Reflow Oven Conveyor Adjust | 18 December, 2001

Hi Dave F,

Tried to use Contaval Pallets but it only worsens the situation. Prior to the retrofit of the Edge Hold Conveyor, our oven profiles were running well. It is probably due to the retrofit as it made the pcb 30mm farther from the bottom heaters thus affecting the thermal uniformity on the board.

regards,

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#18489

Heller 1088 Reflow Oven Conveyor Adjust | 19 December, 2001

So, what is a �Contaval Pallet�?

And who, my I ask, came-up with the cockamamie idea of retrofiting of the edge hold conveyor? Last time I checked, everything was fine, all profiles were working, etc., etc.

Just think, if you move the fixed rail inward by 50 to 70mm towards the center of the oven, your low temperature band may move inward also. Pretty soon, you�ll have a 1/2� throat on your 1088. Mmmm.

This is obviously a side issue, but since the retrofit to add the edge hold conveyor, have you: * Allowed ample time for the oven to stabilize after starting the machine and changing a profile? * Redone the profiles for your products?

So, what did Mark [at Heller] say?

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Sean D

#18493

Heller 1088 Reflow Oven Conveyor Adjust | 20 December, 2001

Hello Gentlemen,

Dave has a good point. Proposing to move the rails for the sake of thermal integrity doesn't seem logical to address you issue. By adding a rail set you have simply added mass (almost like big heat sinks) throughout the oven vs. when you were running with just the mesh chain.

Are you seeing this issue primarily at start up? Are you allowing additional time for the rail sets to heat before running product? Some oven manufacturers offer rail heaters as an option to reduce the heat draw from the rails on the edge of the product. That may be a more cost effective solution that is potentially more viable for actually addressing your problem.

I would also suggest leaning on your supplier to have them offer up a solution.

Good luck, Sean D.

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#18495

Heller 1088 Reflow Oven Conveyor Adjust | 20 December, 2001

Hi Armin!

This is Marc Peo from Heller. Please give me a call at 973-377-6800 Ext 113. We can discuss the best strategies for moving ahead on this. Alternatively, if you would prefer that I call you, please let me know your number and I will initiate contact. Also, please let me know the serial # of the machine so we can get our ducks in a row prior to our conversation.

Looking forward to talking to you!

Best Regards,

Marc

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Dreamsniper

#18496

Heller 1088 Reflow Oven Conveyor Adjust | 20 December, 2001

Hi Marc Definitely we will call you ! But as planned, we will be trying to move the fixed conveyor starting this morning and I think we need the two lead screws at both front and rear machined. We rang our local supplier here down under (australia) who installed the rails and they said that they can't service the machine until January. Also had requested through e-mail at least a copy of the drawings of the edge hold conveyor or even the parts lists so we could order extra lead screws to be machined but still haven't got any reply. We understand that we need a longer oven for our new products and definitely be acquiring a 8 zone oven this coming march 2002 but for the time being we need to fix the 20 - 22 deg. C delta T on our oven to get our products running with an achievable quality. We've run experiments with the oven and measured a Delta T of 7 deg. C across the board starting from a point which is 50mm farther from the fixed edge rail (closer to the center of the oven) to the center point of the wide width board which is the oven's center. Also measured a delta T of 7 to 10.5 deg. C from the edge of the moveable rail which is roughly 100mm away from the center of the oven. The only question that lies ahead is "How will it affect (in real scenario)the temperature profile when the fix edge is moved at the center of the oven as what Dave F just mentioned in the Forum..."

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Dreamsniper

#18497

Heller 1088 Reflow Oven Conveyor Adjust | 20 December, 2001

Hi Dafe F,

The edge hold conveyor was installed due to the double sided process on our new products. Remember the Stencil Printing Adhesives versus Dispensing in the forum a year ago? Well that led us to acquiring a Camalot 3800...This time it's the oven's thermal profile issues... Thanks to your un-ending support....

cheers mate !

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