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Solder wave

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I am using a Novastar 12S solder wave with Kester water solu... - May 05, 2007 by jmabie  

What did it cost ? ... - May 14, 2007 by jmabie  

#50116

Solder wave | 5 May, 2007

I am using a Novastar 12S solder wave with Kester water soluable fux 22-2425. I have used this for years without problems on an old Hollis machine. Just started using the Novastar and after fine tuning I get itermitten bridging on the front of the PCB. Setting POT 260 preheat 137 dwell tile 2.1 sec.

I use a foam fluxer and when I apply the flux with pray bottle is seems to limit bridgin. Foam fluxer is at max output.

Anyone ?

JErry

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#50120

Solder wave | 7 May, 2007

Try to slow down your conveyor speed. This reduces contact length and improves the peel-back.

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#50121

Solder wave | 7 May, 2007

Hi Jerry,

I bet you have dross build up on your wave. Are you running nitrogen? If not this could be the case.

Hope this helps!

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#50123

Solder wave | 7 May, 2007

How much flux are you putting on the board when using your foam fluxer? How does this compare to your flux supplier recommendation?

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#50124

Solder wave | 7 May, 2007

The spray bottle puts more flux on the board but I am not sure how to measure ? I just got the Novastar 12S and its very difficult to set up. When I fix one problem another one show up. When I do get good results I dont make changes and then after a few boards It all goes bad and I am back to adjustments.

Jerry

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#50125

Solder wave | 7 May, 2007

Are the pallets hot and killing the foam head as they pass over or is the air pressure on the air knife toi high travelling back along the board killing the foam. If these are OK make sure you have sufficient back flow onthe wave and you are draining the solder off the board properly. hope it helps cheers Greg york

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#50126

Solder wave | 7 May, 2007

4 Fluxer Operation 4.1 Set-Up and Check-Out the Fluxer 4.1.1 Spray Fluxer Set-Up and Check-Out 4.1.1.1 Pass a sample unsoldered board through the machine. 4.1.1.2 Remove the board just after passing through the fluxer and the air knife. 4.1.1.3 Inspect the board. There should be: � A thin coating of flux over the complete board. � Evidence that the flux has just entered the through holes. 4.1.2 Foam Fluxer Set-Up and Check-Out 4.1.2.1 Check that the flux head is stable and not changing height or �moving around.� 4.1.2.2 Adjust the air pressure to get the smallest bubbles. 4.1.2.3 Use an unsoldered board or a �LevChek� [Hexacon Electric Co., 161 W. Clay Ave., Roselle Park, NJ 07204 908-245-6200] 4.1.2.4 Pass a sample unsoldered board or a �LevChek,� through the machine. 4.1.2.5 Remove the board just after passing through the fluxer and the air knife. 4.1.2.6 Confirm that good contact is being made with the foam head. 4.1.2.7 Inspect the board. There should be: � A thin coating of flux over the complete board. � Evidence that the flux has just entered the through holes. NOTE: The �LevChek� depresses the foam head. Check that the foam bubbles making contact are relatively small and there is uniform coverage across the plate. 4.2 Set-Up the Fluxer Air Knife. It's easy to overcoat the board with flux and get good results, the trick is to get good results with a minimum deposit. 4.2.1 Beginning with the air knife set at 90� to the board, adjust the air knife to meet the following two purposes: � Remove excess flux from the surface of the board. � Drive the flux vertically into the plated through holes. 4.3 Check flux penetration into the through holes, as follows: 4.3.1 Place a piece of thermal fax paper on the top side of the un-populated printed board. 4.3.2 Pass the board and paper through the fluxing system. 4.3.3 Check for evidence of the flux wetting of the paper at the through holes. 4.4 Determine the amount of flux on the board. 4.4.1 Get a piece of corrugated cardboard and a weighing scale accurate to 0.01 grams. NOTE: Use cardboard with alcohol fluxes to slow their evaporation and get good data. 4.4.2 Weigh the cardboard. 4.4.3 Run the cardboard across the fluxer. 4.4.4 Weigh the cardboard again. 4.4.5 Calculate change in weight / area of the cardboard 4.4.6 Ask the flux manufacturer to calculate the flux deposition as: (Change in weight / area) X % solids by weight. 4.4.7 Convert the flux deposition to micro-grams/square inch and compare it to the manufacturer's recommendation.

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#50127

Solder wave | 7 May, 2007

Flux foam is not affected by board or pallot.

This wave is not the same as the hollis I used. The hollis wave flowed from middle to left and right side. This wave only flows to the left and its a very slow wave.

Jerry

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#50128

Solder wave | 7 May, 2007

Just as I thought earlier, you have a stagnant wave. You should be able to mechanically adjust it so it flows in the same direction of your boards.

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#50129

Solder wave | 7 May, 2007

Jerry,

If you�re sure your board has sufficient flux it must be that your slow flowing (single lambda) wave produces more oxides then the flux can handle. Due to the conveyer angle the front of the board usually has less flux then the back of the board. Are you also at the max solder pump revolutions? Do you have the possibility to create a backflow at the wave to drain the oxides away from the board?

Last question are you comparing results of a full blown Hollis machine with a nova star 6ft. table top machine? Patrick

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#50130

Solder wave | 7 May, 2007

I have the option of increasing the wave pump but when I do the wave is very unstable. Do you have the possibility to create a backflow at the wave to drain the oxides away from the board? Not sure how to do this

I wish I have the old 1962 7' hollis but it was damaged during our recent move. It worked great for 9 years.

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#50133

Solder wave | 7 May, 2007

Jerry,

At the end of the article in the link you will see how the wave needs to look like. http://www.interfluxusa.com/Technical/No-Residue_implementation.htm

This wave design has been adopted by most machine manufacturers and I would be surprised Novastar doesn�t have that wave design as option (check with them).

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#50134

Solder wave | 7 May, 2007

Jerry,

In your initial post you give 260C as solder pot temp if you�re not using lead-free I would reduce the temp to 250C this will also reduce oxidation rate.

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#50135

Solder wave | 7 May, 2007

Thank you all for your help. I will fire up the wave again Friday to test another run. Keep the comment flowing its been a great help. Anyone suggest a solder wave system for running 40 boards an hour ?

Jerry

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#50137

Solder wave | 7 May, 2007

What is a smart way to determine that the solder in the wave pot is moving at the same speed as the board?

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#50140

Solder wave | 7 May, 2007

Dave,

There is not really a �smart� or scientific way to check this but I know of easy ways and very effective ways.

Fex. an easy way to check is with a 3� spatula, you hold the spatula at the same angle as the board and drag trough the wave simulating a board. The result should be that the surface of the solder flowing to the backside has the same speed as your movement speed, but when you stop the movement the surface flow should stop too.

A very effective way is to open the conveyor width so you can move the board by hand without having to use much force. In this way you can manually push the board trough the wave and watch the backflow behavior. Just make sure you wear heat resistant gloves and a stiffener on the leading edge of the board (to avoid board flooding if the wave is too high).

I always aim for total board thickness immersion. If the wave backflow is correct you will never get overflow because the excess solder will be pushed to the back and not flood the board.

I hate to say this as a flux manufacturer and develloper, but wave soldering is more a physical process than it is a chemical process. Wave dynamics is the most important parameter in 0-defect soldering. To be technically correct if you have the board layout under control and the wave dynamics you will need very little solder wire for touch-up.

Patrick

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#50141

Solder wave | 7 May, 2007

Patrick I think peelback mechanics is more important than wave dynamics. :-)

...and "you can't talk to molten solder", but surfactant will listen.

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SEB

#50143

Solder wave | 7 May, 2007

what type of preheater does the novastar use and what temp. is it set on? I am also use to a hollis wave solder machine. Old and crude but works great.

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#50145

Solder wave | 7 May, 2007

radiant heat. 137c

The hollis was a great machine. The one I had the prehead wass on or off there was no setting. The pot temperature guage was brocken so I had to guess and manually turn the heater on and off. The whole machine was covered with 1 inch of goo. But it gave me 100% perfect boards. I sure miss it. even with the mess and smoke it generated I could alway count on the Hollis. The Novastar looks nice and clean but the wave is irratic and diffucult to adjust. There is only 1/4 wave height so leads drag the pot frame. The hollis has 1/2 wave height.

I dont like the Novastar the pallots get to hot and when placing them on the rail the parts get poped off the board. Its just not a solid machine. The computer is hard to use when a run is going. The machine has to be stopped and then run through a menue to chnage setting. After changes it takes 5 mminutes for the systsem to recover. Very time consuming.

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#50147

Solder wave | 8 May, 2007

Use the good old glass plate?

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#50149

Solder wave | 8 May, 2007

Hi Loco,

Good point!! The good old glass plate works just fine as long as the conveyor or carriers have L shaped fingers. A glass plate is usually about a � inch thick (a lot thicker than the actual board). With L shaped fingers the bottom of the glass plate will still represent the bottom of the board. However with V shaped fingers due to the glass plate being thicker then a board the glass plate will travel must lower then the actual board and produce a false interpretation of the wave condition compared to the actual board.

Jerry,

You mentioned that your wave height was only � inch (which is too low). The machine spec�s call out for a wave height of 3/8 inch which is more reasonable. I would contact the manufacturer about that, something must be wrong.

Patrick

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#50194

Solder wave | 11 May, 2007

Hi Jerry,

Today is Friday and I assume you fired up your machine. Did you achieve any improvements?

Always good know if our suggestions helped.

Y�all have a great weekend, Patrick

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ml

#50196

Solder wave | 11 May, 2007

Novastar is JUNK, that is why you cannot get repeatable results. Check the conveyor rails, you will find they are warped. Novastar uses cheap, non-machined rails. Straight from china or india. Their stuff is garbage. Best to swallow the loss and start over with something else.

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#50197

Solder wave | 11 May, 2007

Authough your response is harsh I tend to agree with you. I bought it used and was told by others at the time its a workable machine. Any suggestions on a machine for 40 boards an hour ? I run 400 boards a week and like to run the solder wave on weekends when I am not interupted by business. I have a budget of 25-30K

Jerry

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#50207

Solder wave | 14 May, 2007

Agreed, I just bought a Electrovert Vectra Elite and have been very pleased with it thus far. I got the dual pot option for lead free changeovers and that has worked great. I can change pots in under 5 minutes, not counting the time to warm up.

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#50208

Solder wave | 14 May, 2007

What did it cost ?

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RDR

#50212

Solder wave | 14 May, 2007

You can get a nice used electrovert in your budget.

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#50249

Solder wave | 16 May, 2007

We got a good deal on ours for around $100K new with not many options. For what its worth I visited Novastar's factory in Pa and was not happy with what I saw there. There were almost no static precautions taken, boards were stacked in cardboard boxes on a rack. Parts were everywhere on racks in disarray. That is the reason we decided to pay the extra and get the Electrovert. Cant beat seeing first hand how these things are built. I take equipment sourcing very seriously for a couple of reasons. 1) If my name is on the justification and req forms that makes me look bad if it turns out to be junk. 2) Me or one of my techs are the one that will have to fix it until its replaced for the life of it. Choose wisely young grasshopper.

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#50263

Solder wave | 17 May, 2007

Since your budget is between 25 and 30K I would say you have plenty of options. Electrovert and Vitronics are both good solid machines. Seho is another option. Seho is extremely user frendly and maintenance freindly and easy to profile however, it is not as robust and the other two mentioned. All three are certainly excellent options to look into.

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