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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


glue measurement

Franky

#17437

glue measurement | 30 August, 2001

I have problem about glue printing measurement ,anybody has process of glue printing . How do you measure? as I know "push test" is the method for testing the strength of connection of component and board but I don't have specification of testing force because on board will have many components and each of component may require differrent testin force ,anyone can help me? 2.)Can I measure the height of glue or measure the glue volumn after prining on board but before placement component like as the solder paste thickness to confirm this process? and anyone already implement this method in your process ,please give me the result and suggestion the method .

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#17438

glue measurement | 30 August, 2001

While I don't understand why, this topic comes-up fairly often on SMTnet. [That the topic recurs indicates there truely is a problem and I'm just too doopy to understand it.] Several things: 1 Check the fine SMTnet Archives. 2 Some glue suppliers know that their customers are driving themselves kookoo trying to figure-out how to do this. So, they sell these little torque screw driver thingies that are set to ratchet at about 80% of the force needed break a properly cured glue connection loose. 3 Just glue a couple [unused, non-functional, extra, test] components on the break-away tab of boards at various points [beginning, middle, end] in the lot. Then use a screw driver, pliers, whatever to bust 'em loose. This of course will require a carefully calibrated elbow and an ear tuned to the music of things breaking. That'll work.

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Dreamsniper

#17448

glue measurement | 1 September, 2001

your glue volume measurement is dictated by your stencil aperture size and thickness when you use stencil printing. Why you need to measure your glue volume deposition? I don't think that this is the right way yet for your undefined problem. What's the problem in your glue process why you come up with the idea of measuring your glue volume ? Get the right aperture size and stencil thickness and way you go!!!!

Dreamy

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JohnW

#17449

glue measurement | 3 September, 2001

Franky,

what method are you using for printing glue? metal stencil or plastic?, and is it on contact or off contact ? and what type of squeegee's are you using? basically give us more infomation.

In term's of measuring height / volume, you can do this with off line equipment, look at the ASC website, we're using their Vision Master to measure height, the algorythm's are not quite right for volume tho' but I do know they're working on it. As far are printers go, I don't think the main ones Dek / MPM and so forth can do it but then I've never tried so I could be wrong.

One thing tho' the reason you want to measure the height / volume, is it for missing / knocked off components ?, if so have you checked your cure profile? John

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George Verboven

#17784

glue measurement | 5 October, 2001

Specifications of testing force are not fixed, but (incase of wave soldering) the value should be at least 120-150 % of the force the wave. So for small chip components we assume that the force from the wave on the component is about 3 Newton, this means that the measured force with your torque equipment should be about 3,5 � 4,5 Newton� However, personally I have a little doubt about this. Well let�s say, theoretically it may be right, but to mine opinion this accepted force (the value 120 � 150% x the force the wave) should be measured directly after preheat section. This because measuring force on a fixed-cold-glued chip component, gives a higher value then a heated Circuit board, chip, glue dot.

Well I do not know if it is any kind of help but we measure for chip components on rigged circuit board (FR-4 and CEM) between 20 � 30 Newton. For Flex foils where components are glued with silver epoxy, we measure about 2 - 5 Newton.

And dave, I think that this topic comes-up fairly often on SMTnet simply because the fact that more and more process control is demand, and quality department is very happy with statistics. But it can also be a great help to find a possible cause in finding an answer to questions like: �glued parts falling off in the wave solder machine�, �Adhesion loss on passives over wave�.

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Sean D

#17794

glue measurement | 5 October, 2001

Hello everyone,

Your chief variable here is going to be your epoxy. Different materials react accordingly to various inspection methods but, DEPENDING on your print parameters and material, you may be able to utilize an inline inspection machine. Traditionally, many in line inspection machines have focused specifically on paste inspection. As I understand it, some applications have been reviewed at CyberOptics (www.cyberoptics.com) involving various epoxies. As a CyberOptics representative I would be happy to get you in touch with your local representative or the factory applications team to run a feasibility study.

As for testing, a universal bond tester could be utilized with modular heads to quickly change push/shear forces to address various test ranges on your product. This is common in the component assembly environment (die shear, wire bond, stud pull testing) but you may be able to get appropriate fixturing for your board to utilize this type of equipment for PCB component shear. This will give you a calibrated process and allow for quick changover of test heads. This would be an offline process. Royce Instruments (www.royceinstruments.com)manufactures the system 552 and 580 universal bond testers. As a representative of Royce, I would be happy to assist you in contacting your local representative or applications engineering for a product based feasibility study.

Please feel free to contact me if you have any questions or concerns.

Sean D. 480-829-8170 ext 14

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#17799

glue measurement | 6 October, 2001

Your point about thermosets getting soft in the preheater of the wave is well taken.

But an adhesive that is used past its expiry or other up-front lack of process control represent 99 & 44/100 percent of the reason for �glued parts falling off in the wave solder machine� and �adhesion loss on passives over wave�. The desire for process control, while reasonable, is misplaced in an expensive force test to control a process step on an activity.

I agree that torque tests can provide information ae a troubleshooting aid. I don't see them as a candidate for charting.

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#17805

glue measurement | 7 October, 2001

No one wants to be limited to one alternative in evaluating such equipment. Who would you suggest as viable alternatives to: * Cyber Optics in evaluating alternate suppliers for inspection equipment? * Royce Instruments in evaluating alternate suppliers for shear testers?

Cyber Optic's niche has alway been measuring solder paste height. So, measuring paste is a departure for them. Where can we get papers written about using such equipment to measure glue deposits?

For years, Royce has been a respected supplier of wire pull and shear testers used in semiconductor fabrication. Your suggestion that they are moving into board shear testing is interesting. Who at Royce should we talk to about this application of the 552 and 580? And how does the price of these units match-up with more traditional solder shear testers?

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George Verboven

#17808

glue measurement | 8 October, 2001

I do not doubt about the power of the 552 and 580, but in some cases it may be overdone. For just a simple (straight forward) shear test, you can also look at: http://www.chatillon.com/products/dpp.html (�Low Capacity Mechanical Force Gauge. These ergonomically designed push & pull gauges are ideal for a wide range of force testing applications.�)

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Sean D

#17814

glue measurement | 8 October, 2001

Hello Dave,

I never claimed that either of these groups were the only alternative but I do feel that they are value additive given the request for information. I more than welcome other suppliers' input as I feel it gives everyone in here the resources necessary to provide a wealth of options for evaluation based on the application. I can't speak for other suppliers and nor would they want me to speak for them. That would be irresponsible and opens up issues for mud slinging due to inaccurate information.

I simply feel that more information equals more options for the engineer thus giving the engineer better information with which to make his decision. Whether or not a sale goes through is dependent on his evaluation, not my recommendation. If you wanna suggest other vendors.....please do so.

Sean

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Eric Chua

#17818

glue measurement | 8 October, 2001

Look like no way you can measure after glue printing. We have been running glue printing for about 2 years and using the "push test" method for testing the strength of connection of component and board. I don't see any problem. For component ( 0603 & 2012 ), I set at 2-3kg force, 3216 component set at 3-4kg force. For "push test", dont't do it on the same location. For printing setting, I set 2 printing per board.

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#17841

glue measurement | 9 October, 2001

No one suggested that you speak for other suppliers and nor would they want� you �to speak for them." You shouldn�t make this something that it isn�t.

All that was requested courteously was suggestions of alternate suppliers that could be considered. There never was a suggestion that you should analyze their capabilities. I�m certain each engineer would prefer to do that.

When you only recommend one supplier, you make it seem like you are advertising in you postings.

See it's really a reasonable request that you provide alternate suppliers' names, because since you assume we don't know the name of your principal, then we must not know the other suppliers either. So, you are doing us a BIG disservice by not helping.

By the way you forgot to answer my other questions, also.

Cyber Optic's niche has always been measuring solder paste height. So, measuring paste is a departure for them. Where can we get papers written about using such equipment to measure glue deposits?

For years, Royce has been a respected supplier of wire pull and shear testers used in semiconductor fabrication. Your suggestion that they are moving into board shear testing is interesting. Who at Royce should we talk to about this application of the 552 and 580? And how does the price of these units match-up with more traditional solder shear testers?

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#17844

glue measurement | 10 October, 2001

Frank, Don't know about point 1 but if they don't fall off I don't worry about it. If they do fall off it's generally because someone has mishandled them before the wave, like shoving them into racks and the like. If they have fallen off and you can't see where the glue deposit was then they weren't there in the first place coz there wasn't any glue. If they ain't there and the glue is, but not deformed then they weren't placed. As to point 2. Print a scrap board - it doesn't even have to be the same type ( same thickness is good though ), cure it without components, and you can measure the height with the little skinny bit at the other end of a set of verniers. This should ease your worried mind about high stand off components. You can even whack a couple of scrap components on by hand and wave them too, doesn't matter if there is no corresponding pads - you just want to know if the ol' glue holds on - yeah? If you don't change the printer setting, as long as you follow normal good printing operations, then you should get the same result each time, no? Some Q.A. people love to make things complicated, be careful you don't make a rod to break your own back. Stick in there!

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Sean D

#17856

glue measurement | 10 October, 2001

Hello all,

My respone here is to add options for evaluation for the engineer. Not to convey that they are the only options as that would be reckless.

Cyberoptics does have a standard line of machines configured for in line paste inspection. Some evaluation of alternative material inspection has been performed due to requirements from the Photonics industry. I don't have papers as this is currently preliminary but I feel for this engineer's application it may offer a possible alternative worth evaluating (based on his application).

As for Royce Instruments, their product line does center on the semiconductor bond test industry but does have broader applications. This is a function of having a very capable machine with standard modular heads yet, depending on the nature and variety of component tests being provided, may not be the most cost effective machine especially if all that is required is a mechanical test piece as found in many SMT test areas. It is simply a flextible all inclusive option. And once again, not the only one.

Lighten up Dave, not all sales reps are evil ya know. "You shouldn't make this something that it isn't."

Respectfully, Sean

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#17864

glue measurement | 10 October, 2001

Geesh!!! Your advertisements are better suited to a banner on SMTnet. Check with Roland for pricing.

You are correct that not all sales types are sleazeballs. Look at this posting by Mike Konrad http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=17829

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#17869

glue measurement | 11 October, 2001

Sean I have to agree with Dave on this issue. As a frequent reader of this forum I appreciate it when company reps clearly note their affiliation, but I like it much better when they are also willing to identify the companies they compete against, "our competitors in this area are X and Y companies", is all you need to include. If you're not willing to tell me that, I have to wonder if it's because a competitor has a product better suited to my needs.

If a salesman is honest enough to tell me he has a product that could be made to do what I want, but that there are other machines better suited to my needs, I'll call him first the next time I need something. On the other hand, the first time I catch a salesman not telling me his machine is not directly intended for my application is probably the last time I'll talk to him or his company.

Mike F

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