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SMT tape boards!

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We are experinecing adhesives left on the boards after runni... - Oct 21, 2005 by

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Feel better now? ... - Oct 28, 2005 by Rob  

Jim

#37263

SMT tape boards! | 21 October, 2005

We are experinecing adhesives left on the boards after running taped boards for placement verification on NPI. We've been using 3M double sided (333) tape for over 15 years. Any other suggestions on a good tape to use? This may be a quality issue from 3M but I am looking at alternatives in the mean time.

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aj

#37264

SMT tape boards! | 21 October, 2005

make sure they are cleaned properly after the tape is removed.

I think there is a spray available but I have never really looked into it.

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KEN

#37272

SMT tape boards! | 21 October, 2005

Pardon my ignorance, but why would you run your fist off on tape?

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bobpan

#37286

SMT tape boards! | 24 October, 2005

Most times its easier to verify the parts......and if you set it aside.......when/if you have a board that ends up missing some parts.....you can use them off the taped one....

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Rob

#37289

SMT tape boards! | 24 October, 2005

You can't really use a pasted board to troubleshoot the program as any components not on target simply slide off with machine vibration and movement as they won't be held by the solder paste.

Whereas on double sided sticky tape they remain in place & you can spot if it's something like a missed rotation or a global offset problem more easily.

And yes, you can use the board for spares!

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KEN

#37295

SMT tape boards! | 24 October, 2005

1. Why would parts be missing? 2. Why would you have a global offset? 3. Why would it not be right the first time?

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trd

#37304

SMT tape boards! | 25 October, 2005

Ken, Some of us out here work with machines that cost $20,000 and not $200,000. Also some of us work for companies that dont spend their profits into upgrading equipment but maintaining what it has.....lacking or not.....so....because of those reasons......some of us....'once in a while'.....will have some parts missing.......

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Rob

#37305

SMT tape boards! | 25 October, 2005

Also we get data from customers in all forms, and sometimes, just sometimes it doesn't match the current iteration of board, and when you have 600 passives with a combined value $1.50 it can save a huge amount of money & time trying to trace the problem, when you can see empty pads, or where the machine has put the parts.

We only ever run one on a total first off, not every time we run a batch.

Regarding offsets, some of our customers are OEMS who use them for some of their lines (as workarounds on problem machines or on prototype machines) and forget to include it in the data.

Obviously it all depends on the volume & values of the boards, but I do remember most of the telecoms boys using this practice on NPI for handsets.

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KEN

#37320

SMT tape boards! | 25 October, 2005

I guess I would rather spend my time demonstrating why a 20K machine can't do its job and how it is really costing the company money. Maybe its unfair to blame the machine. Often the problem is the team surrounding the machine. Poor maintenance, poor training, lack of proper tools, little experience (insert short-comming here). My point is eliminate the tape and let the problem solving begin.

What do you do when you have a lot size of 1 and exact count parts? Oh, this with 3000 passives per board.

Telcom or not. They don't build live product on tape. They test placement rates or accuracy (however accuracy using tape is debateable as it does not simulate solder paste conditions--especially on moving table machines with high inertia).

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Rob

#37326

SMT tape boards! | 26 October, 2005

Hi Ken,

We would build a one off with an exact number of components on a different line, in a different manor completely to a volume, chipshooter job - however, we'd only really be doing a one off like that if it was a prototype as we're not in that sort of business.

We only use a sticky on a high volume board where the data is still suspect after being run through our front end. There is only so much you can dictate to a customer on what you want from them - some offer too much, sometimes based on innaccuracies in the past (stencil thickness'with no blade type spec'd, types of solder paste/reflow profiles based on 4 zone ovens), and some have none, having relied too much on a previous CEM (Time to get the digitiser out...).

Often, on the more high tech boards stickys are not required, as they are designed on better Cad packages with decent information. However, some weeks you build 20K of a 10 yr old heritage board, then other times you build 10k/day of a new board.

I agree that if you were doing this on every job, and everytime you set one up, it would be crazy & there would be something seriously wrong with your process (program varification/machine callibration/staff training etc.) and you're going to find you have a rather big attrition problem with your stock.

It's just another handy tool to have when needed, it's how & when you utilise it that's key.

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trd

#37327

SMT tape boards! | 26 October, 2005

Agreed....Rob....and also Ken its unfair to blame the team when the owner wants a 1980 station wagon to run at 250 mph!!!!! The greatest nascar team would have problems making that happen. And even when you explain....that you need a corvette to go 250......they say....make the station wagon do it!!!

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KEN

#37343

SMT tape boards! | 26 October, 2005

I'm all for "tools in the tool belt". More is better. There is a diminishing return on equipment life. This translates into diminishing quality.

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#37378

SMT tape boards! | 27 October, 2005

> I'm all for "tools in the tool belt". More > is better. There is a diminishing return on > equipment life. This translates into diminishing > quality.

> I'm all for "tools in the tool belt". More > is better. There is a diminishing return on > equipment life. This translates into diminishing > quality.

I'm not interested in banging my head repeatedly on brick walls anymore. The majority of managers don't get their jobs because they are smart or anaylytical. They get them because they are decisive. People that think highly of themselves not admitting to being wrong is the not the usual problem, it's that they don't even recognize that they are wrong and sometimes they don't even recognize they could be wrong.

And the more decisive someone is on average the more they are inaccurate on average.

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Rob

#37391

SMT tape boards! | 28 October, 2005

Feel better now?

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KEN

#37425

SMT tape boards! | 28 October, 2005

okay, okay, okay...I'll use the tape. Yikes man. Take it easy. (kidding)

Well, on second thought...but I could try it. Naw. Crud. Now I don't know what to do.

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#37437

SMT tape boards! | 30 October, 2005

I apologize for my poor english. First: "Double sided sticky tape" is excellent for various reasons; right/left?. Second: NPI? Don't hesitate, If You feel that a certain machine in Your line cofiguration don't place certain/certain's components on the rihgt spots; then use it. Third: "put down a double sided sticky tape" on suspicious spots as a compare to a known good board; for ex. put a "double sided sticky tape" on a certian position (only on that suspicious component/s position/s) and let the machine verify your placement data. after this you should know how much you need to either: 1: offset your placement coordinates (of course You need to find out the root cause of your offsets) 2. get a hint if Your placement machine needs a re-calibration. Fourth: For NPI or protype production; to clean the first pcba of the product or even discard that pcba (or attache temperature probes for oven profiling) should not be a big problem.

/Mika

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#37442

SMT tape boards! | 30 October, 2005

Ken is not of this World! His equipment and "Programming Team" is perfect. The rest of the world uses "sticky" boards when programming. "ALL" the big guys...Panasonic, Fuji...etc suggest using the "sticky" method beofre running any production boards. Sorry Ken, stay up there on your golden pedstal.....the true engineers in the trenches are what make the SMT world go round. Pround to use "Sticky" boards in the USA!!!!!!!!!!!!

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#37476

SMT tape boards! | 31 October, 2005

Hi There.

I use to suffer the same pain,specially when i had limited board quantities. You can use an antiestatic transparency attached to the board using Kapton Tape,than place the double sticky tape. This work perfect,kapton tape residues clean very easy. Also you can use the board with the transparency attached to it,in order to check your printing process.

Hope this help you.

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dougs

#37491

SMT tape boards! | 1 November, 2005

Ken, what software do you use to aid your programming process? i've seen programs like GC-PLACE which could help verify customers cad data and rotations prior to setting up on a line, are there any others that the forum would recommend looking at?

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