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bulk feeding chips

The advantages of bulk feeding vs. tape and reel are numerou... - Feb 03, 2003 by gregp  

#23228

bulk feeding chips | 3 February, 2003

The advantages of bulk feeding vs. tape and reel are numerous. Who is currently employing bulk feeding? If you are, what is the application (HVLM, etc..)? If you are not, why not? I am leaving this question very open initially in order to recieve a broad range of responses.

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Jon Fox

#23233

bulk feeding chips | 3 February, 2003

We are currently NOT using bulk, even though we looked into as a means of reducing machine time and component cost. Unfortunately, since bulk cassettes did NOT take the industry by storm as it was predicted years ago, we were stuck with long lead times and the cost was not that much lower. Our machines have the ability to accept bulk cassettes (with special feeder of course), but the advantages did not cancel out or out measure the disadvantages. Maybe we are an exception to the rule. As far as technology, we are an OEM and build a range of products from RF to analog test equipment. Good post BTW. It would be nice to see some more input on this one, as I would rather use bulk feeders to keep our machines up another 3%-5% of the time due to reel changes.

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Jon Fox

#23234

bulk feeding chips | 3 February, 2003

Application...oh, we are a high volume, low mix (HVLM). Forgot to answer that one earlier.

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#23235

bulk feeding chips | 3 February, 2003

Thanks for the reply Jon. You say your "advantages did not cancel out or out measure the disadvantages". What were the disadvantages other than lead time? Another question...you say your are not currently using bulk. Does this mean that you used bulk feeding in the past?

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Jon Fox

#23238

bulk feeding chips | 3 February, 2003

We have some high runners (components) that are available in bulk and some that are not. It would only help part of the issue. Cost was only a marginal difference, and we were told by the supplier that it was because bulk just hasn't caught on like everyone thought, and since we are talking about 1 or 2 million components at a time, the cost difference was only minor. We would have to buy enough stock for a few years production and being an OEM, our products evolve as the worlds technology advances. We would end up sitting on a lot of bulk cassetes. We were also hoping that the cost advantages would balance out the cost of bulk feeders (which it did not). So no, we have not used them as of yet, but the current ME and myself have used them in the past with Motorola, HP, and Jabil. If it were the world that chip manufacturers told us it was going to be, and equipment manufacturers pushed for it a bit more, it probably wouldn't have been an issue, and my machines would only stop when a tray sequencer or non-passive reel needed replenishment. Oh-well.

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#23250

bulk feeding chips | 4 February, 2003

OK Jon, now let me speak hypothetically. We are in agreeance that bulk feeding can save money through increased machine up time. If this cost savings alone could pay for the bulk feeders (it is just a matter of time before it would) and the minimum order quantity issue was resolved, would bulk feeding be more enticing? In other words, imagine a dereeling fixture that you could place a reel on that would empty the tape into reusable bulk cassettes. You could put 1 to 5 reels into the cassette and throw away the tape and reel. This could be done offline by stockroom or job kitting personnel. All of the advantages of bulk without the quantity issue.

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Jon Fox

#23253

bulk feeding chips | 4 February, 2003

If it takes an extra step, then it is costing my company money to pay that person to do that task. Besides, I prefer to keep the stock personnel busy counting reels from shipments and preparing kits for the production floor. Kind of sounds like buying blue and yellow play-do because they were out of green play-do to me. Maybe it is the Missouri in me...show me. You are right that I would no longer have the quantity issue, but now I will have a quality issue on my hands. They will have to make sure that the cassettes are in fact empty (1), the correct part is being dereeled (2) and that the cassette was properly labeled after filling (3). too many "ifs" for my crew. I live by the KISS method.

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#23269

bulk feeding chips | 5 February, 2003

Your points are all valid. This is probably a service that the component distributers should provide. The reason I am harping on this issue is because I beleive is is possible to add several hundred part numbers to your pick and place on line inventory in an area the size of a matrix tray. This would allow commmon discreets to always be loaded on the machine without affecting the standard feeder capacity. Anyway, the dereeling idea has flaws in that bulk fed components need tighter tolerances (physical size) than tape and reel. At least that is what bulk feeder manufacturers claim is necessary.

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Jon Fox

#23288

bulk feeding chips | 5 February, 2003

I think you just answered a questioned that I never thought to ask. Are bulk parts manufactured differently than standard tape and reel parts? That would explain why there is a bigger price difference in parts from Murata and not from others. As I understand it, Murata laser cuts all their ceramic chips (reason why we used them for IPC-9850 tests). So I guess if all the chips are made the same, then the only cost difference would lie in the packaging. What I mean is, bulk vs. t/n/r parts from Murata are not almost identical (they have a more expensive manufacturing process)and they make that up on tape and reel sales. Other companies, have to use a more expensive process to manufacture bulk chips, so to make up that cost, they have a higher cost for bulk chips, or a cost more similar to their t/n/r chips. Does that make sense? Can anyone confirm or deny my line of thought?

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#23301

bulk feeding chips | 6 February, 2003

I do not know about the cost issues but as I recall the tolerances are tighter on bulk components and this usually means higher cost. I cannot find my bulk feeding summit information but these links give you some idea what was discussed. I don't know if there have been any further talks regarding bulk standards and implementation. Anyway, the fact that you and I are the only ones remotely interested in the subject speaks for itself. Is there anyone out there that is using bulk feeders?http://www.murata.com/articles/0105.html http://www.uic.com/wcms/Images.nsf/(GraphicLib)/Bulk_Feeder_Applications.ppt/$file/Bulk_Feeder_Applications.ppt

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#23309

bulk feeding chips | 7 February, 2003

Bulk parts cassettes... another idea that must have looked good at the time. Too bad the manufacturing trend went from low mix / high volume to high mix / low volume. I guess the feeders have to be too complex to feed the part properly to the machine, raising its price quite a bit and requiring more maintenance and calibration. The problem is that the chip shooter requires high precision picking from the feeders or you get lots of rejects. What is needed is a chip shooter with adaptive picking so that it does not matter how the chip is presented to the head, the machine would know how to pick the part regardless of orientation. Pipe dream?

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#23313

bulk feeding chips | 7 February, 2003

Pick up correction (as far as position) is already available on newer model chipshooters. This doesn't address upside-down fed resistors. The link I provided for Murata tells a story of increased reliability and reduced cost. As components get smaller the reliability of bulk feeding can in some cases exceed that of tape and reel. I think bulk feeding has got a bad rap due to initial reliability problems and this may slow down acceptance. With respect to LMHV and HMLV bulk feeding can potentially help. In some cases, bulk feeders can double (or more) the part number capacity of P&P machines thus reducing changeover time. I beleive the biggest hurdle is the solderability and acceptance of upside down resistors. Do upside-down resistors bother you?

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Stephen

#23314

bulk feeding chips | 7 February, 2003

I don't think it's possible for a turret machine, but I seem to remember some sales guy talking about a camera on his machine that did look at the part before it picked it up.

As far as bulk feeding goes, how would you ensure the resistors are right side up? I would not want to run a board with half the resistors unreadable. Also at one place I worked we had a board where two placements had to be upside down. We were never really told why but I understood it was not to hide the value but for some electical reason to do with the coating on the resistor. shrugs.

Where I am now is extreme high mix/low (but growing) volume. The only thing that lets us, keep up is lots and lots of dedicated parts that never come off the chipshooter.

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#23328

bulk feeding chips | 10 February, 2003

The Universal chipshooter (Sanyo) has automatic X-Y pick-up correction as standard. Are the upside-down resistors an issue for inspection purposes? Do you use AOI? Can you really read markings on 0402 resistors?

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#23354

bulk feeding chips | 12 February, 2003

Greg, you pointed out yourself the many advantages of bulk feeding. I would like to mention that the higher component accuracy and the feeding track accuracy of the bulk feeder contribute to an improved pick failure rate of small ( 0402�s ) components. I can�t provide actual data, because bulk case users went off shore with their manufacturing, but I believe that the costs are already justified with fewer re-works. Stefan

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#23387

bulk feeding chips | 13 February, 2003

So, to really get reliable pickup rates from new bulk feeders, I just need to replace all the chip shooters we have with more recent ones with pickup correction capability. So where is the saving? ;-)

-Upside down resistors? not an issue. so what if you can't read the value? Chip capacitors have no markings. Is the error rate greater for chip caps than chip resistors? I don't think so. We had a long discussion (read "fight") about one in a million upside down resistors. They (the powers that be)wanted QC to desolder them and put them the right way... well, reliability went down, just because a $.0001 resistor could not be read... once the placement is proven and the empty reel replacement procedure is followed, there is no reason to worry, IMO.

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#23442

bulk feeding chips | 20 February, 2003

Claude, I know alot of equipment manufacturers that would like to talk to you about replacing all of your chipshooters! Of course, this will never happen. There probably won't be any sold until all of the used chipshooters are absorbed from the used market. Anyway, bulk feeders on chipshooters is not usually acceptable because the components get shaken too much on the feeder tables causing blackening of the terminations. I was speaking more about the future of bulk feeding and its acceptance on the faster more flexible gantry machines. You say upside down resistors is not an issue. Is one in two (50%) upside down not an issue as well as one in a million? This is one of the major hurdles to implementing bulk feeding on new applications. Can anyone else comment on this?

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#23451

bulk feeding chips | 21 February, 2003

Why don't the component manufacturers simply mark the values on both sides of the resistor? Can't be that difficult.

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genny

#23458

bulk feeding chips | 21 February, 2003

Sure they'll do it...If you're willing to pay double or triple the cost. It might not be as easy as you think. the value is usually marked in white over the black carbon area that actually is the resistor. Underneath is just the white ceramic carrier for the carbon. So the opposite side would have to use a different colour ink to show up.

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#23466

bulk feeding chips | 21 February, 2003

Has anyone actually seen 0402 or 0201 part with the value on it? I haven't. So what would be the big deal if these parts are placed upside down. The only difference I have noticed is usually on a resistor one side is black and the other is white and it's a non-issue with caps.

Just my $0.02

James

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#23527

bulk feeding chips | 26 February, 2003

Are the markings on resistors the actual value? Do AOI machines look for these markings or do they just look to see if a component is present and placed well? Can anyone attest to the solderability of upside down resistors? Can anyone argue that upside down resistors are a problem?

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#23536

bulk feeding chips | 26 February, 2003

Q1: Are the markings on resistors the actual value? A1: Generally, resistor marking indicates the value of the device, where the first two digits are the value and the third digit is the multiplier.

Q2: Do AOI machines look for these markings or do they just look to see if a component is present and placed well? Q2: Some do, some don't. As Mike and the boys said once, you get what you pay for.

Q3: Can anyone attest to the solderability of upside down resistors? A3: Upside down resitors [and capcitors] solder fine.

Q4: Can anyone argue that upside down resistors are a problem? A4: Sure, but on balance, in most cases it's not worth reworking. IPC-A-610C calls this a 'process indicator' for Class 2 and 3 that wouldn't support rework. If the long term reliability of the component was a concern, consider that the best option is to orient up if it by process.

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kenBliss

#23680

bulk feeding chips | 6 March, 2003

gregp

Your question started out asking about the advantages of bulk feeding. Based on the discussion it all comes down to costs. I offer another perspective that I believe is extremely relevant.

Any advantage in manufacturing has to come down to making more profit by either reducing true costs that actually show up on the financial statement or increasing output or increasing sales assuming you can sell the additional capacity in the same given period i.e. one month.

To cut costs you have to remove labor from the facility or shut down a line. Rarely is part cost reduction going to make a big impact although cost reduction is always an issue.

Increasing output and thereby reducing costs is frequently overlooked, even though its impact is huge. Most production lines I have seen even today have way more down time during changeovers and reloads than anyone on the line wants to admit.

If your pick and place machine is down more than 15 minutes per complete changeover with 50 feeders you need to change your method to prestaging your feeders off line so that you simply swap out feeders on the machine. This typically takes no more than 20 seconds per feeder. If your current method is taking longer, give me a call and I will walk you through how simple this is and it definitely is the best KISS method out there.

The only thing I can see bulk feeding would do for you is so you can pour more components into the feeder while the machine is running and thereby eliminating downtime, provided you only make one product day in a day out.

Labor is a true costs but the total cost for the line to sit there is way more per hour. The goal is to maximize uptime and therefore make more profit not worry so much about labor. If your plant produced 20% more product without adding one dime of operation expenses, imagine what that would do to profits. It can be done very easily with no risk with this method.

Ken Bliss kbliss@blissindustries.com

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