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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


SMT Production Tips

Views: 7753

Right folks, i'm sure we have a wealth of experience on here... - Oct 27, 2011 by SJS2303  

#65288

SMT Production Tips | 27 October, 2011

Right folks, i'm sure we have a wealth of experience on here that needs to be tapped into!

If you had to give on piece of advice to a fellow SMD operator/production engineer what would it be?

I'll get it started, for me you must not over edit packages. If it falls outside of convention create a new package and name it appropriately for its anomaly, do not edit standard packages as they are standardised for a reason!

reply »

#65299

SMT Production Tips | 27 October, 2011

What equipment are you talking about? That would help My piece of advice would be clean, clean and clean then clean some more

reply »

#65302

SMT Production Tips | 28 October, 2011

I was talking about pick and place machines.

When you say clean what are you talking about?

reply »

#65303

SMT Production Tips | 28 October, 2011

Always follow the process!

reply »

#65307

SMT Production Tips | 28 October, 2011

First, make sure your pick and place programs are built from CAD data and NOT manually at the machine.

reply »

#65309

SMT Production Tips | 28 October, 2011

Make sure your documentation is correct and it matches what you are building.

reply »

#65326

SMT Production Tips | 31 October, 2011

Second, make sure your fiducial data for pick and place programs are built from CAD data and NOT manually at the machine.

reply »

#65345

SMT Production Tips | 2 November, 2011

Hello all do the maintenance when spicified don't put it off have some spare parts on hand keep it clean follow the process ok 4 things

reply »


cs

#65425

SMT Production Tips | 10 November, 2011

Hello!

What do you mean with "follow the process"?

Christian

reply »

#65427

SMT Production Tips | 10 November, 2011

Third, if component placement is off, fix the machine (i.e. calibrate, check cleanliness of lenses and sensors, damaged nozzle) and not the CAD locations.

reply »

#65443

SMT Production Tips | 14 November, 2011

Christian

We'd guess that Evtimov and Wrongway mean that you should heed the process instructions / work instructions / process documentation

reply »

#65505

SMT Production Tips | 21 November, 2011

Fourth, if groups of components are off, but all others are on, check for either calibration (one head only) or a damaged nozzle (or similar items).

reply »

#65531

SMT Production Tips | 26 November, 2011

I agree with this post about new and standard component names. Standard components should not be changed outside of perhaps widening the tolerance to accept poorly produced components. By purchasing poor quality/cheep components your purchasing department can make life difficult for assembly or testing departments/workers.

New components should as stated be named so that the new feature is shown in the name. I am currently working on a naming convention similar to the IPC. Using dimensions you can check quickly and include the important geometry are important. In the near future Aoi equipment will be testing in 3D so height information is also important.

Within a company the various departments should work with the same naming convention. Yes, mistakes will happen and someone will need to take some time to maintain consistency of the libraries but the time is worth it.

CAD data is not to be changed in most cases but you must be able to evaluate if the data is original. I work in a company where the data is always suspect to tampering or improper conversion. Customers deliver data without Fiducial mark data, non center-point locations and etc. Some Aoi systems such as Omron will automatically adjust for poor data but do not count on it for most systems. It is important personal dealing with these issues be trained to know why and when to change the data.

As mentioned in the other posts a properly calibrated machine is the first thing to check. With a Viscom Aoi you must be able to change from all perpendicular camera views without a change in the components position being apparent. Most suppliers of smt equipment will supply the operators with a means to evaluate the calibration of the equipment. Deciding who will do the calibration is your next issue.

Namaste,

Kevin Tough

reply »

#65567

SMT Production Tips | 2 December, 2011

Fifth, if an individual component is off, but all others are on, * Go back to the CAD file and find out why the centroid is not correct, and fix it there * Check the feeder calibration, In short, you should never "tweak" your pick and place machines or their programs. Although we will admit that it is easier to "tweak" than fix the source of the problem. [Never save tweaks on the machine.]

reply »

#65613

SMT Production Tips | 9 December, 2011

if you have fine pitch on your board go away from HASL.

reply »

#65665

SMT Production Tips | 15 December, 2011

Sixth, make sure you have a feedback loop. Through the course of fixing problems, make sure the "fix" is incorporated back into program generation. For example, if a part definition is made or fixed, make sure the new definition or fixed part definition is put in a data base that will cause it to be used the next time around.

reply »

#65694

SMT Production Tips | 29 December, 2011

Darpy's offset checking trick: One trick I always use is to make the first two placements in every program the same as the fiducial data picked up from a dummy feeder. These two placements are generally skipped. ** If I do have a problem then I unskip them and do a fiducially corrected scan. ** If it reads the fids ok at fid correction but then doesn't go exactly to the center of the marks that are your two first mount data then your fid data is incorrect and so will everything else will be out. You can also use this method to do a very quick head offset check. Do the fid correction and tell the head you want head N to do the dry placement run (on the dummy placement fids ) if your camera scan has told you the fid data is OK. Eventually I will convince the world that the first two mount data should be your fid data but skipped. You can also check if there is any difference between the two. If there is then someone has changed the fid data, probably because they were too lazy to change the data origin to get the fids right in the middle of the camera/sensor. Bad set up also plays a part. [D Jarvis SMTnet]

reply »

Non-heated dispensing system

PCB X-Ray Inspection