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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


SPI Programming

Views: 3654

#80809

SPI Programming | 31 July, 2018

A question for those that carry out SPI.

How do you program? Do you take CAD data for the card which will provide a 1-1 pad outline or do you use the stencil data for the program is the actual tool used to determine the paste volume (Aperture reductions etc.).

I’m interested as in my view with CAD the SPI would be looking for the maximum amount of paste deposited determined by X, Y and Z, but the apertures have been reduced by a certain degree so the paste deposit would be less. Would you then have to ‘tweak’ the program for the deposits to ensure its correctly measuring what has been deposited? Or would you use the stencil data to create the program which would have any changes and aperture reductions already applied therefore no ‘tweaking’. Perhaps the amounts are so small not to make a difference or can be lost in the tolerances applied?

What are your opinions on this what do you find give the best results that can be relied on?

Many thanks in advance.

Cheers, Mark

reply »

#80810

SPI Programming | 31 July, 2018

Paste release is coming from your stencil, so the checkplot is your best reference.

reply »

#80888

SPI Programming | 14 August, 2018

Hello, Mr. Evtimov is correct. Always use data from stencil. All new SPI machines are pretty easy to operate with. You load stencil data, add you CAD data and then adjust your tolerances accordingly.

reply »

#82068

SPI Programming | 27 February, 2019

HI, we're starting to look into 3D SPI and although we always have stencil data we hardly ever get CAD. Will that prove a big problem or in your experience is it just load the stencil data and compare deposits to expected? Thanks, Rob.

reply »

#82069

SPI Programming | 27 February, 2019

Hello, not at all. Usually you can create programs without CAD data or any text files in my experience. Software just names the pads one by one.

reply »

#82070

SPI Programming | 27 February, 2019

Cheers Buckcho, thanks for the quick response.

reply »

#82073

SPI Programming | 27 February, 2019

No problem, mate. Just when you look for SPI ask the suppliers this question to be sure.

reply »

#82110

SPI Programming | 5 March, 2019

Rob,

you can always create a program and inspect the paste with your Checkplot. If you want to take it further though, you will need a centroid file. With centroid file you can lock pads to belong to a reference designator. When you do so you will now have tracebility and will be able to create meaningful reports. In my opinion you should use the full capability of the machine, so try find and attach a centroid file(may be from your pick and place machines).

reply »

#82119

SPI Programming | 7 March, 2019

Thanks Evtimov, what are you using out of interest?

reply »

#82120

SPI Programming | 7 March, 2019

Hello, what do you mean by using? Machine or what kind of file? Btw if you have simple panels(boards) you can easily make your own cad data.

reply »

#82133

SPI Programming | 8 March, 2019

Rob, I have done it different ways. For the centroid you can do offline CircuitCAM or Valor or even pure Excell. I have used even pick and place machines files to extract data for AOI/SPI programming. These locations and coordinates are already there. I used Mirtec SPI machines - you load checkplot then centrroid and than you connect apertures to reference designators. Very easy programming - it requires no more than10min on the machine.

reply »

#82134

SPI Programming | 8 March, 2019

Apologies, both, I meant machine.

reply »

#82136

SPI Programming | 9 March, 2019

Hi, Rob. I have used Parmi and Koh Young SPI. Both have epmSPI software in which you load stencil gerber, load cad data(if you want) connect the pads to the designators, point fiducials and done. Can take from 10-15 up to 30 minutes, depending on how well you operate with the software. It is relatively easy, even the software has a wizard that tells you what steps you have to do. This is done also offline, so that the time you spend on the machine for a new program is 10-15 minutes.

reply »

Led testing color sensors

 Reflow System