Manufacturing / Production Technology, Hardware & Services


NPL defect of the month

11 May 2011 Manufacturing / Production Technology, Hardware & Services

The accompanying optical image shows a side view of a chip scale package (CSP) with open joints – the gold pads have not been wetted during reflow soldering. Close examination shows the process to not be in control with poor solder paste printing leading to pads not covered with paste. The solder paste was found hanging up in the stencil apertures during process review. With no paste there would also not be any flux medium to aid reflow in an air environment.

It is possible, if the balls, pad and a nitrogen environment were being used, that reflow and wetting may have occurred, masking the root cause. The problem is related to poor printing, which may be caused by the design of the pad or stencil, poor printing parameters or blocked stencil apertures. The process needs to be reviewed and corrective action put in place; in-process inspection and training may also be beneficial.

This month’s defect video considers the problem of pad cratering. As always, it can be viewed at www.dataweek.co.za/video





Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

What differentiates EMS companies
EMP 2020 Electronics Manufacturing & Production Handbook, Omnigo , Editor's Choice, Manufacturing / Production Technology, Hardware & Services
One of the major factors that differentiate electronics manufacturers from each other is the quality of the product that they deliver to the client and the time frame that they deliver the product within.

Read more...
How to use spot mask for wave soldering and conformal coating
EMP 2020 Electronics Manufacturing & Production Handbook, Testerion , Editor's Choice, Manufacturing / Production Technology, Hardware & Services
Mask is applied over the open through-holes on a circuit board in the wave soldering process to make sure they stay open. This is necessary because without mask, any contact area on the bottom of the PCB will be fluxed and subsequently soldered.

Read more...
Next-gen UV cure conformal coatings increase performance and speed up production
EMP 2020 Electronics Manufacturing & Production Handbook, Vepac Electronics , Editor's Choice, Manufacturing / Production Technology, Hardware & Services
Electronic circuits are becoming ubiquitous in modern life. Everywhere one looks, more and more processes that were once isolated and manual in nature, are being automated and now connected as the Internet ...

Read more...
Implementation of environmentally sound cleaning
EMP 2020 Electronics Manufacturing & Production Handbook, Quamba Technologies , Editor's Choice, Manufacturing / Production Technology, Hardware & Services
The number of cleaning machines to be acquired was estimated based on the substrate surface that would need to be cleaned in the course of one year, adding a safety margin of 30%.

Read more...
Process defect guide on QFN/LGA and bottom mounted components
EMP 2020 Electronics Manufacturing & Production Handbook , Editor's Choice, Manufacturing / Production Technology, Hardware & Services
A guide by Bob Willis of assembly defects that can occur with these components, which should help newcomers and expert users alike.

Read more...
Materials measurement in situ brings about innovative solutions
EMP 2020 Electronics Manufacturing & Production Handbook, Techmet , Manufacturing / Production Technology, Hardware & Services
Insituware integrates hardware and software technology to enable the rapid assessment of materials during use. It combines advanced analytical sensors, smart devices, and intelligent cloud-based information ...

Read more...
Smart factory starter kit
EMP 2020 Electronics Manufacturing & Production Handbook, Techmet , Manufacturing / Production Technology, Hardware & Services
Around the world, tens of thousands of factories are considering converting their existing factory into a smart factory, or at least smarter. Many executives find this task overwhelming and fraught with ...

Read more...
Equipment selection guide
EMP 2020 Electronics Manufacturing & Production Handbook , Manufacturing / Production Technology, Hardware & Services
Smart factory starter kit    Solder paste printer    New premium Yamaha solder paste printer    Screen printer with fully automatic changeover    Award-winning component mounter    6-axis soldering robot    Flexible ...

Read more...
Solder paste printer
EMP 2020 Electronics Manufacturing & Production Handbook, Truth Electronic Manufacturing , Manufacturing / Production Technology, Hardware & Services
In the solder paste printing process, the printer is crucial for achieving desired print quality. Desen’s advanced automatic in-line solder paste stencil printers offer some of the best accuracy and reliability ...

Read more...
New premium Yamaha solder paste printer
EMP 2020 Electronics Manufacturing & Production Handbook, Truth Electronic Manufacturing , Manufacturing / Production Technology, Hardware & Services
Yamaha Motor’s new premium printer, the YSP10, is compatible with full automation of changeover work and delivers the world’s fastest level tact time. The YSP10 is the successor to the YSP, a high-end ...

Read more...