BEST has experience in developing and patenting sound rework solutions for QFNs and other bottom terminated components.. Our engineers have developed better processes to make QFN rework more repeatable, consistent and reliable. BEST has developed a patent-pending QFN rework process
for simply bumping the pads on leadless devices thereby making them easier to place and rework. We have experience in the proper aperture and stencil designs for the rework of QFNs. Our staff has been challenged with the rework of packages down to 1 x 2mm in size!
We have numerous "high end" rework systems which we use to perform QFN rework and have the right experiences and the right tools for the job. Rework or initial QFN or other bottom side termination component placements for prototype work is performed by IPC-certified technicians who have been specifically trained for leadless device rework and who inspect their work with the latest in QC tools such as endoscopes and X-ray imaging. Each job is returned to you with a disc of the appropriate QFN x-ray image.
Repair of damaged solder mask between QFN pads is a task our experienced repair technicians routinely face. Damaged or missing QFN pads are replaced by following an IPC recommended procedure. This procedure uses specially designed replacement copper BGA pads that are bonded to the board surface with a 2-part epoxy.
The key to successful QFN and other bottom side termination component rework is the proper solder paste printing of the land areas. BEST has the experience to properly design the stencils, even when large ground planes exist on the device. In addition, BEST has the ability to bump the lands of the devices using its patented StencilMate stencil printing technique!. BEST has the ability to analyze the metallurgy, size of the intermetallic and the composition of solder joints formed by the rework process with our analytical lab capabilities.
Recently a large automotive Tier II supplier came to BEST in order to reliably rework QFNs. After developing a profile, BEST completed a PPAP,a risk analysis, process FMEA, process flow diagram and control plan all which were required as part of the customer’s documentation requirements which follow automotive protocols. The rework itself proved effective with a 99% first pass yield as the “bumped” parts were placed into solder paste printed patterns on the PCB. Several hundred complex boards were processed over a few short days to get the customer delivery commitments met. After the process was developed, the customer came in to BEST to audit our quality management system and the specific process.
BEST provides services including leadless component removal, site prep, replacement, salvage, x-ray or optical verification, circuit design changes, as well as pad, trace and mask repair. Our professional solder skills instructors can offer skills development classes in QFN rework.
BEST provides services including leadless component removal, site prep, replacement, salvage, x-ray or optical verification, circuit design changes, as well as pad, trace and mask repair.
Our professional solder skills instructors can offer skills development classes in QFN rework.
We have numerous "high end" rework systems which we use to perform QFN rework and have the right experiences and the right tools for the job. Rework or initial QFN or other bottom side termination component placements for prototype work is performed by IPC-certified technicians who have been specifically trained for leadless device rework and who inspect their work with the latest in QC tools such as endoscopes and 
After developing a profile, BEST completed a PPAP,a risk analysis, process FMEA, process flow diagram and control plan all which were required as part of the customer’s documentation requirements which follow automotive protocols. The rework itself proved effective with a 99% first pass yield as the “bumped” parts were placed into solder paste printed patterns on the PCB. Several hundred complex boards were processed over a few short days to get the customer delivery commitments met. After the process was developed, the customer came in to BEST to audit our quality management system and the specific process. 
