BEST'S QFN REWORK SERVICES CAN SAVE YOUR DESIGN AND SAVE YOU MONEY

Repeatable, reliable, and consistent QFN rework takes advanced processes and a high level of skill. QFN rework may require:

• Designing Custom Stencils & Apertures
• Solder Mask Repair
• Bonding New Pads to the Board

The right QFN rework process will bump the pads on these leadless devices, making rework and placement easier. Finally, the integrity of the QFN rework must be assured using endoscopic and X-Ray inspection of the joints.

HOW BEST'S QFN REWORK SOLVES YOUR PROBLEMS

A successfully executed QFN rework process may save you weeks of lead time and a considerable amount of money, allowing you to meet your customer's delivery requirements when no other process can. BEST did just that for a large Tier II automotive supplier, who came to BEST needing several hundred very complex boards with QFNs needing replacement in a short period of time. If you need to make sure that hard to get components are properly salvaged from PCBs BEST is your resource for carefully and properly salvaging QFN components.

BEST developed QFN rework profiles for the board, and then proceeded to complete a risk analysis, PPAP, FMEA, control plan, and process flow diagram. Due to the customer's documentation requirements and automotive industry protocols, these items were a core part of completing the job.

After the client signed off on the procedure, BEST completed the QFN rework with a 99% successful first pass yield. The QFN parts were "bumped" using BEST's patented StencilMate process, then placed onto solder paste printed patterns on the circuit board. Processing happened within the space of a few short days – which was necessary to satisfy existing delivery commitments. The customer came to BEST after the QFN rework process was developed and audited both the specific process and the quality management system.

THE BEST TECHNICIANS AND TOOLS FOR THE JOB

BEST has extensive experience in developing rework solutions for QFNs, LGAs as well as other bottom terminated components. In fact BEST has been awarded a number of patents for its innovations. Among other techniques, BEST's patented StencilMate™ process can significantly ease the placement and reworking of leadless devices.

Correct solder paste printing of PCB land areas is the key to a successful rework. Our engineers understand the design of proper apertures and stencils for QFN and LGA rework, even when the device uses large ground planes. Small package size QFN rework are no trouble either -- they've successfully handled challenging packages as small as 1x2mm.

Repairing damaged solder mask is second nature to our experienced repair technicians. Any missing or damaged QFN pads are replaced in a procedure that follows IPC recommendations; specially designed copper replacement pads are bonded to the surface of the board using two-part epoxy.

STATE-OF-THE-ART EQUIPMENT ENSURES YOU GET THE BEST RESULTS

BEST uses a number of high end rework systems that are used to perform QFN rework. All QFN rework as well as other placements are done by technicians who have been IPC certified and specifically trained in rework of leadless devices. Each job is inspected using the most modern quality control tools including X-ray imaging and endoscopes. We return each job to you with an accompanying CD of the appropriate X-ray images.

If necessary, BEST can analyze joint metallurgy, inter-metallic junctions, and solder joints using our advanced analytic laboratory whether or not a QFN has been reworked.

REWORK SERVICES WE OFFER

BEST's portfolio of services includes:

√ Removal of Leadless Components such as LGAs
√ Site Prep
√ QFN Part Salvaging
√ Component Replacement
√ X-ray and Optical Verification
√ Circuit Design Changes
√ Repairing of Pads,Traces & Masks