| ??? 03/03/12 15:41 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#186388 - QFN is "lead-less" Responding to: ???'s previous message |
http://en.wikipedia.org/wiki/Quad...ds_package
QFN is one of those modern "lead-less" packages, making them easier/cheaper to manufacture but harder to mount (especially manually) and test. The difference is in the way how the contacts are formed - in PLCC, they are part of the metallic leadframe, protruding from the side edge of plastic package and bent below it to form the "J-shape" lead; in QFN they are just metal pads on the bottom surface of the plastic package. The pitch is also denser on QFN as compared to PLCC, often 0.5mm (compared to 1.27mm for PLCC). JW |
| Topic | Author | Date |
| Precision32 - SiLabs jumps on Cortex-M3 bandwagon | 01/01/70 00:00 | |
| QFN indicates PLCC, doesn't it? | 01/01/70 00:00 | |
| QFN is "lead-less" | 01/01/70 00:00 | |
| harder to mount | 01/01/70 00:00 | |
| Glue | 01/01/70 00:00 | |
| Glue and reflow? | 01/01/70 00:00 | |
| Cyanoacrylic type glue | 01/01/70 00:00 | |
| Is it used in mass production? | 01/01/70 00:00 | |
| I was wrong about the glue type for manufacture | 01/01/70 00:00 | |
| Nevertheless... | 01/01/70 00:00 | |
| Dispense | 01/01/70 00:00 | |
| Again... | 01/01/70 00:00 | |
| re: Glue | 01/01/70 00:00 | |
| I hope this becomes standardized ... | 01/01/70 00:00 | |
| Eh?? | 01/01/70 00:00 | |
| It seems that the industry's heading for a consensus | 01/01/70 00:00 | |
| PLCCs marked QFN | 01/01/70 00:00 | |
| Anyway, | 01/01/70 00:00 | |
| It doesn't have to be a PITA ... | 01/01/70 00:00 | |
| That's the point! | 01/01/70 00:00 | |
Yes, and your starting point matters a great deal | 01/01/70 00:00 |