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Jan Waclawek
03/03/12 08:41
Read: 557 times
Bratislava
Slovakia


 
Msg Score: +1
 +1 Good Answer/Helpful
#186388 - QFN is "lead-less"
Responding to: Richard Erlacher'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

List of 21 messages in thread
TopicAuthorDate
Precision32 - SiLabs jumps on Cortex-M3 bandwagon      Andy Neil      03/03/12 05:54      
   QFN indicates PLCC, doesn't it?      Richard Erlacher      03/03/12 08:15      
      QFN is "lead-less"        Jan Waclawek      03/03/12 08:41      
         harder to mount      Andy Neil      03/03/12 08:49      
            Glue      Per Westermark      03/03/12 09:03      
               Glue and reflow?      Dejan Durdenic      03/03/12 09:10      
                  Cyanoacrylic type glue      Kalpak Dabir      03/03/12 20:26      
                     Is it used in mass production?      Dejan Durdenic      03/04/12 01:55      
                        I was wrong about the glue type for manufacture      Kalpak Dabir      03/04/12 02:38      
                           Nevertheless...      Dejan Durdenic      03/04/12 07:42      
                              Dispense      Per Westermark      03/04/12 07:58      
                                 Again...      Dejan Durdenic      03/05/12 14:13      
               re: Glue      Rob Klein      03/05/12 10:23      
         I hope this becomes standardized ...      Richard Erlacher      03/03/12 15:39      
            Eh??      Andy Neil      03/04/12 12:23      
               It seems that the industry's heading for a consensus      Richard Erlacher      03/05/12 07:39      
            PLCCs marked QFN      Oliver Sedlacek      03/05/12 02:56      
               Anyway,      Dejan Durdenic      03/05/12 14:18      
                  It doesn't have to be a PITA ...      Richard Erlacher      03/05/12 16:30      
                     That's the point!      Andy Neil      03/05/12 17:42      
                        Yes, and your starting point matters a great deal      Richard Erlacher      03/05/12 21:48      

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