Difficultly in using surface mount components

Armageddon

I noticed that FTD has released a new USB converter chip that requires very few external components.· Unforuntatly, the chips are only only available in surface mount versions.·· I'm a hobbiest and don't have industrial equiptment.·· I found a company that sells surface mount to through hole converts cheap.·· They have two versions.· A socketed one designed for programmers on the order of $100 a piece and solder on converters for aprox $10.·· Has anybody on this board tried hand soldering surface mount components?· I'm alittle concerned about the SSOP and QFN packages because the pin pitch is smaller them 1mm!

Also if I lay out my own boards with Eagle, is solder mask essential to getting surface mount components correctly mounted?·· I've noticed with some of the board houses adding a solder mask triples the cost of the board.

Forrest

Adding soldermask to the board should NOT add more than 20% to the cost of the board - if it does, shop elsewhere.

Here's a fully assembled FTDI FT232RL breakout board with a USB connector and for $14.95 www.sparkfun.com/commerce/product_info.php?products_id=718#

Armageddon

Thanks for the info. I'll shop around for cheaper board houses( I currently use www.pcbexpress.com ). I'll also look into the breakout board, but my project has limited space so it may not be possible. I'm currently using the LINX USB modules for my projects which cost about the same price as the breakout board you mention. The LINX USB module is just a FTDI chip with some EEPROM and support components. Pre FT232RL technology.

I was kind of hoping for some general comments on using surface mount components without doing reflow. Fewer and fewer components are available in DIP and surface mount is alot smaller so it's something that would be cool to do in general.

bobledoux

I do surface mount for my hobby applications. I make my own circuit boards using the toner transfer process. See pulsar.gs.com for more on that process.

The soldering part requires no more than a small, 15 watt iron with a fine tip, a head mounted magnifying glass, a tube of flux, small braid, and some small diameter solder.

Heavy use of flux is the key. It prevents solder from forming bridges. For very fine pitch IC's solder braid is used to remove bridges.

Start with SOIC chips and 1208 or 0805 size parts. These are easy to work with.

Any recent ARRL Amateur Radio Handbook has basic techniques described under the Construction chapter.

Try this link

http://www.arrl.org/tis/info/pdf/9904033.pdf

Paul Baker

Armageddon said...
Thanks for the info. I'll shop around for cheaper board houses( I currently use www.pcbexpress.com ).

The cheapest Ive found thus far is Sparkfun's www.batchpcb.com, its a $10 fee then $2.50/sqin which can be any number of boards. Its cheaper going elsewhere when you have large numbers of the same board, but this is the cheapest place Ive found for single count quantities.

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