SparkFun Forums

[crocu]

Hello

I would like to built a 18F97J60 board, but this Pic is TQFT 100 package and not easy to solder on a home made board without special SMT tools. ( too thin pins )

Is there some adaptors available on the market for this package, or maybe a way build home made board with that Pic ?


Your experience will be much appreciated,

[Shifted]

TQFP can be soldered by hand, spark fun has a great SMD soldering tutorial in their tutorials section.

We solder 208 pin PQFP with fine pitch by using a hot air rework machine where I work, we've soldered 144 pin TQFP's by hand with a fine tip solder iron on occasion.

[henryhallam]

You don't even need a fine-tipped soldering iron, any iron will do. You just need solder and desoldering braid. Flux helps. A good magnifying glass or microscope is almost essential.

Apply flux. Position the chip correctly (the hard part). Using two pairs of tweezers and some kind of hands-free magnifying device is the best way. Optionally tack one corner pin down with solder. Cover one whole row of pins with lots o' solder. Repeat for the other 4 rows, then use braid to remove it, leaving a nicely soldered chip! Inspect with the magnifying glass for shorts and open pins (poke each pin with tweezers, if it moves it's not soldered).

On the other hand, removing a TQFP without hot air or IR is very difficult.

[leon_heller]

Removing chips is very easy with ChipQuik.

Leon

[crocu]

Ok for soldering method, but how should i get a PCB with such thin wires without PCB machine ?

is it possible to make it at home ?

I often make home PCBs but with regular components, not SMT ...

[leon_heller]

I don't have a problem making PCBs for fine-pitch devices.

Leon

[crocu]

You must be very experienced, i guess UV exposition must be well calculated, isn't it ?


is there 100% fully working method to succeed with thin PCB wires ?

[Philba]

there are a number of web sites that can take you through making PCBs at home. There are two ways people use:
- photo exposure
- toner transfer
photo will get you finer lines and I know people have done QFNs that way. Toner transfer is a bit harder to get to work for fine pitch but it is possible.

I suggest you use google...

[leon_heller]

Once the process is optimised it works every time.

Leon

[winston]

I use toner transfer for home made PCBs.

Here is a picture of a breakout board I made for a TQFP-100:

http://spectrum.alioth.net/doc/images/2 ... eakout.jpg

The decoupling capacitors are 0603 size, also hand soldered.

[crocu]

This a very good board,

would you please accept to share the PCB template ?

[Philba]

I use toner transfer for home made PCBs.

Here is a picture of a breakout board I made for a TQFP-100:

http://spectrum.alioth.net/doc/images/2 ... eakout.jpg

The decoupling capacitors are 0603 size, also hand soldered.

Nice work Winston. Xilinx says to use 4 layer boards but your's is obviously 2 layer (at most). Have you had any problems from that?

[silic0re]

Also, thought I'd jump in here to note something I've had lots of success with. If you'd rather spend the $5 on a complete breakout board with soldermask and a ground plane, instead of copper clad, toner transfers, and etching chemicals, I've had a lot of luck with Schmartboards:

http://www.schmartboard.com/

They have boards for many parts in many pitches, and have even started making BGA breakouts recently. I have used their normal, cheaper boards (not the EZ ones) with a little bit of solder paste, and it works like a dream.

[leon_heller]

CPLDs will generally work OK on single-sided boards. I often use them on similar home-made PCBs. It depends on the speed and what is on the outputs.

Leon

[crocu]

Thank you very much silic0re for this link.

It is exactly what i'm looking for .
However, board cost about 9$ and shipping cost ~ 75 $ for France !
Is there a cheaper place to order ?


For now, i need to find a hand soldering method for SMT
What will you suggest me to get best results : iron, if so which one ?

or maybe hot air station ( much expensive )

Many thanks for your experience,