Any tips for 4-layer boards?

[Ioannis]

Thats great news! Now, how are you going to solder components?

Ioannis

[Byte_Butcher]

Thats great news! Now, how are you going to solder components?

I've got some good stout radiator solder and a propane torch.

Actually, I'm modestly well setup to do SMD boards. I have a homemade reflow oven (modified toaster oven) and a cheap hot air rework station.
I've done quite a few small SMD boards but nothing quite as tight as the current one.

Here's a basic PIC controller board with RTC and EEPROM on board. Various versions of it lounge around on my bench, being test beds for assorted projects...





Since this latest board has up to 63 parts on less than 5 square inches, I'll definitely cough up the extra $$ to have silkscreen and soldermask on this one.

I'm glad it all went on 2 layers. I was willing to go to 4, but cheaper is better...


steve

[TinkersALot]

Outside of reading temperatures, that is? Just seems like a pretty beefy processor to read/display temperatures, so am merely curious.

[Byte_Butcher]

Outside of reading temperatures, that is? Just seems like a pretty beefy processor to read/display temperatures, so am merely curious.

Nahhh, you're missing the point!
It's not about displaying temperature.... It's a learning platform!
(that photo looks like it was a learning test for the MCP9800)

It's a board that holds a $3 PIC that has lots of I/O .
It has space for additional EEPROM if you feel like doing some data logging. It's got provisions for a DS1302 RTC if you need real time (to go with your data logging, or whatever?) (if you don't need that junk, don't load it)

It's got a connector to connect to an LCD display so you can... display stuff.
It's got an onboard MOSFET to control the brightness of the LCD backlight.

It's got all the excess I/O ins brought out where they can be used to play with all kinds of sensors or... stuff.

That board is not just about reading/displaying temperature. It's useful for all kinds of tasks!

That circuit board, fully loaded with all the options RTC, EEPROM, Onboard voltage regulator, LCD connector, etc costs about $15.

It's a learning tool for a PIC. What would you like to learn today?



steve

[TinkersALot]

Before anything else: Congratulations and Nice Job! This does look like it was a great learning experience -- especially with regard to re-arranging some parts and getting it to route into two layers. Interesting thread to read as well.

Don't mean to be thick-skulled about the purpose of your efforts. It is a neat board and project.

[Byte_Butcher]

Before anything else: Congratulations and Nice Job! This does look like it was a great learning experience -- especially with regard to re-arranging some parts and getting it to route into two layers.

It was actually a very good learning experience for me.
One of the best things I got from it was learning to use the "rats nest" feature on my PCB software.
The Rats Nest always freaked me out so I left it turned off.
After reading the tutorial that Robert posted the link to, I went ahead and turned the rats nest on... and learned to use it.
It really DOES help a lot in getting the parts laid out better and minimizing the amount of traces that have to wander all the way across the board.

Anyway, I should have boards here by the end of next week to test.
Hopefully there aren't too many mistakes...


steve

[Byte_Butcher]

UPS brought my boards yesterday!
I think I'm starting to really enjoy working with surface mount devices...
There's a certain pleasure in being able to put 63 parts (only 61 loaded in this photo), plus room for connections to the outside world (LCD display, sensors, power, etc) on only 4.5 square inches (29 sq cm) of real estate.

I loaded it up and ran it through the oven last night. Dunno if it WORKS yet, but it *looks* OK so far.



Here's a close up of the solder job. It's hard to resist the temptation to put too much solder on the pads. Just the tiniest bit is plenty. These look pretty good.



Big fun!

steve