SparkFun Forums

[lukelukeluke]

So I believe I have found a easy way to do this. I was too lazy to implement a PID algorithm myself, so I just bought a cheapo Chinese PID controller.

http://auberins.com/index.php?main_page ... ducts_id=4

This particular one can be programmed for all sorts of profiles. I was able to use the alarm outputs to control a convecton fan and the oven light.

Be prepared to spend a few hours reading the manual. It is thorough and correct, but this thing has a LOT of configurability and the way it's presented it pretty dense.

You'd also need an SSR and thermocouple- then you're in business. One thing about the thermocouples on this site- they seem to all have fairly heavy metal fittings on the end. You want something more along the lines of what SparkFun sells- just the bare bead. I was able to rip the fitting off the one I bought from Auber, though I wouldn't necessarily recommend doing that.

[darth442]

What's the state of this project? The v2 kit looks nice, but are there any success stories? Has anybody posted additional example code. I've probably just missed the post. Could somebody point me in the right direction? Thanks!

[mooreaa]

On the topic of reflow ovens, I would like to find out if this oven method is good enough for doing very small parts with pads on the under side. In particular, there are many parts I cannot use right now that come in packages whos pads are on the bottom of the chip (BGA, LGA, DFN). I would like to be able to lift this restriction from my designs, and am wondering if a low cost oven reflow method would allow me to use these parts. Or for such parts is a professional oven required?

The cost of these parts are also much more expensive, so if the process has a moderate failure rate, it would almost be cheaper to have them professionaly placed on my prototypes.

Basically it comes down to the unit cost and I am not quite sure how much that is.

Are stencils required? Thats $150.

Do I need to use a batch of solder paste each time? How much does that cost? As much as $50 after shipping?

Basically it looks like each run with a stencil would cost about $200. That means if I had to do two batches of the same board, the repeating cost would be the solder paste @ $50. If I mess up, it would be the cost in parts for that entire board.

It starts to approach the cost of having the parts professionally placed. What are your suggestions and how do you recommend working with small parts? Prototyping already requiers a PCB, how can I start using BGA, LGA, and DFN parts effectively in my designs?

[mooreaa]

Hmm after looking at this issue and staring at my ripped apart toaster for a couple weeks, I ran across this:

http://cgi.ebay.com/NEW-SMD-BGA-IC-Desk ... dZViewItem

I guess that price range may be out side the budget for a lot of people, but this seems like a much cheaper solution to getting a functional reflow unit.

The question is does anyone have experience with these and have any comments suggestions on using these units?

[hooziewhatsit]

On the topic of reflow ovens, I would like to find out if this oven method is good enough for doing very small parts with pads on the under side. In particular, there are many parts I cannot use right now that come in packages whos pads are on the bottom of the chip (BGA, LGA, DFN). I would like to be able to lift this restriction from my designs, and am wondering if a low cost oven reflow method would allow me to use these parts. Or for such parts is a professional oven required?

The cost of these parts are also much more expensive, so if the process has a moderate failure rate, it would almost be cheaper to have them professionaly placed on my prototypes.

Basically it comes down to the unit cost and I am not quite sure how much that is.

Are stencils required? Thats $150.

Do I need to use a batch of solder paste each time? How much does that cost? As much as $50 after shipping?

Basically it looks like each run with a stencil would cost about $200. That means if I had to do two batches of the same board, the repeating cost would be the solder paste @ $50. If I mess up, it would be the cost in parts for that entire board.

It starts to approach the cost of having the parts professionally placed. What are your suggestions and how do you recommend working with small parts? Prototyping already requiers a PCB, how can I start using BGA, LGA, and DFN parts effectively in my designs?

Yes, a cheap, err, inexpensive reflow oven should work well with those pin packages.

You can also check out www.smtstencils.com for inexpensive stencils as well. Stencils aren't required if you can put a consistent amount of paste on the pads. For a prototype I personally don't bother with stencils until I know the design works, and is done changing.

[mooreaa]

Got a few questions along the lines of reflow.

1) How do you handle components on two sides?

2) Can you recommend some places to get solder paste and related chemicals for the process?

3) Can you recommend any additional tutorials, videos, reading etc?

I am trying to jump into this process head first and am looking for any advice that I can get.

[Dutch2]

I've found this place, they seem to have a lot of interesting things:

http://www.stencilsunlimited.com/index.php

they have a toaster oven controller and even sell an "upgraded" toaster oven:

http://www.stencilsunlimited.com/tools_ ... sories.php

And the home of the $325 stencil printer:

http://www.madelltech.com/m2.html

D2.

[corvette123]

heres one reflow controller with software too

www.thesiliconhorizon.com

[ohararp]

Okay,

So after about 2 years of using a hot plate to make boards I finally had to make a 2 sided pcb and needed a reflow oven. I went to Target and picked up this Sweet Oster 6-Slice Toaster Oven. The cool thing about it is that it has a glass top! You can easily check on the progress of your boards through the window!

I set the temp to 420F and place the board on the inside rack. I usually keep both the top and bottom heating elements on. But do place both the rack and the "cookie sheet" below the pcb. I did 20 panels of 4 pcbs last night with no problems.

If you are looking to make stencils for your design we are now offering a service similar to the pololu folks. However, we are offereing a $20 flat rate and allow you to do multiple designs. Only limitation is that the design fit into a 8.5"x11" area. You can check out details at www.ohararp.com/Stencils.html

[corvette123]

hey thats some cheap stencils!!!

whats the smallest pitch parts your stencils can do??

[ohararp]

From the stencils page...

CAPABILITIES - 15 mils/.38mm pitch resolution
Our laser uses a 1.5" Focus Lens to produce the smallest spot size possible. To this end we can cut surface mount pads that are 15 mils x 15 mils or larger.

We can pretty much do any package. However, high pin count TQFP 64 pin and higher packages cause some problems since they require long thin pads. These pads require resizing since they fall below the pitch specs.

Otherwise, if you have had stencils cut with pololu we can match their specs no problem.

[corvette123]

hey i notice youre in the reserves??

i just got out a little while ago...

i spent 2 years in iraq with the 3rd Armored cav...

( and thats one reason im jealous of sparkfun is becuase they are in beautiful colorado!!!)

i miss colorado springs.... ft carson is a wonderful base....

colorado is a wonderful place to live.

sooo much offroading and mountain climbing...

hmmm longs peak trail outside of denver in RMNP...

ahhhh colorado.

8) 8) 8) 8) 8)

but anywhoo..

did u make it to the sandbox??

i was in OIF 1 and OIF 3....

nice to see another military member here 8) 8) 8)

[corvette123]

well out yes but not "technically out"..

im still an inactive reservist until almost 2010!!!!

hahahaha

so i guess im not really out.

i went to a muster last year though

thought i was gonna be called up for sure this year... but it didnt happen.

im sure there will be another muster mid this year.

[corvette123]

and my old unit the 3rd ACR is in iraq right now for the 3rd (yes thats right 3rd) OIF deployment!!

i kind of feel guilty like i should be there too...

[ohararp]

Don't want to hijack this thread...we should talk offline.