Homebrew PCBs

After great success with through hole boards, I have a new project 
starting, one of the components I want to use is the nRF905 from nordic 
semiconductor, the '905 is only available in a QFN package which 
doesn't seem to be the most hobbiest friendly of formats. As far as I 
can tell there are no legs on it...

Is it possible to hand solder one of these, filling in the gap? do they 
make sockets for them (I have found prototype sockets on line but $400-
$500 each they are a bit out of budget)

Any ideas folks?

Anthony

http://www.geocities.com/leon_heller

----- Original Message ----- 
From: "Anthony" <toftat@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, January 25, 2006 3:24 PM
Subject: [Homebrew_PCBs] Making a homebrew board using QFN packages


> After great success with through hole boards, I have a new project
> starting, one of the components I want to use is the nRF905 from nordic
> semiconductor, the '905 is only available in a QFN package which
> doesn't seem to be the most hobbiest friendly of formats. As far as I
> can tell there are no legs on it...
>
> Is it possible to hand solder one of these, filling in the gap? do they
> make sockets for them (I have found prototype sockets on line but $400-
> $500 each they are a bit out of budget)

I have managed to solder the similar packaged ADXL202 onto a home-made PCB. 
It was difficult, though. It helps if you make the pads longer than they are 
on the standard QFN footprint, so that you can get the tip of a soldering 
iron in there.

I tried with the Nordic nRF2401 on a double-sided PCB, but gave up and had 
them mounted by a specialist SMT assembly company. They didn't charge me as 
it was such a small job (it took them about 20 minutes), it was just before 
Xmas, and I'd gone a long way on my motorbike to get to them. 8-) Their 
minimum charge is 50 GBP.

Leon

Not a problem, i have done two boards now with thin QFN (32 and 24 pin i  
think both 0.5mm spacing).
The thermal pad is a bit of a pain though, since one IC needed quite a bit  
of heatsinking. Can't plate vias so i ended up making a large hole and  
filling it with solder. Not ideal but works. Maxim suggests to make a  
large via/hole if you don't need heatsinking, then you can take it off  
with a soldering iron by heating through there.

I solder them by smearing some SMD paste on the board and using hot air  
after careful placement. Works great, bridges can be cleared with solder  
braid, excess solder is pressed out from under the case and beads up at  
the sides. Make the pads longer so that they extend a bit straight outside.

You can even reflow them by putting a soldering iron with a large tip and  
a good sized ball of solder against the top. It will heat through the case  
and melt the solder underneath. Probably useful if there's a bad  
connection.

But, what good is this all when you can't find the part because it got  
lost in the bubbles of the antistatic foam? They already have to put some  
components in SMD reel strips to keep them. Stupid people! why can't they  
use DIL?


ST

On Wed, 25 Jan 2006 16:24:15 +0100, Anthony <toftat@...> wrote:

> After great success with through hole boards, I have a new project
>
> starting, one of the components I want to use is the nRF905 from nordic
>
> semiconductor, the '905 is only available in a QFN package which
>
> doesn't seem to be the most hobbiest friendly of formats. As far as I
>
> can tell there are no legs on it...
>
>
> Is it possible to hand solder one of these, filling in the gap? do they
>
> make sockets for them (I have found prototype sockets on line but $400-
>
> $500 each they are a bit out of budget)
>
>
> Any ideas folks?
>
>
> Anthony
>

> Is it possible to hand solder one of these

Google >"soldering qfn"<. 

--- In Homebrew_PCBs@yahoogroups.com, "Anthony" <toftat@c...> wrote:
>
> After great success with through hole boards, I have a new project

You could reflow it in a wok. Solder paste is (relatively) cheap: $16 at 
http://www.stencilsunlimited.com/solder_products.php. As to skillets being 
less than professional, I would have to agree to the extent that ISO 
certification is unlikely. Otherwise, it works just fine. It's no less 
controlled than hot air, and infinitely better than hand soldering.

----- Original Message ----- 

From: "Anthony" <toftat@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, January 25, 2006 9:24 AM
Subject: [Homebrew_PCBs] Making a homebrew board using QFN packages


> After great success with through hole boards, I have a new project
> starting, one of the components I want to use is the nRF905 from nordic
> semiconductor, the '905 is only available in a QFN package which
> doesn't seem to be the most hobbiest friendly of formats. As far as I
> can tell there are no legs on it...
>
> Is it possible to hand solder one of these, filling in the gap? do they
> make sockets for them (I have found prototype sockets on line but $400-
> $500 each they are a bit out of budget)
>
> Any ideas folks?
>
> Anthony
>
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and 
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>
>
>
>

> They already have to put some components in
> SMD reel strips to keep them.

Tapes are really intended for pick and place machines. But you knew 
that. A cut tape purchase simply means they cut a piece off with the 
quantity you ordered.

> Stupid people! why can't they use DIL?

Then you'll be complaing that your cellphone was too be big...."Why 
can't they make <whatever> smaller?". More than likely, available 
package choices depends on the demand for those packages. 

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> Not a problem, i have done two boards now with thin QFN (32 and 24 
pin i

After more consideration, I am seriously considering getting the MiRF 
devices from sparkfun, that way I don't have to deal with the 
requirements for the RF circuit design either...

Thanks for the responses guys...

--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
wrote:
>
> You could reflow it in a wok. Solder paste is (relatively) cheap: 
$16 at 
> http://www.stencilsunlimited.com/solder_products.php. As to 
skillets being 
> less than professional, I would have to agree to the extent that 
ISO 
> certification is unlikely. Otherwise, it works just fine. It's no 
less 
> controlled than hot air, and infinitely better than hand soldering.
> 
> ----- Original Message ----- 
> From: "Anthony" <toftat@c...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Wednesday, January 25, 2006 9:24 AM
> Subject: [Homebrew_PCBs] Making a homebrew board using QFN packages
> 
> 
> > After great success with through hole boards, I have a new project
> > starting, one of the components I want to use is the nRF905 from 
nordic
> > semiconductor, the '905 is only available in a QFN package which
> > doesn't seem to be the most hobbiest friendly of formats. As far 
as I
> > can tell there are no legs on it...
> >
> > Is it possible to hand solder one of these, filling in the gap? 
do they
> > make sockets for them (I have found prototype sockets on line but 
$400-
> > $500 each they are a bit out of budget)
> >
> > Any ideas folks?
> >
> > Anthony
> >
> >
> >
> >
> >
> > Be sure to visit the group home and check for new Links, Files, 
and 

> > Photos:
> > http://groups.yahoo.com/group/Homebrew_PCBs
> >
> > If Files or Photos are running short of space, post them here:
> > http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>

> You could reflow it in a wok.

Toaster oven would be better. Saw a nice infrared convection toaster 
oven with digital temperature display and controls, if only it was 
programmable.


> Solder paste is (relatively) cheap: $16 

That's $16.00 for 1.2 ounces BTW. 


--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> wrote:
>
> You could reflow it in a wok. Solder paste is (relatively) cheap: $16 
at 
>

----- Original Message ----- 

From: "derekhawkins" <eldata@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, January 25, 2006 12:37 PM
Subject: [Homebrew_PCBs] Re: Making a homebrew board using QFN packages


>> You could reflow it in a wok.
>
> Toaster oven would be better. Saw a nice infrared convection toaster
> oven with digital temperature display and controls, if only it was
> programmable.

Better in what way? If you're buying new, sure, get the toaster oven. I had 
an old skillet on hand, and it stores very compactly. The "face" is open so 
I can readily watch it cook, and even point an IR thermometer at it if I 
want. But I haven't found a need. Medium flame, anywhere in the middle third 
of the dial, gives a usable temp profile.

>> Solder paste is (relatively) cheap: $16
>
> That's $16.00 for 1.2 ounces BTW.

Yup, and it has a shelf life of about a year. 35 grams is more than a 
non-production shop can use in that time. I'll likely throw out more than 
half of it. In the meantime, I gain all the benefits. What can be simpler 
than mashing the tiny parts approximately into place, and then stir frying 
for 4 minutes? (Peanut butter and jelly sandwiches come to mind, but not by 
much.)

> If you're buying new, sure, get the toaster oven.

What's wrong with an old toaster oven if one just happens to have one 
on hand?



--- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> wrote:
>
> Better in what way? If you're buying new, sure, get the toaster oven. 
I had 
> an old skillet on hand, and it stores very compactly. The "face" is

----- Original Message ----- 

From: "derekhawkins" <eldata@...>


>> If you're buying new, sure, get the toaster oven.
> 
> What's wrong with an old toaster oven if one just happens to have one 
> on hand?

Nothing's wrong. Was just wondering what made it better.

On Wed, 25 Jan 2006 18:09:12 +0100, derekhawkins <eldata@...> wrote:

> Tapes are really intended for pick and place machines. But you knew
>
> that. A cut tape purchase simply means they cut a piece off with the
>
> quantity you ordered.

Yes, but they can't simply put them in a box with some antistatic foam  
these days - without the palstic packaging they would get lost.

>
>
>> Stupid people! why can't they use DIL?
>
>
> Then you'll be complaing that your cellphone was too be big...."Why
>
> can't they make <whatever> smaller?". More than likely, available
>
> package choices depends on the demand for those packages.
>

I will never ever complain a phone is too big! If they would just rip out  
all the junk that i don't need and put in a simple circuit that actually  
allows you to call someone there wouold be plenty of space to use "sane"  
smd components. But wait, they did that, and i have such a phone....

ST

> Yes, but they can't simply put them in a box with some antistatic
> foam these days 

Your argument makes sense if you're complaining about a lack of 
package choices and this may have something to do with your 
distributor. If not, then it wasn't economically feasible for your 
preferred package to be manufactured anymore.

Don't get me wrong....I still buy DIP ICs and thru hole components but 
only in quantities for prototype bread boarding. It's SMD all the way 
after that....Smaller and cheaper (in most cases). Heck, we're talking 
things like one hundred .1uf 16V caps for just over a dollar. 

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> 
> Yes, but they can't simply put them in a box with some antistatic 
foam  
> these days - without the palstic packaging they would get lost.
>

I just bought the Sparkfun MIRF units.  They are nice.  I've been
experimenting with cheap RF units and the antenna requirements can
make or break the whole system.  The MIRF have them built in, making
much simplier implementation--once you get past the configuration bits.


--- In Homebrew_PCBs@yahoogroups.com, "Anthony" <toftat@c...> wrote:

>
> After more consideration, I am seriously considering getting the MiRF 
> devices from sparkfun, that way I don't have to deal with the 
> requirements for the RF circuit design either...
> 
>

--- In Homebrew_PCBs@yahoogroups.com, "bob_ledoux" <bobledoux@p...> wrote:
>
> I just bought the Sparkfun MIRF units.  They are nice.  I've been
> experimenting with cheap RF units and the antenna requirements can
> make or break the whole system.  The MIRF have them built in, making
> much simplier implementation--once you get past the configuration bits.
> 
I take it you're referring to the nRF2401A transceiver pair pictured
here:  http://www.sparkfun.com/shop/index.php?shop=1&itemid=396
?
1Mbps is indeed an impressive throughput for $19.95.    What exactly
are you using them for, if you don't mind my asking?

Alan

----- Original Message ----- 

From: "alan00463" <alan00463@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, January 26, 2006 2:28 PM
Subject: [Homebrew_PCBs] Re: Making a homebrew board using QFN packages


> --- In Homebrew_PCBs@yahoogroups.com, "bob_ledoux" <bobledoux@p...> wrote:
>>
>> I just bought the Sparkfun MIRF units.  They are nice.  I've been
>> experimenting with cheap RF units and the antenna requirements can
>> make or break the whole system.  The MIRF have them built in, making
>> much simplier implementation--once you get past the configuration bits.
>>
> I take it you're referring to the nRF2401A transceiver pair pictured
> here:  http://www.sparkfun.com/shop/index.php?shop=1&itemid=396
> ?
> 1Mbps is indeed an impressive throughput for $19.95.    What exactly
> are you using them for, if you don't mind my asking?

I'm using them as well, for a sports training aid, communicating between a 
sensor unit (MSP430) and a processing/display unit (ARM). I'm only using 
them for the prototypes, of course, I'll just use the chips for production.

Leon

On Thu, 26 Jan 2006 02:48:27 +0100, derekhawkins <eldata@...> wrote:

>
> Your argument makes sense if you're complaining about a lack of
>
> package choices and this may have something to do with your
>
> distributor. If not, then it wasn't economically feasible for your
>
> preferred package to be manufactured anymore.
>
>
> Don't get me wrong....I still buy DIP ICs and thru hole components but
>
> only in quantities for prototype bread boarding. It's SMD all the way
>
> after that....Smaller and cheaper (in most cases). Heck, we're talking
>
> things like one hundred .1uf 16V caps for just over a dollar.


Well, i'm all for SMD, but i can see that it will be very expensive to  
make prototypes very soon.
Now you can still sort of find ways to make boards and populating yourself  
for most parts, but i'm really too close to the limits of what i can do  
for comfort here and they are not stopping making things smaller and  
smaller. Power is becoming a real problem - they put 2W losses in a 5x5mm  
thin qfp without blinking an eye - you have TO220 size for that normally.  
If you don't have real good boards with vias and stuff that's turning into  
a real problem. Packages where you could just flange a heatsink on are  
long gone.
If they make the spacing much smaller i simple won't be able to make the  
traces because of underetching, there isn't much headroom left.

What i'm saying is it will be getting too hard to use many parts soon,  
that's all. I would not mind them stopping miniaturization on a package  
level right now, it's plenty small for me. After all, components should be  
made for humans to use, not ants.

ST

They're not made for humans at all anymore. They're made for pick and place 
robots. I just bought a little memory stick at Walmart and it has a clear 
plastic case. Inside I can see surface mount resistors which must only be 
2mm or less long and 1mm wide.

jim ab3cv



After all, components should be
made for humans to use, not ants.

ST

----- Original Message ----- 

From: "Jim Miller" <jtmiller2@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, January 26, 2006 7:48 PM
Subject: Re: [Homebrew_PCBs] Re: Making a homebrew board using QFN packages


> They're not made for humans at all anymore. They're made for pick and 
> place
> robots. I just bought a little memory stick at Walmart and it has a clear
> plastic case. Inside I can see surface mount resistors which must only be
> 2mm or less long and 1mm wide.
>

Murata is producing 01005 capacitors, that's 0.4 mm x 0.2 mm x 0.2 mm!

Leon

Hi Jim,

> They're not made for humans at all anymore. They're made for pick and place
> robots. I just bought a little memory stick at Walmart and it has a clear
> plastic case. Inside I can see surface mount resistors which must only be
> 2mm or less long and 1mm wide.

0603's are 0.060" x 0.030" (1.5mm x 0.75mm) These aren't too bad to deal with.
0402's are 0.040" x 0.020" (1mm x 0.5mm) These are strating to get
tiny, but are pretty standard on cell phone circuit boards. I solder
these very carefully, and try to ensure I have more than one left
because inevitably I'll breath too hard. These are very hard to find
on the floor.

0201's are becoming more popular Grrr. surface tension of the solder
on the tip of your soldering iron is now a pain.

And as Leon mentioned 01005 (half again as big). Thankfully I've never
had to deal with those.

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/

They are for a hot air balloon temperature reporting system.  I use a
Dallas DS18S20 digital sensor to a PIC and then to the MIRF.  The
temperature is transmitted to an LCD in the basket, about 50 feet away..  

I've just received the MIRF's so I haven't finished the software.  

I spent about 100 hours trying to get cheap 433mhz units working well.
 Even with manchester coding and multiple samples I couldn't get
reliable RF transfer.  I did get the units to work by sending a pulse
width modulated signal where the pwm width represented the
temperature.  But because of receiver "switch on" delay I had to
calibrate the unit with an oil bath to translate sent pwm to received
value.

I understand the nRF2401 are becoming widely used for short distance
data transfers.  Each transfer is very few bits, but the rapid update
rate makes it useful for systems like remote keyboards.

Its interesting that Norway, producers of the nRF2401, has a rapidly
growing high tech industry.


--- In Homebrew_PCBs@yahoogroups.com, "alan00463" <alan00463@y...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "bob_ledoux" <bobledoux@p...>
wrote:
> >
> > I just bought the Sparkfun MIRF units.  They are nice.  I've been
> > experimenting with cheap RF units and the antenna requirements can
> > make or break the whole system.  The MIRF have them built in, making
> > much simplier implementation--once you get past the configuration
bits.

> > 
> I take it you're referring to the nRF2401A transceiver pair pictured
> here:  http://www.sparkfun.com/shop/index.php?shop=1&itemid=396
> ?
> 1Mbps is indeed an impressive throughput for $19.95.    What exactly
> are you using them for, if you don't mind my asking?
> 
> Alan
>

> Inside I can see surface mount resistors which must only be 
> 2mm or less long and 1mm wide.

0805 - 2 X 1.25 mm
0603 - 1.6 X .8 mm
0402 - 1 X .5 mm
0201 - .6 X .3 mm

Currently I buy and hand solder down to 0402s (small quantities). 
Down to 0603 is a piece of cake but problem with 0402 is visual 
confirmation of proper solder joint and for that I either use a 
camera (macro shot) or microscope. Just using a DIMM isn't good 
enough.

This is coming from someone who needs glasses in order to read or see 
just about anything properly in a 3' radius. Those with younger eyes 
will be amazed at how something that appears daunting at first soon 
becomes a walk in the park. Many of us can probably recall when 
soldering even a 1206 (3.2 X 1.6 mm) seemed like an impossible task.


--- In Homebrew_PCBs@yahoogroups.com, "Jim Miller" <jtmiller2@c...> 
wrote:
>
> They're not made for humans at all anymore. They're made for pick 
and place 
> robots. I just bought a little memory stick at Walmart and it has a 
clear 
> plastic case. Inside I can see surface mount resistors which must 
only be 

> 2mm or less long and 1mm wide.
> 
> jim ab3cv
> 
> 
> 
> After all, components should be
> made for humans to use, not ants.
> 
> ST
>

----- Original Message ----- 

From: "derekhawkins" <eldata@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, January 27, 2006 3:56 PM
Subject: [Homebrew_PCBs] SMD popular component sizes


>> Inside I can see surface mount resistors which must only be
>> 2mm or less long and 1mm wide.
>
> 0805 - 2 X 1.25 mm
> 0603 - 1.6 X .8 mm
> 0402 - 1 X .5 mm
> 0201 - .6 X .3 mm
>
> Currently I buy and hand solder down to 0402s (small quantities).
> Down to 0603 is a piece of cake but problem with 0402 is visual
> confirmation of proper solder joint and for that I either use a
> camera (macro shot) or microscope. Just using a DIMM isn't good
> enough.
>
> This is coming from someone who needs glasses in order to read or see
> just about anything properly in a 3' radius. Those with younger eyes
> will be amazed at how something that appears daunting at first soon
> becomes a walk in the park. Many of us can probably recall when
> soldering even a 1206 (3.2 X 1.6 mm) seemed like an impossible task.

I routinely use 0805 and don't have problems with 0603, although I'm 63. I 
do need to use plenty of magnification, sometimes a microscope is necessary.

Leon

> I routinely use 0805 and don't have problems with 0603, although I'm 
> 63. I do need to use plenty of magnification, sometimes a microscope 
> is necessary.

Thought I would need a microscope for placement and soldering of 0402s 
but my 5X magnification visor works just fine after a bit of practice. 
Provided you're definitely hand soldering and not reflowing, a "trick" 
to use for easy visual placement of these small components is not to 
use standard reflow pad layouts. Instead, import them into your library 
editor, modify them accordingly and save as new HS (or whatever) 
layouts.


--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" <leon.heller@b...> 
wrote:
>
> 
> I routinely use 0805 and don't have problems with 0603, although I'm 
63. I 
> do need to use plenty of magnification, sometimes a microscope is 
necessary.

> 
> Leon
>

Hi Derek,

> Provided you're definitely hand soldering and not reflowing, a "trick"
> to use for easy visual placement of these small components is not to
> use standard reflow pad layouts. Instead, import them into your library
> editor, modify them accordingly and save as new HS (or whatever)
> layouts.

What would the changes be in the "modify them accordingly" step?

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/

----- Original Message ----- 

From: "Dave Hylands" <dhylands@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, January 27, 2006 5:18 PM
Subject: Re: [Homebrew_PCBs] Re: SMD popular component sizes


> Hi Derek,
> 
>> Provided you're definitely hand soldering and not reflowing, a "trick"
>> to use for easy visual placement of these small components is not to
>> use standard reflow pad layouts. Instead, import them into your library
>> editor, modify them accordingly and save as new HS (or whatever)
>> layouts.
> 
> What would the changes be in the "modify them accordingly" step?

Make them a bit longer. I often do this with the pads for SM chips.

Leon
---
[This E-mail has been scanned for viruses but it is your responsibility 
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

> What would the changes be in the "modify them accordingly" step?

Using 0402 as an example. Here is a picture of a 0402 cap;

http://rocky.digikey.com/WebLib/Panasonic/Web%20Photos/ECD-GOE%
20Series.jpg

Here is a data sheet;

http://www.panasonic.com/industrial/components/pdf/abj0000ce8.pdf

Editing with your imported standard reflow layout, you would;

1. Lengthen the solder area as Leon indicated;

2. Shorten the width to just over .5 mm

3. Shorten the pad area beneath the chip so that the contact area on 
each side of the chip ends where the pad ends under the chip. In 
other words, for 0402, only about .5 X .2 mm (W X L1 or L2) of the 
pad is under each side of the chip.

1 above allows for easy soldering and aids heat dissipation. 2 and 3 
above allow for quick alignment along X and Y axes. Remember, you'll 
be hand soldering so a layout pattern that facilitates sutface 
tension centering is no longer applicable. If heat dissipation 
requirements, say in the case of a resistor, are near the limit of 
the device then either stick with the reflow pattern or use a bigger 
package size with standard pad layout.

--- In Homebrew_PCBs@yahoogroups.com, Dave Hylands <dhylands@g...> 
wrote:

>
> Hi Derek,
> What would the changes be in the "modify them accordingly" step?
> 
> --
> Dave Hylands
> Vancouver, BC, Canada
> http://www.DaveHylands.com/
>

Thanks (to both Derek & Leon) - makes alot of sense.

> > What would the changes be in the "modify them accordingly" step?

> 1. Lengthen the solder area as Leon indicated;
>
> 2. Shorten the width to just over .5 mm
>
> 3. Shorten the pad area beneath the chip so that the contact area on
> each side of the chip ends where the pad ends under the chip. In
> other words, for 0402, only about .5 X .2 mm (W X L1 or L2) of the
> pad is under each side of the chip.

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/

--- In Homebrew_PCBs@yahoogroups.com, "derekhawkins" <eldata@m...> 
wrote:
>
> > You could reflow it in a wok.
> 
> Toaster oven would be better. Saw a nice infrared convection 
toaster 
> oven with digital temperature display and controls, if only it was 
> programmable.
> 
> 
> > Solder paste is (relatively) cheap: $16 
> 
> That's $16.00 for 1.2 ounces BTW. 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
wrote:
> >
> > You could reflow it in a wok. Solder paste is (relatively) cheap: 
$16 
> at 
> >
>

You may be interested in an article that appeared in the Circuit 
Cellar magazine, July, 2004, Issue 168. The author described the 
circuits required to convert a toaster oven to a reflow oven, 
complete with profiles, and down loadable software.

Dave Miller

--- In Homebrew_PCBs@yahoogroups.com, "idaho_huckleberry" 
<dmiller45@j...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "derekhawkins" <eldata@m...> 
> wrote:
> >
> > > You could reflow it in a wok.
> > 
> > Toaster oven would be better. Saw a nice infrared convection 
> toaster 
> > oven with digital temperature display and controls, if only it 
was 
> > programmable.
> > 
> > 
> > > Solder paste is (relatively) cheap: $16 
> > 
> > That's $16.00 for 1.2 ounces BTW. 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Mike Young" <mikewhy@s...> 
> wrote:
> > >
> > > You could reflow it in a wok. Solder paste is (relatively) 
cheap: 
> $16 
> > at 
> > >
> >
> 
> You may be interested in an article that appeared in the Circuit 
> Cellar magazine, July, 2004, Issue 168. The author described the 
> circuits required to convert a toaster oven to a reflow oven, 
> complete with profiles, and down loadable software.
> 
> Dave Miller
>

Sorry, I was getting caught up after being out of town for a few days 
and did not see that this had already been discussed.

----- Original Message ----- 
>> > > You could reflow it in a wok.
>> >
>> > > You could reflow it in a wok. Solder paste is (relatively)
> cheap:
>> $16
>> > at
>> > >
>> >
>>
>> You may be interested in an article that appeared in the Circuit
>> Cellar magazine, July, 2004, Issue 168. The author described the
>> circuits required to convert a toaster oven to a reflow oven,
>> complete with profiles, and down loadable software.
>>
>> Dave Miller
>>
>
> Sorry, I was getting caught up after being out of town for a few days
> and did not see that this had already been discussed.

No worries, Dave. The "problem" with ovens is the presumption that careful 
and very fine control is needed, along with the associated cost and 
complexity. I find this not to be so, and that simply watching for full 
reflow on an open skillet is sufficient. After all, this is all we're doing 
with hot air. In any case, there are so many advantages to reflowing 
compared to hand soldering that it's worth experimenting. After removing the 
need for the thermocouple, control circuitry, and power switching, the only 
thing standing in the way is a $20 tube of paste. This puts it well within 
reach for anyone wanting to experiment with surface mount components. I 
wouldn't categorize it as a life-changing experience, but getting rid of 
that particular bogeyman opens the way for other opportunities.

>
>You may be interested in an article that appeared in the Circuit
>Cellar magazine, July, 2004, Issue 168. The author described the
>circuits required to convert a toaster oven to a reflow oven,
>complete with profiles, and down loadable software.
>
>Dave Miller

But the Evaluation Board used there is no more in production.
Cristian