Reflow soldering on a custom PCB

C

Chris W

Guest
I recently had some through hole custom PCBs made by
http://custompcb.com. Everything worked great. Now I am thinking that
the next project I do will use surface mount components. What I am
wondering is, is there enough solder on those custom PCBs to do reflow
soldering? I don't see anywhere on that web site where it talks about
that although they do talk about a tin/silver plating. Another
prototype surface mount adapter board I got didn't look like there was
any solder to reflow but it did work fine. I just don't want to spend
the money on a custom PCB till I know for sure it will have enough
solder on there to do reflow soldering of surface mount chips.

--
Chris W

Gift Giving Made Easy
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On Sat, 04 Jun 2005 19:01:22 -0500, Chris W <1qazse4@cox.net> wrote:

I recently had some through hole custom PCBs made by
http://custompcb.com. Everything worked great. Now I am thinking that
the next project I do will use surface mount components. What I am
wondering is, is there enough solder on those custom PCBs to do reflow
soldering? I don't see anywhere on that web site where it talks about
that although they do talk about a tin/silver plating. Another
prototype surface mount adapter board I got didn't look like there was
any solder to reflow but it did work fine. I just don't want to spend
the money on a custom PCB till I know for sure it will have enough
solder on there to do reflow soldering of surface mount chips.
Click to expand...

People normally apply solder paste through a stencil, then place the
parts and reflow. I don't think any normal solder coating would be
enough to make reliable joints.

John
 
"Chris W" <1qazse4@cox.net> schreef in bericht
news:8jroe.9557$rb6.9425@lakeread07...
I recently had some through hole custom PCBs made by http://custompcb.com.
Everything worked great. Now I am thinking that the next project I do will
use surface mount components. What I am wondering is, is there enough
solder on those custom PCBs to do reflow soldering? I don't see anywhere
on that web site where it talks about that although they do talk about a
tin/silver plating. Another prototype surface mount adapter board I got
didn't look like there was any solder to reflow but it did work fine. I
just don't want to spend the money on a custom PCB till I know for sure it
will have enough solder on there to do reflow soldering of surface mount
chips.
--
Chris W

Gift Giving Made Easy
Get the gifts you want & give the gifts they want
http://thewishzone.com
Click to expand...
Chris,

AFAIK the plating on the PCB is never used for reflow. That's to say, not on
its own. In the reflow proces a fine grained solder and flux mixture is used
that is put on the PCB by screen print. Then the components are placed and
the PCB is heated by infrared to "reflow" the solder.

petrus bitbyter
 
Also, in normal manufacturing using multiple smd components. an adhesive is
applied to the pcb surface to hold the smd components in place during the
rest of the processes. Otherwise some of the components either shift
position, fall off the pcb, or short to adjoining pads and components.
"PeteS" <ps@fleetwoodmobile.com> wrote in message
news:1117963814.744993.177430@g47g2000cwa.googlegroups.com...
As stated, the short answer is no, there is insufficient solder from
the plating process.

That said, I have had surface mount boards soldered by hand. The
difference is simply the amount of solder used. The person I use has
successfully dealt with 0.5mm pitch ICs and 0201 passives. The one area
you'll really need reflow is BGAs.

If you want a proper reflow, then you'll need to have a stencil made,
as John noted. This is a standard cost item when producing surface
mount boards using a contract manufacturer.

Cheers

PeteS
Click to expand...
 
"Chris W" <1qazse4@cox.net> wrote in message
news:8jroe.9557$rb6.9425@lakeread07...
I recently had some through hole custom PCBs made by
http://custompcb.com. Everything worked great. Now I am thinking that
the next project I do will use surface mount components. What I am
wondering is, is there enough solder on those custom PCBs to do reflow
soldering? I don't see anywhere on that web site where it talks about
that although they do talk about a tin/silver plating. Another
prototype surface mount adapter board I got didn't look like there was
any solder to reflow but it did work fine. I just don't want to spend
the money on a custom PCB till I know for sure it will have enough
solder on there to do reflow soldering of surface mount chips.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com
Click to expand...
No, there is not enough solder on the boards to solder on parts. The solder
there is basically tinning so additional solder will wet the pads cleanly.

Since I only do a few boards at a time, I solder surface mount boards
manually without paste, masks, glue, stencils or other production methods or
devices. I use a small tip Weller iron and 20mil wire solder. On the board,
I flow a dab of solder on one of the component pads for each device to be
mounted. Holding the device in position with a pair of tweezers, I reflow
the solder dab sticking the part to the board by one pin. After aligning the
part so that all of the pins are in the proper position, I apply solder to
another pin on its pad. I push the component to the board and reflow this
second pad insuring that the component seats onto the board and is aligned
properly. I then solder all of the other pins to their pads in the normal
manner. When solder accidentally bridges more than one pin, which happens
occasionally in .5mm parts, I use solder wick to sop up the excess which
leaves a clean joint. My eyes aren't to good so I work under a microscope,
some people can do it with the naked eye. For small quantities, there is no
need for paste, Infrared reflow equipment and the rest.
Bob
 
Sounds like a plan, where labour is not an essential cost. Have at it and
post your results. Cheers.
"Bob Eldred" <nsmontassoc@yahoo.com> wrote in message
news:df2af$42a46af7$42a7d082$28276@msgid.meganewsservers.com...
"Chris W" <1qazse4@cox.net> wrote in message
news:8jroe.9557$rb6.9425@lakeread07...
I recently had some through hole custom PCBs made by
http://custompcb.com. Everything worked great. Now I am thinking that
the next project I do will use surface mount components. What I am
wondering is, is there enough solder on those custom PCBs to do reflow
soldering? I don't see anywhere on that web site where it talks about
that although they do talk about a tin/silver plating. Another
prototype surface mount adapter board I got didn't look like there was
any solder to reflow but it did work fine. I just don't want to spend
the money on a custom PCB till I know for sure it will have enough
solder on there to do reflow soldering of surface mount chips.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com

No, there is not enough solder on the boards to solder on parts. The
solder
there is basically tinning so additional solder will wet the pads cleanly.

Since I only do a few boards at a time, I solder surface mount boards
manually without paste, masks, glue, stencils or other production methods
or
devices. I use a small tip Weller iron and 20mil wire solder. On the
board,
I flow a dab of solder on one of the component pads for each device to be
mounted. Holding the device in position with a pair of tweezers, I reflow
the solder dab sticking the part to the board by one pin. After aligning
the
part so that all of the pins are in the proper position, I apply solder to
another pin on its pad. I push the component to the board and reflow this
second pad insuring that the component seats onto the board and is aligned
properly. I then solder all of the other pins to their pads in the normal
manner. When solder accidentally bridges more than one pin, which happens
occasionally in .5mm parts, I use solder wick to sop up the excess which
leaves a clean joint. My eyes aren't to good so I work under a microscope,
some people can do it with the naked eye. For small quantities, there is
no
need for paste, Infrared reflow equipment and the rest.
Bob
Click to expand...
 
"PeteS" <ps@fleetwoodmobile.com> wrote in message
news:1117963814.744993.177430@g47g2000cwa.googlegroups.com...
As stated, the short answer is no, there is insufficient solder from
the plating process.

That said, I have had surface mount boards soldered by hand. The
difference is simply the amount of solder used. The person I use has
successfully dealt with 0.5mm pitch ICs and 0201 passives. The one area
you'll really need reflow is BGAs.

If you want a proper reflow, then you'll need to have a stencil made,
as John noted. This is a standard cost item when producing surface
mount boards using a contract manufacturer.

Cheers

PeteS
Click to expand...

These new QFN packages are not much fun either..
 
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Hash: SHA1

I've been using this method for years, works very well for me.

*tin the pads with ample solder for reflow
*use a dab of expoy (if working with multiple pin componets)
*alined the chip on the pads and let the expoy set (10-15 min is good)
*flux pen the leads
*and now reflow :)

This is a longer method but I have found over and over this saves me time
and money in the long run. Because the chip is already alined you only need
to heat the chip for 15 seconds (a 16pin QSOP atleast) or so.


Art wrote:

Sounds like a plan, where labour is not an essential cost. Have at it and
post your results. Cheers.
"Bob Eldred" <nsmontassoc@yahoo.com> wrote in message
news:df2af$42a46af7$42a7d082$28276@msgid.meganewsservers.com...

"Chris W" <1qazse4@cox.net> wrote in message
news:8jroe.9557$rb6.9425@lakeread07...
I recently had some through hole custom PCBs made by
http://custompcb.com. Everything worked great. Now I am thinking that
the next project I do will use surface mount components. What I am
wondering is, is there enough solder on those custom PCBs to do reflow
soldering? I don't see anywhere on that web site where it talks about
that although they do talk about a tin/silver plating. Another
prototype surface mount adapter board I got didn't look like there was
any solder to reflow but it did work fine. I just don't want to spend
the money on a custom PCB till I know for sure it will have enough
solder on there to do reflow soldering of surface mount chips.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com

No, there is not enough solder on the boards to solder on parts. The
solder
there is basically tinning so additional solder will wet the pads
cleanly.

Since I only do a few boards at a time, I solder surface mount boards
manually without paste, masks, glue, stencils or other production methods
or
devices. I use a small tip Weller iron and 20mil wire solder. On the
board,
I flow a dab of solder on one of the component pads for each device to be
mounted. Holding the device in position with a pair of tweezers, I reflow
the solder dab sticking the part to the board by one pin. After aligning
the
part so that all of the pins are in the proper position, I apply solder
to another pin on its pad. I push the component to the board and reflow
this second pad insuring that the component seats onto the board and is
aligned properly. I then solder all of the other pins to their pads in
the normal manner. When solder accidentally bridges more than one pin,
which happens occasionally in .5mm parts, I use solder wick to sop up the
excess which leaves a clean joint. My eyes aren't to good so I work under
a microscope, some people can do it with the naked eye. For small
quantities, there is no
need for paste, Infrared reflow equipment and the rest.
Bob
Click to expand...
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As stated, the short answer is no, there is insufficient solder from
the plating process.

That said, I have had surface mount boards soldered by hand. The
difference is simply the amount of solder used. The person I use has
successfully dealt with 0.5mm pitch ICs and 0201 passives. The one area
you'll really need reflow is BGAs.

If you want a proper reflow, then you'll need to have a stencil made,
as John noted. This is a standard cost item when producing surface
mount boards using a contract manufacturer.

Cheers

PeteS
 
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