In message , Jerry Stuckle
writes
On 6/20/2014 3:54 AM, Brian Reay wrote:
Michael Black wrote:


I seem to recall from early articles about surface mount the suggestion
of using a dab of flux to hold the component in place. It was only to
hold it until you actually had something soldered.

That said, I really think a good magnifiying glass or microscope makes
sense. I was trying to figure out something, and got out the jeweller's
loupe, and it's amazing how much bigger everything is. That's not going
to work for soldering, but getting good magnification that will stand on
its own is bound to help a lot. And good lighting. Looking at that board
with the loupe almost makes the idea of soldering surface mount
within my capability.

Michael,

For SMD projects, rather than repairs, you can use a domestic oven to
solder the boards. Ideally, get a small table top model (the type of thing
student or caravaners use) but I did a test run in a full sized kitchen
one. The key thing is to be able to get to 230C or so at least.

You need to plot a graph of the way the oven temp rises using a
thermocouple (I borrowed one but they are cheap enough to buy). Basically
you put the board it with all the components held in place by solder paste.
Set the temp to about 200C and watch as it rises. When it gets to 100, turn
oven off for 3 min, this is known as drying time and is to drive the
solvent from the solder paste, them set temp to 250 or as high as you can
if lower. Now watch carefully, as soon as the solder paste melts and flows
to make the joints, turn off the oven and open the door.

I've tried this a couple of times and the results are surprisingly good. No
dry joints, no moved components.

The graph will help you predict when things are about to 'happen' and the
thermocouple is essential if your oven temp. gauge isn't accurate.


Brian,

I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.

The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.

Don't they often use a blast of hot air?
--
Ian

I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.

The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.


I ahve never heard of a line usiung robot soldering irons!! It would be
far too slow. Lines normally use either wave soldering or IR reflow.

Jeff

On 6/20/2014 8:01 AM, Jeff wrote:

I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.

The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.


I ahve never heard of a line usiung robot soldering irons!! It would be
far too slow. Lines normally use either wave soldering or IR reflow.

Jeff

Jeff,

You'd be surprised how quickly a robot soldering iron makes a connection
- less than 1/2 second per connection (and, of course, you can have
multiple irons working on the same board simultaneously, with proper
programming). The first time I saw it was back in the 70's, but I'm
sure it was in use long before that.

Yes, it's slower than wave or IR reflow. But it's a proven technology
which has been around for decades and does have its uses - i.e.
temperature-sensitive components which can't handle the heat of wave or
IR reflow.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 6/20/2014 7:45 AM, Ian Jackson wrote:
In message , Jerry Stuckle
writes
On 6/20/2014 3:54 AM, Brian Reay wrote:
Michael Black wrote:


I seem to recall from early articles about surface mount the suggestion
of using a dab of flux to hold the component in place. It was only to
hold it until you actually had something soldered.

That said, I really think a good magnifiying glass or microscope makes
sense. I was trying to figure out something, and got out the
jeweller's
loupe, and it's amazing how much bigger everything is. That's not
going
to work for soldering, but getting good magnification that will
stand on
its own is bound to help a lot. And good lighting. Looking at that
board
with the loupe almost makes the idea of soldering surface mount
within my capability.

Michael,

For SMD projects, rather than repairs, you can use a domestic oven to
solder the boards. Ideally, get a small table top model (the type of
thing
student or caravaners use) but I did a test run in a full sized kitchen
one. The key thing is to be able to get to 230C or so at least.

You need to plot a graph of the way the oven temp rises using a
thermocouple (I borrowed one but they are cheap enough to buy).
Basically
you put the board it with all the components held in place by solder
paste.
Set the temp to about 200C and watch as it rises. When it gets to
100, turn
oven off for 3 min, this is known as drying time and is to drive the
solvent from the solder paste, them set temp to 250 or as high as you
can
if lower. Now watch carefully, as soon as the solder paste melts and
flows
to make the joints, turn off the oven and open the door.

I've tried this a couple of times and the results are surprisingly
good. No
dry joints, no moved components.

The graph will help you predict when things are about to 'happen' and
the
thermocouple is essential if your oven temp. gauge isn't accurate.


Brian,

I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.

The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.

Don't they often use a blast of hot air?

No, the ones I've seen actually have a hot tip. A quick touch is all it
needs; in operation it looks like a sewing machine.

The biggest advantage is the connection gets hot, but the part doesn't,
due to the short contact time.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

"Jerry Stuckle" wrote in message
...
On 6/20/2014 8:01 AM, Jeff wrote:
I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.
The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.
I ahve never heard of a line usiung robot soldering irons!! It would be
far too slow. Lines normally use either wave soldering or IR reflow.
You'd be surprised how quickly a robot soldering iron makes a connection
- less than 1/2 second per connection (and, of course, you can have
multiple irons working on the same board simultaneously, with proper
programming). The first time I saw it was back in the 70's, but I'm
sure it was in use long before that.

Yes, it's slower than wave or IR reflow. But it's a proven technology
which has been around for decades and does have its uses - i.e.
temperature-sensitive components which can't handle the heat of wave or
IR reflow.


And back in the 1980s on some Perkin-Elmer processor cards, the whole card
was wired automatically, without there being an underlying PCB

On 2014-06-20 11:02:44 +0000, Jerry Stuckle said:

On 6/20/2014 3:54 AM, Brian Reay wrote:
Michael Black wrote:


I seem to recall from early articles about surface mount the suggestion
of using a dab of flux to hold the component in place. It was only to
hold it until you actually had something soldered.

That said, I really think a good magnifiying glass or microscope makes
sense. I was trying to figure out something, and got out the jeweller's
loupe, and it's amazing how much bigger everything is. That's not going
to work for soldering, but getting good magnification that will stand on
its own is bound to help a lot. And good lighting. Looking at that board
with the loupe almost makes the idea of soldering surface mount within
my capability.

Michael,

For SMD projects, rather than repairs, you can use a domestic oven to
solder the boards. Ideally, get a small table top model (the type of thing
student or caravaners use) but I did a test run in a full sized kitchen
one. The key thing is to be able to get to 230C or so at least.

You need to plot a graph of the way the oven temp rises using a
thermocouple (I borrowed one but they are cheap enough to buy). Basically
you put the board it with all the components held in place by solder paste.
Set the temp to about 200C and watch as it rises. When it gets to 100, turn
oven off for 3 min, this is known as drying time and is to drive the
solvent from the solder paste, them set temp to 250 or as high as you can
if lower. Now watch carefully, as soon as the solder paste melts and flows
to make the joints, turn off the oven and open the door.

I've tried this a couple of times and the results are surprisingly good. No
dry joints, no moved components.

The graph will help you predict when things are about to 'happen' and the
thermocouple is essential if your oven temp. gauge isn't accurate.


Brian,

I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.

The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.

I believe stencilling on solder paste, robot placement of components,
and melting the whole board in a reflow-like process with an accurately
controlled temperature vs. time profile is pretty standard for
complicated multilayer boards nowadays.

--

Percy Picacity

On 6/20/2014 10:05 AM, Percy Picacity wrote:
On 2014-06-20 11:02:44 +0000, Jerry Stuckle said:

On 6/20/2014 3:54 AM, Brian Reay wrote:
Michael Black wrote:


I seem to recall from early articles about surface mount the suggestion
of using a dab of flux to hold the component in place. It was only to
hold it until you actually had something soldered.

That said, I really think a good magnifiying glass or microscope makes
sense. I was trying to figure out something, and got out the
jeweller's
loupe, and it's amazing how much bigger everything is. That's not
going
to work for soldering, but getting good magnification that will
stand on
its own is bound to help a lot. And good lighting. Looking at that
board
with the loupe almost makes the idea of soldering surface mount
within my capability.

Michael,

For SMD projects, rather than repairs, you can use a domestic oven to
solder the boards. Ideally, get a small table top model (the type of
thing
student or caravaners use) but I did a test run in a full sized kitchen
one. The key thing is to be able to get to 230C or so at least.

You need to plot a graph of the way the oven temp rises using a
thermocouple (I borrowed one but they are cheap enough to buy).
Basically
you put the board it with all the components held in place by solder
paste.
Set the temp to about 200C and watch as it rises. When it gets to
100, turn
oven off for 3 min, this is known as drying time and is to drive the
solvent from the solder paste, them set temp to 250 or as high as you
can
if lower. Now watch carefully, as soon as the solder paste melts and
flows
to make the joints, turn off the oven and open the door.

I've tried this a couple of times and the results are surprisingly
good. No
dry joints, no moved components.

The graph will help you predict when things are about to 'happen' and
the
thermocouple is essential if your oven temp. gauge isn't accurate.


Brian,

I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.

The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.

I believe stencilling on solder paste, robot placement of components,
and melting the whole board in a reflow-like process with an accurately
controlled temperature vs. time profile is pretty standard for
complicated multilayer boards nowadays.


That may be the "standard" for high volume production where temperature
sensitive parts are not involved. But it is not the only way it's done.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

Percy Picacity wrote:
I believe stencilling on solder paste, robot placement of components,
and melting the whole board in a reflow-like process with an accurately
controlled temperature vs. time profile is pretty standard for
complicated multilayer boards nowadays.

You are not going to convince Jerry once he has one of his usual
twisted views on reality...

On 6/20/2014 10:55 AM, Rob wrote:
Percy Picacity wrote:
I believe stencilling on solder paste, robot placement of components,
and melting the whole board in a reflow-like process with an accurately
controlled temperature vs. time profile is pretty standard for
complicated multilayer boards nowadays.

You are not going to convince Jerry once he has one of his usual
twisted views on reality...


I'm not going to be convinced I haven't seen what I have seen.

You really need to get out more. Try visiting some assembly plants in
person, for instance - instead of relying on hearsay.

--
==================
Remove the "x" from my email address
Jerry Stuckle

==================

On 6/20/2014 1:32 PM, Brian Reay wrote:
Percy Picacity wrote:
On 2014-06-20 11:02:44 +0000, Jerry Stuckle said:

On 6/20/2014 3:54 AM, Brian Reay wrote:
Michael Black wrote:
I seem to recall from early articles about surface mount the suggestion
of using a dab of flux to hold the component in place. It was only to
hold it until you actually had something soldered.
That said, I really think a good magnifiying glass or microscope makes
sense. I was trying to figure out something, and got out the jeweller's
loupe, and it's amazing how much bigger everything is. That's not going
to work for soldering, but getting good magnification that will stand on
its own is bound to help a lot. And good lighting. Looking at that board
with the loupe almost makes the idea of soldering surface mount within
my capability.
Michael,
For SMD projects, rather than repairs, you can use a domestic oven to
solder the boards. Ideally, get a small table top model (the type of thing
student or caravaners use) but I did a test run in a full sized kitchen
one. The key thing is to be able to get to 230C or so at least.
You need to plot a graph of the way the oven temp rises using a
thermocouple (I borrowed one but they are cheap enough to buy). Basically
you put the board it with all the components held in place by solder paste.
Set the temp to about 200C and watch as it rises. When it gets to 100, turn
oven off for 3 min, this is known as drying time and is to drive the
solvent from the solder paste, them set temp to 250 or as high as you can
if lower. Now watch carefully, as soon as the solder paste melts and flows
to make the joints, turn off the oven and open the door.
I've tried this a couple of times and the results are surprisingly good. No
dry joints, no moved components.
The graph will help you predict when things are about to 'happen' and the
thermocouple is essential if your oven temp. gauge isn't accurate.
Brian,
I hadn't heard of using a domestic oven like this. It sounds like an
interesting idea. But wouldn't it be a bit hard on the components? I
wouldn't think many would like being heated his hot.
The commercial assembly lines I've seen use robot soldering irons
instead of heating the entire board.

I believe stencilling on solder paste, robot placement of components, and
melting the whole board in a reflow-like process with an accurately
controlled temperature vs. time profile is pretty standard for
complicated multilayer boards nowadays.


It is, and has been for some years, in fact decades, even in relatively
small batch production. The quality achievable is far higher that you can
get with manual assembly- once the process is right. Sometimes things like
edge connectors are pressed into holes which have been left solder free on
purpose. The plated through holes are designed to 'cold weld' (like a
crimp) when the connector is pressed home. It isn't soldered. This is
common on COTS boards used in military kit and custom boards in the same
LRUs. It is a very reliable technique.


Robotic soldering irons are NOT "manual assembly".

--
==================
Remove the "x" from my email address
Jerry Stuckle

==================