I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

On Tuesday, November 3, 2015 at 8:04:14 AM UTC-5, A2 wrote:
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



I would try UHMWPE. It will be almost as good as Teflon as far as getting the mold to release the part. And it is quite a bit cheaper than Teflon. I would think it would be good for production molds.

Dan

On Tue, 3 Nov 2015 21:04:14 +0800, A2 wrote:

I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

The machining marks (undercuts) will make the part want to stay in the
mold even if it doesn't stick. Polishing will be a lot of work. If the
mold material is rigid then be sure to have a healthy draft angle
(maybe 4 degrees or more).


--sp


--
Best regards,
Spehro Pefhany
Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8
Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48

"A2" wrote in message
...

I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds
================================================== =============

I've never cast epoxy, just polyurethane and a little silicone, in aluminum
and polyurethane molds, but my guess is that polyurethane rubber would work
well. I would go to www.smooth-on.com and first read their tutorials and
then give them a call. I've been very happy with their support and
products.

-----
Regards,
Carl Ijames
..

"A2" wrote in message
...
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


I was recently asked to quote a job like this although they used a different
material than epoxy and injected it. PVA mold release was used. Teflon
pins, and silicone o-rings protected display screens, harness sockets, and
mounting holes. Aluminum makes a decent mold for this sort of thing, but
because its rigid you do need to do a little planning to make sure your part
will demold ok, like tapered sides, etc.

I've cast other resins in aluminum molds and one trick I like is to stick
something in the sprue to use as a leverage pin to help get the part out of
the mold.

There are commercial hot glues (not your craft store sticks and guns) that
are used for this sort of thing also, but I've not used it.






Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

On 3/11/2015 9:17 PM, wrote:
On Tuesday, November 3, 2015 at 8:04:14 AM UTC-5, A2 wrote:
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



I would try UHMWPE. It will be almost as good as Teflon as far as getting the mold to release the part. And it is quite a bit cheaper than Teflon. I would think it would be good for production molds.

Dan



Thanks, I'll chase up a sample of UHMWPE and do some adhesion / release
tests.

On 3/11/2015 10:40 PM, Spehro Pefhany wrote:
On Tue, 3 Nov 2015 21:04:14 +0800, A2 wrote:

I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

The machining marks (undercuts) will make the part want to stay in the
mold even if it doesn't stick. Polishing will be a lot of work. If the
mold material is rigid then be sure to have a healthy draft angle
(maybe 4 degrees or more).


--sp



Yep, we've got lots of draft on our item. sides & front 14°, rear ~ 4°.

I'm starting to think aluminium might be the best as we know we can get
a polished finish. Not so sure we can get this with UHMWPE.

I was wondering if aluminium molds are routinely coated with something
like that used on non stick fry pans.

On 4/11/2015 1:56 AM, Carl Ijames wrote:
"A2" wrote in message
...

I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds
================================================== =============

I've never cast epoxy, just polyurethane and a little silicone, in aluminum
and polyurethane molds, but my guess is that polyurethane rubber would work
well. I would go to www.smooth-on.com and first read their tutorials and
then give them a call. I've been very happy with their support and
products.

-----
Regards,
Carl Ijames
.



Thanks Carl, I'm a bit worried about using a mold with any flex as we
have to easily locate the encapsulated electronics to 0.5mm which we
were hoping to do by mounting it to a frame and have it located by
dowels on the mold.

On 4/11/2015 10:49 AM, Bob La Londe wrote:
"A2" wrote in message
...
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


I was recently asked to quote a job like this although they used a different
material than epoxy and injected it. PVA mold release was used. Teflon
pins, and silicone o-rings protected display screens, harness sockets, and
mounting holes. Aluminum makes a decent mold for this sort of thing, but
because its rigid you do need to do a little planning to make sure your part
will demold ok, like tapered sides, etc.

Yep, have heaps of draft on the part.

We were hoping to totally avoid a release agent but we might need some.
I'll check out the PVA release. It looks like its available locally here.


I've cast other resins in aluminum molds and one trick I like is to stick
something in the sprue to use as a leverage pin to help get the part out of
the mold.

There are commercial hot glues (not your craft store sticks and guns) that
are used for this sort of thing also, but I've not used it.


We looked at the low temp injection "macromelt"and similar but we need
the properties of the epoxy we are using.
Thanks







Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

You need to talk to a fab line production manager - Encapsulation
is their game. They do long wire frames and attach the die, bond and
encapsulate, saw and polish the saw ends. Touch up the part and 'mark'
the numbers... package and ship. in the Mark pack and label group.

Martin

On 11/3/2015 10:35 PM, A2 wrote:
On 4/11/2015 10:49 AM, Bob La Londe wrote:
"A2" wrote in message
...
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


I was recently asked to quote a job like this although they used a
different
material than epoxy and injected it. PVA mold release was used. Teflon
pins, and silicone o-rings protected display screens, harness sockets,
and
mounting holes. Aluminum makes a decent mold for this sort of thing, but
because its rigid you do need to do a little planning to make sure
your part
will demold ok, like tapered sides, etc.

Yep, have heaps of draft on the part.

We were hoping to totally avoid a release agent but we might need some.
I'll check out the PVA release. It looks like its available locally here.


I've cast other resins in aluminum molds and one trick I like is to stick
something in the sprue to use as a leverage pin to help get the part
out of
the mold.

There are commercial hot glues (not your craft store sticks and guns)
that
are used for this sort of thing also, but I've not used it.


We looked at the low temp injection "macromelt"and similar but we need
the properties of the epoxy we are using.
Thanks







Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

On 4/11/2015 12:54 PM, Martin Eastburn wrote:
You need to talk to a fab line production manager - Encapsulation
is their game. They do long wire frames and attach the die, bond and
encapsulate, saw and polish the saw ends. Touch up the part and 'mark'
the numbers... package and ship. in the Mark pack and label group.

Martin


Thanks Martin, we are encapsulating whole PCB assemblies with cables
attached rather than the dies etc. No doubt the IC packaging guys would
have the knowledge we could use! I'm not sure there is even a fab plant
in Australia these days.

A2 wrote in
:

Yep, we've got lots of draft on our item. sides & front 14°, rear ~
4°.

I'm starting to think aluminium might be the best as we know we can
get a polished finish. Not so sure we can get this with UHMWPE.

I was wondering if aluminium molds are routinely coated with something
like that used on non stick fry pans.



There's a few companies down under that do that. Talk to them!


https://www.google.com.au/search?
q=surface+coating+specialist+Australia+ptfe+alumin ium



--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL

On Tuesday, November 3, 2015 at 11:30:55 PM UTC-5, A2 wrote:




I'm starting to think aluminium might be the best as we know we can get
a polished finish. Not so sure we can get this with UHMWPE.

I was wondering if aluminium molds are routinely coated with something
like that used on non stick fry pans.


You might try UHMWPE anyway. You have to have very sharp cutters and take off about .1 mm on the final pass. And you may be able to flame polish the UHMWPE.
Unfortunately flame polishing oxidises the surface and that is not good for releasing the part from the mold.


UHMWPE is a lot cheaper than aluminume, so it might work out. You can find heaps of posts about using PE for molds on the internet all posted by people with more experience that I have.

Dan

On Wed, 4 Nov 2015 12:35:24 +0800, A2 wrote:

On 4/11/2015 10:49 AM, Bob La Londe wrote:
"A2" wrote in message
...
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to 0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


I was recently asked to quote a job like this although they used a different
material than epoxy and injected it. PVA mold release was used. Teflon
pins, and silicone o-rings protected display screens, harness sockets, and
mounting holes. Aluminum makes a decent mold for this sort of thing, but
because its rigid you do need to do a little planning to make sure your part
will demold ok, like tapered sides, etc.

Yep, have heaps of draft on the part.

We were hoping to totally avoid a release agent but we might need some.
I'll check out the PVA release. It looks like its available locally here.

PVA is a pretty standard release agent for epoxy, polyester, and some
other liquid resins. With a new mold, standard practice is to spray or
dip one coat; let it dry; then spray or dip another one. After a few
uses, one coat usually works.

It's a pain in the rear for any kind of production. I've worked with
it on projects small enough to fit in your hand, and as large as
36-foot boats. Hopefully, one of the other solutions will work for
you, but PVA is pretty reliable. It's not perfect, but it generally
does the job.

--
Ed Huntress



I've cast other resins in aluminum molds and one trick I like is to stick
something in the sprue to use as a leverage pin to help get the part out of
the mold.

There are commercial hot glues (not your craft store sticks and guns) that
are used for this sort of thing also, but I've not used it.


We looked at the low temp injection "macromelt"and similar but we need
the properties of the epoxy we are using.
Thanks







Option 2.
---------
Plastic mold
CNC cut pockets in a ~30mm thick slab
Dowels adjacent recess to locate frame that aligns the electronics.
Is there a plastic that epoxy won't stick to - no release agent needed?
Nylon? UHMWPE? Maybe $$ Teflon?
I imagine a silicone or urethane mold may not be rigid enough.

Any suggestions? Recommendations?
Thanks!



Background:
Prototypes have been cast in a mold made from epoxy and a aerosol mold
release used. It works ok, we ended up making the mold 2 parts as the
completed parts were a little hard to remove.


*The electronics is sat into a 130mm x 50mm x 20mm (5"x2"x3/4") mold
*Their is heaps of draft on the mold for easing release.
*Epoxy poured into the mold.
*After 24 hours they are de-molded.

*These will be made in batches of say 30 to 100 at a time.
*We are happy Doing say 6 at a time with a 24 hr turn around.
*Mold may be 6 units wide or 6 individual molds.

"Ed Huntress" wrote in message
...
On Wed, 4 Nov 2015 12:35:24 +0800, A2 wrote:

On 4/11/2015 10:49 AM, Bob La Londe wrote:
"A2" wrote in message
...
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to
0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


I was recently asked to quote a job like this although they used a
different
material than epoxy and injected it. PVA mold release was used. Teflon
pins, and silicone o-rings protected display screens, harness sockets,
and
mounting holes. Aluminum makes a decent mold for this sort of thing,
but
because its rigid you do need to do a little planning to make sure your
part
will demold ok, like tapered sides, etc.

Yep, have heaps of draft on the part.

We were hoping to totally avoid a release agent but we might need some.
I'll check out the PVA release. It looks like its available locally here.

PVA is a pretty standard release agent for epoxy, polyester, and some
other liquid resins. With a new mold, standard practice is to spray or
dip one coat; let it dry; then spray or dip another one. After a few
uses, one coat usually works.

It's a pain in the rear for any kind of production. I've worked with
it on projects small enough to fit in your hand, and as large as
36-foot boats. Hopefully, one of the other solutions will work for
you, but PVA is pretty reliable. It's not perfect, but it generally
does the job.

--
Ed Huntress

It was recently brought to my attention that there is a PVA glue also. Lots
of things I don't know. That was one of them. The person who pointed it
out to me had tried it as a mold release with mixed to poor results on a
printed plastic mold. Appraently the PVA glue didn't stick to his mold very
well. I suspect not much would stick to his plastic mold very well. I
think I would stick with PVA sold as a mold release.

On Wed, 4 Nov 2015 15:25:43 -0700, "Bob La Londe"
wrote:

"Ed Huntress" wrote in message
.. .
On Wed, 4 Nov 2015 12:35:24 +0800, A2 wrote:

On 4/11/2015 10:49 AM, Bob La Londe wrote:
"A2" wrote in message
...
I'm working on a job where we are epoxy encapsulating some electronics.

My question - what to use for a pilot production mold?

Option 1.
---------
Aluminum
CNC cut pockets
Dowels adjacent recess to locate frame that aligns electronics to
0.5mm
Release coated mold - PTFE / Teflon?
Use release agent? Hope to avoid.


I was recently asked to quote a job like this although they used a
different
material than epoxy and injected it. PVA mold release was used. Teflon
pins, and silicone o-rings protected display screens, harness sockets,
and
mounting holes. Aluminum makes a decent mold for this sort of thing,
but
because its rigid you do need to do a little planning to make sure your
part
will demold ok, like tapered sides, etc.

Yep, have heaps of draft on the part.

We were hoping to totally avoid a release agent but we might need some.
I'll check out the PVA release. It looks like its available locally here.

PVA is a pretty standard release agent for epoxy, polyester, and some
other liquid resins. With a new mold, standard practice is to spray or
dip one coat; let it dry; then spray or dip another one. After a few
uses, one coat usually works.

It's a pain in the rear for any kind of production. I've worked with
it on projects small enough to fit in your hand, and as large as
36-foot boats. Hopefully, one of the other solutions will work for
you, but PVA is pretty reliable. It's not perfect, but it generally
does the job.

--
Ed Huntress

It was recently brought to my attention that there is a PVA glue also. Lots
of things I don't know. That was one of them. The person who pointed it
out to me had tried it as a mold release with mixed to poor results on a
printed plastic mold. Appraently the PVA glue didn't stick to his mold very
well. I suspect not much would stick to his plastic mold very well. I
think I would stick with PVA sold as a mold release.

This is one to be careful about. PVA can refer to polyvinyl acetate
(wood glue), or polyvinyl alcohol (a polymer release agent.)

--
Ed Huntress

"A2" wrote in message
...
On 4/11/2015 12:54 PM, Martin Eastburn wrote:
You need to talk to a fab line production manager - Encapsulation
is their game. They do long wire frames and attach the die, bond and
encapsulate, saw and polish the saw ends. Touch up the part and 'mark'
the numbers... package and ship. in the Mark pack and label group.

Martin


Thanks Martin, we are encapsulating whole PCB assemblies with cables
attached rather than the dies etc. No doubt the IC packaging guys would
have the knowledge we could use! I'm not sure there is even a fab plant in
Australia these days.

I assume you have already accounted for adequate epoxy thickness to kick and
cure easily without being so thick as to overheat and scorch. To thin and
it can be hard to cure without adding heat. To thick and it will over heat
and burn itself.

"Bob La Londe" wrote in
:

It was recently brought to my attention that there is a PVA glue also.
Lots of things I don't know. That was one of them. The person who
pointed it out to me had tried it as a mold release with mixed to poor
results on a printed plastic mold. Appraently the PVA glue didn't
stick to his mold very well. I suspect not much would stick to his
plastic mold very well. I think I would stick with PVA sold as a mold
release.

Polyvinyl acetate = Glue
Polyvinyl alcohol = Mould release



--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL

COB - Chip on Board. :-)

There are fabs in Malaysia Philippines, and all about out there.

Boat builders might help. They deal with plastics. Surf boards...

Any plastic company worth their salt - your suppliers ? ! Normally
companies have technical engineers that have specialties in their
products and use.

I'd try the plastic company. Even if it is offshore. They might
send someone or a small team to help you select the correct product
for the job without chemical or heat burning the product....

Martin Eastburn - retired from Semi and Test companies.

On 11/3/2015 10:59 PM, A2 wrote:
On 4/11/2015 12:54 PM, Martin Eastburn wrote:
You need to talk to a fab line production manager - Encapsulation
is their game. They do long wire frames and attach the die, bond and
encapsulate, saw and polish the saw ends. Touch up the part and 'mark'
the numbers... package and ship. in the Mark pack and label group.

Martin


Thanks Martin, we are encapsulating whole PCB assemblies with cables
attached rather than the dies etc. No doubt the IC packaging guys would
have the knowledge we could use! I'm not sure there is even a fab plant
in Australia these days.