Flex PCB questions

A

asimlink

Guest
Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB====

Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim
 
asimlink <asimlink@gmail.com> writes:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB====

Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim
Click to expand...
Sorry I can't help, but I am curious as to why this is done - anyone
know? What is the point of a flex PCB inside a rigid one? Or does it
stick out one end or something?

--

John Devereux
 
On Mon, 14 Feb 2011 21:55:27 -0800 (PST), asimlink
<asimlink@gmail.com> wrote:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB====
Click to expand...
This looks to me as if you want a flex PB to connect two normal rigid
PCBs - so the flex is not embedded in a single rigid PCB.

Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?
Click to expand...
I would treat the flex PC as a cable, to be attached to the rigid PCs
with a suitable connector, or soldered to some pads on the edge of the
rigid PCBs. The flex PCB would then connect to the top or bottom
signal layers of the rigid PCB.

Best Regards,

Asim
Click to expand...
--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
John Devereux <john@devereux.me.uk> writes:

asimlink <asimlink@gmail.com> writes:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB====

Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim

Sorry I can't help, but I am curious as to why this is done - anyone
know? What is the point of a flex PCB inside a rigid one? Or does it
stick out one end or something?
Click to expand...
OK I see now - I missed the ASCII art sketch somehow (and in fact I
suspect it can't be done like that).

--

John Devereux
 
On Tue, 15 Feb 2011 10:41:15 +0000, John Devereux
<john@devereux.me.uk> wrote:

asimlink <asimlink@gmail.com> writes:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB====

Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim

Sorry I can't help, but I am curious as to why this is done - anyone
know? What is the point of a flex PCB inside a rigid one? Or does it
stick out one end or something?
Click to expand...
Usually, it is because the two boards need to be either at an angle,
or folded one over the other. If I were doing it, they would be
designed as three separate boards, with the flex board connected via a
connector at each end...

Charlie
 
On Feb 17, 5:34 am, Charlie E. <edmond...@ieee.org> wrote:
On Tue, 15 Feb 2011 10:41:15 +0000, John Devereux



j...@devereux.me.uk> wrote:
asimlink <asiml...@gmail.com> writes:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB===
Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim

Sorry I can't help, but I am curious as to why this is done - anyone
know? What is the point of a flex PCB inside a rigid one? Or does it
stick out one end or something?

Usually, it is because the two boards need to be either at an angle,
or folded one over the other.  If I were doing it, they would be
designed as three separate boards, with the flex board connected via a
connector at each end...

Charlie
Click to expand...
Dear Friends,

I definitely would love to design it as separate boards but reality is
that the board has to be made in the form factor as i mentioned in my
last post.
Charlie has well explained the reason why we need to do it that way.
There is already a board made in this way and I need to revise the
design with changes to circuit in the same form factor.

Regards,

Asim
 
On Feb 17, 12:09 pm, asimlink <asiml...@gmail.com> wrote:
On Feb 17, 5:34 am, Charlie E. <edmond...@ieee.org> wrote:



On Tue, 15 Feb 2011 10:41:15 +0000, John Devereux

j...@devereux.me.uk> wrote:
asimlink <asiml...@gmail.com> writes:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB===
Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim

Sorry I can't help, but I am curious as to why this is done - anyone
know? What is the point of a flex PCB inside a rigid one? Or does it
stick out one end or something?

Usually, it is because the two boards need to be either at an angle,
or folded one over the other.  If I were doing it, they would be
designed as three separate boards, with the flex board connected via a
connector at each end...

Charlie

Dear Friends,

I definitely would love to design it as separate boards but reality is
that the board has to be made in the form factor as i mentioned in my
last post.
Charlie has well explained the reason why we need to do it that way.
There is already a board made in this way and I need to revise the
design with changes to circuit in the same form factor.

Regards,

Asim
Click to expand...
Dear Friends,

I have found this manufacturer which makes such kind of pcbs and they
call them Rigid Flex PCBs.
http://www.saturnflex.com/rigid-flex.htm

But my question about which layer to choose for embedded flex pcb in
my pcb stack? remains un answered.

Regards,

Asim
 
On Feb 17, 12:09 pm, asimlink <asiml...@gmail.com> wrote:
On Feb 17, 5:34 am, Charlie E. <edmond...@ieee.org> wrote:



On Tue, 15 Feb 2011 10:41:15 +0000, John Devereux

j...@devereux.me.uk> wrote:
asimlink <asiml...@gmail.com> writes:

Hi Group,

I am in design process of a 12 layer board. This is first time i need
to design embedded flex pcb for my design.
This board requires a two layer flex pcb which is embedded in some of
the layer of the board. I have discussed with pcb manufacturers in
china but they usually answer questions when board is already made.
This maybe because of the language barrier we have between, and due to
time constraints i cant afford to go for this approach, that i first
design pcb and then let the manufacturer find errors in my design.

My board looks like this:
======Rigid PCB=======------FLEX PCB----=====RIGID PCB===
Following is the 12 layer Stack which i plan to design:
1. Top Signal
2. Power Plane
3. Mid Signal1
4. Mid Signal2
5. Power Plane
6. Mid Signal3
7. Mid Signal4
8. Power Plane
9. Mid Signal5
10. Mid Signal6
11. Power Plane
12. Bottom Signal

Total thickness required for the Rigid pcb is 1.25mm

Questions:
1. I need to know how embedded flex pcb are designed
2. Can someone tell me how do i select which layer to choose for
embedded flex pcb in my pcb stack?

Best Regards,

Asim

Sorry I can't help, but I am curious as to why this is done - anyone
know? What is the point of a flex PCB inside a rigid one? Or does it
stick out one end or something?

Usually, it is because the two boards need to be either at an angle,
or folded one over the other.  If I were doing it, they would be
designed as three separate boards, with the flex board connected via a
connector at each end...

Charlie

Dear Friends,

I definitely would love to design it as separate boards but reality is
that the board has to be made in the form factor as i mentioned in my
last post.
Charlie has well explained the reason why we need to do it that way.
There is already a board made in this way and I need to revise the
design with changes to circuit in the same form factor.

Regards,

Asim
Click to expand...
I have found an interesting article on rigid flex pcbs. i am reading
it to understand what i need to do.
i would like to share with the group:
http://pcdandf.com/cms/magazine/41/4466

Regards,

Asim
 
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