PCB fab for SHF laminates with immersion silver plating and solder resist?


Neil Smith G4DBN
 

I need to get some silver-plated PCBs made for high power 10 GHz SSPAs using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the PCBs into a milled copper housing.

Does anyone have experience of PCB fabs who can do immersion silver finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a quote from Eurocircuits and I've used them previously. I know there are some Chinese fabs that can do silver, but it is an expensive business and I want to be 100% sure of the quality.

I need the boards milling with rounded corners and a pocket for the devices.  I'd like solder resist if that is an option, so I can do reflow of the passives and thermal monitor chips without them sliding about the place.

Price for a 40 x 40 mm board in 30-off, with milling, silvering and resist on an I-Tera laminate is about £12 each for 5 day service from their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C needs a special quote. Anyone know of a supplier with these capabilities that offers better pricing?

Neil G4DBN


Mark GM4ISM
 

Hi Neil

 Never used them myself but a few years ago at EuMW I did discuss with Trackwise, a UK based fab house, the idea of supporting  the amateur radio community with  small volume specialised PCBs. They sounded positive. The quality of the samples they had   on display was very high.

They are still about, maybe worth asking if you haven't heard of them before.   No import duty :)

Mark GM4ISM

On 29/04/2021 12:17, Neil Smith G4DBN wrote:
I need to get some silver-plated PCBs made for high power 10 GHz SSPAs using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the PCBs into a milled copper housing.

Does anyone have experience of PCB fabs who can do immersion silver finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a quote from Eurocircuits and I've used them previously. I know there are some Chinese fabs that can do silver, but it is an expensive business and I want to be 100% sure of the quality.

I need the boards milling with rounded corners and a pocket for the devices.  I'd like solder resist if that is an option, so I can do reflow of the passives and thermal monitor chips without them sliding about the place.

Price for a 40 x 40 mm board in 30-off, with milling, silvering and resist on an I-Tera laminate is about £12 each for 5 day service from their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C needs a special quote. Anyone know of a supplier with these capabilities that offers better pricing?

Neil G4DBN




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Dave G8KHU
 

Neil
Minnitron in Ramsgate may be worth asking for a quote - http://www.minnitron.co.uk

I've used their prototyping service (pcbpanel.co.uk ) and the quality and turnround was good and the price very competative for a UK manufactuer. Unfortuanately they don't do Rogers on the prototyping service.

I asked them about Rogers 4033C and 4350B and they carry both as standard stock items but I haven't sent them any designs for quote as yet so I can't comment on price. I'll be doing that in the next week or so and can let you know if their standard service is as competative as their protypes.

Dave G8KHU


KENT BRITAIN
 

Most of the RF field is between the Copper Trace and the Ground Plane.
Some Silver on top of the PCB trace will have very little effect on losses.
Kent WA5VJB



On 29/04/2021 12:17, Neil Smith G4DBN wrote:
> I need to get some silver-plated PCBs made for high power 10 GHz SSPAs
> using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the
> PCBs into a milled copper housing.
>
> Does anyone have experience of PCB fabs who can do immersion silver
> finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a
> quote from Eurocircuits and I've used them previously. I know there
> are some Chinese fabs that can do silver, but it is an expensive
> business and I want to be 100% sure of the quality.
>
> I need the boards milling with rounded corners and a pocket for the
> devices.  I'd like solder resist if that is an option, so I can do
> reflow of the passives and thermal monitor chips without them sliding
> about the place.
>
> Price for a 40 x 40 mm board in 30-off, with milling, silvering and
> resist on an I-Tera laminate is about £12 each for 5 day service from
> their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C
> needs a special quote. Anyone know of a supplier with these
> capabilities that offers better pricing?
>
> Neil G4DBN
>
>
>
>
>
>

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ian hope (2E0IJH)
 

Cant comment on Minnitron's pricing or quality, but they seemed a great company when I did some contract wiring for them a few years ago, seemed a very proffesional outfit, very clean and high standards from what I saw going on.
 
Ian
M5IJH

 
 
Sent: Thursday, April 29, 2021 at 1:54 PM
From: "Dave G8KHU" <david@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?
Neil
Minnitron in Ramsgate may be worth asking for a quote - http://www.minnitron.co.uk

I've used their prototyping service (pcbpanel.co.uk ) and the quality and turnround was good and the price very competative for a UK manufactuer. Unfortuanately they don't do Rogers on the prototyping service.

I asked them about Rogers 4033C and 4350B and they carry both as standard stock items but I haven't sent them any designs for quote as yet so I can't comment on price. I'll be doing that in the next week or so and can let you know if their standard service is as competative as their protypes.

Dave G8KHU


Neil Smith G4DBN
 

Ah, good point.  I was thinking about coplanar waveguide with fences of vias at each side rather than isolated microstrip, with narrow gaps so there are significant fields through the air, for an effective epsilon_r of the average of the substrate and air. Perhaps that might not be worth the extra effort at 10 GHz, even at 40+ watts? I had almost convinced myself to try direct waveguide launch from a probe milled from the PCB, but I had a lie-down and thought better of it.

I've seen several boards with vapourised output microstrips cause by thermal cycling and delamination so I want to avoid any thermal issues if at all possible, even though I'll be using fluid cooling on these.

Neil G4DBN

On 29/04/2021 14:03, KENT BRITAIN wrote:
Most of the RF field is between the Copper Trace and the Ground Plane.
Some Silver on top of the PCB trace will have very little effect on losses.
Kent WA5VJB



On 29/04/2021 12:17, Neil Smith G4DBN wrote:
> I need to get some silver-plated PCBs made for high power 10 GHz SSPAs
> using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the
> PCBs into a milled copper housing.
>
> Does anyone have experience of PCB fabs who can do immersion silver
> finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a
> quote from Eurocircuits and I've used them previously. I know there
> are some Chinese fabs that can do silver, but it is an expensive
> business and I want to be 100% sure of the quality.
>
> I need the boards milling with rounded corners and a pocket for the
> devices.  I'd like solder resist if that is an option, so I can do
> reflow of the passives and thermal monitor chips without them sliding
> about the place.
>
> Price for a 40 x 40 mm board in 30-off, with milling, silvering and
> resist on an I-Tera laminate is about £12 each for 5 day service from
> their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C
> needs a special quote. Anyone know of a supplier with these
> capabilities that offers better pricing?
>
> Neil G4DBN
>
>
>
>
>
>

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-- 
Neil
http://g4dbn.uk


Neil Smith G4DBN
 

Sounds expensive! I'll have to send them some sample Gerbers and see what price they come up with.

Neil G4DBN

On 29/04/2021 14:12, ian hope (2E0IJH) wrote:
Cant comment on Minnitron's pricing or quality, but they seemed a great company when I did some contract wiring for them a few years ago, seemed a very proffesional outfit, very clean and high standards from what I saw going on.
 
Ian
M5IJH
 
 
Sent: Thursday, April 29, 2021 at 1:54 PM
From: "Dave G8KHU" <david@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?
Neil
Minnitron in Ramsgate may be worth asking for a quote - http://www.minnitron.co.uk

I've used their prototyping service (pcbpanel.co.uk ) and the quality and turnround was good and the price very competative for a UK manufactuer. Unfortuanately they don't do Rogers on the prototyping service.

I asked them about Rogers 4033C and 4350B and they carry both as standard stock items but I haven't sent them any designs for quote as yet so I can't comment on price. I'll be doing that in the next week or so and can let you know if their standard service is as competative as their protypes.

Dave G8KHU
_._,_._,_


Neil Smith G4DBN
 

No duty on Eurocircuits, and they charge UK VAT, so there isn't much of an advantage for UK fabs.  The awkward bit is that for 100+ boards, most fabs prices start to level off, but in the 10-30 quantity, the UK fabs I've asked before were just wanting silly money and it rather put me off asking again.

Neil G4DBN

On 29/04/2021 13:54, Mark GM4ISM via groups.io wrote:
Hi Neil

 Never used them myself but a few years ago at EuMW I did discuss with Trackwise, a UK based fab house, the idea of supporting  the amateur radio community with  small volume specialised PCBs. They sounded positive. The quality of the samples they had   on display was very high.

They are still about, maybe worth asking if you haven't heard of them before.   No import duty :)

Mark GM4ISM



On 29/04/2021 12:17, Neil Smith G4DBN wrote:
I need to get some silver-plated PCBs made for high power 10 GHz SSPAs using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the PCBs into a milled copper housing.

Does anyone have experience of PCB fabs who can do immersion silver finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a quote from Eurocircuits and I've used them previously. I know there are some Chinese fabs that can do silver, but it is an expensive business and I want to be 100% sure of the quality.

I need the boards milling with rounded corners and a pocket for the devices.  I'd like solder resist if that is an option, so I can do reflow of the passives and thermal monitor chips without them sliding about the place.

Price for a 40 x 40 mm board in 30-off, with milling, silvering and resist on an I-Tera laminate is about £12 each for 5 day service from their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C needs a special quote. Anyone know of a supplier with these capabilities that offers better pricing?

Neil G4DBN






Tim, VK2XAX
 

Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim

--
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


Neil Smith G4DBN
 

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim


Stefan
 

Neil

How many dollars are those devices?

Stefan

----- Original Message -----
From: "Neil Smith G4DBN" <neil@g4dbn.uk>
To: <UKMicrowaves@groups.io>
Sent: Friday, April 30, 2021 8:40 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?


typo sorry, missed the 1.

https://www.mouser.co.uk/datasheet/2/90/CMPA901A035F-1665444.pdf

and

https://www.mouser.co.uk/datasheet/2/90/cmpa801b025-876408.pdf for the older one I have.

Neil G4DBN

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim




Neil Smith G4DBN
 

Mouser list them at £350 delivery and duty paid, so that should include local UK purchase tax. Digikey have no current stock. Verical and Arrow have stock. Not sure of the dollar price, have a look on Octopart or try to beg a sample from Wolfspeed? 

They will need a declaration of use statement and may not ship to some locations (at least that’s what happened with my 025 device).

On 30 Apr 2021, at 00:11, Stefan <comlab@...> wrote:

Neil

How many dollars are those devices?

Stefan
----- Original Message ----- From: "Neil Smith G4DBN" <neil@...>
To: <UKMicrowaves@groups.io>
Sent: Friday, April 30, 2021 8:40 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?


typo sorry, missed the 1.

https://www.mouser.co.uk/datasheet/2/90/CMPA901A035F-1665444.pdf

and

https://www.mouser.co.uk/datasheet/2/90/cmpa801b025-876408.pdf for the older one I have.

Neil G4DBN

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim












Stefan
 


ah cheers Neil thank you

----- Original Message -----
Sent: Friday, April 30, 2021 9:33 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?

Mouser list them at £350 delivery and duty paid, so that should include local UK purchase tax. Digikey have no current stock. Verical and Arrow have stock. Not sure of the dollar price, have a look on Octopart or try to beg a sample from Wolfspeed? 

They will need a declaration of use statement and may not ship to some locations (at least that’s what happened with my 025 device).

https://au.mouser.com/ProductDetail/Wolfspeed-Cree/CMPA901A035F shows 622 AUD

Neil G4DBN



On 30 Apr 2021, at 00:11, Stefan <comlab@...> wrote:

Neil

How many dollars are those devices?

Stefan
----- Original Message ----- From: "Neil Smith G4DBN" <neil@...>
To: <UKMicrowaves@groups.io>
Sent: Friday, April 30, 2021 8:40 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?


typo sorry, missed the 1.

https://www.mouser.co.uk/datasheet/2/90/CMPA901A035F-1665444.pdf

and

https://www.mouser.co.uk/datasheet/2/90/cmpa801b025-876408.pdf for the older one I have.

Neil G4DBN

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim












Tim, VK2XAX
 

Hi Stefan,

The CMPA801B025F is ~$635 from Mouser in AU

https://au.mouser.com/ProductDetail/Wolfspeed-Cree/CMPA801B025F?qs=FhbYA5MVMOWms%252Bq06Tnnjw%3D%3D

The CMPA901B035F is ~$611 from Mouser in AU

https://au.mouser.com/ProductDetail/Wolfspeed-Cree/CMPA901A035F?qs=BJlw7L4Cy78O8lOH7Btn7w%3D%3D

Why the higher power part costs less is a mystery!

regards

Tim

On 30/4/21 9:11 am, Stefan wrote:
Neil

How many dollars are those devices?
--
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


Stanislaw Ziemczonek
 

Neil,
Considering Kent's comments, it would be more sensible to use a laminate with a glued (pressed) layer of copper (I don't remember the type) than electrochemically applied , in which the copper layer on the laminate side is uneven and causes losses due to surface conduction of microwaves
73's de Staszek SP6GWB

Most of the RF field is between the Copper Trace and the Ground Plane.
Some Silver on top of the PCB trace will have very little effect on losses.
Kent WA5VJB



On 29/04/2021 12:17, Neil Smith G4DBN wrote:
> I need to get some silver-plated PCBs made for high power 10 GHz SSPAs
> using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the
> PCBs into a milled copper housing.
>
> Does anyone have experience of PCB fabs who can do immersion silver
> finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a
> quote from Eurocircuits and I've used them previously. I know there
> are some Chinese fabs that can do silver, but it is an expensive
> business and I want to be 100% sure of the quality.
>
> I need the boards milling with rounded corners and a pocket for the
> devices.  I'd like solder resist if that is an option, so I can do
> reflow of the passives and thermal monitor chips without them sliding
> about the place.
>
> Price for a 40 x 40 mm board in 30-off, with milling, silvering and
> resist on an I-Tera laminate is about £12 each for 5 day service from
> their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C
> needs a special quote. Anyone know of a supplier with these
> capabilities that offers better pricing?
>
> Neil G4DBN
>
>
>
>
>
>

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Dave G8KHU
 

Rogers certainly do this - their Lo-Pro range - as  well as the deposited versions. I'm sure other manufacturers offer it too.
https://rogerscorp.com/-/media/project/rogerscorp/documents/advanced-connectivity-solutions/english/data-sheets/ro4000-lopro-laminates.pdf

<< it would be more sensible to use a laminate with a glued (pressed) layer of copper (I don't remember the type) than electrochemically applied , in which the copper layer on the laminate side is uneven and causes losses due to surface conduction of microwaves
73's de Staszek SP6GWB>>

Dave G8KHU


Dominique Dehays
 

Gm all,

I agree with G4DBN that a waveguide transition at the output will be better. Maybe this one would be more reliable if it is solid copper rather than a microstrp launcher.
See for exemple what has been done with our 24 Ghz 5w amps.

73
Dom



Neil Smith G4DBN
 

Thanks for all of the suggestions and ideas. I'll get some quotes and see about ordering some PCBs so I can have a play. I've bought two of the CMPA901A035F devices, and the total I suggested before was indeed ex VAT, so the inclusive price, delivered, is £420 each.  It almost sounds cheap if you say it REALLY fast.

I am an expert investor in bottomless money-pits, me. Oh yes. Ask my wife.  Actually, on reflection, don't.

Neil G4DBN