Need advice on SMD connector adaptation to 2.54mm pitch connector

Hello,

I want to connect an existing PCB (the blue PCB on the picture) made for 2.54mm pitch header connector to a micro SMD connector of 0.8mm pitch. See the dimensions of this connector at the bottom of the figure. B is 10.2mm.
My first idea is to design a tiny PCB on which one side is soldered with the SMD microconector and the other side with pads that can be soldered to the 2.54mm holes of the blue PCB.

Do you think that this solution would work? I don't know how to solder the pads to the 2.54mm holes? Any suggestion?

Any optimization or alternatives are welcomed


in advance, thank you

Michel

Soldering pads are not necessary.Instead, use a 2.54 pitch simple header ( board-to-board) then solder tiny SMD connector to this additional PCB.
Simpler..

BigBoss said:

Soldering pads are not necessary.Instead, use a 2.54 pitch simple header ( board-to-board) then solder tiny SMD connector to this additional PCB.
Simpler..

Click to expand...

Thank you BissBoss for the suggestion.

I need the height of the assembly to be as thin as possible: around 5mm. Sorry to forget this detail.
Standard 2.54mm pin headers are of 7mm height that is too much thick. Unless you know special flat models?

thx

You didn't tell how much lateral (horizontal) room is available. Also, is it assembly of a few prototypes or larger quantities? With sufficient room, I would use edge metallized pads. Reflow soldering of bottom pads could work, too.

Edge metallization example

FvM said:

You didn't tell how much lateral (horizontal) room is available. Also, is it assembly of a few prototypes or larger quantities? With sufficient room, I would use edge metallized pads. Reflow soldering of bottom pads could work, too.

Click to expand...

Thank you FvM for your help.
I don't have lateral space.
For the moment it is for prototypes purpose but I would like to use the same technics for large quantities.

The existing (blue) PCB do not have edge metallized pads/castellated PCB, so I don't see how to it to the other PCB
If I make the green PCB with edge metallized pads, how can I solder edges with the 2.54mm holes of the blue PCB?

michcfr said:

Thank you BissBoss for the suggestion.
I need the height of the assembly to be as thin as possible: around 5mm. Sorry to forget this detail.
Standard 2.54mm pin headers are of 7mm height that is too much thick. Unless you know special flat models?
thx

Click to expand...

Use similar one like that..
https://www.mouser.com.tr/ProductDe...BGHln7q6pmyCtg3ewPhFrcOiYA2cent0ReY2aSRDnaw==

If I make the green PCB with edge metallized pads, how can I solder edges with the 2.54mm holes of the blue PCB?

Click to expand...

On top of the pin header pads.

- - - Updated - - -

but I would like to use the same technics for large quantities.

Click to expand...

Isn't it cheaper to redesign the blue PCB?

FvM said:

On top of the pin header pads.
- - - Updated - - -

Click to expand...

ok, I see. Thank you.

FvM said:

- - - Updated - - -
Isn't it cheaper to redesign the blue PCB?

Click to expand...

I don't know yet, but the blue PCB is something widely spread in the Chinese market (Alibaba) for few $ and there are many other type of blue PCB I have to adapt in the same way.
I think that the total cost is higher because of the "wasted" time for the blue PCB part realisation: sourcing components, design the PCB, assembling, testing.... in addition there are: stock mgt, leading time issues....

"Patching" the blue PCB seems to be the best strategy. Does it makes sense?

- - - Updated - - -

BigBoss said:

Use similar one like that..
https://www.mouser.com.tr/ProductDe...BGHln7q6pmyCtg3ewPhFrcOiYA2cent0ReY2aSRDnaw==

Click to expand...

Thank you BigBoss
This connector is 8.3mm height. Nothing more flat? 4mm or less?