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General => General Technical Chat => Topic started by: daqq on July 31, 2019, 09:50:49 am

Title: Built in resistors in PCB
Post by: daqq on July 31, 2019, 09:50:49 am

This is pretty awesome:

https://www.pcbcic.com/wp-content/uploads/2017/10/5-Ohmega_Design_Version_18_1.pdf (https://www.pcbcic.com/wp-content/uploads/2017/10/5-Ohmega_Design_Version_18_1.pdf)

Basically resistive material is built into the conductive layers (even internal) of a PCB and the technology seems pretty precise, enabling stuff like termination/pullup resistors on the inner layers between the balls of a fine pitch BGA.

Title: Re: Built in resistors in PCB
Post by: Brutte on July 31, 2019, 11:44:30 am

Carbon ink comes to mind, although carbon ink can be only applied to surface and vias (no internal layers afaik).

I am not sure how to integrate that in a toolchain (managing libraries, testing, DRC, etc). For termination of GHz signals under FPGA it might have its place but in mainstream electronics the access to this kind of service seems quite limited. For analog applications and 3% tolerance - niche market.

I am waiting for a built-in transistor  :popcorn:

Title: Re: Built in resistors in PCB
Post by: soldar on July 31, 2019, 03:26:02 pm

I can see in the future PCBs where the tracks are really printed and the ICs are embedded inside the PCB, not on the surface.

Title: Re: Built in resistors in PCB
Post by: daqq on July 31, 2019, 05:45:17 pm

Quote

I can see in the future PCBs where the tracks are really printed and the ICs are embedded inside the PCB, not on the surface.

Some of this is actually being done already:
https://www.microsemi.com/product-directory/services/3710-package-miniaturization-services (https://www.microsemi.com/product-directory/services/3710-package-miniaturization-services)
https://nmi.org.uk/wp-content/uploads/2016/10/1-IMAPS_UK_2016_Ostmann.pdf (https://nmi.org.uk/wp-content/uploads/2016/10/1-IMAPS_UK_2016_Ostmann.pdf)

The initial costs must be insane, but probably worth it.

Title: Re: Built in resistors in PCB
Post by: GlennSprigg on August 01, 2019, 12:00:30 pm

I was led to believe that some original IC's, had 'Pseudo' components, like....
Very thin 'tracks' as resistors, and very CLOSE tracks as Capacitors ??

Title: Re: Built in resistors in PCB
Post by: SiliconWizard on August 01, 2019, 01:30:53 pm

Yes you can embed components inside a PCB.
https://www.we-online.com/web/fr/index.php/show/media/04_leiterplatte/2015_1/webinare_4/embedding/WE_CBT_ECT_How_to_handle_a_PCB_project_with_embedded_components.pdf (https://www.we-online.com/web/fr/index.php/show/media/04_leiterplatte/2015_1/webinare_4/embedding/WE_CBT_ECT_How_to_handle_a_PCB_project_with_embedded_components.pdf)

Title: Re: Built in resistors in PCB
Post by: @rt on August 01, 2019, 02:15:25 pm

If I etch the copper I might get a capacitor.