Copper attachments for pcb, For better thermal and grounding

[nikhil_56]

Hi
We are trying to attach copper base (0.5mm thickness) with rogers pcb. Rogers pcb already got manufactured additionally we are trying to pour some lead in between pcb base (ground plane) and copper plane, why means we are using this for high power applications for better heat dissipation and better grounding we are doing this process. can any one suggest process that need to follow.

like the issue is when we are trying to attach pcb with copper base because there are no vias, due to air inbetween the pcb and copper base it is not getting attached properly!

for what kind of substrate (material) it is ok to attach pcb with copper, and for which material it is not recommended to attach or soldered.

in my case substrates that we are using:
1. rogers 4350b 20mil thickness
2. RT duriod 5880
3. Rogers 6035HTC 30mils thickness.

 

[aliarifat794]

The issue you're facing, where air between the PCB and the copper base prevents proper attachment, is common when there are no vias. Clean the PCB ground plane and make it free from contaminants. Make the copper base clean. It must be free of oxidation. Use thermally Conductive Adhesives. Avoid Soft or Flexible Substrates. For more info about Rogers PCB, you can see here: https://www.pcbway.com/blog/12/What_is_a_Rogers_PCB_PCB_Knowledge_372fe809.html

 

[nikhil_56]

The issue you're facing, where air between the PCB and the copper base prevents proper attachment, is common when there are no vias. Clean the PCB ground plane and make it free from contaminants. Make the copper base clean. It must be free of oxidation. Use thermally Conductive Adhesives. Avoid Soft or Flexible Substrates. For more info about Rogers PCB, you can see here: https://www.pcbway.com/blog/12/What_is_a_Rogers_PCB_PCB_Knowledge_372fe809.html

Like my doubt is:

Is it ok to attach copper base 0.5mm thickness with rogers 6035HTC PCB(30mils). We are using for high power applications that's why we are trying to attach copper and PCB.

 

[biff44]

You can solder the back side (if it is a solid copper ground plane) to a thick copper plate. this plate will be easier to attach to a heat sink, and if it is thick enough the heat will spread laterally, giving you a lower thermal resistance.

But ideally you DO use via holes. gold holes are vias to the ground plane backside. but screws, like on the bottom, can kind of work if the frequency is not too high