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1answer
139 views

Will PCB board house accept this QFN thermal pad via design (KiCad)?

I am going to be ordering this board from JLCPCB which has some 0.2 mm hole diameter thermal vias on a QFN pad, and it says on their capabilities page that the smallest via hole size is 0.3 mm, BUT ...
5
votes
5answers
2k views

How closely should I space my thermal vias?

How closely do you pack your thermal vias? I know that more vias divides the amount of heat each via can move and that smaller vias allows more vias to be packed together. Knowing this, it seems ...
25
votes
7answers
13k views

Optimize heat sink design - connect cooling pad on PCB backside by vias

In one of my current projects I'm using an MC7805 in a D2PAK package to generate my logic supply of 5 V from an available 24 VDC supply. The current required by the circuit is 250 mA. ...
0
votes
2answers
303 views

What can I do about this thermal pad?

I recently made a board for the TPA3004D2 Class-D Amplifier Chip. It has a fairly large thermal pad on the bottom for heat dissipation. I used an existing TQFP-48 library in Eagle that had a thermal ...
3
votes
1answer
7k views

Thermal vias in Eagle (CAD)

I'm making a part in Eagle (4.15) for a SOIC-8 package. There is a thermal pad in the center and I'm trying to add vias stitching the top and bottom pads together. In the Eagle package editor there ...
10
votes
1answer
478 views

Purpose of exposed ground pads

I have a Beckhoff EL2008 8-channel digital output terminal that I took apart because I'm using an ASIC that is inside the module, Beckhoff's ET1200. There is essentially a ring of ground pads,some ...
2
votes
3answers
385 views

Do I need to use thermals on vias for reliability?

This question is further to Why thermal reliefs on vias? I have recently been advised (by someone I consider an expert) that I should add thermal reliefs to vias which are connected to planes, even ...
6
votes
3answers
5k views

SOT-223 Thermal Pad and Vias

I am using a LDO with a SOT-223 footprint and since it might get hot, I wanted to make a nice thermal pad under it to dissipate that heat. I googled and I only found thermal pads, but i wanted some ...