PCB Fabrication Questions

Thread Starter

phillipsoasis

Joined Aug 22, 2022
63
I am working on my first PCB, and I am looking for some advice and direction. I am using KiCad 7, and so far it is working well. I have some more general questions regarding pcb fabrication and what options to choose.

1. I am considering PCBWay to make my 4 layer board due to cost and delivery speed. Any pros or cons I should be aware of? Are there other manufacturers that you have used that you prefer?

2. The KiCad default for min hole size is 0.5 mm. PCBWay offers 0.15, 0.2, 0.25, 0.3, 0.8, 1.0 mm options. What should I use? I ran into an error in the DRC for the pcb as I am using a vertical microUSB connector on the board, and the holes in the footprint are 0.4444 and KiCad complained.

3. Following on from my second question, what are some good rules of thumb for all of the options presented by PCBWay? I am a bit overwhelmed by all the choices. The fastest signal on my board is the 2.34 MHz clock for an SPI interface to a Raspberry Pi. The rest is just switching some high current lines with relays and some analog measurements.

Screenshot from 2023-10-24 10-06-03.png
 

BobTPH

Joined Jun 5, 2013
8,664
2. The KiCad default for min hole size is 0.5 mm. PCBWay offers 0.15, 0.2, 0.25, 0.3, 0.8, 1.0 mm
Surely you must be misinterpreting that. JLCPCB allows any hole size between 0.2 and 6.3 mm. As I understand it they have mill bits in various sizes and rout the holes that are not one of those sizes. Perhaps the sizes listed are the size of mill bits they use, but can make any size hole.
 

eetech00

Joined Jun 8, 2013
3,823
I am working on my first PCB, and I am looking for some advice and direction. I am using KiCad 7, and so far it is working well. I have some more general questions regarding pcb fabrication and what options to choose.

1. I am considering PCBWay to make my 4 layer board due to cost and delivery speed. Any pros or cons I should be aware of? Are there other manufacturers that you have used that you prefer?

2. The KiCad default for min hole size is 0.5 mm. PCBWay offers 0.15, 0.2, 0.25, 0.3, 0.8, 1.0 mm options. What should I use? I ran into an error in the DRC for the pcb as I am using a vertical microUSB connector on the board, and the holes in the footprint are 0.4444 and KiCad complained.

3. Following on from my second question, what are some good rules of thumb for all of the options presented by PCBWay? I am a bit overwhelmed by all the choices. The fastest signal on my board is the 2.34 MHz clock for an SPI interface to a Raspberry Pi. The rest is just switching some high current lines with relays and some analog measurements.

View attachment 305782
I use JLCPCB. Excellent service.

Looks like your board could use defaults for a four layer board.

The microUSB library part should be designed to the actual physical parts' requirements.
Not the other way around.;)
 

liaifat85

Joined Sep 12, 2023
48
The minimum hole size depends on your design and the components you plan to use. Smaller holes can be useful for fine-pitch components or for dense layouts. 0.5 mm is a common default size for many PCB design software, but smaller sizes are available too.

If your microUSB connector has holes with a diameter of 0.4444 mm and KiCad's minimum hole size is 0.5 mm, it will indeed trigger DRC error. In this case, you should either adjust the hole size in your footprint to meet the minimum requirement, or choose a minimum hole size option that supports the existing holes.

By the way, there is a 'questions' section in PCBway's website too. You can post your question there like this.
https://www.pcbway.com/project/question/RF_PCB_design.html
Their engineers may guide you further.
 

Thread Starter

phillipsoasis

Joined Aug 22, 2022
63
Just an aside for others reading this post. I sent a question to the support group at JLCPCB asking them what distance would they suggest to use between high current power (500 msec pulses of 3-10 A @ 15V ) planes such as I have on my board. I have read that 0.5 mm is sufficient. I also asked if they would recommend placing these power planes on the top of the board for better heat dissipation. Their response was:

Hi there,
Good day!
I am sorry that we here only do fabrication. we are not able to answer pure technicial questions.
You may email to the design engineer support@easyeda.com for help.
Best regards,
Jonas

I am not trying to dis JLCPCB, just provide information based on my experience. I will most likely use JLCPCB for my board because of price.
 
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