Circuit, PCB analysis tools

[JoergS5]

@zapta said in Circuit, PCB analysis tools:

The OP seems to prefer local apps over web apps so may not be a good fit.

this is only my personal taste, please everyone may go ahead talking about every software. Because this thread is meant to be a general discussion for all users, it may be interesting for others to use online tools, also. (And there are very good online tools like GeoGebra without registering, I use some of them).

I have the same problem with Micro-Cap, because it's not open source, I cannot modify it. But being so powerful, I'll proceed with it, looking at KiCad at the same time.

[zapta]

@joergs5, it seems that EasyESA also support simulation with an easy to use GUI which is very nice https://www.youtube.com/watch?v=5eoOV1IxkIU

@PCR, I see that Kicad 6 is out. Originally it was supposed to be released May 2021. I was waiting for it. Will see how difficult the transition is.

BTW, all of Duet's board are designed with Kicad.

[rjenkinsgb]

@zapta said in Circuit, PCB analysis tools:

The OP seems to prefer local apps over web apps

There is a fully downloadable version of EasyEDA - I don't like using anything web-based for files I want to control!

It can also import kicad files; I've used it to view Duet board files.

I'm criticizing kicad in any sense, just being sure there are no misunderstandings re. easyeda.

[JoergS5]

I have a different question about which reflow oven to use, maybe someone can help me.

I am thinking about buying a T-962A reflow oven and then modifying it (better temperature control, better heating). Is this a good idea or are there better options? I plan to develop small PCBs for interfaces, maybe 100x200 mm maximal, but two sides.

[JoergS5]

@rjenkinsgb EasyEDA is a nice program. I appreciate that there are a lot of circuits of other users where I can learn from them. Micro-Cap and KiCad have their uses also.

[zapta]

@joergs5 said in Circuit, PCB analysis tools:

T-962A reflow oven

I used a similar over in the past, with stencils, paste, and manual vacuums component picker but gave it away. It was too much of a hassle for my use cases.

Now I just solder the parts using tweezers and a fine solder iron, and with the Chinese stereo microscope I have, I can get down to 0402 components and 0.5mm pitch ICs.

Another option I am using now is JLCPCB SMD service which is reasonably priced so I try to include as many components that are available at JLCPCB and then solder the rest by hand.

I used to have a fancy Metcal soldering system but gave it away and now using this cheapo chineese that give me about the same results. They are so cheap that I have a few of them, each each a different tip and temperature setting. https://www.aliexpress.com/item/4000129151281.html

For manual soldering, I recommend getting good flux paste such as AmTech (spelling?) and a cheap optical stereo microscope, you don't need high magnification, ~x5 works well for PCB worked. I am using this one https://www.amazon.com/gp/product/B00A15N1ZA there are many models, including ones with long boom base. The light ring is important.

YMMV.

[rjenkinsgb]

@joergs5 said in Circuit, PCB analysis tools:

I am thinking about buying a T-962A reflow oven

We use normal (good) temperature controlled irons for general work, and I have a cheap ebay hot air tool that works fine for surface mount ICs, when needed.

If you want complete boards, use JLCPCB - it's cheaper to have them also supply the parts and assemble the PCBs, than to buy the separate components!

[dc42]

@JoergS5 I use a domestic electric hotplate for reflow soldering small prototype boards. No need for a reflow oven unless you are going into production.

[JoergS5]

Thank you all for your feedback, so a reflow oven would be exaggerated. I'll look into your proposals.

[JoergS5]

@dc42 said in Circuit, PCB analysis tools:

domestic electric hotplate for reflow soldering

that's intersting, maybe I can solder with this my solar modules (I bought raw cells) with tab wire as well. I can buy a cheap one for 260 °C. Is this sufficient, or do I need one with variable temperature, there is one for 50 to 350 °C.

The cheap one is https://www.amazon.co.uk/POHOVE-Heating-Soldering-Heating-Soldering-Laboratory/dp/B08XJGJN59 and the 50..350 is https://www.amazon.co.uk/Microcomputer-Electric-Heating-Preheating-Soldering/dp/B07WJ4THGP

[zapta]

@joergs5 , you may want to look also for hot plates that are intended for PCB reflow. There are many on Aliexpress and amazon and typically they come with good temperature display and control.

E.g.

https://www.aliexpress.com/item/1005002103189787.html

https://www.aliexpress.com/item/1005002103189787.html

Make sure to pick a hot plate that gets hot enough to reflow the solder you use. Some plates are used for 'preheating' which requires lower temperatures, below solder melting point.

https://www.youtube.com/watch?v=bz6OONg5hmg

You may want to look also on youtube for PCB paste/stencil techniques.

[JoergS5]

@zapta thanks a lot for your hints! I am used to look for videos first, but in this case I forgot to search for it.

There are big differences of prices...

I saw the video now, I am really surprised to learn something new, that avoiding temperature shock is an important reason.

[zapta]

@joergs5, when I was still using the reflow oven I looked for way to simplify the paste and part placement process. Some of my attempts included 3D printed parts like the ones below but eventually gave up on solder paste all together. YMMV

https://www.thingiverse.com/thing:1119914

https://www.thingiverse.com/thing:675336

https://www.thingiverse.com/thing:607270

https://www.thingiverse.com/thing:530949

[JoergS5]

@zapta

the last hour I'm thinking about how

• to place the paste onto the PCB with the robot arm
• fix the PCB on the heating plate
• control the quality of paste and SMB elements with camera and OpenCV

Similar to what you've done with your thingiverse objects.

[rjenkinsgb]

@joergs5 said in Circuit, PCB analysis tools:

Now having a few days for learning something new, I would be interested in analysing circuits and learning electronics. Maybe buying a reflow oven and experimenting.

---

@joergs5 said in Circuit, PCB analysis tools:

the last hour I'm thinking about how

to place the paste onto the PCB with the robot arm
fix the PCB on the heating plate
control the quality of paste and SMB elements with camera and OpenCV

I would very seriously suggest you get past the basics of designing and building / programming conventional circuits, using prototyping boards or stripboard etc., before even considering anything to do with surface mount assembly!

Surface mount is great for mass production, once designs are proven - but it is definitely not a good way of learning basic electronics or prototyping general circuits.

Even commercial designs that will eventually be surface mount construction often have the first prototypes built with conventional components - it's far easier to change parts or modify things, than on a fixed-layout surface mount PCB.

[JoergS5]

@rjenkinsgb said in Circuit, PCB analysis tools:

definitely not a good way of learning basic electronics

Sorry if you got a wrong impression of my knowledge. I learned electronic basics 43 years ago, when I made my ham radio exam. I have gaps in my knowledge like IGBT and which software to use, but I have electronic knowledge. And I love soldering. Currently I use breadboards for trying out new ideas, but they are unstable for normal usage.

[rjenkinsgb]

@joergs5 said in Circuit, PCB analysis tools:

I learned electronic basics 40 years ago, when I made my ham radio exam.

OK, sorry for the misunderstanding; I got the impression from your initial post that you were a complete beginner.

[Also a radio ham for 40+ years - G8TBF / G0WTK]

[JoergS5]

@rjenkinsgb said in Circuit, PCB analysis tools:

ham for 40+ years - G8TBF / G0WTK]

I am DF3TP

[zapta]

@joergs5 said in Circuit, PCB analysis tools:

to place the paste onto the PCB with the robot arm
fix the PCB on the heating plate
control the quality of paste and SMB elements with camera and OpenCV

You may want to look also at prior art in the area of makers' SMD assembly techniques and tools. There are all kind of attempt to make the process less painful and more efficient.

For example, this for automated pick and place https://openpnp.org or this for reflow temperature stabilization using vapor phase https://www.youtube.com/watch?v=czwRntpEzgg . DIY SMD technology can be an interesting hobby on its own.

[dc42]

@joergs5 I doubt that you will be able to achieve accurate solder paste placement for fine pitch components using a robot arm. When I was building SMD prototypes, I used to buy a cheap Mylar solder stencil. Hobbytronics does them in the UK, and Pololu in the US. JLCPCB now sells inexpensive stainless steel ones too.