Effect of moon phase on tombstoning

Description

Many factors play a role in the overall outcome of PCB assembly, especially when very small components are involved. Broadly speaking, tombstoning is a problem with very small 2-pin components (0201 caps and such) and we've filtered out the following challenges:
- proper paste application
- component placement
- designing for "good" thermal properties of the PCB with regard to tombstoning
- moon phase
It seems that the effect of moon phase is least understood and researched, so I'm now designing a small PCB that is cheap, not useless (if the assembly process was successful), and - most importantly - contains some 0201 components.

Project Logs

Collapse

Nr. 15
Christoph • 4 days ago • 0 comments

20220519 - 23:44 - no tombstones.
Nr. 14
Christoph • 05/11/2022 at 20:27 • 0 comments

20220511 - 22:17 - no tombstones.
Nr. 13
Christoph • 05/01/2022 at 20:50 • 0 comments

20220501 - 11:11 - no tombstones.
Nr. 12
Christoph • 04/24/2022 at 21:05 • 0 comments

20220424 - 15:35 - 360R didn't sink into one of the pads. That counts!
I also accidentally used low temp paste on this board, so it's double cursed.
Nr. 7 also had a problem with the 360R resistor, maybe that value is especially sensitive.
Nr. 11
Christoph • 04/18/2022 at 20:10 • 0 comments

20220418 - 21:47 - no tombstones.
Nr. 10
Christoph • 04/15/2022 at 21:36 • 0 comments

20220415 - 23:29 - no tombstones.
Nr. 9
Christoph • 04/04/2022 at 18:01 • 0 comments

20220404 - 19:54 - no tombstones.
Paste for 240 and 360 Ohm resistors required manual rework prior to reflow because of sloppy squeegee action.
Nr. 8
Christoph • 03/30/2022 at 20:53 • 0 comments

20220330 - 20:05 - no tombstones.
I do admit that I swapped two resistors. Might be significant.
Nr. 7 - Major breakthrough!
Christoph • 03/20/2022 at 18:35 • 0 comments

There was a little pause because we had holidays and went on vacation so I missed the last full moon (20220318), but there are plenty of parts left.
Soldered Nr. 7 today - 20220320 - 18:27
One resistor (the 360R one) didn't sink into the solder on one side, resulting in an open connection. I'll generously count this as the first tombstone in this experiment:
Nr. 6
Christoph • 02/21/2022 at 16:47 • 0 comments

20220221 - 16:11 - no tombstones.

View all 19 project logs

Discussions

Bharbour wrote 12/31/2021 at 21:07

Maybe you need a rubber chicken on your bench? :)

Are you sure? yes | no

Christoph wrote 12/31/2021 at 22:18

I can add various arcane helpers along the way and see if they have any effect! Thanks for the suggestion

Are you sure? yes | no

Dan Maloney wrote 10/19/2020 at 21:04

First thing that comes to mind is the SMD Challenge kit on Tindie: https://www.tindie.com/products/makersbox/smd-challenge/

That goes down to 0201, but starts at 1206 so you can get warmed up. Little pricey, but they do have volume discounts.

Good luck, interested to see your results.

Are you sure? yes | no

Christoph wrote 10/19/2020 at 21:49

Well it doesn't have to be a design that's already done. Designing a custom PCB for this project wouldn't be a problem. I'd then simply order a batch of 25 or so (that would already be enough for half a year)

Are you sure? yes | no

Dan Maloney wrote 10/19/2020 at 22:08

True, like I said, just what popped into my head. The other thought I had was to pass the boards around to various people who can do the test at various times of the month. Could help get better statistics and possibly control for skill level.

Are you sure? yes | no

Christoph wrote 10/20/2020 at 18:08

Replying to your top level comment because I can't reply to the other one.

Passing the boards around might be fun, otoh if I just publish the design everyone can add their results to the pile.

I'm now leaning towards a PCB with no actual function that just has some 0201 footprints in two different styles (more and less prone to tombstoning) and with different thermal surroundings. I'd place a mix of caps and resistors, maybe 16 per PCB. That's plenty to get me dizzy for a week until the next is due.

Are you sure? yes | no

Effect of moon phase on tombstoning

Description

Project Logs

Collapse

Nr. 15

Nr. 14

Nr. 13

Nr. 12

Nr. 11

Nr. 10

Nr. 9

Nr. 8

Nr. 7 - Major breakthrough!

Nr. 6

Discussions

Similar Projects

Global View

blinktronicator

FFCPStep

Möbius Flex

Effect of moon phase on tombstoning

Become a Hackaday.io member

Just one more thing

Description

Project Logs Collapse

Enjoy this project?

Discussions

Become a Hackaday.io Member

Similar Projects

Does this project spark your interest?

Report project as inappropriate

Send message

Remove Member

Project Logs

Collapse