Solder through-hole penetration?

[Drew Eckhardt]

I used to use solid solder with liquid RMA flux. Didn't have problems soldering on one side of the board and having it flow through to the other.

I lost the flux and solder in a move, and bought a roll of Kester no-clean flux core solder. Penetration is spottier now - I'm probably touching up 1 in 20 joints on the component side of the board. Should I blame the switch to flux-core, the no-clean flux, or attrophied soldering skills?

I'm still using the same Metcal MX500 with a 700 degree tip (movers didn't loose that; my test leads and multi-meter are a different story).

[clem_o]

Probably due to the flux-core. Liquid flux gets there (flows) before the copper has time to oxidize due to the heat of the solder / iron; flux core requires melting of the solder first, oxidizing the work partially.

Personally have not tried commercial liquid flux, but something I've worked with a reasonable number of times is rosin melted in a suitable carrier - it can be brushed on prior to soldering, aiding the solder flow.

Cheers

[Drew Eckhardt]

Originally posted by clem_o
Probably due to the flux-core. Liquid flux gets there (flows) before the copper has time to oxidize due to the heat of the solder / iron; flux core requires melting of the solder first, oxidizing the work partially.

Yep, that's the ticket.

I tried a flux pen with the same Kester no-clean flux and found that it solved my problem.

[clem_o]

Good to know!

If you decide to move in the future better put the good stuff in a bag and carry it yourself! :-)

Cheers

[mitwrong]

Hi, Gents:

From my experience, It's not difficult to solder PTH boards.

First prepare rosin and dip into solvent until it becomes liquid rosin flux. solvent could be menthol spirit or thinner, Next get an air pump ( the one used in aquarium ) with the air stone. Before soldering, pour rosin flux in plastic bowl with the air pump on, then you will find rosin bubble flows at the top part of the bowl, place the PCB ( to be soldered ) over the bubble, the rosin bubble will cracked under the PCB, and the holes were filled with a thin film of rosin, then insert component and solder, this way, you will find the solder flows nicely up and down the holes. If dip solder to be applied, do the insertion before rosin flux, then the PCB will
be more soldered professionally.




WE SOLDER ACCORDING TO IPC SPECIFICATION

[clem_o]

Interesting technique! Thanks!

Cheers