PCB Cleaning

Discussion in 'Electronic Design' started by Jon Slaughter, Jan 15, 2010.

  1. Is it safe to soak a pcb in acetone for several minutes to clean it up all
    the flux? The board only has some QFN's, SMT LED's, and passive SMT's. I
    imagine the acetone won't harm these packages?
     
    Jon Slaughter, Jan 15, 2010
    #1
    1. Advertising

  2. Jon Slaughter

    Bob Eld Guest

    "Jon Slaughter" <> wrote in message
    news:hipkai$h07$-september.org...
    > Is it safe to soak a pcb in acetone for several minutes to clean it up all
    > the flux? The board only has some QFN's, SMT LED's, and passive SMT's. I
    > imagine the acetone won't harm these packages?


    I think acetone, MEK and similar solvents are too harsh. They can dissolve
    or swell some plastics and may damage components.

    I use 91% isopropyl alcohol or denatured ethanol both are mild and work
    well. Use a small brush to loosen flux then wipe with a soft clean cloth.
    Re-do if any residue remains.
     
    Bob Eld, Jan 15, 2010
    #2
    1. Advertising

  3. On Fri, 15 Jan 2010 05:42:06 -0600, "Jon Slaughter"
    <> wrote:

    >Is it safe to soak a pcb in acetone for several minutes to clean it up all
    >the flux? The board only has some QFN's, SMT LED's, and passive SMT's. I
    >imagine the acetone won't harm these packages?


    Do you think the epoxy used in making the PCB might react?

    I would not "soak" anything in a solvent other than something like a
    metal or other NON-porous material.

    PCB material is VERY porous, even though it may not appear so.

    It is epoxy and fiberglass.
     
    Archimedes' Lever, Jan 16, 2010
    #3
  4. On Fri, 15 Jan 2010 19:44:42 -0800, John Larkin
    <> wrote:

    >I've never seen a pcb be affected by a short time in acetone.



    "...soak for several minutes" is NOT "a short time".
     
    Archimedes' Lever, Jan 16, 2010
    #4
  5. Alcohol worked pretty well. It left a small amount of residue in some
    areas(white stuff which I have no what it is) and didn't get teh really
    burned flux off well. I'd say it was about 97-99% effective in removing the
    flux but not greating in making a pretty board. Luckily I only care about
    looks with my women ;)
     
    Jon Slaughter, Jan 16, 2010
    #5
  6. Jon Slaughter

    Tim Williams Guest

    "Phil Hobbs" <> wrote in message
    news:...
    >> I'm not sure if the name methylated spirits is used globally - maybe you
    >> know it as denatured alcohol ???

    >
    > Not the same thing. Methylated spirits is methanol, denatured alcohol is
    > ethanol with something really bad tasting added--used to be benzene, now
    > usually kerosene IIRC.


    No,
    "Traditionally, the main additive is 10% methanol, giving rise to the term
    methylated spirit"

    Denatured, in general, can include bitter stuff, but AFIAK benzene and such
    were removed a long time ago because people kept dying or something. OTOH,
    the article also says British regs add mineral spirits.
    http://en.wikipedia.org/wiki/Denatured_alcohol

    Tim

    --
    Deep Friar: a very philosophical monk.
    Website: http://webpages.charter.net/dawill/tmoranwms
     
    Tim Williams, Jan 16, 2010
    #6
  7. Jon Slaughter

    Mycelium Guest

    On Sun, 17 Jan 2010 10:06:12 -0600, "mook johnson" <> wrote:

    >
    >"John Larkin" <> wrote in message
    >news:...
    >> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <>
    >> wrote:
    >>
    >>>
    >>>"Bob Eld" <> wrote in message
    >>>news:hipunq$h3h$-september.org...
    >>>>
    >>>> "Jon Slaughter" <> wrote in message
    >>>> news:hipkai$h07$-september.org...
    >>>>> Is it safe to soak a pcb in acetone for several minutes to clean it up
    >>>>> all
    >>>>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's.
    >>>>> I
    >>>>> imagine the acetone won't harm these packages?
    >>>>
    >>>> I think acetone, MEK and similar solvents are too harsh. They can
    >>>> dissolve
    >>>> or swell some plastics and may damage components.
    >>>>
    >>>> I use 91% isopropyl alcohol or denatured ethanol both are mild and work
    >>>> well. Use a small brush to loosen flux then wipe with a soft clean
    >>>> cloth.
    >>>> Re-do if any residue remains.
    >>>>
    >>>
    >>>+1 on the alcohol recommendation. use an acid brush with the bristles cut
    >>>down to 1/2" long. squirt the alcohol inside the hollow brush handle and
    >>>it
    >>>will wick down the bristles while you are scrubbing.

    >>
    >> IPA tends to leave white residue when used to clean rosin flux.
    >>
    >>>Once the heavy buildup is loose, put paper towel between the board and the
    >>>brush and repeat allowing the papertowel to absorb the liquified flus and
    >>>alcohol mix.

    >>
    >> For really clean boards, the last step should be a squirt rinse with
    >> clean solvent.
    >>
    >> John

    >
    >
    >By alcohol I was referrring to 190 proof Everclear from the liquor store.
    >Seem I always have some handy for some reason. Keep the cap closed tight so
    >it doesn't absorb water.
    >
    >I've never had a problem with white residue.
    >
    >
    >
    >

    Grain alcohol and isopropyl alcohol (IPA) are two entirely different
    molecules. One is for drinking, and the other is the solvent, and is
    used in labs.
     
    Mycelium, Jan 17, 2010
    #7
  8. Jon Slaughter

    jadu Guest

    jadu had written this in response to
    http://www.electrondepot.com/electrodesign/Re-PCB-Cleaning-450232-.htm :

    John Larkin wrote:





    -------------------------------------
    Nice article If you are interested you can visit the
    www.leelaelectronics.in and
    browse many ultrasonic cleaners. Not just ultra sonic PCB cleaners but you
    will
    find many types of ultrasonic cleaners like table top cleaners , larger
    ultrasonic
    & other applications


    ##-----------------------------------------------#
    Delivered via http://www.electrondepot.com
    Electronics Enthusiasts' Community of the Ne
    Web and RSS access to your favorite newsgroup -
    sci.electronics.design - 368644 messages and counting
    ##-----------------------------------------------##
     
    jadu, Jan 19, 2010
    #8
  9. Jon Slaughter

    JosephKK Guest

    On Sat, 16 Jan 2010 12:39:05 -0800 (PST), mickgeyver <> wrote:

    >On Jan 16, 11:24 am, John Larkin
    ><> wrote:
    >> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <>
    >> wrote:
    >>
    >>
    >>
    >>
    >>
    >> >"Bob Eld" <> wrote in message
    >> >news:hipunq$h3h$-september.org...

    >>
    >> >> "Jon Slaughter" <> wrote in message
    >> >>news:hipkai$h07$-september.org...
    >> >>> Is it safe to soak a pcb in acetone for several minutes to clean it up
    >> >>> all
    >> >>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's. I
    >> >>> imagine the acetone won't harm these packages?

    >>
    >> >> I think acetone, MEK and similar solvents are too harsh. They can dissolve
    >> >> or swell some plastics and may damage components.

    >>
    >> >> I use 91% isopropyl alcohol or denatured ethanol both are mild and work
    >> >> well. Use a small brush to loosen flux then wipe with a soft clean cloth.
    >> >> Re-do if any residue remains.

    >>
    >> >+1 on the alcohol recommendation.  use an acid brush with the bristles cut
    >> >down to 1/2" long.  squirt the alcohol inside the hollow brush handle and it
    >> >will wick down the bristles while you are scrubbing.

    >>
    >> IPA tends to leave white residue when used to clean rosin flux.
    >>
    >> >Once the heavy buildup is loose, put paper towel between the board and the
    >> >brush and repeat allowing the papertowel to absorb the liquified flusand
    >> >alcohol mix.

    >>
    >> For really clean boards, the last step should be a squirt rinse with
    >> clean solvent.
    >>
    >> John

    >
    >IPA dissolves the rosin. The white stuff left over is not soluble in
    >IPA
    >but is soluble in water. I always follow IPA cleaning with a good
    >scrubbing
    >w/toothbrush and warm water then blow dry. Baking in warm oven is
    >optional.
    >al


    Ah, so that is why some people have told be to use (distilled / deionized)
    water for the last rinse.
     
    JosephKK, Jan 20, 2010
    #9
  10. On Tue, 19 Jan 2010 19:38:24 -0800, "JosephKK"<>
    wrote:

    >On Sat, 16 Jan 2010 12:39:05 -0800 (PST), mickgeyver <> wrote:
    >
    >>On Jan 16, 11:24 am, John Larkin
    >><> wrote:
    >>> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <>
    >>> wrote:
    >>>
    >>>
    >>>
    >>>
    >>>
    >>> >"Bob Eld" <> wrote in message
    >>> >news:hipunq$h3h$-september.org...
    >>>
    >>> >> "Jon Slaughter" <> wrote in message
    >>> >>news:hipkai$h07$-september.org...
    >>> >>> Is it safe to soak a pcb in acetone for several minutes to clean it up
    >>> >>> all
    >>> >>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's. I
    >>> >>> imagine the acetone won't harm these packages?
    >>>
    >>> >> I think acetone, MEK and similar solvents are too harsh. They can dissolve
    >>> >> or swell some plastics and may damage components.
    >>>
    >>> >> I use 91% isopropyl alcohol or denatured ethanol both are mild and work
    >>> >> well. Use a small brush to loosen flux then wipe with a soft clean cloth.
    >>> >> Re-do if any residue remains.
    >>>
    >>> >+1 on the alcohol recommendation.  use an acid brush with the bristles cut
    >>> >down to 1/2" long.  squirt the alcohol inside the hollow brush handle and it
    >>> >will wick down the bristles while you are scrubbing.
    >>>
    >>> IPA tends to leave white residue when used to clean rosin flux.
    >>>
    >>> >Once the heavy buildup is loose, put paper towel between the board and the
    >>> >brush and repeat allowing the papertowel to absorb the liquified flus and
    >>> >alcohol mix.
    >>>
    >>> For really clean boards, the last step should be a squirt rinse with
    >>> clean solvent.
    >>>
    >>> John

    >>
    >>IPA dissolves the rosin. The white stuff left over is not soluble in
    >>IPA
    >>but is soluble in water. I always follow IPA cleaning with a good
    >>scrubbing
    >>w/toothbrush and warm water then blow dry. Baking in warm oven is
    >>optional.
    >>al

    >
    >Ah, so that is why some people have told be to use (distilled / deionized)
    >water for the last rinse.



    If the final IPA rinse is with clean enough IPA and nothing is left on
    the board, there will be nothing to form any halo with.
     
    Archimedes' Lever, Jan 20, 2010
    #10
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Replies:
    1
    Views:
    989
    tamil
    Feb 7, 2006
  2. Steven G.

    Cleaning PCB - Alcohol

    Steven G., Feb 21, 2004, in forum: Hobby Electronics
    Replies:
    20
    Views:
    2,040
    Richard Freeman
    Feb 26, 2004
  3. kreed

    Cleaning mouse urine from PCB

    kreed, Nov 28, 2007, in forum: Hobby Electronics
    Replies:
    9
    Views:
    1,175
    Allan
    Dec 14, 2007
  4. DaveC

    Cleaning leaked electrolytic & corrosion on PCB

    DaveC, Apr 10, 2010, in forum: Electrical Engineering
    Replies:
    6
    Views:
    2,770
    Robert Latest
    Apr 11, 2010
  5. DaveC
    Replies:
    21
    Views:
    943
    JosephKK
    Apr 21, 2010
Loading...

Share This Page