From Newsgroup: sci.electronics.repair

On some boards, the SMD components are glued down prior to wave
soldering.

What is the best method for removing these parts, preferably without
damage?
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From Newsgroup: sci.electronics.repair

On Wed, 29 Jan 2025 11:41:20 +0100, HW <none@no.no> wrote:

On some boards, the SMD components are glued down prior to wave
soldering.

What is the best method for removing these parts, preferably without
damage?

Unaware of one.

Remove to replace only.

RL
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From Newsgroup: sci.electronics.repair

On 29 Jan 2025 at 12:29:57 GMT, "legg" <legg@nospam.magma.ca> wrote:

On Wed, 29 Jan 2025 11:41:20 +0100, HW <none@no.no> wrote:

On some boards, the SMD components are glued down prior to wave
soldering.

What is the best method for removing these parts, preferably without
damage?

Unaware of one.

Remove to replace only.

RL

Expensive or proprietory chips are regularly removed from donor boards with a mixture of hot air, flux and perhaps LMP solder, for reuse. But I agree no one is going to reuse a resistor or capacitor.
--

Roger Hayter
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From Newsgroup: sci.electronics.repair

On 1/29/2025 4:41 AM, HW wrote:

On some boards, the SMD components are glued down prior to wave
soldering.

What is the best method for removing these parts, preferably without
damage?

Most of the adhesives used for this soften at solder-melting
temperatures, so the parts can be fairly easily removed with hot air.

For large components, or less heat-sensitive underfill materials (I'm
looking at you, Apple...) some scavengers have had success using a mill
to grind away the PCB (for scavenging the part from a scrap board) or
the part itself (for removing a failed part to replace it). Obviously,
it's important to get the PCB exactly level to the milling plane, and
precise depth control is critical.
--
I'm part of the vast libertarian conspiracy to take over the world and
leave everyone alone.
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From Newsgroup: sci.electronics.repair

On 29 Jan 2025 12:39:08 GMT, Roger Hayter <roger@hayter.org> wrote:

On 29 Jan 2025 at 12:29:57 GMT, "legg" <legg@nospam.magma.ca> wrote:

On Wed, 29 Jan 2025 11:41:20 +0100, HW <none@no.no> wrote:

On some boards, the SMD components are glued down prior to wave
soldering.

What is the best method for removing these parts, preferably without
damage?

Unaware of one.

Remove to replace only.

RL

Expensive or proprietory chips are regularly removed from donor boards with a >mixture of hot air, flux and perhaps LMP solder, for reuse. But I agree no one >is going to reuse a resistor or capacitor.

Epoxy dhesive is used on wave-solderable SMD assemblies, to
prevent parts being swept away in the wave process, or in
subsequent reapplication of reflow processes.

There is a body size, pinspacing limitation that prevents
most complex/costly parts from this manufacturing technique.
Consult your part vendor if in doubt.

The epoxy adhesive used, once cured, will not be degraded
at a later time by temperatures provided by hot air and bonds
stronger than most IC packaging material fracture stress limits.

RL
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