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Using lead free solder, Pb solder, Pb pca pb joints pb s pb j pb p pb solder – MITSUBISHI ELECTRIC V29 User Manual

Page 45: Displays used to indicate pb-free

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PAGE 45

MODELS: WD-52627 / 52628 / 62627 / 62628 / 62827 / 62927 / 73727 / 73827 / 73927

Using Lead Free Solder

Pb Solder

The above symbol indicates Lead (Pb) Free solder was
used during the construction of PWBs. Only Lead
Free solder
should be used when servicing these
PWBs.

Solder must be compatible with that used by the
manufacturer. Leaded solder can not be used on
PWBs manufactured with Pb-free solder. The Mitsub-
ishi standard for service requires the use of Tin-Silver-
Copper (Sn-96.5, Ag-3.0, Cu-0.5). It can be obtained
through the Parts Department.
Order part number: PB FREE SOLDER

Lead Free solder has a higher melting point, and does
not “wet” as well as leaded solder. This means it does
not adhere as readily to the solder iron tip, and the
surface to be soldered. To counteract this, the flux
used is more corrosive.

The following cautions must be taken when using Pb
Free solder.

Higher temperatures can cause the PWB to
warp, detaching surface mount
components.

Higher temperatures may
cause thermal damage to
components.

Higher temperatures can cause
plastics, such as connectors,
relays, LEDs electrolytic
capacitors, etc. to melt or
warp.

Higher temperatures can cause
surface oxidation resulting in
poor solder spread-ability and
wet-ability.

The flux is more corrosive.

The time required for a good solder connection may
take longer.

Poor wet-ability can cause solder balls.

Higher temperatures can cause flux spattering.

Soldering iron tip life is shortened.

Dull finish solder joints (not shiny) can appear to be
a “cold” solder joint.

In general a tip temperature of 700° F will usually provide
good results.

Displays used to indicate Pb-free

PCBs will be marked, indicating the level of Pb-free con-
struction. Table 1 defines the levels by phase and shows
the different symbols that will be displayed on the PCB.
Additionally, a PCB constructed using Pb-free solder may
be simply marked LFS.

When possible, the indication will be placed close to the
part number that is screened onto the PCB (not the part
label). Figure 1 is an example of a PCB showing the
display and its location.

Pb-Free

Phase

Definition

Display

Short Display (When the

area is too small)

Phase-1

PCB's constructed using
Pb-free solder.

Phase-2

Solder, PCB surface
finishing and component
lead plating is Pb-free.
Components may have
internal Pb.

Phase-3

Solder, PCB surface
finishing and components
are Pb-free. (100% Pb-
free)

Table 1: Pb-Free Phases and Symbols

Pb PCA

Pb Joints

Pb S

Pb J

Pb P

Pb Solder

Pb-Free

Display

Figure 2: Pb-Free display on PWB

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