This standard covers design and end product requirements of discrete
wiring boards which utilize discrete wires to interconnect termination
areas on or within flexible or rigid materials that may contain common
on-board foil electrical conductors.
Units  Unless otherwise specified, dimensions will be metric (SI).
Classification  This standard provides levels (1, 2, 3, 4, etc.) to
reflect progressive increases in sophistication for tooling, materials,
and processing.  Selections of the classification should be based on the
minimum need.  The reference of a single level does not preclude
invoking specific requirements defined in other levels.
Designation  The discrete wiring system (part number) shall be in the
following form and as specified herein:
IPC-DW-425/S               (A1)                   E(2112)
-------------------------------------------------------------
Where S is the             Type                  Edge Board
Specification          (See 1.3.2.1)            Plating Level
Number Sheet                                (See 1.3.3  1.3.3.1)
 (See 1.3.2)
  H(5211)                 T(1111)                 L(4511)
---------------------------------------------------------------
Hole Plating           Terminal Plating           Lands or
  Level                    Level                Surface Plating
(See 1.3.3  1.3.3.1)  (See 1.3.3  1.3.3.1)  (See 1.3.3  1.3.3.1)
Specification Sheet  Beginning with page 10 of this document are a
series of specification sheets.  Each sheet outlines a discrete wiring
system and indicates a connection type (see 1.3.2.1).  The discrete
wiring systems contained in this standard represent known techniques.
As new systems are available, they will be added to future revisions.
User and system developers are encouraged to supply information on new
systems for review by the IPC Discrete Wiring Committee.  Users that
wish to invoke this specification for discrete wiring systems not listed
in the specification sheets shall place a zero (0) for the specification
sheet number (IPC-DW-425A/0).
Connection Type  The connection types listed describe the routing and
terminating of discrete wires to form point to point electrical
connections.  A letter type designator is assigned to each generic
connection type in effect on the date of publication and may not be all
inclusive.  Listing of the trade name does not imply endorsement by the
IPC.
Type A-Mechanically Separable Connections
A1 - Solderless Wrap Connection
A2 - Clip Termination Connection
A3 - Insulation Displacement
Type B-Semi-Permanent Connections
B1 - Wrapped and Soldered Connection
B2 - Reflowed Solder Connection
B3 - Heat Shrinkage Solder Connection
Type C-Permanent Connections
C1 - Plated-Through or Blind Via Hole Connection
C2 - Welded Pin
C3 - Welded Land
Plating Area  The user of a discrete wiring system can indicate the
areas of the discrete wiring system to be plated.  This is accomplished
by a letter designation system as follows:
E...........................edge board contacts
H...........................hole plating
T...........................terminal plating
L......................surface or land plating
Each plating area shall be followed by four numbers indicating the type
of plating and thickness level required (see 1.3.3.1).  If an area does
not need plating the letter designation shall still be included followed
by four "1"s (see example 1.3.3.1 and 3.5.2.1-3.5.2.4).
Example:
The designation T (1111) would indicate a terminal with no plating.
The designation E (2112) is an edgeboard contact with 14.17g (1/2 oz.)
copper and .000254 mm [0.000010"] gold.
Plating  The plating required on the end product discrete wiring system
shall be designated in the following form:
                             E       2       1       1      2
                              ------------------------------------
                              |       |       |       |      |
Plated area (see 1.3.3)--------       |       |       |      |
                                      |       |       |      |
Copper plating level (see 3.5.2.4)-----       |       |      |
                                              |       |      |
Tin lead plating level (see 3.5.2.3)-----------       |      |
                                                      |      |
Nickel plating level (see 3.5.2.1)---------------------      |
                                                             |
Gold plating level (see 3.5.2.2)------------------------------