IPC-CM-770D-1996 - 第85页

January 1996 IPC-CM-770 IPC-1-00253 Figure 17-3 Typical Pin Terminals board hole tolerance, and the number of pins to be inserted. In general, the hole and plating tolerances for compliant pins are wider than for non-com…

IPC-CM-770

Januaty

1996

printed boards. To provide mechanical strength to the ter- minal serves as the feed through device through the glass

minal and the resultant connection, most terminals are seal. See Figure

17-3.

designed for through-the-board mounting, either with

crimping, rolling, or flaring on the back side of the board,

or by an interference fit or “press fit” into the board.

Solder-only mounting may be used when the terminals are

only used as test points.

Cup Terminals

cup terminals are not normally

attached to printed boards, but are often used as part of a

connection technique which does interface with a printed

board. Cup terminals are designed for either soldering (see

Figure

17-4)

or crimping (see Figure

17-5).

Terminals can be generally categorized as follows:

Turret Terminals

This type of terminal has guide slots

to assist in retaining the attaching wires, and is available

with mounting bases designed for funnel flange or roll

flange retention, or for press-fit installation. See Figure

17.1.2 Solderless (Wire) Wrap PinslPosts

Pins are

available in single and double ended types, with and with-

out solder carrying characteristics; single pin end with a

socket on the other end, with and without self solder carry-

ing characteristics; rectangular and square varieties. Vari-

17-1.

guide

slot

dase

clearance

IPC-I-O0251

Figure 17-1 Typical Turret Terminals

B. Bifurcated Terminals

This type of terminal contains ous self retaining features for securing to the printed board

two posts for lead or wire attachment. Bifurcated terminals are also available, as are plating and base material. There

are normally available only with their bases designed for are those that require soldering to the printed board and

funnel flange or roll flange retention. See Figure

17-2.

those that do not. Compliant pins depend on an expanded

lnsulatlon

clearance

Polnt

entry

same for

upper conductor

IPC-I-O0252

Figure 17-2 Typical Bifurcated Terminals

C. Pin Terminals

These terminals are designed for use section of the pin for retention in the printed board. Other

where space is limited, and are normally used only in the types require the insertion machine to crimp the pin on

“press-fit’’ style. One variation of the pin terminal is the both sides of the printed board for retention.

third type is

hook terminal. This type of terminal is usually found on held in place completely by the solder. The choice depends

relays and other hermetic seal devices, where the hook ter- on consideration such as the type of tooling available, the

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January

1996

IPC-CM-770

IPC-1-00253

Figure 17-3 Typical Pin Terminals

board hole tolerance, and the number of pins to be inserted.

In general, the hole and plating tolerances for compliant

pins are wider than for non-compliant pins. Most all thick-

nesses of printed boards can be accommodated. Typical

mating interface), four sharp edges (for solderless wrap-

ping), and a uniform cross section. The finished loose pins

are usually put on a continuous secondary carrier to facili-

tate machine insertion and handling. See Figure 17-6. This

carrier strip is normally an expendable item and is not used

as part of the final product. There are other square pin sizes

manufactured with drawn wire as well as rectangular ver-

sions. These pins are designed to be used with mating con-

nectors as well as solderless wrapping.

Stamped PinslPosts Square and Rectangular

These

pins, in 0.64 mm square as well as other square and rect-

angular sizes are manufactured from flat stock in a continu-

ous strip (see Figure 17-7).

The connection of stamped pins is designed to be near or

in the area of the minted board. where raw comnleted

pins are described as follows:

-Insulation

clearance

Conductors shall

bottom in cup

Conductor shall

be in line contact

with inner wall

terminal

Top route conductor

shall bottom against

bottom route conductor

IPC-1-00254

Figure 17-4 Typical Solder Cup Terminal

Insulation

clearance

Inspection hole

conductor visible

Insulation

IPC-I-

Figure 17-5 Typical Crimp Terminal

Drawn Wire PinslPosts Square or Rectangular

most edges will be covered by solder or at the very ends, where

popular size in the industry is the 0.64 mm square variety. raw edges are of little consequence.

The pins are manufactured from a drawn wire. This method

of manufacture offers four smoothly finished surfaces (for

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IPC-CM-770

Januaty

1996

CARRIER

EXPENDABLE

STRIP

IPC-1-00257

Figure 17-6 Expendable Carrier Strip

IPC-1-00258

Figure 17-7 Stamped Pins

The cut away “carrier” is an expendable section. This type

of pin is designed to be used with matching connectors as

well as wire wrapping. By nature of manufacture, stamped

pin/posts have the disadvantage of having only two smooth

surfaces (for mating interference) and therefore sometimes

require orientation. They also have only two sharp edges

for wire wrapping.

C. Non-solder Carrying

Non-soldering type pin/posts are

designed without solder carrying capabilities and require

the addition of solder at assembly with the printed board

either through the use of solder preforms, wave soldering

methods or similar means.

These are available in stamped and drawn wire versions.

Press-Fit

Press-fit solderless wrapposts are available

that provide gas-tight solderless connections to plated-

through holes through the use of their compliant retention

features (Figure

17-8).

E. Solder Carrying

Solder carrying pindposts are

designed to retain their own metered quantities of solder,

usually a tin lead alloy. The solder may be supplied in the

form of an extra thick coating on a predetermined area of

a pin. The solder “rivet” is more controllable in manufac-

ture as to quantity and position and is more stable metal-

lurgically.

This solder feature on pins, etc., lends itself to mass solder-

ing by vapor phase condensation, infrared, hot oil, and

‘4.

RETENTION AREAS

COMPLIANT COMPLIANT

TYPE TYPE

IPC-1-00259

Figure 17-8 Compliant Press-fit Pins

IPC-1-00256

Figure 17-9 Solder Carrying Pins

other such methods. Solderability should be verified in

accordance with

J-STD-002.

These products are designed to be used with mating con-

nectors as well as wire wrapping and are available in

stamped or drawn wire versions. See Figure

17-9.

17.1.3 Hook-up Wires

Interconnection wires can be

insulated or uninsulated, and solid or stranded.

Solid uninsulated wire is used for point to point connec-

tions on a printed board and in similar cases where no

flexibility is required.

Solid insulated wire is used for point to point connections

on a printed board where the wire cross printed board

traces or a potential for short circuits exists. The insulation

may be applied by the wire manufacturer (insulated wire)

or by adding insulation tubing (sleeving) to bare wire.

Solid insulated wire is also used for wire wrapping, where

the rigidity of the solid wire is required for consistent con-

nections.

Stranded uninsulated wire, by itself, is not a useful con-

figuration, since the wire strands tend to come unwrapped.

Stranded insulated wire is the type most often used for

interconnecting assemblies, and where flexibility is

required.

Wires are selected based on a large number of consider-

ations, approximately in the following order:

Flexibility required? (Select solid or stranded.)

Insulation required? (Select bare or insulated.)

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