IPC-TM-650 EN 2022 试验方法.pdf - 第790页

1.0 Scope 1.1 To determine the effect on the connector of the stresses produced by transient acceleration or deceleration forces resulting from handing, transportation, or field operation. 2.0 Reference Documents 2.1 Inf…

6.0 Notes

6.1

Acceptance criteria shall be established as the maxi-

mum level at which stable electrical contact is maintained.

This resistance is an inherent characteristic of any given con-

nector contact design and is (when the connector is properly

applied) well below that resistance level required for circuit

function.

IPC-3-7-1

Figure 1

IPC-TM-650

Number

3.7

Subject

Low Level Circuit Connectors

Date

7/75

Revision

Page2of2

1.0 Scope

1.1

To determine the effect on the connector of the stresses

produced by transient acceleration or deceleration forces

resulting from handing, transportation, or field operation.

2.0 Reference Documents

2.1

Information in this section is intended to parallel the test

method described in EIA-RS-364/TP-27.

3.0 Test Specimen

3.1

A connector (plug and receptacle) complete with appli-

cable guide, keying, and engaging hardware or a card- edge

receptacle and mating nominal-thickness printed circuit

board.

3.2 Mounting and Termination

3.2.1 Right Angle, Two-Piece Connector

The receptacle

shall be mounted and terminated normally during this test;

receptacles designed for mounting on non-rigid bases (e.g.,

motherboards, metal-plate back panels, etc.) shall be

mounted on the smallest section of such a base that will

accommodate the test specimen. The plug shall be termi-

nated normally during the test and shall be mounted on a

nominal-thickness printed circuit board extending the full

width of the plug; the board shall extend a minimum of four

inches from the receptacle when the connector is mated.

3.2.2 Card-Edge Receptacle The receptacle shall be

mounted and terminated normally during this test (see 3.2.1).

The mating printed circuit board shall extend the full width of

the receptacle and shall extend a minimum of four inches from

the receptacle when mated.

3.2.3 Parallel, Two-Piece Connector The receptacle and

plug shall be terminated normally during this test; both com-

ponents shall be mounted on nominal-thickness printed circuit

boards extending the full width of each. The printed circuit

boards shall extend a minimum of four inches from each com-

ponent when the connector is mated.

3.3 Fixturing

3.3.1 Right Angle Connector

The test specimen shall be

held in an adequate resonant free fixture. (Figure 1, Reference

Example.)

3.3.2 Parallel Connector The test specimen shall be held

in an adequate resonant free fixture. (Figure 2, Reference

Example.)

3.4 The connector shall be wire (or printed circuit boards)

designed such that a continuous electrical circuit (comprising

all contacts in series) is formed when the plug (or board) and

receptacle are mated.

4.0 Apparatus

4.1

A shock machine capable of producing the specified

input shock pulse as shown in Figures 3 and 4. The machine

may be of a free- or accelerated-fall, resilient rebound, non-

resilient, hydraulic or pneumatic actuated, or other type.

4.2 A shock measurement system consisting of an accelera-

tion sensitive transducer (accelerometer) and appropriate

impedance matching, amplifying and recording instrumenta-

tion. The entire system shall exhibit a frequency response

within the limits shown in Figure 5.

4.2.1 A piezoelectric accelerometer used as the transducer

shall have a minimum fundamental resonant frequency of 14

KHz (a resonant frequency >30 KHz is recommended). For

suitable low frequency response, the RC time constant of the

accelerometer and its load shall be

RC >0.2 where: R – load resistance (ohms)

C – accelerometer capacitance, plus

shunt capacitance of the load and

the inter-connecting cable (farads)

4.2.2 A strain gage accelerometer used as the transducer

shall have a minimum undamped natural frequency >1500 Hz,

with damping from 0.64 to 0.70 of critical.

2215 Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST METHODS MANUAL

Number

3.8

Subject

Mechanical Shock, Connectors

Date

7/75

Revision

Originating Task Group

N/A

Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only

and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this

material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.

Equipment referenced is for the convenience of the user and does not imply endorsement by the IPC.

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ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES

4.3 A circuit monitor capable of supplying a continuous cur-

rent of 100 milliamperes and of detecting discontinuities in this

current >1 microsecond.

5.0 Procedure

5.1 Calibration

5.1.1

The shock machine shall be set up to provide an

acceleration waveform conforming to Table I and Figure 3 or

4 as specified in the individual connector specification; if a

specific waveform is not specified, the terminal peak sawtooth

waveform shall be used.

5.1.2 The fixtured test sample or a suitable dummy load

shall be mounted on the shock machine during the calibration

procedure. Any dummy load shall have the same mass and

center of gravity as that of the test sample and shall be fix-

tured in a similar manner (a reject connector provides an ideal

dummy load).

For half-sine pulse of less than 3 milliseconds duration, it is

not required that the envelope fall within the tolerances speci-

fied in Figure 3. The faired (smoothed) amplitude of the mea-

sured pulse shall be within ± 20 percent of the ideal ampli-

tude. The measured duration shall be within ± 15 percent of

the specified duration. The velocity change of the faired pulse

shall be within ± 10% of the ideal change. The duration of the

pulse shall be measured at the 0.1A point on the pulse; the

base line duration of the pulse shall be calculated as the dura-

tion measured at the 0.1A point divided by 0.94. (For toler-

ance limits for measuring system frequency response see Fig-

ure 5.)

NOTE: The oscillogram should include a time about 3D long

with the pulse located approximately in the center. The inte-

gration to determine velocity change should extend from 0.4D

before the pulse to 0.1D beyond the pulse. The acceleration

amplitude of the ideal half sine pulse is A and its duration is D.

Any measured acceleration pulse which can be contained

between the broken line boundaries is a nominal half sine

pulse of nominal amplitude A and nominal duration D. The

IPC-3-8-1

Figure 1 Right Angle Connector Fixture (Suggested)

IPC-TM-650

Number

3.8

Subject

Mechanical Shock, Connectors

Date

7/75

Revision

Page2of5