IPC-TM-650 EN 2022 试验方法.pdf - 第298页

Where: D1 = Hole diameter D2 = Land diameter L = Load (force) Note: The formula given utilizes the diameter of both the land and the hole in the determination of the area of the land, rather than the radius of each. Thus…

1 Scope This test method is to determine the land bond

strength of unsupported holes, after repeated soldering and

unsoldering, by mechanical pull in the perpendicular plane.

2 Applicable Documents

IPC-2221

Generic Standard on Printed Board Design

3 Test Specimen Any unsupported component hole

sample or test coupon ‘‘A’’ or ‘‘A/B’’ described in IPC-2221.

Three holes per sample or test coupon shall be tested.

4 Apparatus or Material

4.1 Soldering Iron

60-watt soldering iron capable of pro-

ducing a tip temperature of 232 °C to 260 °C [450 °F to

500 °F].

4.2 Force Tester Vertical pull force tester capable of oper-

ating at a speed of 50.0 mm [2.0 in] per minute and measur-

ing up to 9 kg [20 pounds] load.

4.3 Tinned or solder coated copper wire.

5 Procedure

5.1 Preparation

5.1.1

If conductors are connected to the land area, the fol-

lowing procedure is to be followed:

Take a sharp model knife and cut conductor at least 6.0 mm

[0.2 in] away from the land. Place blade of knife on edge of

land area where conductor enters. While holding the blade

down, pull conductor to the land and use knife blade as ful-

crum to break conductor from land without disturbing bond of

the land.

5.1.2 Insert wire so that the portion extending from the sol-

dered side of the circuit may be fitted into the gripping mecha-

nism of a tensile tester. The wires shall have a diameter

between 150 µm and 500 µm [5,906 µin and 19,685 µin] less

than the diameter of the hole. The wires shall not be clinched.

Select suitable wire of sufficient length to connect to gripping

mechanism of bond strength tester.

5.1.3 Insert wire in holes in selected lands and solder to

lands by machine or hand, as applicable. The wire shall not be

clinched.

5.2 Soldering Cycles

5.2.1

The hand soldering and desoldering operation of the

wire shall be performed as follows:

Step 1: Solder wire into lands

Step 2: Remove (desolder) wire from lands

Step 3: Resolder wire into lands

Step 4: Remove (desolder) wire from lands

Step 5: Resolder wire into lands

During the desolder and solder steps, solder every other land

in the row and allow the specimen to cool to room tempera-

ture. Then solder the remaining lands.

5.2.2 During the solder and desoldering steps, the soldering

and/or desoldering iron shall have a tip temperature as follows

(see 6.1):

Method A: 260 °C [500 °F] - Default method

Method B: 315 °C [599 °F]

Method C: 371 °C [700 °F]

5.3 Pull Test

5.3.1

Following the fifth cycle, clamp the test specimen suf-

ficiently in the jaws of the bond tester to assure that the test

specimen is perpendicular to the direction of pull.

5.3.2 Apply a pull at the rate of 50.0 mm per minute [2.0 in

per minute] to the wire on the pattern side of the test speci-

men.

5.3.3 The load must be applied perpendicular to the major

surface of the land. The load shall be applied until failure

occurs or the minimum force as specified by the procurement

documentation is reached. The formula to calculate force for

circular lands is as follows:

π(D2

–D1

)

3000 Lakeside Drive

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.4.21

Subject

Land Bond Strength, Unsupported Component Hole

Date

01/07

Revision

Originating Task Group

Rigid Printed Board Performance Task Group

(D-33a)

Material in this Test Methods Manual was voluntarily established by Technical Committees of 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 IPC.

Page1of2

ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES

Where:

D1 = Hole diameter

D2 = Land diameter

L = Load (force)

Note: The formula given utilizes the diameter of both the land

and the hole in the determination of the area of the land,

rather than the radius of each. Thus, a factor of four is applied

to the numerator as the area of a circle as defined by using

the diameter is (π * (diameter)

)/4.

5.4 Evaluation Examine test specimen for loosening of

bond and for loosening of the land from the base material. It

shall be considered a failure when a land around an unsup-

ported hole is loosened.

6 Notes

6.1

Breaking of a wire, or wire pull-out, shall not be consid-

ered a failure, but the wire shall be resoldered and pulled

again.

6.2 The following details are to be specified in the applicable

performance specification:

a. Test specimen, if other than specified in 3.

b. Force, if other than specified in 5.3.3.

IPC-TM-650

Number

2.4.21

Subject

Land Bond Strength, Unsupported Component Hole

Date

01/07

Revision

Page2of2

Scope

This

test method covers three procedures used to

determine the bow and twist percentage of individual rigid

printed boards, rigid portions of rigid-flex printed boards,

and/or multiple printed panels. Measurements on non-

rectangular samples pose a unique testing problem and may

necessitate careful evaluation of the requirements imposed by

the users of this test method. This test method does not

describe the special considerations necessary when testing

the bow and twist of printed board assemblies (i.e., compo-

nent placement & weight, edge supports & connectors, etc.).

The first two procedures describe production (Go/No-Go)

methods that generally characterize the bow and twist as

being no more than a specific value. The other procedure is a

referee method used to precisely determine the twist.

1.1

Definitions

Bow

and twist are defined in IPC-T-50.

The definitions are repeated in this test method for conve-

nience.

1.1.1

Bow (Sheet, Panel, or Printed Board)

The

devia-

tion from flatness of a board characterized by a roughly cylin-

drical or spherical curvature such that, if the product is rect-

angular, its four corners are in the same plane (see Figure 1).

1.1.2

Twist

The

deformation of a rectangular sheet, panel,

or printed board that occurs parallel to a diagonal across its

surface, such that one of the corners of the sheet is not in the

plane that contains the other three corners (see Figure 2).

2 Applicable Documents

IPC-T-50

Terms

and Definitions for Interconnecting and

Packaging Electronic Circuits

IPC-TM-650

Test

Methods

Test Specimens

The

test specimens shall be in the form

of either printed boards or multiple printed panels (single-

sided, double-sided, multilayer, or rigid-flex boards).

3.1 For

non-rectangular test specimens, the most conve-

nient way to measure bow and twist is approximating a rect-

angle over the test specimen. To accomplish this, an imagi-

nary rectangle that totally encloses the sample must be

superimposed over the test specimen. The dimensions of this

superimposed rectangle should be the smallest that will fully

enclose the specimen. Although this technique will give an

approximation of bow and twist, the actual noted values will

be less than the actual bow and twist of the sample.

IPC-2422-1

Figure

1 Box

BOW

With constraining f

orce applied

to both corners of the same edge.

1 & 2 deflection from surface plane.

IPC-2422-2

Figure

2 Twist

oints A, B, C

Touching Base

With constraining force

applied to one corner only.

2215

Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.22

Subject

Bow

and Twist (Percentage)

Date

6/99

Revision

Originating Task Group

Rigid Printed Board Test Methods Task Group

(7-11d)

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.

age1of5

ASSOCIA

TION CONNECTING

ELECTRONICS INDUSTRIES

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ