IPC-TM-650 EN 2022 试验方法.pdf - 第756页

1 Scope These methods determine the physical endurance of representative coupons of printed boards to a series of high temperature excursions from ambient. The temperature excursions cause thermo-mechanical fatigue of th…

Parameters Comments

Failure Type & Distance (between drilled hole walls, or hole wall to plane

edge). Examples:

PTH-PTH, 11.0 mils, Nelco 4000-11

PTH-Plane (GND), 15.0 mils, FR406 (dicy-cured)

Current Limiting Resistor Value (default is 1.0 meg-ohm or 10

ohms)

Assembly Process Simulation: Examples

No Bake, No Preconditioning

Bake (specify), No Preconditioning

Bake (specify), 3X @ 260 °C Preconditioning (specify profile)

Bake (specify), 6X @ 260 °C Preconditioning (specify profile)

Bake (specify), 6X @ 230 °C Preconditioning (specify profile)

Bake (specify), 5X @ 245 °C Preconditioning (specify profile)

CAF Test Parameters: Examples

15 Vdc, 50 °C, 80% RH, drilled hole wall to hole wall spacings

100 Vdc, 65 °C, 87% RH, drilled hole wall to hole wall spacings

10 Vdc, 65 °C, 85% RH, drilled hole wall to hole wall spacings

Material(s) Tested: Examples

FR406 (dicy-cured)

Nelco 4000-11

Reporting Dates: Examples

Date Tested: August 2006

Date CAF Test Coupon Manufactured: February 2006

IPC-TM-650

Number

2.6.25

Subject

Conductive Anodic Filament (CAF) Resistance Test: X-Y Axis

Date

02/21

Revision

Page 11 of 11

1 Scope These methods determine the physical endurance

of representative coupons of printed boards to a series of high

temperature excursions from ambient. The temperature

excursions cause thermo-mechanical fatigue of the electrical

interconnect structures.

The test coupon is resistance heated by passing DC current

through the coupon to bring the temperature of the copper to

a designated temperature. Switching the current on and off

creates thermal cycles between room temperature and the

designated temperature within the sample. The laminate and

surrounding materials are heated to different extents depend-

ing on the thermal conductivity of the materials. The thermal

cycling can accelerate latent interconnect anomalies to failure.

The number of cycles achieved permits a quantitative assess-

ment of the performance.

1.1 Method A Description Method A uses a coupon with

two or more independent electrical nets. The designation for

these nets is either a power net (P) or a sense net (S). Each

electrical net consists of plated barrels and conductors (inter-

nal and external). DC current is passed through one electrical

net to heat the coupon to a designated temperature. When

the electrical net is at the designated temperature, the DC

current is turned off and cooling fans are turned on to cool the

coupons to ambient temperature. One heating and cooling

sequence represents a thermal cycle. Thermal cycling is con-

tinued to either a set number of cycles or a failure. Tempera-

ture coefficient of resistance (TCR) is estimated by proprietary

algorithms.

A failure is based on a percentage change in the bulk resis-

tance of the coupon at the designated test temperature. The

percentage change is measured independently for each elec-

trical net being tested. When the percentage change is

exceeded, the test is stopped for the coupon.

1.2 Method B Description Method B uses a coupon with

one electrical net. The net consists of via structures con-

nected by external and/or internal circuit lines in a daisy chain.

DC current is passed through the electrical net to heat the

coupon to a designated temperature. When the electrical net

is at the designated temperature, the DC current is turned off

and a cooling fan is turned on to cool the coupons to ambient

temperature. One heating and cooling sequence represents a

thermal cycle. Thermal cycling is continued to either a set

number of cycles or a failure. Temperature coefficient of resis-

tance (TCR) is measured.

A failure is based on a percentage change in the bulk resis-

tance of the coupon at the designated test temperature. The

percentage change is measured independently for each elec-

trical net being tested. When the percentage change is

exceeded, the test is stopped for the coupon.

2 Applicable Documents

2.1 IPC

IPC-MDP-650 Method Development Packet

IPC-TM-650 Test Methods Manual

2.1.1 Microsectioning

2.5.35 Capacitance of Printed Board Substrates After

Exposure to Assembly, Rework, and/or Reliability

Tests. (At the time of publication of this test method,

2.5.35 is in development.)

2.6.27 Thermal Stress, Convection Reflow Assembly

Simulation

3 Test Specimens A typical daisy chain test coupon for

each method is shown in Figure 3-1 and Figure 3-2.

1. www.ipc.org

2. Current and revised IPC Test Methods are available on the IPC Web site (www.ipc.org/html/testmethods.htm)

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.6.26

Subject

DC Current Induced Thermal Cycling Test

Date

5/14

Revision

Originating Task Group

PTV Reliability Test Methods (6-10c)

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.

Page1of10

IPC-2626-3-1

Figure 3-1 Method A Test Coupon

IPC-2626-3-2

Figure 3-2 Method B Test Coupon

IPC-TM-650

Number

2.6.26

Subject

DC Current Induced Thermal Cycling Test

Date

5/14

Revision

Page2of10