IPC-TM-650 EN 2022 试验方法.pdf - 第693页

• During the initial cycle after the high temperature dwell. Peak resistance during this cycle shall be the reference resistance. • At or near the end of the peak temperature dwell, after the coupon has reached temperatu…

4.1.4 Deviations to the test specimen design/construction

or use of an alternate test specimen shall be AABUS.

5 Apparatus

5.1 Drying Oven

The oven shall be capable of maintaining

a uniform set temperature within the 105 to 125 °C range.

5.2 Environmental Test Chamber

5.2.1 Dual Chamber Option An automatically controlled

dual temperature environmental test chamber or other

apparatus capable of maintaining the upper and lower

temperatures.

5.2.2 Single Chamber Option An automatically controlled

environmental test chamber or other apparatus capable of

maintaining the upper and lower temperatures.

5.2.3 The system shall have adequate environmental con-

trols to maintain the tolerance range and limits listed in

6.5.1.3.

5.2.4 The system should accommodate verifiable calibration

compliance. See note 7.1 for additional considerations.

5.2.5 Deviations to the equipment requirements and

acceptability of the alternative methods shall be AABUS.

5.3 Microscope The magnification used for defect recogni-

tion shall be in agreement with the inspection requirements/

capabilities defined in the applicable performance specifica-

tion (e.g., IPC-6012, IPC-6013, IPC-6018, etc.) and the IPC-

A-600 visual workmanship standard.

5.4 Resistance Measurements

5.4.1

The resistance measurement shall have enough pre-

cision to clearly determine the resistance percent change as

required by the user for the resistance level of each test speci-

men’s nets.

5.4.2 The total system uncertainty from resistance, tem-

perature and time/cycle variations shall be less than 10% of

the failure criteria required by the user. For example, if the

required failure criteria is 5% then the total system uncertainty

shall be no greater than 0.50%.

5.4.3 The resistance measurement system shall be capable

of recording resistances at least once per cycle, at or near the

end of the peak temperature dwell, after the coupon has

reached temperature stabilization.

5.5 Temperature Measurements

5.5.1

The temperature measurement system should be

capable of recording temperatures at least once per second

throughout a complete cycle for both a representative test

specimen and the heating/cooling medium. The system shall

be capable of demonstrating the change rate defined in 3.1

and 3.2 and documenting a representative cycle.

6 Procedure

6.1 Conditioning

6.1.1

The test specimen(s) shall be conditioned by drying in

an oven to remove moisture for a minimum of six (6) hours at

105 to 125 °C. This conditioning process is mandatory if this

method is used for qualification purposes.

This method shall replicate the assembly process. The

requirement for conditioning (bake/drying) shall be in accor-

dance with product/process lot Quality Conformance criteria.

If conditioning of the printed board is not part of the normal

assembly process, and this method is being used for quality

conformance testing, then conditioning is not a requirement.

6.1.2 Test specimens that are thicker or more complex may

require longer baking times to achieve acceptable moisture

levels. Record the bake times and temperature if different than

those stated in 6.1.1. See IPC-1602 for additional guidance

on baking to achieve acceptable moisture levels.

6.1.3 Deviations to the conditioning requirements in 6.1.1

such as when used for quality conformance criteria and/or any

changes to the time and temperature shall be AABUS.

6.2 Reflow Simulation

6.2.1

The test specimen(s) shall be subjected to six (6)

reflow simulation cycles in accordance with IPC-TM-650,

Method 2.6.27 prior to Thermal Shock or Thermal Cycling.

6.2.2 The reflow profile shall be in accordance with IPC-

TM-650, Method 2.6.27, as specified.

6.2.3 Other profiles or reflow simulation testing for other

than 6 cycles are AABUS.

6.3 Interconnect Resistance Measurements Intercon-

nect resistance measurements shall be taken at the following

times:

• Prior to the test (initial ambient after reflow simulation).

IPC-TM-650

Number

2.6.7.2

Subject

Thermal Shock, Thermal Cycle and Continuity

Date

3/2020

Revision

Page2of5

• During the initial cycle after the high temperature dwell. Peak

resistance during this cycle shall be the reference

resistance.

• At or near the end of the peak temperature dwell, after the

coupon has reached temperature stabilization, peak resis-

tance during the cycle shall be recorded.

6.4 Qualification (also see 6.6 and Table 6-2) For quali-

fication testing, the product environment and life expectancy

should be taken into consideration to determine the tempera-

ture extremes and number of cycles. Qualification testing

parameters shall be AABUS.

6.4.1 Historical Examples Historical examples as

described in Table 6-1 were not product focused.

6.4.2 Cycles The test specimen(s) shall be subjected to

the specified number of cycles between the specified tem-

perature extremes.

6.4.2.1 Tolerances The tolerance associated with the hot

cycle is +/-5 °C. The tolerance associated with the cold cycle

is +/-5 °C.

6.4.3 Dwell Time at Extremes During each cycle, the test

specimen(s) shall be subjected to each temperature extreme

for the time required for stabilization and resistance measure-

ment (15 minutes when a dual chamber is used).

6.4.4 Temperature Change Rate The rate of change

between temperature extremes, both high to low and low to

high, shall be as high as possible. The temperature change

shall be at least 10 °C per minute for at least the center 60%

of each transition period, hot to cold and cold to hot.

6.4.5 Temperature Documentation

6.4.5.1

The temperature of a representative test specimen

shall be recorded at the end of the dwell at each temperature

extreme, for every cycle.

6.4.5.2 A temperature profile from at least one complete

cycle shall be recorded during each test in accordance with

5.5.1 and 6.4.2.1 and included in the test report. This shall

include the temperatures of a representative test specimen

and the hot/cold media. Recording data every second for this

purpose is recommended.

6.4.6 Dual Chamber Systems For dual chamber systems:

• The transfer time between chambers shall be less than two

(2) minutes.

• The thermal capacity of each chamber shall be such that

the ambient temperature shall reach the specified tempera-

ture within two (2) minutes after the test specimens have

been transferred to the appropriate chamber.

6.5 Quality Conformance (see also 6.6 and Table 6-2)

6.5.1 Temperature Cycling

The test specimen(s) shall be

subjected to one hundred (100) cycles of temperature cycling

to the extremes defined below:

6.5.1.1 The high temperature extreme shall be the least of

the following:

• Material T

– 10 °C (lowest T

of the materials used in the

specimen, but not lower than 125 °C)

• Reflow peak temperature – 25 °C

• 210 °C

Note 1. The originating subcommittee for this Test Method

was not able to obtain industry consensus on a default

method for determining T

. Therefore, methods to determine

(as specified in the procurement documentation or AABUS)

may include:

• Lowest T

listed on the Material Data Sheet

•T

(from TMA) listed on the Specification Slash sheet

• Actual T

of the material, determined after reflow simulation

6.5.1.2 The low temperature extreme shall be one of the

following:

Table 6-1 Historical Qualiﬁcation

Temperature Extremes

Cycles

Temperature

Range °C

Test

Condition

Previous Use

100 -40 to +85 B

Generic for IPC-4103,

RT/duroid® materials

100 -55 to +105 C

Generic for IPC-4101,

G10 materials

100 -55 to +125 D

Generic for IPC-4101,

Epoxy materials

100 -65 to +150 E

Generic for IPC-4101,

FR-5 materials

100 -65 to +170 F

Generic for IPC-4101,

Polyimide materials

Note 1. Test Conditions B through F are from the previous revision to this

test method.

IPC-TM-650

Number

2.6.7.2

Subject

Thermal Shock, Thermal Cycle and Continuity

Date

3/2020

Revision

Page3of5

• -40 °C

• -55 °C (default)

• -65 °C

6.5.1.3 Tolerances The tolerance associated with the hot

cycle is +/-5 °C. The tolerance associated with the cold cycle

is +/-5 °C.

6.5.1.4 Dwell Time at Extremes During each cycle, the

test specimen(s) shall be subjected to each temperature

extreme for the time required for stabilization plus time

required to record all measurements (up to 15 minutes when

a dual chamber is used).

6.5.2 Temperature Change Rate The rate of change

between temperature extremes, both high to low and low to

high, shall be as high as possible. The temperature change

shall be at least 1 °C per second for at least the center 60%

of each transition period, hot to cold and cold to hot. Note

that for thicker coupons greater than 2.5 mm [0.100 in], this

change rate may not be achievable.

6.5.2.1 Temperature Documentation

6.5.2.1.1

The temperature of a representative test speci-

men shall be recorded at the end of the dwell at each tem-

perature extreme, for every cycle.

6.5.2.1.2 A temperature profile from at least one complete

cycle shall be recorded during each test and included in the

test report. This shall include the temperatures of a

representative test specimen and the hot/cold media. The

temperatures shall be taken at sufficient frequency to show

compliance to 5.5.1 and 6.5.1.3. Recording data every sec-

ond for this purpose is recommended.

6.6 Testing Summary

A summary of Qualification and Quality Conformance testing

is listed below in Table 6-2.

6.7 Evaluation

6.7.1 Resistance Change

The change in resistance

between the first and each succeeding temperature cycle

shall be determined. The maximum allowable percent change

in resistance between the first and any subsequent cycle

shall be 5% unless otherwise specified.

6.7.2 Results Test results including cycles to failure, corre-

sponding percent change of the failure, and the percent

change of the final cycle shall be documented.

6.8 Deviations Deviations to the stated requirements or

additional requirements defined here shall be AABUS.

Table 6-2 Comparison of Qualiﬁcation and Quality Conformance Testing

Item Qualiﬁcation Quality Conformance / Acceptance Testing

Conditioning 6 hours minimum, 105 - 125 °C

Reflow Simulation 6 cycles, 230, 245 or 260 °C profile

Temperature Min AABUS -40 °C, -55 °C (default), -65 °C

Temperature Max AABUS min. of:

-10 °C

Reflow peak -25 °C

210 °C

Sample Change Rate

> 10 °C/min for both hot and

cold

> 1 °C/sec for both hot and cold

Number of Cycles AABUS 100

Failure Threshold AABUS 5%

Resistance Data 1 reading/cycle near the end of the high temperature dwell

Temperature Data

1 reading/cycle near the end of the high and low temperature dwells (sample)

1 reading/sec through 1 complete cycle (sample and media)

Note 1. Acceptance testing and quality conformance testing as described in IPC-6010 series printed board performance specifications.

IPC-TM-650

Number

2.6.7.2

Subject

Thermal Shock, Thermal Cycle and Continuity

Date

3/2020

Revision

Page4of5