IPC-TM-650 EN 2022 试验方法--.pdf - 第693页

• D uring the initial c ycle after t he high temperature dwell. Peak r e s i s t a n c e d u r i n g t h i s c y c l e b e th e r e f e r e n c e resistance. • A t or near the end of the peak temperature dwell, after the…

4.1.4

Deviations to the test specimen design/construction

or use of an alternate test specimen

be AABUS.

5 Apparatus

5.1 Drying Oven

The oven 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 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

be AABUS.

5.3 Microscope

The magnification used for defect recogni-

tion

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 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

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

be no greater than 0.50%.

5.4.3

The resistance measurement system 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

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) 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

replicate the assembly process. The

requirement for conditioning (bake/drying)

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

be AABUS.

6.2 Reflow Simulation

6.2.1

The test specimen(s) 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 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

be taken at the following

times:

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

Number

2.6.7.2

Subject

Thermal Shock, Thermal Cycle and Continuity

Date

3/2020

Revision

IPC-TM-650

—

shall

Page

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

resistance during this cycle

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

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

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) 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)

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,

be as high as possible. The temperature change

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

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

be recorded during each test in accordance with

5.5.1 and 6.4.2.1 and included in the test report. This

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

be less than two

(2) minutes.

• The thermal capacity of each chamber

be such that

the ambient temperature

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) be

subjected to one hundred (100) cycles of temperature cycling

to the extremes defined below:

6.5.1.1

The high temperature extreme be the 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

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 be one of the

following:

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

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

test method.

Number

2.6.7.2

Subject

Thermal Shock, Thermal Cycle and Continuity

Date

3/2020

Revision

IPC-TM-650

—

shall

Table

6-1

Historical

Qualification

Temperature

Extremes

Note

Cycles

Temperature

Range

Test

Condition1

Use

shall

least

Note

shall

Page

• -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)

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,

be as high as possible. The temperature change

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

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

be recorded during each test and included in the

test report. This

include the temperatures of a

representative test specimen and the hot/cold media. The

temperatures

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

be determined. The maximum allowable percent change

in resistance between the first and any subsequent cycle

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

be documented.

6.8 Deviations

Deviations to the stated requirements or

additional requirements defined here

be AABUS.

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)

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

Number

2.6.7.2

Subject

Thermal Shock, Thermal Cycle and Continuity

Date

3/2020

Revision

IPC-TM-650

shall

Table

6-2

Comparison

Qualification

and

Quality

Conformance

Testing

Note

Item

Qualification

Quality

Conformance

Acceptance

Testing1

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