IPC-TM-650 EN 2022 试验方法.pdf - 第651页

fine mist from a previously sterilized atomizer or nebulizer. In spraying the test and control items, care should be taken to spray all surfaces which are exposed during use or mainte- nance. If the surfaces are nonwetti…

5.1.6

The

stock cultures may be kept for not more than four

months at 6 ± 4°C [42.8 ± 7.2°F] at which time subcultures

shall be made and new stocks shall be selected from the

subcultures.

5.1.7

genetic or physiological changes occur, obtain new

cultures as specified above. Subcultures used for preparing

new stock cultures or the spore suspension shall be incu-

bated at 30 ± 1°C [86 ± 1.8°F] for nine to 12 days or longer.

5.1.8

Prepare

a spore suspension of each of the five fungi

by pouring into one subculture of each fungus, a 10-ml por-

tion of a sterile solution containing 0.05 g per liter of a non-

toxic wetting agent such as sodium dioctyl sulfosuccinate or

sodium lauryl sulfate.

5.1.9

Use

a sterile platinum or nichrome inoculating wire to

scrape gently the surface growth from the culture of the test

organism.

5.1.10

Pour

the spore charge into a sterile 125-ml glass-

stoppered Erlenmeyer flask containing 45 ml of sterile water

and 50 to 75 solid glass beads, 5 mm in diameter.

5.1.11

Shake

the flask vigorously to liberate the spores from

the fruiting bodies and to break the spore clumps.

5.1.12

Filter

the dispersed fungal spore suspension, through

a 6 mm layer of glass wool contained in a glass funnel, into a

sterile flask.

5.1.13 This

process should remove large mycelial fragments

and clumps of agar which could interfere with the spraying

process.

5.1.14

Centrifuge

the filtered spore suspension aseptically

and discard the supernatant liquid.

5.1.15

Resuspend

the residue in 50 ml of sterile water and

centrifuge. Wash the spores obtained from each of the fungi

in this manner three times.

5.1.16

Dilute

the final washed residue with sterile mineral-

salts solution in such a manner that the resultant spore sus-

pension shall contain 1,000,000 ± 200,000 spores per ml as

determined with a counting chamber.

5.1.17 Repeat

this operation for each organism used in the

test and blend equal volumes of the resultant spore suspen-

sion to obtain the final mixed spore suspension. The spore

suspension may be prepared fresh each day or may be held

at 6 ± 4°C [42.8 ± 7.2°F] for not more than seven days.

5.2

Viability of Inoculum Control

With

each daily group

of tests, place each of three pieces of sterilized filter paper, 1

inch square, on hardened mineral-salts agar in separate Petri

dishes. Inoculate these with the spore suspension by spraying

the suspension from a sterilized atomizer until initiation of

droplet coalescence. Incubate these at 30 ± 1°C [86 ± 1.8°F]

at a relative humidity not less than 85% and examine them

after seven days of incubation. There shall be copious growth

on all three of the filter paper control specimens. Absence of

such growth requires repetition of the test.

5.3

Control Items

5.3.1

addition to the viability of inoculum control, known

susceptible substrates shall be inoculated along with the test

item to insure that proper conditions are present in the incu-

bation chamber to promote fungus growth.

5.3.2

The

control items shall consist of cotton duck

8.25-ounce strips that are 5 cm, that have been dipped

intoa solution containing 10% glycerol, 0.1% potassium

dihydrogen orthophosphate (KH

0.1% ammonium

nitrate (NH

0.025% magnesium heptahydrate sul-

fate (MgSO

•7H

O),

and 0.05% yeast extract (pH 5.3),

and from which the excess liquid has been removed.

5.3.3

The

strips should be hung to air dry before being

inoculated and placed into the chamber.

5.4

Inoculation of Test and Control Item

5.4.1

Mount

the test and control items on suitable fixtures or

suspend from hangers. No cleaning of the test item shall be

permitted for 72 hours prior to the beginning of the fungus

test. Equipment handling prior to and during the fungus test

shall be accomplished without contamination of the equip-

ment.

5.4.2

Precondition

the chamber and its contents at: 30 ±

1°C [86 ± 1.8°F] and 95 ± 2% relative humidity for at least four

hours.

5.4.3

Inoculate

the test and control items with the mixed

fungus spore suspension by spraying it on and into the test

and control items (if not hermetically sealed) in the form of a

IPC-TM-650

Number

2.6.1.1

Subject

Fungus

Resistance – Conformal Coating

Date

07/00

Revision

age2of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

fine

mist from a previously sterilized atomizer or nebulizer. In

spraying the test and control items, care should be taken to

spray all surfaces which are exposed during use or mainte-

nance. If the surfaces are nonwetting, spray until initiation of

droplet coalescence. Incubation is to be started immediately

following the inoculation.

5.5

Test Incubation of Test Items

5.5.1

Incubate

test items under static temperature of

28-30°C [82.4-86°F] with a minimum 85% relative humidity.

5.5.2

After

seven days, inspect the growth on the control

items to be assured that the environmental conditions are

suitable for growth. If inspection reveals that the environmen-

tal conditions are unsuitable for growth, the entire test shall be

repeated.

5.5.3

the control items show satisfactory fungus growth,

continue the test for a period of 28 days from the time of

inoculation, or as specified.

5.6

Evaluation

5.6.1

Report

those specimens which were found to be nutri-

ent to fungus growth.

5.6.2

Corrosion

should be noted separately from the fungus

test results.

6.0 Notes

6.1

Source for Micro-organisms

6.1.1

American

Type Culture Collection

10801 University Blvd.

Manassas, VA 20110-2209 (USA)

703-365-2700

http://www.atcc.org

6.2

Secondary Sources for Microorganisms

6.2.1

Pioneering

Research Division

U.S. Army Natick

Laboratories

Natick, Massachusetts 01760

6.2.2

North

University St.

Peoria, IL 61604

Contact: Dr. Stephen Peterson

309-685-4011

6.3

After

evaluation, the materials and the test chamber

must be decontaminated by exposure on all sides to ultravio-

let rays (360 nm) for a minimum of two hours, or sprayed with

a solution of 1:750 zephiran chloride solution. (One part zephi-

ran chloride to 750 parts distilled water).

6.4

Safety

Observe

all appropriate precautions on MSDS

for chemicals involved in this test method.

IPC-TM-650

Number

2.6.1.1

Subject

Fungus

Resistance – Conformal Coating

Date

07/00

Revision

age3of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

1 Scope This test method defines the procedures to deter-

mine the moisture absorption properties of metal clad or

unclad flexible dielectrics.

2 Applicable Documents None

3 Test Specimen Prepare three specimens 10 cm x 10 cm

[approx.4 in x 4 in].

4 Apparatus

4.1 Test Chamber

Oven capable of maintaining the speci-

men at 105 - 110 °C [221 - 230 °F].

4.2 Analytical Balance Analytical balance having an accu-

racy of ± 0.001 gram.

4.3 Miscellaneous

4.3.1

Vessel for holding distilled water

4.3.2 Etcher

4.3.3 Chemical etchants

4.3.4 Desiccator - Capable of holding 30% RH at 23 °C ±

2 °C [73.4 °F ± 3.6 °F]

4.3.5 40 mm dia. x 125 mm long (minimum size) glass-

stoppered evaluating bottles

4.3.6 Absorbent, lint-free paper

4.3.7 25-30 mm [approx. 5-6 in] wide, 25 mm [approx.1 in]

diameter, elastomeric (70-80 durometer hardness Shore A)

roller

4.3.8 Dry polyethylene film that is cut larger in size than

work area

4.3.9 Hard, flat, non-absorbent surface (e.g., plate glass)

4.3.10 Distilled Water

4.3.11 Thermometer for distilled water

5 Procedure

5.1 Preparation

5.1.1

If the specimen under test is a metal clad dielectric,

proceed to 5.1.2. If it is an adhesive coated dielectric, lami-

nate it with a release sheet next to adhesive or laminate to

copper foil using time, temperature, and pressure, which will

impart a normal state of cure to the adhesive. If the specimen

is a bare dielectric, proceed directly to 5.1.3.

5.1.2 Etch away all copper from the specimen using the

chemical etchants and etcher and wash thoroughly with dis-

tilled water.

5.1.3 Weighing Bottle Tare Weight Dry a weighing bottle

and its glass stopper for each specimen at 105 °C - 110 °C

[221 °F - 230 °F] for a minimum of one hour. Immediately

place both the bottle and its stopper in a desiccator, allow

both to cool to room temperature, stopper the bottle and then

weigh and record to nearest 0.001 gram. Return each stop-

pered weighing bottle to desiccator.

5.2 Test

5.2.1

Dry the specimen(s) from 5.1.3 in an oven at 105 °C -

110 °C [221 °F - 230 °F] for one hour±5minutes. Place each

specimen in a tared weighing bottle, re-stopper and then

weigh to nearest 0.001 gram. Repeat the drying cycle at least

once or until constant weight is reached. Record this constant

weight. Return weighing bottles to desiccator.

5.2.2 Immerse the specimen for 24 hours - 0 minutes/+30

minutes in a container filled with distilled water at a tempera-

ture of 23 °C±2°C[73.4 °F ± 3.6 °F]. Specimens should rest

individually on edge, supported by a racking system in the

container and shall not be in surface-to-surface contact with

each other.

5.2.3 Remove the specimens individually from the water and

lay on a panel of dry polyethylene film, which, in turn, is laid on

a flat surface. Using an elastomeric roller, roll the surface of

the specimen three or four times in one direction until the sur-

face is free of water. Turn the specimen over on a dry area of

the polyethylene film and repeat the preceding step. Place the

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.6.2

Subject

Moisture Absorption, Flexible Printed Wiring

Date

2/12

Revision

Originating Task Group

Flexible Circuits Test Methods Subcommittee

(D-15)

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.

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