1Scope This method covers the determination of the force necessary to propagate a tear in flexible insulating mate-rials that range between the thickness of approx.12µm to 100µm[approx.0.0005in to0.004in].This test method is bad on ASTM D1938.
2Applicable Documentshalf的复数形式
ASTM D1938Standard Test method for Tear propagation Resistance(Trour Tear)of Plastic Film and Thin Sheeting by a Single Tear Method
3Test Specimen Preparations
3.1If the specimens to be tested are clad flexible dielectric materials,the copper foil shall be fully etched(removed)using standard commercial practices.If the dielectric material to be tested is unclad,u the material as it exists for this test method.If the specimens are flexible insulating bonding mate-rial that inherently has an adhesive that is not fully cured,full curing of this adhesive shall be accomplished before the material is tested.
3.2The specimens shall be of the single-tear type and shall consist(e Figure1)of strips75mm[approx.3in]long by25mm[approx.1in]wide and shall have a clean longitu-dinal slit50mm[ap
prox.2in]long cut with a sharp razor blade or the equivalent(Note:All dimensions shall be mea-sured to within a0.5%tolerance.)
3.3If the specimen is compod of a ba dielectric plus adhesive coated on one or both sides,the thickness of the ba dielectric needs to be measured,either via cross-ctional analysis or if feasible,removal of the adhesive lay-er(s).The thickness of the specimen below the slit(e Figure 1)shall be measured in three places and recorded in millime-ters or microns[in].This provides the ur of this test method with knowledge of only the ba dielectric film thickness.
3.4Sufficient specimens shall be cut to provide a minimum of five specimens in both transver and longitudinal axes and identified.Specimens shall be free of nicks or other defects that might cau premature test failure.Verification of lack of defects in the slit shall be done using a minimum magnifica-tion of3X.4Test Equipment
4.1Constant Strain Rate Tensile Test Machine This test machine shall have a weighing head that can measure the load applied to tear the specimen.It should be equipped with a device for recording the load carried by the specimen and amount of paration of the grips during the test.The testing machine shall be esntially free from inertia lag at the specified rate of testing and shall indicate the
load with an accuracy of±2%of the indicated value,or better.A device shall be included to control the grip paration rate at 250mm[approx.10in]±5%per minute.
4.2Thickness Measuring Devices Suitable micrometers, or thickness gages,reading to2.5µm[approx.0.10in]or less shall be ud for measuring the thickness of the specimens.
4.3Cutter The cutter shall be a sharp razor blade or the equivalent.
5Conditioning
5.1Conditioning Condition the specimens at23°C±2°C [73.4°F±3.6°F]and50%±5%relative humidity for not less than24hours prior to test.
5.2Test Conditions Conduct tests in the Standard Labo-ratory Conditions of23°C±2°C[73.4°F±3.6°F]and50%±5%relative humidity.
6Procedure
6.1Secure tongue A(Figure1)in one grip and tongue B in the other grip of the tensile testing machine using an initial grip paration of50mm[approx.2in].Align the specimen so that its major axis coincides with an imaginary line joining the cen-ters of the grips.
6.2Using a grip paration speed of250mm[approx.10in] /minute,start the tensile test machine and record the load necessary to propagate the tear through the entire unslit 25mm[approx.l in]portion.
6.3Test not less than five(5)specimens in each of the transver and longitudinal directions.
3000Lakeside Drive,Suite309S
Bannockburn,IL60015-1249 IPC-TM-650
TEST METHODS MANUAL Number
2.4.17.1幼儿启蒙
Subject
Propagation Tear Strength,Flexible Insulating Material
Date感谢信英文
1/13
红发会
Revision
B
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 u or adaptation is entirely voluntary.IPC disclaims all liability of any kind as to the u,application,or adaptation of thispgp
material.Urs are also wholly responsible for protecting themlves against all claims or liabilities for patent infringement.
Equipment referenced is for the convenience of the ur and does not imply endorment by IPC.
Page1of2
7Calculations
7.1Low Extensible Films
For ba dielectric films that
have load-time charts characterized by Figure 2,the average tear propagation force in grams [ounces]is obtained by aver-aging the load indicated on the chart over the time period,disregarding the initial and final portions of the curve.Record the average load value reading from the tensile testing machine.The average resistance to tearing shall be calcu-lated from all specimens tested in each of the transver and longitudinal directions.
7.2High Extensible Films
For ba dielectric films that
have load-time charts characterized by Figure 3,the initial force to continue the propagation of the slit and the maximum
force attained are obtained from the chart and reported in grams [ounces].The initial force may be more readily detected by placing a dot approximately 3mm [1/8in]in diameter at the ba of the razor blade slit with a wax pencil.As the load is applied to the sample,the dot area is obrved.When the lo
ad is just sufficient to begin the extension of the slit,a ‘‘blip’’is introduced on the chart (e Figure 3)by pushing the appropriate button on the recorder or the equivalent to mark this point.The maximum load is the highest reading on the chart as indicated.Calculate the average of the five initial tear-propagation forces and the average of the five maximum tear-propagation forces in grams [ounces]for the transver and longitudinal directions of the material test specimens.
8Report 8.1
Report the average ba dielectric film thickness only of the specimens tested.This provides the ur of this test method with the ba dielectric film thickness only,if required,by the flexible circuitry material specifications.
8.2
For low extensible ba dielectric films described in 7.1,report the average of the five average tear propagation deter-minations in grams [ounces]for the transver and longitudi-nal specimens.
8.3
neckFor high extensible ba dielectric films described in 7.2,report the average of the five initial tear-pro
pagation forces and the average of the five maximum tear-propagation forces in grams [ounces]for the transver and longitudinal specimens.
IPC-24171-1
Figure 1Single-tear
英语口语论坛specimens
northlandIPC-24171-2
Figure 2Load-time chart for low-extensible ba dielectric
films
IPC-24171-3
Figure 3Load-time chart for high extensible ba dielectric films IPC-TM-650
Number 2.4.17.1Subject
Propagation Tear Strength,Flexible Insulating Materialstereo
Date 1/13
heidelberg
Revision B
Page 2of 2
