1Scope This test method is to determine the land bond strength of unsupported holes,after repeated soldering and unsoldering,by mechanical pull in the perpendicular plane.
2Applicable Documents
IPC-2221Generic Standard on Printed Board Design
3Test Specimen Any unsupported component hole sample or test coupon‘‘A’’or‘‘A/B’’described in IPC-2221. Three holes per sample or test coupon shall be tested.
4Apparatus or Material
4.1Soldering Iron60-watt soldering iron capable of pro-ducing a tip temperature of232°C to260°C[450°F to 500°F].
4.2Force Tester Vertical pull force tester capable of oper-ating at a speed of50.0mm[2.0in]per minute and measur-ing up to9kg[20pounds]load.
4.3Tinned or solder coated copper wire.
5Procedure
5.1Preparation
5.1.1If conductors are connected to the land area,the fol-lowing procedure is to be followed:
Take a sharp model knife and cut conductor at least6.0mm [0.2in]away from the land.Place blade of knife on edge of land area where conductor enters.While holding the blade down,pull conductor to the land and u knife blade as ful-crum to break conductor from land without disturbing bond of the land.
5.1.2Inrt wire so that the portion extending from the sol-dered side of the circuit may be fitted into the gripping mecha-nism of a tensile tester.The wires shall have a diameter between150µm and500µm[5,906µin and19,685µin]less than the diameter of the hole.The wires shall not be clinched. Select suitable wire of sufficient length to connect to gripping mechanism of bond strength tester.5.1.3Inrt wire in holes in lected lands and solder to lands by machine or hand,as applicable.The wire shall not be clinched.
5.2Soldering Cycles
西湖岸5.2.1The hand soldering and desoldering operation of the wire shall be performed as follows:
Step1:Solder wire into lands
Step2:Remove(desolder)wire from lands
Step3:Resolder wire into lands
Step4:Remove(desolder)wire from lands
Step5:Resolder wire into lands
During the desolder and solder steps,solder every other land in the row and allow the specimen to cool to room tempera-ture.Then solder the remaining lands.
5.2.2During the solder and desoldering steps,the soldering and/or desoldering iron shall have a tip temperature as follows (e手机复制卡
病毒研究所6.1):
Method A:260°C[500°F]-Default method
Method B:315°C[599°F]
Method C:371°C[700°F]
5.3Pull Test
5.3.1Following the fifth cycle,clamp the test specimen suf-ficiently in the jaws of the bond tester to assure that the test specimen is perpendicular to the direction of pull.
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5.3.2Apply a pull at the rate of50.0mm per minute[2.0in per minute]to the wire on the pattern side of the test speci-men.
5.3.3The load must be applied perpendicular to the major surface of the land.The load shall be applied until failure occurs or the minimum force as specified by the procurement documentation is reached.The formula to calculate force for circular lands is as follows:
4L合照
π(D22–D12)
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 this
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.
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Where:
D1=Hole diameter D2=Land diameter L =Load (force)
Note:The formula given utilizes the diameter of both the land and the hole in the determination of the area of the land,rather than the radius of each.Thus,a factor of four is applied to the numerator as the area of a circle as defined by using the diameter is (π*(diameter)2)/4.
5.4Evaluation Examine test specimen for looning of
bond and for looning of the land from the ba material.It shall be considered a failure when a land around an unsup-ported hole is looned.
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6Notes 6.1
Breaking of a wire,or wire pull-out,shall not be consid-ered a failure,but the wire shall be resoldered and pulled again.
6.2
The following details are to be specified in the applicable performance specification:
蓝色给人的感觉a.Test specimen,if other than specified in 3.
b.Force,if other than specified in 5.3.3.
IPC-TM-650
Number 2.4.21Subject
Land Bond Strength,Unsupported Component Hole
Date 01/07
Revision F
Page 2of 2
