Time to Delamination (TMA Method)

1 ScopeThis method describes the method for deter-mining the time to Delamination of laminates and printedboards through the use of a thermomechanical analyzer(TMA). Applicable DocumentsIPC-TM-650 Method , Glass Transition Temperatureand Z-Axis Thermal Expansion by Test SizeSpecimens shall be approximately mm mm [ in x in] by the thickness of the Quantity and SamplingUnless otherwise specified,two specimens shall be tested, to be taken from random loca-tions of the material in Apparatus or Drying ChamberAir circulating oven capable of main-taining 105 2 C [221 F]. Cutting EquipmentDiamond blade or wheel, sandingequipment, or equivalent, to provide a specimen of the sizeand edge quality DesiccatorDessication chamber capable of maintain-ing an atmosphere less than 30% RH at 23 C [ F].

2 TesterThermal Mechanical Analyzer (TMA) capable ofdetermination of dimensional change to within mm[ in] over the specified temperature Specimen clad laminates shall be tested as is. Multilayerprinted boards may be sampled with internal conductorspresent. (For determination of a multilayer board s bond integ-rity, presence of internal conductors is preferred.) shall be cut to the specified size usingappropriate procedures and equipment to minimize mechani-cal stress or thermal edges shall be smooth and burr-free by means onsanding or equivalent (to allow the specimen to rest com-pletely flat on the mounting stage). Use care to minimizestress or heat on the specimen shall be preconditioned by baking for 2hours at 105 2 C [221 F], then cooled to room tem-perature in a the specimen from the dessicator and placethe specimen on the stage of the TMA taking care that thesample is centered and resting flat on the the TMA s probe onto the specimen and applya force of Newtons [5g]; then lower the furnace intoplace around the the temperature ramp (or scan) from an initialtemperature no higher than 35 C [95 F].

3 The scan at the specified rate. Unless other-wise specified, the scan rate shall be 10 C/minute (see ). the scan reaches the specified isothermal tem-perature, hold at that temperature for 10 minutes or to otherwise specified, the isothermal temperature shallbe 260 C [500 F].If the instrument allows real time display of the data, terminatethe experiment after evidence of Delamination is EvaluationThe time to Delamination is determined asthe time from the onset of the isotherm to failure. Failure is anyevent or deviation of the data plot where the thickness isshown to have irreversibly changed. The scan in Figure 1 istypical of an epoxy material at 260 C [500 F] isothermal tem-perature. On occasion, some materials will delaminate beforeThe Institute for Interconnecting and Packaging Electronic Circuits2215 Sanders Road Northbrook, IL 60062-6135 IPC-TM-650 TEST METHODS to Delamination (TMA Method) Date12/94 RevisionOriginating Task GroupMIL-P-13949 Test Methods Task Group (7-11b)Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC.

4 This material is advisory onlyand its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of thismaterial. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent referenced is for the convenience of the user and does not imply endorsement by the isotherm is reached. In this case, the temperature at thetime of failure shall be the time to Delamination as determined in the time at which any other plot event has taken placewhich was not determined to be the configuration of the sample ( , whetherexternal or internal foil is present). the ramp rate and isothermal temperature ifother than that epoxy laminates and similar materials, the recom-mended isothermal temperature is 260 C [500 F].

5 For polyim-ides and other high temperature materials, the isothermaltemperature may be increased to 288 C [550 F]. For othermaterial types, consult with the material of the instrument should be carried outaccording to the manufacturer s Tgof the material may be obtained from this test,which is similar to Method It should be noted that theTgso obtained is a first pass faster ramp rate will decrease the time to run, providesome greater distinction between materials, and provide acloser equivalence to the Thermal Stress test, rate of 100 C/minute [212 F/minute] is recommended forsuch to Delamination (TMA Method) Date12/94 RevisionPage2of2