IEC 60749-7 pdf download

IEC 60749-7 pdf download Semiconductor devices Mechanical and climatic test methods Part 7: Internal moisture content measurement and the analysis of other residual gases
1 Scope The purpose of this part of IEC 60749 is to test and measure the water vapour and other gas content of the atmosphere inside a metal or ceramic hermetically sealed device. It is applicable to semiconductor devices sealed in such a manner but generally only used for high reliability applications such as military or aerospace. It can be destructive (Methods 1 and 2) or non-destructive (Method 3).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60749-8, Semiconductor devices Mechanical and climatic test methods – Part 8: Sealing 1 )
3 Test apparatus
The apparatus for testing the internal water vapour content and that of other gases shall be as follows for the chosen method.
3.1 Method 1 Method 1 measures the water vapour content of the device atmosphere by mass spectro- metry. The apparatus for method 1 shall consist of:
a) A mass spectrometer capable of reproducibly detecting the specified moisture content for a given volume package with a factor of ten sensitivity safety margin (i.e. for a specified limit of 5 000 1 0 6 by volume 2) , 0,01 ml, the mass spectrometer shall demonstrate a 500 1 06 by volume or less absolute sensitivity to moisture for a package volume of 0,01 ml). The smallest volume shall be considered the worst case. The calibration of the mass spectrometer shall be accomplished at the specified moisture limit ( 20 %) using a package simulator which has the capability of generating at least three known volumes of gas 1 0 % on a repetitive basis by means of a continuous sample volume purge of known moisture content 1 0 %. Moisture content shall be established by the standard generation techniques (i.e. double pressure, divided flow, or cryogenic method). The absolute moisture shall be measured by a moisture dew point analyzer. The calibration operation shall be performed:
every day for the spectrometer measurement calibration;
every year for the absolute moisture generator (connected to the simulator) versus the national standards.
Gas analysis results obtained by this method shall be considered valid only in the moisture range or limit bracketed by at least two (volume or concentration) calibration points (i.e. 5 000 1 0 6 by volume between 0,01 ml and 0,1 ml or 1 000 1 0 6 by volume to 5 000 1 0 6 by volume between 0,01 ml to 0,1 ml). A best fit curve shall be used between volume calibration points. Corrections of sensitivity factors deviating greater than 1 0 % from the mean between calibration points shall be required.