Reacting and/or sintering ceramics in mfg. electronic components - using simple electronic program control circuit for partial oxygen pressure and temp. in furnace

摘要

The components consist of posistors, varistors, barrier layer capacitors, piezoelectric elements, etc. During reaction and/or sintering, the actual partial oxygen pressure (PaO2) is adjusted according to the momentary desired temp. (T ref) of the ceramic and according to a time-temp. program. The program is obtd. via >=1 programmable pocket calculator fed with values of T ref and the desired partial oxygen pressure (PrefO2). The calculator is pref. connected via an interface circuit to variable gain amplifiers providing control signals e.g. to flowmeters feeding O2 and N2 into the sintering furnace. A ZrO2 probe is pref. used to measure PaO2 and create a signal fed to one VGA for comparison with the momentary desired value of PrefO2. The electrical properties of reacted ceramics and/or the sintered mouldings made from the ceramics, depend on PaO2 during reaction and/or sintering. The invention provides a very simple electronic programmer adusting PaO2.