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ASIC for Capacitive Ceramic Pressure Sensors
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| Project Class: |
Mixed-mode IC |
| Technical Aspects: |
capacity/frequency converter |
| Timeframe: |
1998 - 1999 |
| Development: |
Mentor Graphics EDA tools, EUROPRACTICE analog models and standard cells libraries |
| Prototyping: |
an Alcatel Microelectronics 2 µm A/D CMOS technology/EUROPRACTICE MPW run, 10pcs in CSOIC16 package |
| Production: |
an Alcatel Microelectronics 2 um A/D CMOS technology/EUROPRACTICE run, 28k chips for flip-chip assembly |
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| Detailed Information: |
The circuit converts the output of the capacitive pressure diaphragm into a digital signal, which is further processed by a microprocessor including sensor's nonlinearity and temperature compensations. This low complexity ASIC contains RC-oscillators, control logic as well as a built-involtage divider.
Maximum working frequency is under 1 MHz, supply voltage +5V, chip area approximately 4,3 sqmm.
An Alcatel Microelectronics A/D CMOS technology was chosen for processing of the chip because of the minimum costs and no limitations in the core area - total size of the chip was given by the pad pitch which had to be accommodated to direct on ceramics flip-chip assembly.
The circuit was prototyped by the EUROPRACTICE MPW run and 10 samples encapsulated in CSOIC 16 were delivered to our customer. After having passed all the functionality and reliability tests, an order for the small volume production was placed including complete mask set fabrication. 22 wafers were produced and tested in the Delta test house with an average yield of 93%. Tested and inked wafers were delivered to the customer for further processing (flip-chip assembly). Once a mask set has been fabricated and approved, a customer can easily order another small volume runs without any additional NRE charges. |
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| Picture 1: |
Flip-chip assembly for production |
| Picture 2: |
Layout |
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Picture 1
Picture 2
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