Hermetically encapsulated sensor and process for its production

US6591703B2 · kind B2 · utility

Assignee

• BALLUFF GMBH · DE

Inventors

• Ernst Gass · Herznach, CH
• Michael Fritton · Wernau, DE
• Josef Mayer · Rosenheim, DE
• Walter L. Roth · Wolfschlugen, DE

Key dates

• Filing date: May 2, 2001
• Grant date: Jul 15, 2003
• Expiry date: May 24, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49007
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor has a housing, in which there is arranged a thermosetting molding compound which is encapsulated in a linear region in the longitudinal direction of the housing by a thermoplastic molding compound. The two molding compounds meet at a conical contact surface. An electrical terminal element is electrically connected to a printed-circuit board via lines. The printed-circuit board is embedded into the two molding compounds at the level of the center line, the thermosetting molding compound enclosing all the electrically active components and conductor tracks of the printed-circuit board. Annular grooves are arranged on the outer side of the thermosetting molding compound. Due to the encapsulation, the thermoplastic molding compound engages in these annular grooves in a positively and non-positively engaging manner. The groove arrangement has the advantage that effective sealing is ensured both when there is an increase in the temperature and when there is a decrease in the temperature of the sensor, since either the one groove surfaces or the other groove surfaces provide effective sealing on account of the respectively differing material expansion of the two molding compounds…