Esec, Trading Sa

Esec Sa

Eugen Mannhart

Tsing Dschen

Reto Schubiger

Felix Leu

Matthias Krieger

Alois Ulrich

Thomas Günther

Andr&eacute; Odermatt

August Enzler

Thomas Guenther

An apparatus for mounting semiconductor chips comprises a loading station for the presentation of substrates, a first transport system and a second transport system. The first transport system removes one substrate after the other from the loading station and passes them on to the second transport system which transports the substrates in steps to a dispensing or soldering station and to a bonding station. A sensor with two coils arranged at a distance to one another is arranged in such a way that one end of the substrate transported by the first transport system travels through a gap formed between the two coils. The signal delivered by the sensor is used to determine a control signal which indicates whether or not the first transport system should pass the substrate on to the second transport system.

Apparatus for mounting semiconductor chips

An apparatus for the mounting of semiconductor chips comprises a bondhead with a pick-up tool with a longitudinal drill hole to which vacuum can be applied for the gripping and transport of a semiconductor chip. To detect whether the pick-up tool has gripped the semiconductor chip, a body with a reflecting surface is arranged in the longitudinal drill hole of the pick-up tool which, when passing over the light source on absence of the semiconductor chip deflects light shining from underneath into the longitudinal drill hole of the pick-up tool into a horizontal plane. The pick-up tool has locations which are pervious to the deflected light of the light source. At least one optical element is arranged on the bondhead which concentrates at least part of the deflected light emerging laterally from the pick-up tool onto a photosensor.

A pressure transducer for the production of a controlled under or overpressure comprises a valve to which compressed air can be applied, a motor for adjusting the position of the valve block, a sensor for measuring the pressure to be controlled and an electronic controller. The valve comprises a valve block working together with a valve seat. The rotational movement of the shaft of the motor is converted into a longitudinal movement of the valve block by means of a coupling. Between the shaft of the motor and the valve block, a spring is inserted which applies a mechanical load to the motor so that the motor does not reach the set speed given by the controller but turns slower. The load on the motor is dependent on the position of the valve block. For the controller, this is equivalent to a linearization of the characteristic curve of the regulated system.

Pressure transducer

A pressure sensor for measuring a pressure p contains a membrane with a front and a rear clamped into a body. The pressure p can be applied to the rear of the membrane. The front of the membrane is actively linked to a piston. In addition, a force transmitter is present with which a predetermined force can be applied to the piston. For the purpose of re-calibration, the membrane of the pressure sensor can be deformed by the force transmitter under precisely defined conditions and the output signal re-calibrated. A positioner can also be foreseen instead of the force transmitter.

Pressure sensor with means for re-calibration

The invention concerns an apparatus for mounting semiconductor chips on a substrate with which the substrate is forwarded in steps in a first direction to a bonding station for the presentation of a next substrate position. In order that curved substrates or substrates otherwise slightly shifted in their position at right angles to the transport direction can be presented with positional accuracy at the bonding location, it is suggested that the position of the longitudinal edge of the substrate is measured at right angles to the transport direction at the level of the bonding station and then to carry out a corrective movement with the substrate. An optical sensor with two light barriers arranged next to each other is suggested for the sensor.

Apparatus for mounting semiconductor chips on a substrate

A method of aligning the bonding head of a bonder, in particular a die bonder, or of a pick and place machine comprising the steps of a) placing an alignment plate provided with two plane parallel surfaces on a supporting surface which is set plane parallel to the bonding surface upon which the semiconductor chip will be bonded to the carrier material; b) calibration of a measuring device, the signal of which is dependent upon the position of the alignment plate; c) grasping the alignment plate with the bonding head of the bonder and holding the alignment plate free at a slight distance above the measuring device; and d) alignment of the bonding head until the signal from the measuring device is equal to the signal following step b).

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Cham, Switzerland

Eugen Mannhart