Browse Prior Art Database

Measurement of Current Amplification Factor

IP.com Disclosure Number: IPCOM000094459D
Original Publication Date: 1965-Jan-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Wuestenhagen, J: AUTHOR

Abstract

The transistor adapter used in U.S. Patent 3,054,948 is modified so that a transistor in chip form with metal ball external connections can have its current amplification factor measured without the influence of lead inductances and capacitances. The measurement of current amplification factor is excellent even for chip transistors with cutoff frequencies in the 500 mc range.

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Measurement of Current Amplification Factor

The transistor adapter used in U.S. Patent 3,054,948 is modified so that a transistor in chip form with metal ball external connections can have its current amplification factor measured without the influence of lead inductances and capacitances. The measurement of current amplification factor is excellent even for chip transistors with cutoff frequencies in the 500 mc range.

The left-hand drawing is a top view of the center conductor of the triplate transmission line that forms the basic structure for the transistor adapter having chip transistor 1 positioned on it. The distance between the centers of the terminating semicircles of lines 2 and 3 is equal to the distance between the collector and base ball connections of transistor 1 under test. Rivet 4 is the emitter ball contact. Rivet 4 is connected to outer conductor 5 which is the ground terminal. Line 6 connects the null instrument of current amplification factor measurement circuit shown in the patent to the collector line 3.

As shown in the right-hand drawing, chip holder 7 positions transistor 1 correctly on the center conductor with the collector ball on line terminal 3, the emitter ball on terminal 4 and the base on terminal 2. Nylon needle 8 presses transistor 1 firmly against the terminals. The transistor adapter brings the 50 ohm transmission line terminals very close to the metal ball external connections to transistor 1. The lead inductances and capacita...