Chip package with emitter finger cells spaced by different spacings from a heat sink to provide reduced temperature variation
Chip packages and methods of forming a chip package. The chip package includes a power amplifier and a thermal pathway structure configured to influence transport of heat energy. The power amplifier includes a first emitter finger and a second emitter finger having at least one parameter that is selected based upon proximity to the thermal pathway structure.
1. An assembly comprising:
a chip package having an external surface;
a chip inside the chip package, the chip including a bipolar junction transistor having a collector, a base layer on the collector, a first plurality of emitter fingers arranged in a first cell on a first portion of the base layer, a second plurality of emitter fingers arranged in a second cell on a second portion of the base layer, and a collector contact region separating the first cell from the second cell; and
a first heat sink on the chip, the first heat sink configured to influence an operating temperature of the first plurality of emitter fingers and the second plurality of emitter fingers,
wherein the first plurality of emitter fingers have a first plurality of different spacings within the first cell, the second plurality of emitter fingers have a second plurality of different spacings within the second cell, the first plurality of different spacings are different than the second plurality of different spacings, and the first cell and the second cell are spaced by different distances on the chip from the first heat sink.
2. The assembly of claim 1 wherein the first heat sink is a through-substrate via or a conductive via.
3. The assembly of 1 further comprising:
a second heat sink on the chip, the second heat sink configured to influence the operating temperature of the first plurality of emitter fingers and the second plurality of emitter fingers.
4. The assembly of claim 3 wherein the first heat sink is directly connected with the bipolar junction transistor, and the second heat sink is directly connected with the bipolar junction transistor.
5. The assembly of claim 4 wherein the first heat sink and the second heat sink are through-substrate vias.
6. The assembly of claim 4 wherein the first heat sink and the second heat sink are conductive vias.