THERMOELECTRIC HEAT PUMP CASCADE USING MULTIPLE PRINTED CIRCUIT BOARDS WITH THERMOELECTRIC MODULES
A thermoelectric heat pump cascade and a method of manufacturing such are disclosed herein. In some embodiments, a thermoelectric heat pump cascade includes a first stage plurality of thermoelectric devices attached to a first stage circuit board and a first stage thermal interface material between the thermoelectric devices and the heat spreading lid over the thermoelectric devices. The thermoelectric heat pump cascade component also includes a second stage plurality of thermoelectric devices attached to a second stage circuit board where the second stage plurality of thermoelectric devices has a greater heat pumping capacity than the first stage plurality of thermoelectric devices, and a second stage thermal interface material between the second stage plurality of thermoelectric devices and the first stage plurality of thermoelectric devices. In this way, a greater temperature difference can be achieved while allowing for protection of the thermoelectric devices, simplifying design, and improving reliability of the product.
1 . A thermoelectric heat pump cascade component, comprising:
a first stage circuit board;
a first stage plurality of thermoelectric devices attached to the first stage circuit board;
a first stage heat spreading lid over the first stage plurality of thermoelectric devices;
a first stage thermal interface material between the first stage plurality of thermoelectric devices and the first stage heat spreading lid;
a second stage circuit board;
a second stage plurality of thermoelectric devices attached to the second stage circuit board where the second stage plurality of thermoelectric devices has a greater heat pumping capacity than the first stage plurality of thermoelectric devices; and
a second stage thermal interface material between the second stage plurality of thermoelectric devices and the first stage plurality of thermoelectric devices.
2 . The thermoelectric heat pump cascade component of claim 1 further comprising:
a second stage heat spreading lid over the second stage plurality of thermoelectric devices; and
wherein the second stage thermal interface material is between the second stage heat spreading lid and the first stage plurality of thermoelectric devices.
3 . The thermoelectric heat pump cascade component of claim 1 wherein:
the first stage plurality of thermoelectric devices contains a same number of thermoelectric devices as the second stage plurality of thermoelectric devices; and
the second stage plurality of thermoelectric devices has a greater heat pumping capacity than the first stage plurality of thermoelectric devices because each thermoelectric device of the second stage plurality of thermoelectric devices has a greater heat pumping capacity than a respective thermoelectric device of the first stage plurality of thermoelectric devices.
4 . The thermoelectric heat pump cascade component of claim 1 wherein:
the first stage plurality of thermoelectric devices contains fewer thermoelectric devices than the second stage plurality of thermoelectric devices.
5 . The thermoelectric heat pump cascade component of claim 4 wherein:
each thermoelectric device of the second stage plurality of thermoelectric devices has a same heat pumping capacity as each thermoelectric device of the first stage plurality of thermoelectric devices.
6 . The thermoelectric heat pump cascade component of claim 1 wherein:
two or more of the first stage plurality of thermoelectric devices have different heights relative to the first stage circuit board; and
an orientation of the first stage heat spreading lid is such that a thickness of the first stage thermal interface material is optimized for the first stage plurality of thermoelectric devices.
7 . The thermoelectric heat pump cascade component of claim 2 wherein:
two or more of the second stage plurality of thermoelectric devices have different heights relative to the second stage circuit board; and
an orientation of the second stage heat spreading lid is such that a thickness of the second stage thermal interface material is optimized for the second stage plurality of thermoelectric devices.
8 . The thermoelectric heat pump cascade component of claim 1 wherein the first stage thermal interface material is chosen from the group consisting of: solder and thermal grease.
9 . The thermoelectric heat pump cascade component of claim 1 wherein the first stage heat spreading lid further comprises a lip that extends from a body of the first stage heat spreading lid around a periphery of the first stage heat spreading lid.
10 . The thermoelectric heat pump cascade component of claim 9 wherein a height of the lip relative to the body of the first stage heat spreading lid is such that, for any combination of heights of the first stage plurality of thermoelectric devices within a predefined tolerance range, at least a predefined minimum gap is maintained between the lip of the first stage heat spreading lid and a first surface of the first stage circuit board, wherein the predefined minimum gap is greater than zero.
11 . The thermoelectric heat pump cascade component of claim 10 further comprising an attach material that fills the at least the predefined minimum gap between the lip of the first stage heat spreading lid and the first surface of the first stage circuit board around the periphery of the first stage heat spreading lid.
12 . The thermoelectric heat pump cascade component of claim 11 wherein the lip of the first stage heat spreading lid and the attach material absorb force applied to the first stage heat spreading lid so as to protect the first stage plurality of thermoelectric devices.
13 . The thermoelectric heat pump cascade component of claim 11 wherein the attach material is chosen from the group consisting of: an epoxy and a resin.
14 . The thermoelectric heat pump cascade component of claim 2 wherein the second stage heat spreading lid further comprises a lip that extends from a body of the second stage heat spreading lid around a periphery of the second stage heat spreading lid.
15 . The thermoelectric heat pump cascade component of claim 14 wherein a height of the lip relative to the body of the second stage heat spreading lid is such that, for any combination of heights of the second stage plurality of thermoelectric devices within a predefined tolerance range, at least a predefined minimum gap is maintained between the lip of the second stage heat spreading lid and a first surface of the second stage circuit board, wherein the predefined minimum gap is greater than zero.
16 . The thermoelectric heat pump cascade component of claim 15 further comprising an attach material that fills the at least the predefined minimum gap between the lip of the second stage heat spreading lid and the first surface of the second stage circuit board around the periphery of the second stage heat spreading lid.
17 . The thermoelectric heat pump cascade component of claim 16 wherein the lip of the second stage heat spreading lid and the attach material absorb force applied to the second stage heat spreading lid so as to protect the second stage plurality of thermoelectric devices.
18 . The thermoelectric heat pump cascade component of claim 16 wherein the attach material is chosen from the group consisting of: an epoxy and a resin.
19 . A method of fabricating a thermoelectric heat pump cascade component, comprising:
attaching a first stage plurality of thermoelectric devices to a first stage circuit board;
applying a first stage thermal interface material between the first stage plurality of thermoelectric devices and a first stage heat spreading lid;
attaching a second stage plurality of thermoelectric devices to a second stage circuit board; and
applying a second stage thermal interface material between the first stage plurality of thermoelectric devices and the second stage plurality of thermoelectric devices.
20 . The method of claim 19 further comprising:
attaching a second stage heat spreading lid over the second stage plurality of thermoelectric devices; and
wherein applying the second stage thermal interface material comprises applying the second stage thermal interface material between the second stage heat spreading lid and the first stage plurality of thermoelectric devices.