Thermoelectric devices on ceramic
The disclosure is related to structures and method of making thermoelectric devices. The structures include an electrically nonconductive and thermally conductive substrate with direct bonded or electroplated copper. Thermoelement pairs are formed on a barrier layer deposited on the outer layers of the substrate in gaps formed from insulator material deposited on the barrier layer. Openings in the barrier layer may be filled with an insulator to isolate thermoelements, which may then be bridged by a metal layer. Thermoelement pairs may be combined to form larger devices.
1 . A thermoelectric apparatus, the apparatus comprising:
a first stage comprising:
a copper substrate comprising:
a first copper layer with an opening; and
a substrate;
wherein the first copper layer is direct bonded or electroplated onto one face of the substrate;
a barrier layer disposed on the first copper layer with an opening coterminous with the opening in the first copper layer;
an insulator disposed on the substrate through the opening in the first copper layer and the opening in the barrier layer and on the barrier layer to form a first insulator gap on one side of the opening in the barrier layer and a second insulator gap on other side of the opening in the barrier layer;
an n-type thermoelectric layer disposed in the first insulator gap;
a p-type thermoelectric layer disposed in the second insulator gap;
a metal layer disposed on the n-type thermoelectric layer, the p-type thermoelectric layer, and on the insulator between the n-type thermoelectric layer and the p-type thermoelectric layer;
an overcoat layer disposed on the metal layer with a gap disposed between the n-type thermoelement layer and the p-type thermoelement layer;
a metal pad disposed in the gap and on the overcoat layer;
a solder layer in contact with the metal pad;
a surface layer in contact with the solder layer;
a second copper layer disposed on the surface layer; and
a second substrate disposed on the second copper layer;
where the surface layer is made of one of TiW/Pt/Au, Ni/Au, and Ni/Pd/Au; and
where the solder layer is made of one of Au/Sn, Sn—Ag—Cu, and Bi—Sn.
2 . The thermoelectric apparatus of claim 1 , further comprising:
a plurality of energy filter layers disposed between the n-type thermoelectric layer and the barrier layer and between the p-type thermoelectric layer and the barrier layer.
3 . The thermoelectric apparatus of claim 2 , wherein the plurality of energy filter layers comprises graphene.
4 . The thermoelectric apparatus of claim 1 , where the substrate is a ceramic that is not electrically conductive and is thermally conductive.
5 . The thermoelectric apparatus of claim 1 , wherein the barrier layer comprises a plurality of sublayers and at least one of the plurality of sublayers is made up of at least one of: cobalt, iridium, nickel, osmium, palladium, platinum, rhenium, ruthenium, rhodium, and tantalum/tantalum nitride.
6 . The thermoelectric apparatus of claim 1 , wherein
the n-type thermoelectric layer is made of one or more of: Bi—Te—Se, SiGe—P, Mg 3 Bi 2 , Mg—Sb—B—Te, In—Sb, Bi—Sb, Pb—Se, Sn—S—Se, Half-Heusler alloys, full Heusler alloys, Fe-V-W-Al, Yb—Ba—Co—Sb, La—Te, Pr—Te, SiGe—C, and Yb—Al; and
the p-type thermoelectric layer is made of one or more of: Bi—Sb—Te, SiGe—B, Zintl compounds, Yb—Mn—Sb, Ce—Fe—Co—Sb, Ce—Pd, Cs—Bi—Te, Pb—Te, and Zn—Sb.
7 . The thermoelectric apparatus of claim 1 , where the metal layer is made of a plurality of sublayers and at least one of the plurality of sublayers is made of at least one of aluminum, cobalt, gold, iridium, nickel, osmium, palladium, platinum, rhenium, ruthenium, rhodium, tantalum/tantalum nitride, and titanium tungsten.
8 . The thermoelectric apparatus of claim 7 , wherein a sublayer of the plurality of sublayers that is distal to the barrier layer is made of at least one of: cobalt, iridium, osmium, palladium, gold, platinum, rhenium, ruthenium, and rhodium.
9 . The thermoelectric apparatus of claim 1 , further comprising a bonding layer disposed on the metal layer and made of at least one of: sintered silver, AuSn, eutectic solder, metallic ink, and solder.
10 . The thermoelectric apparatus of claim 9 , further comprising a second direct bond copper substrate disposed on the bonding layer.
11 . The thermoelectric apparatus of claim 10 further comprising a second stage identical to the first stage and disposed on the first stage in an inverted position so that complementing thermoelectric n-type and p-type pairs are formed.