Increasing the efficiency of solar cells by transfer of solder

Patent metadata

Field	Value
Publication number	US-9227259-B2
Application number	US-201213591305-A
Country	US
Kind code	B2
Filing date	Aug 22, 2012
Priority date	Aug 22, 2012
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

Thickening a contact grid of a solar cell for increased efficiency. A mold containing soldering material is heated. The mold is aligned with the contact grid such that the soldering material is in physical contact with the contact grid. The mold is re-heated, transferring the solder material from the mold to the contact grid to create a thickened contact grid.

First claim

We claim:

1. A method comprising:
for a first body comprising a first mold, the first mold comprising at least two hollowed out areas containing a first solder material and at least two non-hollowed out areas, heating the first body such that the first solder material forms into at least one spherical ball within each hollowed out area;
aligning the first body with a second body, the second body comprising a diode in communication with an inactive layer, the inactive layer including a contact grid with a first thickness, and the first solder material in physical contact with the contact grid, including aligning at least two first respective segments of the contact grid with the at least two hollowed out areas, and aligning at least second and third respective segments of the contact grid with the at least two non-hollowed out areas; and
re-heating the first body including the first solder material softening and transferring from the first body to the second body to form a first solder layer from the solder material on the contact grid, wherein the first solder layer increases the first thickness across an entire length of the inactive layer, wherein the first solder layer comprises a second thickness corresponding to a maximum thickness of the first solder layer occurring at the at least first respective segments, and a third thickness corresponding to a thickness of the first solder layer occurring at the at least second and third respective segments, and wherein the third thickness is less than the second thickness.

2. The method of claim 1 , further comprising a second mold different than the first mold, the second mold comprising at least one hollowed out area containing a second solder material, heating the second mold such that the second solder material forms into at least one spherical ball within the hollowed out area;
aligning the second body with the second mold such that the second solder material is in physical contact with the contact grid having the second thickness;
re-forming the second body with the contact grid, including re-heating the second mold including the second solder material softening and transferring from the second mold to the re-formed second body, including increasing the second thickness of the contact grid to a fourth thickness greater than the second thickness.

3. The method of claim 1 , wherein the first mold is comprised of glass.

4. The method of claim 1 , wherein the solder material is lead free.

5. The method of claim 1 , wherein the contact grid includes a landing area, and further comprising placing the solder in contact with the landing area when aligning the first body with the second body.

6. A method comprising:
for a first body comprising a first mold, the first mold comprising at least two hollowed out areas containing a first solder material and at least two non-hollowed out areas, heating the first body such that the first solder material forms into at least one spherical ball within each hollowed out area;
aligning the first body with a second body, the second body comprising a diode in communication with an inactive layer, the inactive layer including a contact grid with a first thickness, and the first solder material in physical contact with the contact grid, including aligning at least two first respective segments of the contact grid with the at least two hollowed out areas, and aligning at least second and third respective segments of the contact grid with at least two non-hollowed out areas;
re-heating the first body including the first solder material softening and transferring from the first body to the second body to form a first solder layer from the solder material on the contact grid, wherein the first solder layer increases the first thickness across an entire length of the inactive layer, wherein the first solder layer comprises a second thickness corresponding to a maximum thickness of the first solder layer occurring at the at least first respective segments, and a third thickness corresponding to a thickness of the first solder layer occurring at the at least second and third respective segments, and wherein the third thickness is less than the second thickness; and
applying a second re-heating of the first body with a second solder material until a desired thickness of the contact grid across the inactive layer is achieved.

7. The method of claim 1 , wherein the second thickness is universal across the contact grid.

8. The method of claim 1 , wherein the third thickness includes areas of the contact grid between adjacently positioned spherical balls of the first solder material.

9. The method of claim 6 , wherein the second thickness is universal across the contact grid.

10. The method of claim 6 , wherein the third thickness includes areas of the contact grid between adjacently positioned spherical balls of the first solder material.

11. The method of claim 6 , further comprising the first body comprising a second mold, the second mold comprising hollowed out areas shaped differently than the hollowed out areas of the first mold.

Assignees

• Haag Michael
• Kellmann Ruediger
• Schmidt Markus
• IBM

Inventors

• Haag Michael
• Kellmann Ruediger
• Schmidt Markus

Classifications

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• B23K3/0638

  for viscous material feeding, e.g. solder paste feeding (B23K3/0623 takes precedence) · CPC title

• B23K1/0016

  Soldering of electronic components · CPC title

• B23K1/20 Primary

  Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating · CPC title

• B23K2101/42

  Printed circuits · CPC title