U.S. patent application number 11/782609 was filed with the patent office on 2008-08-07 for metal trace fabrication for optical element.
This patent application is currently assigned to SOL FOCUS, INC.. Invention is credited to Harold Ackler, Hing Wah Chan, David G. Duff, John S. Fitch, David K. Fork, Scott E. Solberg, Michael C. Weisberg.
Application Number | 20080186593 11/782609 |
Document ID | / |
Family ID | 39675132 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080186593 |
Kind Code |
A1 |
Chan; Hing Wah ; et
al. |
August 7, 2008 |
METAL TRACE FABRICATION FOR OPTICAL ELEMENT
Abstract
A system may include an optical element including a surface
defining a recess, conductive material disposed within the recess,
and a solder mask disposed over a portion of the conductive
material. The solder mask may define an aperture through which
light from the optical element may pass. Some aspects provide
creation of an optical element including a surface defining a
recess, deposition of conductive material on the surface such that
a portion of the deposited conductive material is disposed within
the recess, and substantial planarization of the surface to expose
the portion of the conductive material disposed within the
recess.
Inventors: |
Chan; Hing Wah; (San Jose,
CA) ; Ackler; Harold; (Sunnyvale, CA) ;
Solberg; Scott E.; (Mountain View, CA) ; Fitch; John
S.; (Los Altos, CA) ; Fork; David K.; (Los
Altos, CA) ; Duff; David G.; (Portola Valley, CA)
; Weisberg; Michael C.; (Woodside, CA) |
Correspondence
Address: |
FISH & RICHARDSON P.C.
P.O. BOX 1022
MINNEAPOLIS
MN
55440-1022
US
|
Assignee: |
SOL FOCUS, INC.
Palo Alto
CA
PALO ALTO RESEARCH CENTER INCORPORATED
Palo Alto
CA
|
Family ID: |
39675132 |
Appl. No.: |
11/782609 |
Filed: |
July 24, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60899150 |
Feb 2, 2007 |
|
|
|
Current U.S.
Class: |
359/726 ;
359/738; 427/162 |
Current CPC
Class: |
H01L 2924/00014
20130101; H01L 31/0547 20141201; H01L 2224/05568 20130101; H01L
2224/13101 20130101; Y02E 10/52 20130101; H01L 24/16 20130101; H01L
2924/00014 20130101; H01L 2924/00014 20130101; H01L 2224/0554
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
2224/0556 20130101; H01L 2224/13101 20130101; H01L 31/054 20141201;
H01L 2224/05573 20130101; Y10T 156/10 20150115; H01L 24/13
20130101; H01L 2224/0555 20130101; H01L 2224/05599 20130101; H01L
2924/014 20130101; H01L 2224/16237 20130101 |
Class at
Publication: |
359/726 ;
359/738; 427/162 |
International
Class: |
G02B 27/32 20060101
G02B027/32; B05D 5/06 20060101 B05D005/06 |
Claims
1. A method comprising: creating an optical element including a
surface defining a recess; depositing conductive material on the
surface such that a portion of the deposited conductive material is
disposed within the recess; and substantially planarizing the
surface to expose the portion of the conductive material disposed
within the recess.
2. A method according to claim 1, wherein substantially planarizing
the surface comprises chemical-mechanical polishing the conductive
material and the surface.
3. A method according to claim 1, wherein creating the optical
element comprises molding the optical element with a mold defining
the optical element and the recess.
4. A method according to claim 1, wherein depositing the conductive
material comprises spraying molten conductive material onto the
optical element.
5. A method according to claim 4, wherein depositing the conductive
material further comprises placing a stencil on the optical element
prior to spraying the molten conductive material onto the optical
element.
6. A method according to claim 1, wherein the optical element
comprises a transparent portion including the surface.
7. A method according to claim 1, further comprising: depositing a
reflective material on the optical element, the reflective material
not being applied to the surface; depositing an electrical isolator
on the reflective material, the electrical isolator not being
applied to the surface; and depositing the conductive material on
the electrical isolator.
8. A method according to claim 7, wherein depositing the conductive
material on the electrical isolator comprises placing a stencil on
the electrical isolator prior to metal spraying the conductive
material onto the electrical isolator.
9. A method according to claim 1, further comprising; depositing a
solder mask over the exposed portion of the conductive material,
wherein the solder mask defines an aperture through which light
from the optical element may pass.
10. A method according to claim 9, further comprising: coupling a
terminal of a solar cell to the exposed portion of the conductive
material, wherein a portion of the solar cell is disposed over the
aperture.
11. An apparatus comprising: an optical element including a surface
defining a recess; conductive material disposed within the recess;
and a solder mask disposed over a portion of the conductive
material, wherein the solder mask defines an aperture through which
light from the optical element may pass.
12. An apparatus according to claim 11, wherein the optical element
comprises a transparent portion including the surface, and light
may pass from the transparent portion through the aperture.
13. An apparatus according to claim 11, wherein the surface and an
exposed surface of the conductive material are substantially
coplanar.
14. An apparatus according to claim 11, further comprising: a
reflective material disposed on the optical element and not on the
surface; an electrical isolator disposed on the reflective material
and not on the surface; and second conductive material is disposed
on the electrical isolator.
15. An apparatus according to claim 11, further comprising: a solar
cell comprising a terminal, wherein the aperture exposes a portion
of the conductive material, wherein the terminal is coupled to the
exposed portion of the conductive material, and wherein a portion
of the solar cell is disposed to receive the light from the
aperture.
16. A method comprising: creating an optical element including a
surface defining a recess; depositing a material on areas of the
surface other than the recess; depositing conductive material on
the material and within the recess; and removing the material and
any conductive material deposited thereon.
17. A method according to claim 16, wherein depositing the
conductive material comprises spraying molten conductive material
onto the optical element.
18. A method according to claim 17, wherein depositing the
conductive material further comprises placing a stencil on the
optical element prior to spraying the molten conductive material
onto the optical element.
19. A method according to claim 16, further comprising: depositing
a reflective material on the optical element, the reflective
material not being applied to the surface; depositing an electrical
isolator on the reflective material, the electrical isolator not
being applied to the surface; and depositing the conductive
material on the electrical isolator.
20. A method comprising: depositing a conductive material on an
optical element; depositing photoresist on the conductive material;
removing a portion of the photoresist to expose a portion of the
conductive material; plating the exposed portion of the conductive
material with a second conductive material; removing a remaining
portion of the photoresist; and removing unplated portions of the
conductive material.
21. A method according to claim 20, wherein: the conductive
material and the second conductive material are substantially
similar, and removing the unplated portions comprises etching the
unplated portions and a portion of the second conductive
material.
22. A method according to claim 20, wherein: the conductive
material and the second conductive material are different; and
removing the unplated portions comprises selectively etching the
unplated portions without etching the second conductive material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application Ser. No. 60/899,150, filed on Feb. 2, 2007 and
entitled "Concentrated Photovoltaic Energy Designs", the contents
of which are incorporated herein by reference for all purposes.
BACKGROUND
[0002] 1. Field
[0003] Some embodiments generally relate to electrical systems
incorporating one or more optical elements. More specifically,
embodiments may relate to an optical element efficiently adapted
for interconnection to electrical devices.
[0004] 2. Brief Description
[0005] In some conventional devices, an optical element (e.g., a
lens) may include metal traces for interconnection to an electrical
circuit. The metal traces may be fabricated on and/or within the
optical element using any of several known techniques. For example,
the metal traces may be deposited using thin or thick film
lithography. Lithography, however, requires expensive equipment and
time-consuming processes.
[0006] Since a typical optical element does not include
distinguishing surface features, lithographic techniques also
require fiducial marks for proper alignment of the metal traces on
the optical element. However, the placement of the fiducial marks
on the optical element is also difficult due to the lack of surface
features and the material of which the optical element is composed
(e.g., glass).
[0007] What is needed is a system to efficiently incorporate metal
traces into an optical element.
SUMMARY
[0008] To address at least the foregoing, some aspects provide a
method, means and/or process steps to create an optical element
including a surface defining a recess, deposit conductive material
on the surface such that a portion of the deposited conductive
material is disposed within the recess, and substantially planarize
the surface to expose the portion of the conductive material
disposed within the recess.
[0009] Creation of the optical element may include molding the
optical element with a mold defining the optical element and the
recess. Also or alternatively, deposition of the conductive
material may include placing a stencil on the optical element prior
to metal spraying the conductive material onto the optical
element.
[0010] In some aspects, a reflective material is deposited on the
optical element and not on the surface, an electrical isolator is
deposited on the reflective material but not on the surface, and
the conductive material is deposited on the electrical isolator.
Aspects may include deposition of a solder mask over the exposed
portion of the conductive material, wherein the solder mask defines
an aperture through which light from the optical element may pass.
Further to the foregoing aspects, a terminal of a solar cell may be
coupled to the exposed portion of the conductive material such that
a portion of the solar cell is disposed over the aperture.
[0011] In other aspects, provided are an optical element including
a surface defining a recess, conductive material disposed within
the recess, and a solder mask disposed over a portion of the
conductive material. The solder mask may define an aperture through
which light from the optical element may pass. The optical element
may comprise a transparent portion including the surface, and light
may pass from the transparent portion through the aperture.
[0012] According to further aspects, a reflective material may be
disposed on the optical element and not on the surface, an
electrical isolator may be disposed on the reflective material and
not on the surface, and second conductive material may be disposed
on the electrical isolator. Some aspects include a solar cell
having a terminal coupled to a portion of the conductive material
exposed by the aperture, wherein a portion of the solar cell is
disposed to receive the light from the aperture.
[0013] The claims are not limited to the disclosed embodiments,
however, as those in the art can readily adapt the description
herein to create other embodiments and applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The construction and usage of embodiments will become
readily apparent from consideration of the following specification
as illustrated in the accompanying drawings, in which like
reference numerals designate like parts.
[0015] FIG. 1 is a flow diagram of a method according to some
embodiments.
[0016] FIG. 2 is a perspective view of a portion of an optical
element according to some embodiments.
[0017] FIG. 3 is a cross-sectional view of a portion of an optical
element according to some embodiments.
[0018] FIG. 4 is a perspective view of a portion of an optical
element with conductive material disposed thereon according to some
embodiments.
[0019] FIG. 5 is a cross-sectional view of a portion of an optical
element with conductive material disposed thereon according to some
embodiments.
[0020] FIG. 6 is a perspective view of a substantially planarized
portion of an optical element according to some embodiments.
[0021] FIG. 7 is a cross-sectional view of a substantially
planarized portion of an optical element according to some
embodiments.
[0022] FIG. 8 is a flow diagram of a method according to some
embodiments.
[0023] FIG. 9A is a perspective view of a transparent optical
element according to some embodiments.
[0024] FIG. 9B is a cross-sectional view of a transparent optical
element according to some embodiments.
[0025] FIG. 10A is a perspective view of a transparent optical
element with reflective material disposed thereon according to some
embodiments.
[0026] FIG. 10B is a cross-sectional view of a transparent optical
element with reflective material disposed thereon according to some
embodiments.
[0027] FIG. 11A is a perspective view of an optical element with an
electrical isolator disposed thereon according to some
embodiments.
[0028] FIG. 11B is a cross-sectional view of an optical element
with an electrical isolator disposed thereon according to some
embodiments.
[0029] FIG. 12A is a perspective view of an optical element with
conductive material disposed thereon according to some
embodiments.
[0030] FIG. 12B is a cross-sectional view of an optical element
with conductive material disposed thereon according to some
embodiments.
[0031] FIG. 13A is a perspective view of an optical element after
planarization of a portion thereof according to some
embodiments.
[0032] FIG. 13B is a cross-sectional view of an optical element
after planarization of a portion thereof according to some
embodiments.
[0033] FIG. 14A is a perspective view of a solder mask deposited on
an optical element according to some embodiments.
[0034] FIG. 14B is a cross-sectional view of a solder mask
deposited on an optical element according to some embodiments.
[0035] FIG. 15 is a close-up cross-sectional view of an optical
element including a solar cell according to some embodiments.
DETAILED DESCRIPTION
[0036] The following description is provided to enable any person
in the art to make and use the described embodiments and sets forth
the best mode contemplated for carrying out some embodiments.
Various modifications, however, will remain readily apparent to
those in the art.
[0037] FIG. 1 is a flow diagram of process 10 according to some
embodiments. Process 10 may be performed by any combination of
machine, hardware, software and manual means.
[0038] Initially, an optical element is created at S12. The optical
element includes a surface defining a recess, and may be composed
of any suitable material or combination of materials. According to
some embodiments, the optical element may be configured to
manipulate and/or pass desired wavelengths of light. The optical
element may comprise any number of disparate materials and/or
elements (e.g., lenses, mirrors, etc.) according to some
embodiments.
[0039] The optical element may be created using any combination of
devices and systems that is or becomes known. Some embodiments of
S12 include depositing a liquid or powder into a mold and cooling,
heating and/or pressuring the mold. The mold may define the optical
element as well as the aforementioned recesses. Alternatively, the
recesses may be formed (e.g., by etching, milling, etc.) after the
optical element is molded.
[0040] FIG. 2 is a perspective view of a portion of optical element
100 according to some embodiments, and FIG. 3 is a cross-sectional
view of optical element 100. FIGS. 2 and 3 show only a portion of
optical element 100 in order to illustrate that optical element 100
may exhibit any suitable shape or size. Element 100 may be
fabricated according to S12 of FIG. 1, but S12 is not limited
thereto.
[0041] The illustrated portion of optical element 100 comprises
surface 110, recess 120 and recess 130. In the present description,
surface 110 includes portions of element 100 which define recess
120 and recess 130. As mentioned above, recess 120 and recess 130
may have been defined by a mold used to create optical element 100
or formed after creation of optical element 100.
[0042] Returning to process 10, conductive material is deposited on
the surface of the optical element at S14. The material is
deposited such that a portion of the deposited material is disposed
within the defined recess. The conductive material may be composed
of any combination of one or more materials. In some embodiments,
the conductive material comprises nickel. Moreover, the conductive
material may be deposited using any suitable process that is or
becomes known, including but not limited to sputtering, chemical
vapor deposition, sol gel techniques and thermal spraying (e.g.,
twin wire arcing, plasma spraying).
[0043] FIG. 4 is a perspective view of optical element 100 after
S14 according to some embodiments. FIG. 5 is a cross-sectional view
of optical element 100 as shown in FIG. 4. Conductive material 140
is depicted covering surface 110 of element 100.
[0044] Conductive material 140 is disposed within the recesses
defined by surface 110. A thickness of material 140 within recesses
120 and 130 is greater than a thickness of material 140 on other
portions of surface 110, but embodiments are not limited thereto.
Moreover, a thickness of material 140 on the other portions of
surface 110 need not be as uniform as shown in FIG. 5. Generally, a
height of conductive material 140 on various portions of surface
110 may depend on the technique used to deposit material 140 at
S14.
[0045] The surface of the optical element is substantially
planarized at S16. The planarization exposes the portion of the
conductive material disposed within the recess. Chemical-mechanical
polishing may be employed at S16 to substantially planarize the
surface, but embodiments are not limited thereto. Planarization may
comprise removing an uppermost portion of the surface of the
optical element as well as an upper layer of the conductive
material.
[0046] FIGS. 6 and 7 depict element 100 after some embodiments of
S16. As shown, conductive material 140 is disposed within recess
120 and recess 130 and is substantially flush with adjacent
portions of surface 110. According to some embodiments, conductive
material 140 may be electrically coupled to an electrical device
and/or to other conductive traces.
[0047] FIG. 8 is a flow diagram of process 200 according to some
embodiments. Process 200 may be performed by any combination of
machine, hardware, software and manual means.
[0048] Process 200 begins at S210, at which an optical element is
created. As described with respect to S12, the optical element
includes a surface defining a recess, and may be composed of any
suitable material or combination of materials. The optical element
may be created using any combination of devices and systems that is
or becomes known.
[0049] FIG. 9A is a perspective view of optical element 300 created
at S210 according to some embodiments, and FIG. 9B is a
cross-sectional view of element 300. Optical element 300 may be
molded from low-iron glass at S210 using known methods.
Alternatively, separate pieces may be glued or otherwise coupled
together to form element 300. Optical element 300 may comprise an
element of a solar concentrator according to some embodiments.
[0050] Element 300 includes convex surface 310, pedestal 320
defining recesses 322, 324, 326 and 328, and concave surface 330.
Recesses 322, 324, 326 and 328 may have been defined by a mold used
to create optical element 300 or formed after creation of optical
element 300. The purposes of each portion of element 300 during
operation according to some embodiments will become evident from
the description below.
[0051] A reflective material is deposited on the optical element at
S220. The reflective material may be intended to create one or more
mirrored surfaces. Any suitable reflective material may be used,
taking into account factors such as but not limited to the
wavelengths of light to be reflected, bonding of the reflective
material to the optical element, and cost. The reflective material
may be deposited by sputtering or liquid deposition.
[0052] FIGS. 10A and 10B show perspective and cross-sectional
views, respectively, of optical element 300 after some embodiments
of S220. Reflective material 340 is deposited on convex surface 310
and concave surface 330. Reflective material 340 may comprise
sputtered silver or aluminum. The vertical and horizontal surfaces
of pedestal 320 may be masked at S220 such that reflective material
340 is not deposited thereon, or otherwise treated to remove any
reflective material 340 that is deposited thereon.
[0053] Next, at S230, an electrical insulator is deposited on the
optical element. The insulator may comprise any suitable insulator
or insulators. Non-exhaustive examples include polymers,
dielectrics, polyester, epoxy and polyurethane. The insulator may
be deposited using any process that is or becomes known. In some
embodiments, the insulator is powder-coated onto the optical
element.
[0054] Some embodiments of S230 are depicted in FIGS. 11A and 11B.
Insulator 350 is deposited on convex surface 310 or, more
particularly, on reflective material 340. Again, S230 is executed
such that insulator 350 is not deposited on the vertical and
horizontal surfaces of pedestal 320. According to the illustrated
embodiment, insulator 340 is not deposited on concave surface 330
(i.e., on reflective material 340 deposited on concave surface
330).
[0055] Returning to process 200, a pattern of conductive material
is deposited on the surface and the electrical isolator at S240
such that a portion of the deposited conductive material is
disposed within the defined recess. The conductive material may be
composed of any combination of one or more materials (e.g., nickel,
copper). Sputtering, chemical vapor deposition, thermal spraying,
lithography, and or other techniques may be used at S240 to deposit
the conductive material on the surface and on the electrical
isolator.
[0056] FIG. 12A is a perspective view and FIG. 12B is a
cross-sectional view of optical element 300 after S240 according to
some embodiments. Conductive material 360 covers pedestal 320 and
portions of insulator 350. FIG. 12B shows conductive material 360
disposed within recesses 322 and 326. Conductive material 360
disposed in recesses 322 and 326 is contiguous with, and therefore
electrically connected to, conductive material 360 disposed on
insulator 350. Although conductive material 360 appears to extend
to a uniform height above element 300, this height need not be
uniform.
[0057] Conductive material 370, which may be different from or
identical to material 360, also covers portions of insulator 350.
Conductive material 360 and conductive material 370 define a gap to
facilitate electrical isolation from one another. Embodiments such
as that depicted in FIGS. 12A and 12B may include placing a stencil
in the shape of the illustrated gap on electrical isolator 350 and
depositing conductive material 360 and 370 where shown and on the
stencil. Removal of the stencil may then result in the apparatus of
FIGS. 12A and 12B.
[0058] Conductive materials 360 and 370 may create a conductive
path for electrical current generated by a photovoltaic (solar)
cell coupled to element 300. Conductive material 360 and conductive
material 370 may also, as described in U.S. Patent Application
Publication No. 2006/0231133, electrically link solar cells of
adjacent solar concentrators in a solar concentrator array.
[0059] At S250, the surface of the optical element is substantially
planarized to expose the portion of the conductive material
disposed within the recess. Planarization may comprise
chemical-mechanical polishing or any other suitable system. As
described above, planarization may also comprise removing an
uppermost portion of the surface of the optical element as well as
an upper layer of the conductive material.
[0060] FIGS. 13A and 13B show optical element 300 after some
embodiments of S250. Conductive material 360 remains disposed
within recesses 322 through 328 and electrically coupled to
conductive material 360 deposited on electrical isolator 350.
Conductive material 360 disposed within recesses 322 through 328 is
also substantially flush with adjacent portions of pedestal
320.
[0061] According to some embodiments, S240 and S250 may comprise
placing a material (e.g., wax, polymer) on areas of surface 320
other than recesses 322, 324, 326 and 328. The material may
comprise a material which resists adhesion to the conductive
material. The material may be dip-coated, contact-printed, stamped,
rolled, painted, etc. onto surface 320.
[0062] Conductive material 360 may be thereafter deposited onto the
material and recesses 322, 324, 326 and 328. The material is then
removed using a chemical stripping method, for example, thereby
removing any conductive material that has adhered to the
material.
[0063] After formation of apparatus 300 of FIGS. 13A and 13B, a
solder mask defining an aperture is deposited over the exposed
portion of the conductive material at S260. The solder mask may
protect the surface surrounding the conductive material during
subsequent soldering of electrical contacts to the exposed
conductive portions. The solder mask may be deposited using a
stencil and a ceramic spray and/or may be deposited using
photolithographic techniques.
[0064] FIGS. 14A and 14B show a perspective view and a
cross-sectional view, respectively, of optical element 300
including solder mask 380. Solder mask 380 defines aperture 385
through which portions of conductive material 360 are visible.
Solder mask 380 may therefore allow soldering of electrical
elements to the visible portions while protecting other portions of
conductive material 360.
[0065] In this regard, a terminal of a solar cell is coupled to the
exposed portion of the conductive material at S270. The terminal
may be coupled such that a portion of the solar cell is disposed
over the aperture. The portion of the solar cell may comprise an
area for receiving photons from which the solar cell generates
electrical current.
[0066] FIG. 15 is a close-up cross-sectional view of element 300
after S270 according to some embodiments. Solar cell 390 may
comprise a solar cell (e.g., a III-V cell, II-VI cell, etc.) for
receiving photons from optical element 300 and generating
electrical charge carriers in response thereto. Solar cell 390 may
comprise any number of active, dielectric and metallization layers,
and may be fabricated using any suitable methods that are or become
known.
[0067] Solder bumps 392 and 394 are coupled to conductive material
360 disposed in recesses 322 and 326, respectively. Solder bumps
392 and 394 are also respectively coupled to terminals 393 and 395
of solar cell 390. Various flip-chip bonding techniques may be
employed in some embodiments to electrically and physically couple
terminals 393 and 395 to the conductive material disposed in
recesses 322 and 326. In some embodiments, unshown terminals of
solar cell 390 are coupled to conductive material 360 disposed in
recesses 324 and 328 of element 300.
[0068] According to some embodiments, a protection layer is applied
to the exposed portions of conductive material 360 disposed in
recesses 322 through 328 prior to S270. The protection layer may
comprise a lower layer of nickel and an upper layer of gold. A
portion of the gold layer may dissipate during coupling of the
terminal at S270.
[0069] Some embodiments may avoid deposition of solder mask 380 at
S260 by replacing solder bumps 392 and 394 by other interconnects
that do not require melting to couple terminals 393 and 395 to
conductive material 360 disposed in recesses 322 and 326. Examples
of such materials include gold stud bumps and conductive die
attaches including silver-filled epoxy. In these embodiments, the
coupling may be established by known methods such as ultrasonic
welding and other direct chip attachment methods.
[0070] According to some embodiments, a thin layer of conductive
material is deposited on entire surfaces 310 and 320 of optical
element 300. Photoresist is then applied to entire surfaces 310 and
320. The photoresist is patterned and developed such that the
photoresist covers all portions of the conductive material except
for exposed portions where metal traces are desired. Metal plating
is applied which adheres to the exposed portions but not to the
photoresist. The photoresist is then removed, and the thin layer of
conductive material is removed. The thin layer may be removed by
selectively etching in a case that the thin material differs from
the metal plating material. In some embodiments, etch time may be
controlled to remove the thin layer while leaving a suitable
thickness of the metal traces.
[0071] Apparatus 300 may generally operate in accordance with the
description of aforementioned U.S. Patent Application Publication
No. 2006/0231133. With reference to FIG. 15, solar rays enter
surface 398 and are reflected by reflective material 340 disposed
on convex surface 310. The rays are reflected toward reflective
material 340 on concave surface 330, and are thereafter reflected
toward aperture 385. The reflected rays pass through aperture 385
and are received by window 396 of solar cell 390. Those skilled in
the art of optics will recognize that combinations of one or more
other surface shapes may be utilized to concentrate solar rays onto
a solar cell.
[0072] Solar cell 390 receives a substantial portion of the photon
energy received at surface 398 and generates electrical current in
response to the received photon energy. The electrical current may
be passed to external circuitry (and/or to similar
serially-connected apparatuses) through conductive material 360 and
conductive material 370. In this regard, solar cell 390 may also
comprise a terminal electrically coupled to conductive material
370. Such a terminal would exhibit a polarity opposite to the
polarity of terminals 393 and 395.
[0073] The several embodiments described herein are solely for the
purpose of illustration. Embodiments may include any currently or
hereafter-known versions of the elements described herein.
Therefore, persons in the art will recognize from this description
that other embodiments may be practiced with various modifications
and alterations.
* * * * *