Ex Parte Hostetler

Board of Patent Appeals and Interferences

Jun 5, 2011

11233321 (B.P.A.I. Jun. 5, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte TIMOTHY S. HOSTETLER
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Appeal 2010-002153
Application 11/233,321
Technology Center 3700
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Before SALLY C. MEDLEY, MICHAEL P. TIERNEY, and
MICHAEL L. HOELTER, Administrative Patent Judges.

HOELTER, Administrative Patent Judge.

DECISION ON APPEAL
Appeal No. 2010-002153
Application No. 11/233,321

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A. STATEMENT OF THE CASE
This is a decision on appeal by the real party in interest, Hewlett-
Packard Development Company, LP (hereinafter “Appellant”), under 35
U.S.C. § 134(a), from a final rejection of claims 19-25 and 31-32, the only
claims on appeal. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.

References Relied on by the Examiner
Garcia U.S. 5,317,346 May 31, 1994
Edwards U.S. 5,363,553 Nov. 15, 1994
Baughman U.S. 5,441,593 Aug. 15, 1995

The Invention
This invention pertains to a fabrication process for an inkjet print head
whereby break trenches are etched into one side of a substrate to form the
initial breakthrough and control substrate chipping when an ink feed slot is
abrasively formed through the substrate from another side.
Independent method claim 19 is representative of the invention and is
reproduced below:
19. A fluid ejection device produced by a process, the
process comprising:
fabricating a thinfilm structure on a device substrate;
forming a peripheral break trench structure in a first
surface of the device substrate circumscribing a region in which
a feed slot is to be formed through the substrate;
forming a guide break trench in the first surface within
the peripheral break trench structure; and
subsequently abrasively machining the device substrate
from a second surface of the substrate to the break trench
structure to form the feed slot. [(App. Br. Claims App. 17).]
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The Rejections on Appeal
1. Claims 19-24 are rejected under 35 U.S.C. § 103(a) as being obvious
over Baughman in view of Edwards (Ans. 4).
2. Claim 25 is rejected under 35 U.S.C. § 103(a) as being obvious over
Baughman, Edwards and Appellant’s admission of prior art (Ans. 7).
3. Claims 31 and 32 are rejected under 35 U.S.C. § 103(a) as being
obvious over Baughman, Garcia, and Edwards (Ans. 7).

B. ISSUE
Would one of ordinary skill in the ink-jet print head art have had
reason to etch a plurality of trenches in a first substrate surface before
abrading an ink feed slot through the substrate to these trenches from a
second substrate surface when it was known to make an etching in a primary
surface and sandblast an ink slot to that etching from a secondary surface?

C. FINDINGS OF FACT
1. Baughman teaches etching a primary surface of an ink-jet print head
substrate (Baughman 1:20-22, 6:43-56 and Fig. 6B).
2. Baughman’s etching encompasses the area where a feed slot is to
break through to this primary surface (Baughman 6:54-68, Fig. 6C).
3. Baughman teaches “mechanical abrasion, e.g., sandblasting” a feed
slot from a secondary surface to the etching on the primary surface
(Baughman 6:64-68 and Fig. 6C).
4. Edwards teaches etching a “pilot hole” in a circuit board to eliminate
“misregistration” (Edwards 8:24-41).
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5. Garcia discloses a trench surrounding and in communication with a
plurality of ink slots that are subsequently formed in an ink-jet print head
substrate (Garcia 2:58-66 and 5:64 to 6:2).

D. PRINCIPLES OF LAW
“The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 416 (2007).

E. ANALYSIS
Appellant separately argues independent method claim 19,
independent apparatus claim 31 and each of dependent claims 23-25 and 32.
Appellant’s arguments regarding these claims are addressed below with the
remaining non-argued claims standing or falling with these argued claims.

1. Claims 19, 23, and 24 are Obvious over Baughman in view of
Edwards

Independent method claim 19 requires forming a “peripheral break
trench” in a first surface of a substrate that circumscribes a feed slot region,
forming a “guide break trench” within the peripheral break trench and
thereafter “abrasively machining” a feed slot from a second surface of the
substrate to the peripheral break trench. Dependent claims 23 and 24 further
require the interior guide trench to have a deeper depth (claim 23) and a
wider width (claim 24) than the peripheral trench.
The Examiner finds that Baughman teaches the required features of
claim 19 except that Baughman “may not expressly disclose forming a guide
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break trench in the first surface within the peripheral break trench structure”
(Ans. 5). The Examiner finds that Edwards “teaches forming a guide trench
in a surface by etching a pilot hole” and that the “advantage of forming a
guide trench slot or pilot hole is to improve the location precision” of a
subsequently drilled hole (Ans. 5). The Examiner concludes that “it would
have been obvious to form a guide trench slot or pilot hole in any surface to
improve the location precision of a drilled hole” (Ans. 5). Appellant
disputes these findings and contends that i) Baughman fails to teach forming
a peripheral break trench structure; ii) Baughman’s trench does not
circumscribe the feed slot region; iii) Baughman does not teach the order of
the claimed process and iv) Edward’s pilot hole is not a trench and does not
cure the deficiencies of Baughman (App. Br. 9-13; Reply Br. 2-6).

a. Baughman Teaches a Peripheral Break Trench Structure
Appellant contends that Baughman does not teach a “peripheral break
trench structure” (App. Br. 10, Reply Br. 2-3). Appellant’s Specification
states that a peripheral break trench structure is used to stop the propagation
of shallow chips “by allowing them to be terminated by breaking through” to
the trench from another side (Spec. 11:35 to 12:11). Baughman teaches
etching a first side of a substrate and subsequently machining from another
side through the substrate to the etching (Baughman 6:43-68). Appellant
fails to provide evidence that Baughman’s etching does not possess the
characteristics of a break trench structure and that the breakthrough of
Baughman’s machining does not occur at Baughman’s trench. We agree
with the Examiner that while the role of Appellant’s breakthrough trench is
provided, no unexpected result occurs (Ans. 5-7). We find that one skilled
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in the art would have understood that Baughman’s etching is a break trench
structure because Baughman’s etching is where one skilled in the art would
have reasonably expected the breakthrough to occur. Further, Baughman’s
etching extends beyond and surrounds the breakthrough opening (Baughman
5:40-43, 6:21-22 and Figs. 4-6). We find that Baughman teaches a peripheral
break trench structure.

b. Baughman’s Etching Circumscribes a Region in which a
Feed Slot is to be Formed

Appellant contends that Baughman’s trench does not “circumscribe”
the ink slot because Baughman’s trench occurs “on and in the ink slot”
rather than surrounding or encircling the ink slot (App. Br. 10- 11; Reply Br.
2-3). We disagree. Baughman’s Figures 6B and 6C (below) illustrate top
etching 18a formed prior to the breakthrough opening of ink slot 18.

Baughman’s Figures 6B (above left) and 6C (above right) illustrate substrate
12 that is etched (18a) on top before ink slot 18 is abraded from the bottom.

Baughman depicts etching 18a as encompassing a wide area,
including the area where the ink slot breakthrough opening will occur
(Baughman Fig. 6). Baughman states that, “ink fill slot 18 is extended by
means of extension 18a” to shorten the distance between the ink slot and the
ink discharge ports (Baughman 4:51-65). Based on the record presented, we
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are not persuaded by Appellant’s contentions and we find that the Examiner
provided a credible and sufficient basis for finding that Baughman’s etching
18a surrounds or circumscribes the subsequently formed feed slot 18.

c. Baughman Teaches the Order of the Claimed Process
Appellant contends that Baughman teaches abrading the ink feed slot
before etching the upper trench (App. Br. 11-12). Baughman teaches both
processes, i.e., etching prior to forming the ink feed slot as well as etching
after forming the ink feed slot (Baughman 5:35-42, 6:43-68 and Figs. 4 and
6). The Examiner specifically referenced Baughman’s Figures 6C and 6D
and Baughman column 6, lines 64-68 where it states that the main part of the
feed slot “is then formed” (i.e., formed after etching)(Ans. 4). We find that
Baughman teaches the order of the process as claimed.

d. Baughman and Edwards Teach a Guide Trench

Appellant contends that Edwards does not cure the deficiencies of
Baughman and that the combination of Baughman and Edwards do not
teach, “forming a guide break trench” (App. Br. 12, Reply Br. 4). More
specifically, Appellant contends that Edwards’ “pilot hole is not a trench”
and that modifying Baughman to include a pilot hole “is not possible”
because once Baughman’s trench is formed, “all of the substrate surface
within the boundaries of the portion 18a is gone” (Reply Br. 4-5).
"Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references." In re Merck & Co., 800 F.2d 1091, 1097
(Fed. Cir. 1986). The Examiner relied on Edwards as teaching, “forming a
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guide trench in a surface by etching a pilot hole having depth” (Ans. 5).
Edwards specifically teaches etching a pilot hole for the benefit of avoiding
“misregistration” when making through-holes (Edwards 8:24-41). One
skilled in the art at the time of the invention would have known to form a
pilot hole in Baughman’s substrate 12 “within the peripheral break trench”
as claimed in order to avoid misregistration of the subsequently formed
through-hole.

e. A Guide Trench can Provide the Initial Breakthrough
Location

As regarding dependent claims 23 and 24, Appellant contends that the
claimed depth and width of the guide trench “helps to control” the known
chipping problem (App. Br. 13; Spec. 2:9-35). However, Appellant’s
Specification does not state that the guide trench controls chipping; instead,
the Specification states that the guide trench serves to provide the “initial
breakthrough” of the slot formed from the other side (Spec. 11:33-35, 12:2-
6, 13:2-6). It is the perimeter trench that serves as the “chip stop feature”
not the guide trench as contended (Spec. 11:35 to 12:1).
An obviousness analysis may include recourse to the “common sense
available to the person of ordinary skill that do[es] not necessarily require
explication in any reference.” Perfect Web Tech., Inc. v. InfoUSA, Inc., 587
F.3d 1324, 1329 (Fed. Cir. 2009). We do not find fault with the Examiner’s
reasoning for combining Baughman and Edwards since Edwards teaches
etching a pilot hole to avoid misregistration of a through hole (Edwards
8:24-41). One skilled in the art would thus have reason to expect that a pilot
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hole or trench formed in one surface would provide the initial breakthrough
when removing material from an opposite surface as taught by Baughman.
Based on the record presented, we hold that claims 19, 23, and 24 are
directed to the application of a known technique (forming a pilot trench) to a
known device ready for the improvement (Baughman’s etched substrate) to
yield a predictable result (initial breakthrough at the pilot trench). Based on
the above, we affirm the rejection of claims 19, 23, and 24 as well as
dependent claims 20-22 since these latter claims were not separately argued.

2. Dependent Claim 25 is Obvious over Baughman, Edwards and
Appellant’s Admission of Prior Art

Claim 25 depends from independent claim 19 and further requires
etching the silicon substrate via a tetra methyl ammonium hydroxide
(TMAH) wet etch process. The Examiner relies on Appellant’s admission
that TMAH etching processes are known and that this process has
advantages over other “wet etchants” (Ans. 7 citing Spec. 4:9-28).
Appellant contends the Examiner misunderstood Appellant’s Background
section stating that this section pertains to using the TMAH process “for
forming a feed slot, not a break trench” and there is no admission that this
process can be used to make a break trench (App. Br. 14).
Appellant does not dispute that TMAH is a known “anisotropic
etchant for silicon” (Spec. 4:9-10). Baughman teaches using anisotropic
etching for both etching a trench on one side of a substrate and forming a
feed slot from an opposite side (Baughman 5:59 to 6:15). In view of
Baughman, one skilled in the art would know to use an anisotropic etchant,
such as the known TMAH etchant, to etch both sides of a substrate. For the
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above reasons, we affirm the rejection of dependent claim 25 as being
obvious over Baughman, Edwards, and Appellant’s admission of prior art.

3. Claims 31and 32 are Obvious over Baughman, Garcia, and
Edwards

Independent apparatus claim 31 requires a peripheral trench
circumscribing a region, a guide trench and “a feed slot formed in the
region.” Dependent claim 32 further requires the feed slot to be “formed by
subsequently abrasively machining” the substrate from a second surface.
The Examiner finds that as an “alternative to the analysis of claim 19,”
Garcia teaches a peripheral break trench that circumscribes “a region in
which a feed slot is to be formed through the substrate” (Ans. 8 (bold in
original) citing Garcia’s Figs. 1 and 2 and item 15). Appellant contends that
Garcia’s item 15 is a trench having “the same configuration as the slot
extension 18a of Baughman” and as such, Garcia’s “trench 15 is not a
peripheral break trench” and does not circumscribe “a region having a feed
slot” as claimed (App. Br. 14-15). Garcia, like Baughman, teaches a shallow
upper “trench” that surrounds ink slots which extend “from the trench
through the substructure” to its bottom (Garcia 2:58-66). In addition, like
Baughman, Garcia teaches that the upper trench is formed before the ink
slots are formed (Garcia 6:1). For reasons similar to those above, we hold
that claims 31 and 32 are directed to the combination of known elements
(peripheral trench, guide trench and feed slot) for their known purpose (an
ink supply route through a substrate) to achieve a predictable result (a
precision print head). We affirm the Examiner’s rejection of claims 31 and
32 as being obvious in view of Baughman, Garcia, and Edwards.
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F. CONCLUSION OF LAW
One of ordinary skill in the ink-jet print head art would have had
reason to etch a plurality of trenches in a first substrate surface before
abrading an ink feed slot through the substrate to these trenches from a
second substrate surface because it was known to etch a primary surface and
sandblast an ink slot to that etching from a secondary surface.

G. ORDER
1. The rejection of claims 19-24 under 35 U.S.C. § 103(a) as being
obvious over Baughman in view of Edwards is affirmed.
2. The rejection of claim 25 under 35 U.S.C. § 103(a) as being obvious
over Baughman, Edwards, and Appellant’s admission of prior art is
affirmed.
3. The rejection of claims 31 and 32 under 35 U.S.C. § 103(a) as being
obvious over Baughman, Garcia, and Edwards is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).
AFFIRMED

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