Aрpellant L.B. Plastics, Inc. (“L.B. Plastics”) appeals from the final judgment of the United States District Court for the Western District of North Carolina granting summary judgment of noninfringement in favor of Amerimax Home Products, Inc. and Amerimax Diversified Products, Inc. (collectively “Amerimax”). We hold that the asserted claims of U.S. Patent No. 6,463,700 (filed Jan. 16, 2001) (“'700 patent”) were not literally infringed, and that L.B. Plastics cannot invoke the doctrine of *1305 equivalents in the circumstances of this case. We therefore affirm.
BACKGROUND
L.B. Plastics and Amerimax both sell gutter guards, which are devices that can be attached to a conventional gutter in order to allow the free flow of water into the gutter while filtering out dirt, leaves, and other debris. The claimed invention relates to a composite gutter guard that snaps onto existing gutters.
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L.B. Plastics filed the application that resulted in the '700 patent on January 16, 2001. The application described a gutter guard that includes a guard panel to which is attached a “mesh layеr.” U.S. Patent Application No. 09/760,557 (“'557 application”). The original claims of the '557 application required the guard panel and mesh layer to be attached by “a heat weld connecting said mesh layer to said guard panel.” Id.
On December 5, 2001, the U.S. Patent and Trademark Office (“PTO”) rejected the claims submitted by L.B. Plastics “as being unpatentable over U.S. Patent No. 5,555,680 to Sweers in view of U.S. patent No. 5,406,754 [(“'754 patent”)] to Cosby.” In rejecting the application, the examiner explained:
Sweers does not disclose welding a continuous weld along the entire edge of the mesh layer. However, Cosby discloses using spot weld every 12 inches аlong the mesh layer.... It would have been obvious to one having ordinary skill in the art at the time the invention was made to modify Sweers by adding welds disclosed by Cosby and to make the welds continuous without breaks in order to create a better bond between layers and to prevent debris from entering between layers.
J.A. at 121 (emphasis added). In its response, L.B. Plastics argued that a continuous weld line would distinguish the spot welding disclosed in the Cosby prior art because it would stop debris from flowing beneath the mesh layer and into the gutter. J.A. at 131. The examiner then allowed the claims to issue after L.B. Plastics amended the claims to re *1306 quire “a continuous heat weld defining an uninterrupted longitudinal weld.”
The '700 patent issued on October 15, 2002. The '700 patent contains fourteen claims, of which three are independent. Claim 1 is representative and claims:
A composite gutter guard adapted for being positioned at an opening of a longitudinally extending, generally U-shaped gutter used for collecting and distributing rainwater runoff from the roofs of residential homes and other buildings, said gutter guard comprising:
(a) an elongate polymer guard panel defining a plurality of spaced filter openings, said guard panel being adapted to extend laterally across the opening of the gutter and longitudinally along the length of the gutter;
(b) a polymer-coated mesh layer overlying said guard panel in an area of said filter openings and cooperating with said guard panel to capture and separate debris from rainwater runoff entering the gutter, said mesh layer having first and second opposing side edges and first аnd second opposing end edges; and
(c) a continuous heat weld defining an uninterrupted longitudinal weld line connecting said mesh layer to said guard panel, and extending from one end edge of said mesh later [sic] to the opposing end edge of said mesh layer.
'700 patent (emphasis added to show amendment during prosecution). Each of the other independent claims, claims 9 and 14, similarly requires that the guard panel be welded to the mesh layer and that the resulting “weld line” be “continuous.” 1
Two prior art patents, U.S. Patent No. 5,555,680 to Sweers and U.S. patent No. 5,406,754 (“'754 patent”) to Cosby are relevant and were cited during prosecution of thе '700 patent. J.A. at 120. Both Sweers and Cosby disclose gutter guards. Sweers discloses a one-piece gutter guard, while Cosby has a separate screen which the claims require to be “directly connected” to the guard panel. '754 patent col.6 1.17. Cosby’s specification discloses several means of “directly сonnectfing]” the screen to the guard panel. It first states that “[t]he fine mesh screen [ ] can be attached by adhesive, mechanical fastener, or heat welded to the wire mesh.” Id. col 4 1.65-col.5 1.1. An example then illustrates the method of “bondfing] ... approximately every 12 inches.” Id. col.5 11.40-44. Then the specification again states that “[a]n adhesive can be applied ... or some other means of attachment can be made.” Id. col.6 II.l — 4.
The specification of the '700 patent criticizes prior art attachment means, stating: “[t]he attachment means used in other pri- or art gutter guards incorporating multiple layers is generally less effective, and more costly, time consuming, and labor intensive.” '700 patent col.l 11.27-29.
On February 24, 2004, L.B. Plastics filed this action against Amerimax, alleging that Amerimax’s competing gutter guard infringed the '700 patent. Amerimax’s gutter guard is comprised of a mesh screen attached to a guard panel by means of an adhesive, hot glue, which is later cooled. This glue does not soften or melt the mesh *1307 or the guard panel. L.B. Plastics argued that Amerimax’s gutter guard literally infringed the '700 patent because the “continuous heat weld” limitation of that patent was broad enough to encompass the hot glue adhesive used by Amerimax. In the alternative, L.B. Plastics contended that its patented weld and Amerimax’s hоt glue adhesive were equivalent. Both parties moved for summary judgment on infringement. The court granted Amerimax’s motion and denied L.B. Plastics’s motion.
The district court first held that no reasonable jury could conclude that Ameri-max’s gutter guard literally infringes L.B. Plastics’s patent because Amerimax’s process does not involve “heаt weld” or “welding.” In construing those terms, the district court first recognized that, while the claims do not define the terms, a standard dictionary defining “weld” as “to unite [plastics] by heating and allowing the [plastics] to flow together” was consistent with the statement in the specification that the mesh “fuse[]” to the polymer guard panel.
L.B. Plastics, Inc. v. Amerimax Home Prods., Inc.,
Turning to the doctrine of equivalents, the district court held that summary judgment in favor of Amerimax was aрpropriate for two reasons. First, the district court credited expert testimony that, while the methods of welding and gluing with adhesives accomplish the same function of joining two objects to each other, they were not equivalents because they accomplish a different result in a different way since welding involvеs allowing the molecules of the two objects to interface, thereby connecting them, whereas joining with adhesives involves the introduction of a third substance.
See Warner-Jenkinson Co. v. Hilton Davis Chem. Co.,
L.B. Plastics timely appealed the district court’s judgment to this court. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). We review a district court’s grаnt of summary judgment of nonin-fringement without deference.
Flex-Rest, LLC v. Steelcase, Inc.,
DISCUSSION
I Literal Infringement
L.B. Plasties first argues that the district court erred in construing the term “weld” to require melting of the screen and guard panel, and that consequently the district court’s grant of summary judgment of noninfringement was improper.
In construing claims we search for the ordinary and customary meaning of a claim term to a person of ordinary skill in the art. We determine this meaning by looking first at intrinsic evidence such as surrounding claim language, the specification, the prosecution history, and also at extrinsic evidence, which may include expert testimony and dictionaries.
Phillips v. AWH Corp.,
Since the intrinsic record provides no further guidance to the meaning of the terms “weld,” “fuse” or “ultrasonic or heat welding,” the district court properly turned to extrinsic evidence in this case and consulted dictionaries.
See Phillips,
Consequently, wе conclude that the district court correctly construed the term “welding.” The district court granted summary judgment of no literal infringement after it found that “[tjhere is no dispute that the mesh layer in Amerimax’s gutter guard is not attached to the guard panel by ‘welding’ as construed above.”
L.B. Plastics,
*1309 II Infringement under the Doctrine of Equivalents
However, L.B. Plastics maintains that Amerimax infringes under the doctrine of equivalents. “The doctrine of equivalents allows the patentee to claim those insubstantial alterations that were not captured in drafting the original patent claim but which could be created through trivial changes.”
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co.,
We have held that when a specification excludes certain prior art alternatives from the literal scope of the claims and criticizes those prior art alternatives, the patentee cannot then use the doctrine of equivalents to capturе those alternatives. In
Dawn Equipment Co. v. Kentucky Farms Inc.,
The rule of these cases applies here as well. The specification of the '700 patent criticizes prior art attachment means, stating that “[t]he attachment means used in other prior art gutter guards ... is generally less effective, and more costly, time consuming, and labor intensive.” '700 patent col.l 11.27-30. The specification emphasizes that the “novel construction” of the invention, by contrast, “facilitates an effective and securе attachment.” Id.-, II.24-26. 3 There is no question but that the *1310 prior art attachment means included adhesives; thus the specification must be read to criticize the use of adhesives as attachment means. See '754 patent col.4 11.67— 68; id. col.6 II.1-4. However, L.B. Plastics argues that the prior art referenced in the specification did not specifically disclose a continuous attachment using adhesives. But since the patentee elected to distinguish prior art attachment means and to limit its claim to continuous welded attachments, a person of ordinary skill in the field of the invention reading the specification would clearly conclude that the inventor thought that adhesive attachments genеrally were undesirable. Under these circumstances L.B. Plastics cannot now use the doctrine of equivalents to include adhesive attachments.
We therefore affirm the district court’s holding that L.B. Plastics cannot resort to the doctrine of equivalents here.
CONCLUSION
For the foregoing reasons, the decision below is affirmed.
AFFIRMED
COSTS
No costs.
Notes
. Thus claim 9 requires “a longitudinal weld line connecting said mesh lаyer to said guard panel, and extending continuously from one end edge of said mesh layer to the other;” and claim 14, a method claim, requires "welding the mesh layer to the guard panel along a continuous and uninterrupted longitudinal weld line extending from one end edge of the mesh layer to the opposing end edge of the mesh layer.” '700 patent col.5 II.3-6, col.6 11.18-21.
. L.B. Plastics argues that “welding” includes attachment by adhesives, citing testimony of the inventor of the '700 patent that “one of ordinary skill in the relevant art ... considers [heat welding and hot melt gluing] to be essentially the same.” Pet'r Br. at 30-31. This testimony is irrelevant as there is no suggestion that Davis testified that the term "welding” has a special meaning within the art that is different from its ordinary meaning.
. The specification states:
Unlike some prior art gutter guards which have a relatively fine-mesh metal layer overlying a perforated polymer guard panel, the gutter guard of the present invention includes a coated mesh layer and perforated guard рanel formed of like polymer materials, such as PVC. This novel construction facilitates an effective and secure attachment of the composite by ultrasonic or heat welding along the entire length of the gutter guard. The attachment means used in other prior art gutter guards incorporating multiple layers is generally *1310 less effective, and more costly, time consuming, and labor intensive. '700 patent col.2 11.20-30.
