OT:RR:NC:N2:209
Victoria DeCarr
Analog Devices, Inc.
One Analog Way
Wilmington, MA 01887
RE: The country of origin of an integrated circuit
Dear Ms. DeCarr:
In your letter dated August 18, 2025, you requested a country of origin ruling on a Wafer Level Chip Scale
Packaged Product (WLCSP).
The item concerned is an integrated circuit (IC) referred to as the AZ33A Device. This IC is a 24-bit
delta-sigma Analog-to-Digital Converter (ADCs) that measures and reports analog input voltages.
STAGE 1: FABRICATION PROCESS
The fabrication process stage occurs in Singapore. During the fabrication process, the wafer receives many of
the components and characteristics of a WLCSP, but the subject item is not fully completed due to the
omission of essential electrical circuitry.
Manufacturing steps undertaken in Singapore include:
Manufacture of bare silicon wafer
Epitaxial Growth
Oxidation
Thin-Film Deposition
Lithography
Dry etch by plasma
Wet etch
Ion Implantation
Diffusion by furnace
Chemical cleaning
Metal Wiring Process/Metallization
Wafer acceptance test
After fabrication, the wafers are sent to Taiwan.
STAGE 2: WLP FRONT-END
In the WLP front-end process, a polymer layer encapsulates the wafer with select areas exposed. A photo
resist layer is applied to create the Redistribution Layer (“RDL”) line pattern where a copper plating is
applied. Copper plating in the selected open area will form RDL metal line. The photo resist is then removed.
A second polymer layer is applied to encapsulate the RDL lines as well as the exposed area on the wafer,
only leaving a select area still exposed where RDL line needs to be connected to bump through UBM pad. In
the next process, called under bump metal (UBM), a layer of copper plating metal is applied in the exposed
area to create a bonding pad for the solder ball. Finally, solder balls are placed onto UBM, and with a reflow
solder ball will bond to UBM pad forming solder bump.
Manufacturing steps undertaken in Taiwan include:
Polymer coating
Annealing (Curing)
Lithography
Wet etch
Copper metal deposition
Copper metal plating
Chemical clean
Solder ball mounting
Solder ball reflows
Final Visual Inspection
After the RDL layer application and the UBM, the completed WLCSP is formed.
STAGE 3: WLP BACKEND
The back-end process occurs in the Philippines. Here the completed WLCSP is evaluated, trimmed, mounted,
and sawed to improve functionality. However, the back-end process does not transform the WLCSP.
Manufacturing steps undertaken in the Philippines include:
Wafer level testing
Trim
Wafer backside grinding (silicon thinning)
Backside lamination (optional)
Laser Marking
Wafer mount and sawing
Tape and reel
Section 304 of the Tariff Act of 1930, as amended (19 U.S.C. 1304), provides that unless excepted, every
article of foreign origin imported into the United States shall be marked in a conspicuous place as legibly,
indelibly, and permanently as the nature of the article (or its container) will permit, in such a manner as to
indicate to the ultimate purchaser in the United States, the English name of the country of origin of the
article. Congressional intent in enacting 19 U.S.C. 1304 was “that the ultimate purchaser should be able to
know by an inspection of the marking on the imported goods the country of which the goods is the product.
The evident purpose is to mark the goods so that at the time of purchase the ultimate purchaser may, by
knowing where the goods were produced, be able to buy or refuse to buy them, if such marking should
influence his will.” See United States v. Friedlander & Co., 27 C.C.P.A. 297, 302 (1940).
Part 134 of the U.S. Customs and Border Protection (“CBP”) Regulations (19 CFR 134) implements the
country of origin marking requirements and exceptions of 19 U.S.C. 1304. Section 134.1(b), CBP
Regulations (19 CFR 134.1(b)), defines “country of origin” as the country of manufacture, production, or
growth of any article of foreign origin entering the United States. Further work or material added to an article
in another country must effect a substantial transformation in order to render such other country the “country
of origin” within the meaning of the marking laws and regulations.
A substantial transformation occurs when, as a result of manufacturing process, a new and different article
emerges, having a distinct name, character or use, which is different from that originally possessed by the
article or material before being subjected to the manufacturing process. See United States v.
Gibson-Thomsen Co., Inc., 27 C.C.P.A. 267 (C.A.D. 98) (1940).
Based upon the facts presented, it is the opinion of this office that the front-end processing that takes place in
Taiwan is both meaningful and complex, resulting in the creation of wafers which incorporate numerous
finished IC die. All non-originating materials, used in the manufacture of the wafers containing the AZ33A
Device (IC die), are substantially transformed as a result of the front-end processing. The manufacturing
steps under taken in Taiwan enable the electrical connectivity of the IC die and imparts the essence to the
AZ33A Device. As the electrical circuit is substantially completed during the front-end process, we find that
the ICs undergo a substantial transformation during the front-end stage of the manufacture. The AZ33A
Device IC die, does not undergo a substantial transformation as a result of the back-end processing that takes
place in the Philippines. The AZ33A Device IC die retains its identity and predetermined end use which was
established as a result of the front-end processing. Therefore, since a substantial transformation does not
occur as a result of the back-end processing that takes place within the Philippines, the country of origin of
the finished AZ33A Device will be the Taiwan for country of origin marking purposes.
The holding set forth above applies only to the specific factual situation and merchandise description as
identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations
(CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the
information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and
complete in every material respect. In the event that the facts are modified in any way, or if the goods do not
conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and
Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2.
Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic
verification by CBP.
This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection
Regulations (19 C.F.R. 177).
A copy of the ruling or the control number indicated above should be provided with the entry documents
filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact
National Import Specialist Steven Pollichino at [email protected].
Sincerely,
(for)
Denise Faingar
Acting Director
National Commodity Specialist Division