What Every Member of the 

Trade Community Should Know About: 

 Diodes, Transistors 

& Similar 

Semiconductor

Devices

AN INFORMED COMPLIANCE PUBLICATION 

MARCH 2006 
Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

NOTICE:

This publication is intended to provide guidance and information to the trade community. 

It reflects the position on or interpretation of the applicable laws or regulations by U.S. 

Customs and Border Protection (CBP) as of the date of publication, which is shown on 

the front cover. It does not in any way replace or supersede those laws or regulations. 

Only the latest official version of the laws or regulations is authoritative. 

Publication History 

First Published January 2000 

Revised July 2002 

Revised January 2004 

Reviewed With No Changes May 2005 

Reviewed with No Changes March 2006 

PRINTING NOTE: 

This publication was designed for electronic distribution via the CBP website 

(http://www.cbp.gov) and is being distributed in a variety of formats. It was originally set 

up in Microsoft Word97®. Pagination and margins in downloaded versions may vary 

depending upon which word processor or printer you use. If you wish to maintain the 

original settings, you may wish to download the .pdf version, which can then be printed 

using the freely available Adobe Acrobat Reader®. 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

PREFACE 

On December 8, 1993, Title VI of the North American Free Trade Agreement Implementation 

Act (Pub. L. 103-182, 107 Stat. 2057), also known as the Customs Modernization or “Mod” Act, 

became effective. These provisions amended many sections of the Tariff Act of 1930 and 

related laws. 

Two new concepts that emerge from the Mod Act are “informed compliance” and “shared 

responsibility,” which are premised on the idea that in order to maximize voluntary compliance 

with laws and regulations of U.S. Customs and Border Protection, the trade community needs to 

be clearly and completely informed of its legal obligations. Accordingly, the Mod Act imposes a 

greater obligation on CBP to provide the public with improved information concerning the trade 

community's rights and responsibilities under customs regulations and related laws. In addition, 

both the trade and U.S. Customs and Border Protection share responsibility for carrying out 

these requirements. For example, under Section 484 of the Tariff Act, as amended (19 U.S.C. 

1484), the importer of record is responsible for using reasonable care to enter, classify and 

determine the value of imported merchandise and to provide any other information necessary to 

enable U.S. Customs and Border Protection to properly assess duties, collect accurate 

statistics, and determine whether other applicable legal requirements, if any, have been met. 

CBP is then responsible for fixing the final classification and value of the merchandise. An 

importer of record’s failure to exercise reasonable care could delay release of the merchandise 

and, in some cases, could result in the imposition of penalties. 

The Office of Regulations and Rulings (ORR) has been given a major role in meeting the 

informed compliance responsibilities of U.S. Customs and Border Protection. In order to 

provide information to the public, CBP has issued a series of informed compliance publications 

on new or revised requirements, regulations or procedures, and a variety of classification and 

valuation issues. 

This publication, prepared by the National Commodity Specialist Division, ORR, is a study of the 

classification of diodes, transistors and similar semiconductor devices. “Diodes, Transistors & 

Similar Semiconductor Devices” provides guidance regarding the classification of imported 

merchandise. We sincerely hope that this material, together with seminars and increased 

access to rulings of U.S. Customs and Border Protection, will help the trade community to 

improve voluntary compliance with customs laws and to understand the relevant administrative 

processes. 

The material in this publication is provided for general information purposes only. Because 

many complicated factors can be involved in customs issues, an importer may wish to obtain a 

ruling under Regulations of U.S. Customs and Border Protection, 19 C.F.R. Part 177, or to 

obtain advice from an expert who specializes in customs matters, for example, a licensed 

customs broker, attorney or consultant. 

Comments and suggestions are welcomed and should be addressed to the Assistant 

Commissioner at the Office of Regulations and Rulings, U.S. Customs and Border Protection, 

1300 Pennsylvania Avenue, NW, (Mint Annex), Washington, D.C. 20229. 

Sandra L. Bell 

Acting Assistant Commissioner 

Office of Regulations and Rulings 

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DIODES, TRANSISTORS AND SIMILAR SEMICONDUCTOR DEVICES OF HEADING 

8541 ................................................................................................................................ 7

LAW AND INTERPRETATION .................................................................................... 7 

GENERAL CONSIDERATIONS .................................................................................. 7 

GENERAL EXCLUSIONS ........................................................................................... 9 

MODULES AND ASSEMBLIES CONTAINING DIODES, TRANSISTORS AND 

SIMILAR SEMICONDUCTOR DEVICES...................................................................... 10

DIODES, TRANSISTORS AND SIMILAR SEMICONDUCTOR DEVICES VS. 

HEADING 8542............................................................................................................. 14

MATERIAL AND PARTS.............................................................................................. 14

CONCLUSION .............................................................................................................. 17

TYPICAL PRODUCTS OF THIS GROUP..................................................................... 18

ADDITIONAL INFORMATION...................................................................................... 19

ADDITIONAL INFORMATION...................................................................................... 20

THE INTERNET ............................................................................................................. 20 

CUSTOMS REGULATIONS .............................................................................................. 20 

CUSTOMS BULLETIN ..................................................................................................... 20 

IMPORTING INTO THE UNITED STATES............................................................................ 21 

INFORMED COMPLIANCE PUBLICATIONS ......................................................................... 21 

VALUE PUBLICATIONS................................................................................................... 22 

“YOUR COMMENTS ARE IMPORTANT” ............................................................................. 23 

 

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DIODES, TRANSISTORS AND SIMILAR SEMICONDUCTOR DEVICES 

OF HEADING 8541 

 Heading 8541, Harmonized Tariff Schedule of the United States (HTSUS) 

provides for: 

Diodes, transistors and similar semiconductor devices; 

photosensitive semiconductor devices, including photovoltaic 

cells whether or not assembled in modules or made up into 

panels; light-emitting diodes; mounted piezoelectric crystals; 

parts thereof. 

 This Informed Compliance Publication will be limited to the first grouping of 

products under this heading, “[d]iodes, transistors and similar semiconductor devices.” 

This document is intended to assist in the classification of these products. ABB Power 

Transmission v. United States, 896 F.Supp. 1279, 19 CIT 1044 (1995), and significant 

rulings in this area will be cited and/or discussed. Not all of the rulings cited address the 

classification of products in this group. However, these rulings are illustrative of general 

classification principles that apply to the products of this group. The cited rulings should 

be consulted in their entirety for complete product descriptions and analysis. 

LAW AND INTERPRETATION 

 The products of this group are classified in the following subheadings: 

8541.10.00 Diodes, other than photosensitive or light- 

 emitting diodes... 

Transistors, other than photosensitive 

 transistors: 

8541.21.00 With a dissipation rate of less than 

 1 W... 

8541.29.00 Other... 

8541.30.00 Thyristors, diacs and triacs, other than 

 photosensitive devices... 

8541.50.00 Other semiconductor devices... 

GENERAL CONSIDERATIONS 

Classification of merchandise under the Harmonized Tariff Schedule of the 

United States is in accordance with the General Rules of Interpretation (GRI's). GRI 1 

provides that classification shall be determined according to the terms of the headings 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

and any relative section or chapter notes (Legal Note/L.N.). Legal Note 5 (a), Chapter 

85 provides: 

"Diodes, transistors and similar semiconductor devices" are 

semiconductor devices the operation of which depends on 

variations in resistivity on the application of an electric field. 

Legal Note 5 also specifies that: 

For the classification of the articles defined in this note, 

headings 8541 and 8542 shall take precedence over any 

other heading in the tariff schedule which might cover them 

by reference to, in particular, their function. 

The Harmonized Commodity Description and Coding System Explanatory Notes 

(E.N.) constitute the official interpretation of the HTSUS. While not legally binding nor 

dispositive, the E.N.s provide a commentary on the scope of each heading of the 

HTSUS and are generally indicative of the proper interpretation of these headings. See 

T.D. 89-80, 54 FR 35127, 35128 (August 23, 1989). 

 Explanatory Note 85.41 (A) tells us that at room temperature the resistivity of 

semiconductor materials lies between that of conductors and insulators. The McGrawHill Multimedia Encyclopedia of Science and Technology, © 1994, defines electrical 

resistivity as “The electrical resistance offered by a material to the flow of current, times 

the cross-sectional area of current flow and per unit length of current path; the 

reciprocal of the conductivity. Also known as resistivity; specific resistance.” Although 

neither the HTSUS nor the Explanatory Notes defines “variations in resistivity,” E.N. 

85.41 (A) (II) provides the following example in regard to the operation of a transistor: 

The operation of a transistor depends on the variation in 

resistivity between two of the terminals upon the application 

of an electric field to the third terminal. The applied control 

signal or field is weaker than the resulting action brought 

about by the change in resistance and thus amplification 

results. 

Semiconductor material is doped for electronics. The McGraw-Hill Multimedia 

Encyclopedia of Science and Technology, © 1994, defines this type of doping as “[t]he 

addition of impurities to a semiconductor to achieve a desired characteristic, as in 

producing an n-type or p-type material. Also known as semiconductor doping.” The 

doping produces an excess of electrons or a negative charge in n-type material. It 

produces a deficiency of electrons (holes) or a positive charge in p-type material. It is 

this excess or deficiency of electrons that allows semiconductor material to conduct 

electricity. 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

The semiconductor devices of this grouping are usually formed from one or more 

junctions between p-type and n-type semiconductor material. They are considered 

“active” as opposed to “passive” electronic elements that can produce, rectify, modulate 

or amplify an electrical signal (see Chapter 85, L.N. 4 and E.N. 85.34). They are used 

in the following types of applications: detection, rectification, switching, amplification, 

oscillation, frequency conversion, controlled rectification, etc. These devices are 

classified in heading 8541 whether mounted with their leads or packaged (housed, 

encapsulated components or elements), unmounted (chips, dice, elements), or undiced 

discs and wafers. The one exception, noted in E.N. 85.41 (A), concerns natural 

semiconductor materials (e.g. galena). In natural semiconductor material, naturally 

occurring impurities act as dopants. They are classified in heading 8541 only when 

mounted with their terminals or leads, or packaged. 

Diodes and transistors are provided for in heading 8541. Diodes are two terminal 

devices with a single p-n junction. They allow current to pass in one direction only and 

block or resist it in the reverse direction. Thus, they can rectify electricity in a circuit. 

Transistors have three or four terminals and usually have an emitter, a base, and a 

collector. They may have a PNP or NPN configuration, depending on how the 

semiconductor was doped. The following examples of “similar semiconductor devices” 

are given in E.N. 85.41 (A) (III): thyristors, triacs, diacs, varactors, field effect devices 

such as gridistors, and gunn effect devices. 

Diodes and transistors are specified by name in heading 8541, HTSUS. Similar 

semiconductor devices are a class designation. As previously mentioned the 

Explanatory Notes provide a definition of diodes and transistors and certain similar 

semiconductor devices. These standard products, single elements packaged with their 

terminals or leads, do not usually present classification issues. In NY B87638, August 

5, 1997, certain diodes described as silicon rectifiers, fast recovery rectifiers, and 

Schottky barrier rectifiers, were classified in subheading 8541.10.0080, HTSUS, as 

“[d]iodes, other than photosensitive or light-emitting diodes: [o]ther: [o]ther.” 

GENERAL EXCLUSIONS 

 Certain semiconductor devices which differ from the semiconductor devices of 

heading 8541 in that their functioning is based on temperature, pressure, etc. are 

excluded from this heading. E.N. 85.41 (A) lists non-linear semiconductor resistors, 

such as thermistors, varistors, and magneto-resistors as examples. These devices are 

classified in heading 8533 as resistors. HQ 084651, August 2, 1989, concerns the 

classification of zinc oxide varistors (GE-MOV). These are voltage dependent resistors 

(VDRs) that exhibit symmetrical, non-linear, voltage-current characteristics. They were 

classified in subheading 8533.40.00, HTSUS. 

 Photosensitive semiconductor devices, light emitting diodes (LEDs and laser 

diodes), and mounted piezo-electric crystals, while also classified in heading 8541, are 

separate product groupings, and not a subject of this Publication. 

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MODULES AND ASSEMBLIES CONTAINING DIODES, TRANSISTORS 

AND SIMILAR SEMICONDUCTOR DEVICES 

 The major issues concerning this product group involve modules and assemblies 

containing these devices. The Court of International Trade (CIT) decision in ABB Power 

Transmission v. United States, 896 F.Supp. 1279, 19 CIT 1044 (1995), is instructive in 

establishing the scope of heading 8541, HTSUS, with regard to this product group. It is 

noted that neither the Harmonized Tariff Schedule of the United States nor the 

Explanatory Notes address this issue directly. 

The merchandise before the Court was thyristor modules for use in high voltage 

direct current conversion stations (New England-Hydro Quebec project). Thyristors are 

one of the devices listed in E.N. 85.41 as a type of “similar semiconductor device.” 

These thyristor modules consisted of six thyristor elements connected in series, 

heatsinks, voltage divider circuits and electronic “firing” circuitry. They were mounted 

on a frame of epoxy resin and aluminum. They were designed to allow the flow of 

electrical current in one direction only, thus their function was rectification. 

In HQ 085027, January 31, 1990, they had been classified as “static converters” 

under subheading 8504.40.00, HTSUS. This ruling was modified by HQ 086518, 

November 9, 1990, and the thyristor modules were classified as “parts of static 

converters” under subheading 8504.90.00, HTSUS. In ABB Power the plaintiff did not 

dispute Customs contention that these thyristor modules were parts of static converters. 

Their assertion was that they were more appropriately classified under heading 8541, 

HTSUS. This assertion was based on L.N. 2, Chapter 85, which states that “[h]eadings 

8501 to 8504 do not apply to goods described in heading...8541...”; and L.N. 5, 

Chapter 85, which states in part “...headings 8541 and 8542 shall take precedence over 

any other heading in the tariff schedule which might cover them by reference to, in 

particular, their function.” The plaintiff asserted that these thyristor modules were 

classified in subheading 8541.30.00, HTSUS, which provides for “[t]hyristors, diacs, 

triacs, other than photosensitive devices,” or alternatively in subheading 8541.50.00, 

HTSUS, which provides for “[o]ther semiconductor devices.” 

 The issue therefore before the Court was the meaning of the term 

“semiconductor device.” The Court said “The meaning of a tariff term is a question of 

law to be decided by the court. Hasbro, 879 F .2d at 840.” When tariff terms are not 

clearly defined the Court will look to the common and commercial meaning of the term. 

Dictionaries, lexicons, and scientific authorities are usually consulted. The principal 

question before the Court was whether the imported merchandise could be classified in 

heading 8541, HTSUS. If it could, then it was precluded from classification in heading 

8504. 

Expert testimony was provided that the thyristor module functioned as a 

semiconductor gate. It was stated that they functioned as a single semiconductor 

element because they were fired simultaneously. The Court found that the thyristors in 

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these modules acted in unison and that the operation of the modules as a whole was 

dependent on variations in resistivity on the application of an electric field (L.N. 5 (a), 

Chapter 85). The Court agreed with the plaintiff that “[w]hile the heatsinks, firing 

circuitry and voltage divider circuitry contribute to the function of the module as a 

thyristor, there is no question...that the principal and sole function of a thyristor module 

is imparted by the thyristors acting in unison by variation of resistivity on the application 

of an electric field.” Although the Court recognized that these modules contained 

significant components in addition to thyristors, the function of the module fell within the 

definition of a thyristor as a similar semiconductor device. The CIT determined that 

these thyristor modules, as described in the court record, were classified in subheading 

8541.30.00, HTSUS. Since the Court found that these modules were classified in 

heading 8541, HTSUS, they were precluded from classification in heading 8504, 

HTSUS. 

This court decision was cited in two Headquarters rulings: HQ 960323, May 5, 

1997, which revoked NY 884870, and in HQ 958726, May 5, 1997, which revoked HQ 

086223 and 085540. The merchandise under consideration in these two rulings was 

Bridge Rectifier Diodes (BRD’s). They were composed of four discrete rectifier diodes 

or elements connected together into a rectifier bridge, some with mountings, housings 

and integral cooling devices. Each of the four diodes was a two terminal device with a 

single p-n junction. The BRD’s were four terminal devices with an asymmetrical 

voltage-current characteristic. Their function was rectification. These BRD’s have 

applications in a variety of consumer and industrial products (e.g. power supplies). 

Based on the rationale in ABB Power Transmission, it was determined that the function 

that these modules performed fell within the definition of a diode. They were classified 

as “[d]iodes, other than photosensitive or light-emitting diodes...” in subheading 

8541.10.00, HTSUS. 

The rationale used in the CIT decision, and the two rulings based on it, is similar 

to that expressed in several other ruling concerning modules and assemblies of the 

devices of heading 8541, HTSUS. HQ 084660, September 7, 1989, concerns the 

classification of power transistors and Darlington transistors. These contained 

Darlington transistor chips. The chips contained two or more transistors and resistors 

on the same piece of semiconductor material. Technically, each chip could have been 

considered a monolithic integrated circuit. The finished device (power 

transistor/Darlington transistor) was an assembly containing two transistor chips and six 

diode chips mounted on a thick-film substrate. It was determined, however, that they 

functioned as a transistor. It was found that “...Darlington transistors modules satisfy 

the Explanatory Notes description of how transistors operate electronically. Also, none 

of these provisions or any other section or chapter notes specifically exclude transistor 

modules operating in an identical manner as transistors from heading 8541.” 

Industry practice was also considered in HQ 084660. The Joint Electronic 

Device Engineering Council (JEDEC) considered these devices discrete semiconductor 

devices. As stated in this ruling, “The JEDEC defines a discrete semiconductor device 

as a ‘device that is specified to perform an elementary electronic function and that is not 

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divisible into separate components functional in themselves.’ They list transistors as 

examples of discrete semi- conductor devices, and state that ‘other semiconductor 

structures having the physical complexity of integrated circuits but performing 

elementary electronic functions (e.g., complex Darlington transistors) are usually 

considered to be discrete semiconductor devices.” 

E.N. 85.42 (II) also makes a distinction between discrete components and 

integrated circuits. It emphasizes that discrete components are indivisible and have a 

single active or single passive electrical function. Components made of several 

electrical circuit elements and having multiple electrical functions are not considered 

discrete components. These devices, therefore, were not considered hybrid integrated 

circuits under heading 8542, HTSUS. The Darlington transistors were classified in 

subheadings 8541.21.00 or 8541.29.00, HTSUS, as “[t]ransistors, other than 

photosensitive...” depending on their dissipation rate. 

In HQ 084659, August 25, 1989, the classification of a Bipolar Darlington 

Transistor Module (BDTM), a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and an Insulated Gate Bipolar Transistor Module (IGBT) was considered. The 

reasoning was similar to that of HQ 084660. These devices were assemblies mounted 

on direct bond copper circuit board (DBCCB) and, therefore, did not meet L.N. 5 (b) (ii), 

Chapter 85, with regard to hybrid integrated circuits. This ruling states that “[a]ll three 

are mounted on a Direct Bond Copper Circuit Board which does not involve the 

thin/thick film technology traditionally used to produce hybrid integrated circuits.” It was 

determined that they functioned as discrete transistors. They were classified in 

subheadings 8541.21.00 or 8541.29.00, HTSUS, as “[t]ransistors, other than 

photosensitive...” depending on their dissipation rate. 

In NY 884779, May 6, 1993, U.S. Customs also classified certain Schottky 

rectifier diodes, consisting of two diodes packaged together as a single device, in 

subheading 8541.10.00, HTSUS, as “[d]iodes, other than photosensitive or light emitting 

diodes.” 

In NY 814750, October 10, 1995, U.S. Customs held that laser diodes imported 

without optical lenses were classifiable under subheading 8541.40.20, as “light-emitting 

diodes” and laser diode modules with optical lenses attached were classifiable under 

subheading 9013.80.60, as “other optical appliances and instruments, not specified or 

included elsewhere in this chapter.” The reason for the distinction between the 

classification of the laser diodes and the laser diode modules centered on the inclusion 

of glass selfoc lenses in the laser diode modules. This ruling was modified by HQ 

965524, August 29, 2002, in which both the laser diodes and laser diode modules with 

optical lenses attached were classified as “light-emitting diodes” under subheading 

8541.40.20. 

The laser diode modules were designed for use in optical digital data 

transmission. In NY 814750, U.S. Customs determined that the lenses were essential 

to the operation of the laser diode modules because the lenses collimate and focus the 

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light into the core of the fiber optics and therefore classified the modules as optical 

appliances under heading 9013. In HQ 965524, however, it was determined that the 

essential character of the laser diode modules was imparted by the laser diode, which, 

through its p-n junction, converted electrical energy into optical energy. While 

headquarters recognized that the collimating lens focused (or made coherent) the 

converted light energy onto a fiber stub for transmission, the essence of the fiber optic 

communication system was its use of light energy. Headquarters found the modules at 

issue to be substantially similar to those in NEC Electronics, Inc. v. U.S. 21 C.I.T. 327 

(1997), affirmed, 144 F. 3d 788 (CAFC 1998), in which the court upheld that laser 

diodes modules were classifiable under subheading 8541.40.20. 

In NEC, the court found that pursuant to GRI 3(b), goods comprised of different 

components must be classified as though they were wholly made of the material or 

component, which gives them their essential character. The court found that the laser 

diode component gave the laser diode module its essential character. U.S. Customs 

has since followed this finding for similar products (also see HQ 960815, July 1, 1998). 

The NEC decision revokes, by operation of law, any rulings concerning the classification 

of laser diode modules substantially similar to those therein considered (see Section 

152.16(e), Customs Regulations, 19 CFR 152.16(e)) that classify such articles in a 

heading other than 8541. 

Headquarters found that NY 814750 was inconsistent with the NEC decision and 

modified it as reflected within HQ 965524, which ruled that both the laser diodes and 

laser diode modules with optical lenses are classifiable under subheading 8541.40.20, 

which provides for “light-emitting diodes.” 

However, not all assemblies or modules which contain diodes, transistors, or 

similar semiconductor devices are classified in heading 8541, HTSUS. HQ 951710, 

February 1, 1993, concerns a different kind of assembly. The product is described as a 

diode unit. It contained a filter for eliminating radio interference, a fuse, a choke for 

reducing ripple, three power diodes, a printed circuit board assembly (PCBA) for 

supervising the function of the unit, three circuit breakers, etc. The unit allowed current 

of less than 1000 volts to pass in one direction from a DC power source and prevented 

capacitors from discharging on momentary voltage decrease. This ruling modified HQ 

951513 in which the diode unit was classified in subheading 8536.30.00, HTSUS, as 

"[e]lectrical apparatus for switching or protecting electrical circuits, or for making 

connections to or in electrical circuits, for a voltage not exceeding 1,000 V: [o]ther 

apparatus." 

When considering heading 8541, HTSUS, it was determined that the diode unit 

contained several divisible components that performed multiple functions. It was not 

found to be similar to the modules under consideration in HQ 084660. Since this 

assembly was not described by heading 8541, HTSUS, Legal Note 5 to chapter 85 did 

not apply. It was determined that the diode unit was classified in subheading 

8537.10.00, HTSUS, as “[b]oards, panels (including numerical control panels), 

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consoles, desks, cabinets and other bases, equipped with two or more apparatus of 

heading 8535 or 8536, for the electric control or the distribution of electricity....” 

Therefore, in following ABB Power Transmission and the aforementioned rulings, 

it is of primary importance to determine how the module or assembly is designed and 

what is its function or functions. The function of the module or assembly as a whole 

must fall within the definition of a diode, transistor or similar semiconductor device (i.e. 

acting in unison by variation in resistivity on the application of an electric field). All other 

components must contribute to this function. 

DIODES, TRANSISTORS AND SIMILAR SEMICONDUCTOR DEVICES 

VS. HEADING 8542 

Legal Note 5, Chapter 85, distinguishes between “[d]iodes, transistors and similar 

semiconductor devices” and “[e]lectronic integrated circuits and microassemblies” 

(monolithic integrated circuits, hybrid integrated circuits and microassemblies). The 

later group of products is provided for in heading 8542. E.N. 85.42 (II) distinguishes 

these groups of products further. Integrated circuits are not considered discrete 

components because they consist of several electronic circuit elements and have 

multiple electrical functions. Microassemblies combine and interconnect discrete active, 

or active and passive components in a molded module, micromodule, or similar type 

module. Semiconductor devices of L.N. 5 (a), Chapter 85, are considered discrete 

active components. Discrete components are indivisible and have a single electrical 

function. 

In HQ 084660 and HQ 084659, certain transistor modules (see previous 

discussion) were classified in heading 8541 and distinguished from the products of 

heading 8542. They were found to be in each case a discrete semiconductor device. In 

HQ 084660 this was the principal distinction between the Darlington transistor and a 

hybrid integrated circuit. In HQ 084659 a second distinction existed in that the transistor 

modules were not constructed using thin or thick film technology as specified in 

L.N.5(b)(ii), Chapter 85. 

MATERIAL AND PARTS 

There is a wide variety of chemicals, metals, and other materials used in the 

manufacture of semiconductor devices. Most of these materials are provided for in 

other headings and chapters. This would include chemical elements such as silicon, 

and chemical compounds such as gallium arsenide. The following examples are 

illustrative only of general classification principles or of the classification of specific 

products. They are intended to aid in distinguishing between “[d]iodes, transistors and 

similar semiconductor devices;...parts thereof” of heading 8541, HTSUS, and the 

materials used in their manufacture. 

 The exclusions of Section XVI and Chapter 85 apply to this product group. L.N. 

1 (f), Section XVI, excludes from this section: 

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Precious or semiprecious stones (natural, synthetic or 

reconstructed) of headings 7102 to 7104, or articles wholly 

of such stones of heading 7116, except unmounted worked 

sapphires and diamonds for styli (heading 8522). 

In NY B87954, October 31, 1997, U.S. Customs determined that sapphire wafers 

that would be used as platforms for the epitaxial deposition of Group III-V 

semiconductors were classified in subheading 7104.90.5000, HTSUS, as synthetic or 

reconstructed precious or semiprecious stones. 

L.N. 1 (b), Chapter 85, excludes from this chapter: 

Articles of glass of heading 7011. 

In HQ 087044, May 21, 1990, U.S. Customs determined that certain glass 

sleeves used as housings for diodes were classified in subheading 7011.90.00, HTSUS, 

as "[g]lass envelopes (including bulbs and tubes), open, and glass parts thereof, without 

fittings, for electric lamps, cathode-ray tubes or the like...[o]ther..." 

The distinction between semiconductor material and semiconductor devices has 

been addressed in several rulings (see below). Heading 3818, HTSUS, covers two 

groups of materials when they are doped for use in electronics: chemical elements in 

the form of discs, wafers or similar forms; and chemical compounds in the form of 

cylinders, rods, discs, wafers and similar forms (see also E.N. 85.41 and E.N. 38.18). 

The goods of heading 3818 may have been subjected to the following types of 

processing: polishing, and coating with a uniform epitaxial layer. However, if the 

materials (discs, wafers) have been more extensively worked, by such processes as 

selective diffusion (doping) to create discrete regions, they would be classified in 

heading 8541. Under GRI 2 (a) an incomplete or unfinished article would be classified 

in heading 8541 if it has the essential character of the complete or finished article. 

Diffusion and similar technologies allows dopants to be selectively introduced to the 

desired depth and width in the starting material (e.g. uniformly doped wafer/substrate) to 

form the desired semiconductor device. When considering semiconductor materials in 

the aforementioned forms, it is the selective diffusion process that imparts the essential 

character of a semiconductor device of heading 8541. This is a critical distinction 

between the products of heading 3818, HTSUS, and 8541, HTSUS. 

In NY 836027, January 31, 1989, U.S. Customs held that mercury-cadmiumtelluride wafers were classified in heading 3818.00.0000, HTSUS, as “[c]hemical 

compounds doped for use in electronics.” These wafers had not been extensively 

worked by selective diffusion or other similar process. HQ 953265, May 14, 1993, 

concerns whether certain 2” unmounted wafers consisting of gallium phosphate, an LED 

chemical material, were classified in heading 3818, HTSUS, as “[c]hemical elements 

doped for use in electronics,” or in heading, 8541, HTSUS, as unfinished LEDs. 

Although this ruling involves a different product group of heading 8541 than under 

discussion here, it is illustrative of pertinent classification principles. The finishing 

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processes necessary to manufacture LEDs from these wafers included cutting the 

wafers into precisely sized chips, then mounting, wiring, and housing them. It was 

determined that the imported wafers did not possess the essential character of a 

complete LED. They were classified in subheading 3818.00.00, HTSUS. 

The following rulings concern materials which are used in semiconductor 

production but which do not rise to the level of a part, or which do not possess the 

essential character of the devices of heading 8541, HTSUS. In NY C83905, February 

24, 1998, U.S. Customs determined that certain chemicals, Tertiarybutylarsine, 

Dimethylcadmium, and Diethylcadmium, which are used in the semiconductor and 

electrical industries, were classified in subheading 2931.00.9050, HTSUS. Heading 

2931, HTSUS, provides for “[o]ther organo-inorganic compounds.” NY B83101, 

November 13, 1998, concerns the classification of certain semi-manufactured articles of 

artificial graphite. After further processing the finished products were used in a variety 

of industrial, semiconductor, mechanical and electrical applications. These products 

were classified in subheading 3801.10.5000. Gold bonding wire with dopant and 

aluminum bonding wire of various compositions were the subject of B80730, January 7, 

1997. They were classified in subheadings 7108.13.7000 and 7605.19.0000, HTSUS, 

respectively. 

As can be seen from the aforementioned rulings, in distinguishing between 

materials used in the manufacture of semiconductors and the products of heading 8541, 

it is important to look at the essential character, use, function, degree of manufacture, 

and subsequent manufacture or processing of a good. 

With regard to parts, L.N. 2, Section XVI, provides: 

Subject to note 1 to this section, note 1 to chapter 84 and to 

note 1 to chapter 85, parts of machines (not being parts of 

the articles of heading 8484, 8544, 8545, 8546 or 8547) are 

to be classified according to the following rules: 

(a) Parts which are goods included in any of the headings of chapters 

84 and 85 (other than headings 8409, 8431, 8448, 8466, 8473, 8485, 

8503, 8522, 8529, 8538 and 8548) are in all cases to be classified in their 

respective headings; 

(b) Other parts, if suitable for use solely or principally with a particular 

kind of machine, or with a number of machines of the same heading 

(including a machine of heading 8479 or 8543) are to be classified with the 

machines of that kind or in heading 8409, 8431, 8448, 8466, 8473, 8503, 

8522, 8529 or 8538 as appropriate. However, parts which are equally 

suitable for use principally with the goods of headings 8517 and 8525 to 

8528 are to be classified in heading 8517; 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

(c) All other parts are to be classified in heading 8409, 8431, 8448, 

8466, 8473, 8503, 8522, 8529 or 8538 as appropriate or, failing that, in 

heading 8485 or 8548. 

With the product group under consideration, the principal issue concerning parts 

involves establishing sole or principal use under L.N. 2 (b), Section XVI. Facts that may 

be considered in making this determination are: design characteristics, function, and 

use. If a product has more than one use, principal use would have to be determined. 

Because of this consideration, rulings on one product (e.g. housings, heatsinks, etc.) 

may not apply to a similar product designed for a different use. The following rulings 

are illustrative of products that were found to be parts under subheading 8541.90.00, 

HTSUS. HQ 950868, December 31, 1992, concerns the classification of semiconductor 

bases made of copper. Semiconductors would be mounted on these bases. The 

mounted device would subsequently be mounted on a heat sink to allow for the 

dissipation of heat. It was found that they were solely or principally used as parts of 

semiconductors. Heatsink/heat spreading substrates and submounts are the subject of 

HQ 955988, March 7, 1994, and HQ 955949, March 7, 1994. They were made to 

customer specifications. They were designed to absorb, store, and remove excess 

heat. They were classified in subheading 8541.90.00, HTSUS, as parts of 

semiconductor devices, and in subheading 8542.90.00, HTSUS, as parts of electronic 

integrated circuits, depending on their dedicated use (design specifications). In NY 

869903, January 15, 1992, alumina housings for power transistors were classified in 

subheading 8541.90.00, HTSUS. This ruling states that these housings “...have no 

other use except as part of the power transistor.” 

CONCLUSION 

 The classification of electronic devices and apparatus continues to be 

problematic because of the ever increasing variety of products and variations available. 

As can be seen from this brief discussion of the classification of “[d]iodes, transistors 

and similar semiconductor devices” it is vital to have complete information upon which 

to make an informed decision. In making a classification decision, it is necessary to 

consider the following: the pertinent sections of law and legal precedent, official 

interpretation of the law, common and commercial meanings, use, function, degree of 

fabrication, etc. It is the responsibility of the importer to exercise reasonable care with 

regard to the classification of imported products. If the classification of a particular 

device is questionable, it is recommended that a binding ruling be requested from U.S. 

Customs. Requests can be addressed to U.S. Customs and Border Protection, Customs 

Information Exchange (C.I.E.), One Penn Plaza, 10th Floor, New York, NY 10119, 

Attention: Binding Rulings Section. 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

TYPICAL PRODUCTS OF THIS GROUP 

 

SEMICONDUCTOR WAFER DISC TYPE DIODE 

DESIGNED FOR HIGH 

POWER RECTIFICATION 

DIODE: 8541.10.0040 

TRANSISTOR: 8541.21.0040 

OR 8541.29.0040 8541.10.00 

TRYRISTORS, DIACS, TRIACS: 

8541.30.0040 

OTHER: 8541.50.0040 

 

DIODE THREE PHASE DIODE BRIDGE 

8541.10.00 8541.10.00 

HQ 958726 

HQ 960323 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

 

 MOSFET MODULE INSULATED GATE BIPOLAR 

POWER SEMICONDUCTOR TRANSISTOR MODULE (1GBT)

DISSIPATION RATE >1 W DISSIPATION RATE > 1 W 

8541.29.00 8541.29.00 

HQ 084659 HQ 084659 

THYRISTOR MODULE 

INTERNAL COMPONENTS CONTAINING 

TWO MOUNTED CHIPS 

8541.30.00 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

ADDITIONAL INFORMATION 

The Internet 

The home page of U.S. Customs and Border Protection on the Internet’s World Wide 

Web, provides the trade community with current, relevant information regarding CBP 

operations and items of special interest. The site posts information -- which includes 

proposed regulations, news releases, publications and notices, etc. -- that can be 

searched, read on-line, printed or downloaded to your personal computer. The web site 

was established as a trade-friendly mechanism to assist the importing and exporting 

community. The web site also links to the home pages of many other agencies whose 

importing or exporting regulations that U.S. Customs and Border Protection helps to 

enforce. The web site also contains a wealth of information of interest to a broader 

public than the trade community. For instance, on June 20, 2001, CBP launched the 

“Know Before You Go” publication and traveler awareness campaign designed to help 

educate international travelers. 

 

The web address of U.S. Customs and Border Protection is http://www.cbp.gov

Customs Regulations 

The current edition of Customs Regulations of the United States is a loose-leaf, 

subscription publication available from the Superintendent of Documents, U.S. 

Government Printing Office, Washington, DC 20402; telephone (202) 512-1800. A 

bound, 2003 edition of Title 19, Code of Federal Regulations, which incorporates all 

changes to the Regulations as of April 1, 2003, is also available for sale from the same 

address. All proposed and final regulations are published in the Federal Register, which 

is published daily by the Office of the Federal Register, National Archives and Records 

Administration, and distributed by the Superintendent of Documents. Information about 

on-line access to the Federal Register may be obtained by calling (202) 512-1530 

between 7 a.m. and 5 p.m. Eastern time. These notices are also published in the 

weekly Customs Bulletin described below. 

Customs Bulletin 

The Customs Bulletin and Decisions (“Customs Bulletin”) is a weekly publication that 

contains decisions, rulings, regulatory proposals, notices and other information of 

interest to the trade community. It also contains decisions issued by the U.S. Court of 

International Trade, as well as customs-related decisions of the U.S. Court of Appeals 

for the Federal Circuit. Each year, the Government Printing Office publishes bound 

volumes of the Customs Bulletin. Subscriptions may be purchased from the 

Superintendent of Documents at the address and phone number listed above. 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

Importing Into the United States 

This publication provides an overview of the importing process and contains general 

information about import requirements. The February 2002 edition of Importing Into the 

United States contains much new and revised material brought about pursuant to the 

Customs Modernization Act (“Mod Act”). The Mod Act has fundamentally altered the 

relationship between importers and U.S. Customs and Border Protection by shifting to 

the importer the legal responsibility for declaring the value, classification, and rate of 

duty applicable to entered merchandise. 

The February 2002 edition contains a section entitled "Informed Compliance." A key 

component of informed compliance is the shared responsibility between U.S. Customs 

and Border Protection and the import community, wherein CBP communicates its 

requirements to the importer, and the importer, in turn, uses reasonable care to assure 

that CBP is provided accurate and timely data pertaining to his or her importation. 

Single copies may be obtained from local offices of U.S. Customs and Border 

Protection, or from the Office of Public Affairs, U.S. Customs and Border Protection, 

1300 Pennsylvania Avenue NW, Washington, DC 20229. An on-line version is 

available at the CBP web site. Importing Into the United States is also available for 

sale, in single copies or bulk orders, from the Superintendent of Documents by calling 

(202) 512-1800, or by mail from the Superintendent of Documents, Government Printing 

Office, P.O. Box 371954, Pittsburgh, PA 15250-7054. 

Informed Compliance Publications 

U.S. Customs and Border Protection has prepared a number of Informed Compliance 

publications in the “What Every Member of the Trade Community Should Know 

About:...” series. Check the Internet web site http://www.cbp.gov for current 

publications. 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

Value Publications 

Customs Valuation under the Trade Agreements Act of 1979 is a 96-page book 

containing a detailed narrative description of the customs valuation system, the customs 

valuation title of the Trade Agreements Act (§402 of the Tariff Act of 1930, as amended 

by the Trade Agreements Act of 1979 (19 U.S.C. §1401a)), the Statement of 

Administrative Action which was sent to the U.S. Congress in conjunction with the TAA, 

regulations (19 C.F.R. §§152.000-152.108) implementing the valuation system (a few 

sections of the regulations have been amended subsequent to the publication of the 

book) and questions and answers concerning the valuation system. A copy may be 

obtained from U.S. Customs and Border Protection, Office of Regulations and Rulings, 

Value Branch, 1300 Pennsylvania Avenue, NW, (Mint Annex), Washington, D.C. 20229. 

Customs Valuation Encyclopedia (with updates) is comprised of relevant statutory 

provisions, CBP Regulations implementing the statute, portions of the Customs 

Valuation Code, judicial precedent, and administrative rulings involving application of 

valuation law. A copy may be purchased for a nominal charge from the Superintendent 

of Documents, Government Printing Office, P.O. Box 371954, Pittsburgh, PA 15250-

7054. This publication is also available on the Internet web site of U.S. Customs and 

Border Protection. 

The information provided in this publication is for general information 

purposes only. Recognizing that many complicated factors may be 

involved in customs issues, an importer may wish to obtain a ruling under 

CBP Regulations, 19 C.F.R. Part 177, or obtain advice from an expert 

(such as a licensed Customs Broker, attorney or consultant) who 

specializes in customs matters. Reliance solely on the general 

information in this pamphlet may not be considered reasonable care.

Additional information may also be obtained from U.S. Customs and Border Protection 

ports of entry. Please consult your telephone directory for an office near you. The 

listing will be found under U.S. Government, Department of Homeland Security. 

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Diodes, Transistors & Similar Semiconductor Devices 

March 2006 

“Your Comments are Important” 

The Small Business and Regulatory Enforcement Ombudsman and 10 regional 

Fairness Boards were established to receive comments from small businesses about 

Federal agency enforcement activities and rate each agency’s responsiveness to small 

business. If you wish to comment on the enforcement actions of U.S. Customs and 

Border Protection, call 1-888-REG-FAIR (1-888-734-3247). 

REPORT SMUGGLING 1-800-BE-ALERT OR 1-800-NO-DROGA 

Visit our Internet web site: http://www.cbp.gov

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