What Every Member of the 

Trade Community Should Know About: 

Diodes, Transistors and 

Similar Semiconductor 

Devices 

AN INFORMED COMPLIANCE PUBLICATION 

FEBRUARY 2010 
Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

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 

Reviewed With No Changes February 2008 

Reviewed With No Changes March 2009 

Reviewed With No Changes February 2010 

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 Word 2003®. 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 and Similar Semiconductor Devices 

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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. 

Regulations and Rulings (RR) of the Office of International Trade 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 of Regulations and 

Rulings is entitled "Diodes, Transistors and Similar Semiconductor Devices.” It provides 

guidance regarding the classification of these items. 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 U.S. Customs and 

Border Protection, Office of International Trade, Executive Director, Regulations and Rulings, 

799 9th Street N.W. 7th floor, Washington, D.C. 20229-1177. 

Sandra L. Bell 

Executive Director, Regulations and Rulings 

Office of International Trade 

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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............................................9

DIODES, TRANSISTORS AND SIMILAR SEMICONDUCTOR DEVICES 

VS. HEADING 8542...................................................................................13

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

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

TYPICAL PRODUCTS OF THIS GROUP .................................................17

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 and any 

relative section or chapter notes (Legal Note/L.N.). Legal Note 8 (previously Note 5) (a) 

Chapter 85 provides: 

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Diodes, Transistors and Similar Semiconductor Devices 

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"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 8 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 Nomenclature, except in the case of 

heading 8523, 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. 

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. 5 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, 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

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. 

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 

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Diodes, Transistors and Similar Semiconductor Devices 

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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 

stated 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 the thyristors in a module functioned as a single semiconductor 

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

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 

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February 2010 

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 

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.” 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. 

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

Module (BDTM), a Metal Oxide Semiconductor Field Effect Transistor (MOS-FET) 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, Customs and Border Protection (CBP) 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, CBP 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, CBP determined that the lenses were essential to the operation of the laser 

diode modules because the lenses collimate and focus the 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. CBP has since 

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

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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), 

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 8, Chapter 85, distinguishes between “[d]iodes, transistors and similar 

semiconductor devices” and “[e]lectronic integrated circuits (monolithic integrated 

circuits, hybrid integrated circuits and multichip integrated circuits). The latter group of 

products is provided for in heading 8542, HTSUS. E.N. 85.42 (I), (II), and (III) 

distinguishes these groups of products further. Electronic Integrated circuits are not 

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February 2010 

considered discrete components because they consist of several electronic circuit 

elements and have multiple electrical functions. Prior to February 3, 2007, heading 

8542 included microassemblies. However, as of February 3, 2007 microassemblies are 

classified in Subheading 8548.90.01. (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. 8(a), Chapter 85, (diodes, 

transistors, and similar semiconductor devices) 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: 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, CBP 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, CBP determined that certain glass sleeves used as 

housings for diodes were classified in subheading 7011.90.00, HTSUS, as "[g]lass 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

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-cadmium-telluride 

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 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, CBP 

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 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

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, 8487, 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; 

(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 8487 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 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

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 CBP. 

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. 

TYPICAL PRODUCTS OF THIS GROUP 

 

 

SEMICONDUCTOR WAFER 

DIODE: 8541.10.0040 

TRANSISTOR: 8541.21.0040 

OR 8541.29.0040 

TRYRISTORS, DIACS, TRIACS: 

8541.30.0040 

OTHER: 8541.50.0040 

DISC TYPE DIODE 

DESIGNED FOR HIGH 

POWER RECTIFICATION 

8541.10.00 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

 

DIODE 

8541.10.00 

THREE PHASE DIODE BRIDGE 

8541.10.00 

HQ 958726 

HQ 960323 

 

 MOSFET MODULE 

POWER SEMICONDUCTOR 

DISSIPATION RATE >1 W 

8541.29.00 

HQ 084659 

INSULATED GATE BIPOLAR 

TRANSISTOR MODULE (1GBT) 

DISSIPATION RATE > 1 W 

8541.29.00 

HQ 084659 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

 

THYRISTOR MODULE 

INTERNAL COMPONENTS CONTAINING 

TWO MOUNTED CHIPS 

8541.30.00 

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Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

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, the “Know Before You Go” publication 

and traveler awareness campaign is 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 and Border Protection 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 edition of Title 19, Code of Federal Regulations 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 and Similar Semiconductor Devices 

February 2010 

Importing into the United States 

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

information about import requirements. The current 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 current 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 and Similar Semiconductor Devices 

February 2010 

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. 

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. 

22
Diodes, Transistors and Similar Semiconductor Devices 

February 2010 

“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

23