Chapter 85 covers electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles. This chapter mainly includes equipment for the production, conversion, storage, transmission, distribution, control, regulation, and protection of electrical energy, as well as apparatus operating on electromagnetic principles. Thyristors and triacs, as power electronic devices, are used to control current switching and regulate power, and fall within the scope of semiconductor devices of this chapter. Heading 8541 covers semiconductor devices; light-emitting diodes; mounted piezoelectric crystals; and parts thereof. Specifically includes diodes, transistors, thyristors, photosensitive semiconductor devices, light-emitting diodes, other semiconductor devices, etc. Thyristors and triacs belong to the thyristor devices under this heading, used for power electronic control, such as dimming, speed regulation, inversion, etc. First 2 digits 85: Chapter 85, electrical machinery and equipment and parts thereof. Digits 3-4 41: Heading 8541, semiconductor devices; light-emitting diodes; mounted piezoelectric crystals; and parts thereof. Digits 5-6 30: Subheading 854130, specifically thyristors and triacs. This subheading further distinguishes thyristors (unidirectional) and triacs (bidirectional), both of which are three-terminal or four-terminal semiconductor switching devices used for AC or DC power control. Thyristors and triacs are semiconductor switching devices with controllable conduction characteristics, used in power electronic circuits. They differ from ordinary diodes (854110) or transistors (854120) because they have a four-layer structure (PNPN) and trigger control function. They are also not photosensitive devices (854140) or light-emitting diodes (854140), as their function does not involve photoelectric conversion. Therefore, they are classified under 854130.

Product Name: The specific name of the declared commodity, such as thyristor, triac, thyristor module, etc. Brand: Manufacturer or brand name, such as ST, Infineon, Toshiba, etc. Model: Specific model or specification code, such as BT136, BTA16, etc. Structure Type: Indicate whether it is a thyristor (unidirectional) or triac (bidirectional). Rated Current: The on-state average current or RMS current of the device, in A. Rated Voltage: The off-state repetitive peak voltage or reverse repetitive peak voltage of the device, in V. Package Type: Such as TO-220, TO-92, module, etc. Purpose: Specific application field, such as dimmer, motor speed control, power switch, etc. Product Name: Triac; Brand: ST; Model: BTA16-600B; Structure Type: Bidirectional; Rated Current: 16A; Rated Voltage: 600V; Package Type: TO-220; Purpose: Used in AC motor speed control circuit. Misdeclaring a triac as a thyristor; the two have different structures, and although classified under the same code, their parameters differ. Incorrect unit for rated current, such as filling 16A as 16mA, resulting in parameter mismatch. Incomplete brand and model information, affecting customs valuation and origin determination.

Core classification criteria: Thyristors and triacs are semiconductor devices with a four-layer PNPN structure that can be triggered into conduction via a control electrode, used for power control. According to HS notes, heading 8541 includes semiconductor devices whose function is based on semiconductor properties. Both thyristors and triacs meet this definition and are not more specifically named in other headings, so they are classified under 854130. 854110 Diodes: Diodes are two-terminal devices, conduct in one direction, and have no control electrode; thyristors are three-terminal or four-terminal, have a control electrode, and can control conduction. 854120 Transistors: Transistors are three-terminal devices with amplification and switching functions, but have NPN or PNP structures; thyristors have a four-layer structure and maintain conduction after triggering. 854140 Photosensitive semiconductor devices and light-emitting diodes: Photosensitive devices and LEDs involve photoelectric conversion, while thyristors and triacs do not involve the photoelectric effect and are only used for current control. 853650 Switches: Mechanical switches use physical contact for on/off, while thyristors are semiconductor contactless switches, classified differently. Does it have a four-layer PNPN structure? Does it have a control electrode (gate)? Is it used for power control rather than signal amplification? Does it not involve photoelectric conversion? Is it not more specifically named in other headings?

What is the difference between a thyristor and a triac? A thyristor conducts in one direction and can only control current in one direction; a triac can conduct in both directions and is used in AC circuits. Both are classified under 854130, but the structure type must be specified when declaring. How to find the HS code for a thyristor? Determine that it is a semiconductor device based on function and structure, then classify under heading 8541, subheading 854130. You can refer to the customs tariff or consult a professional customs broker. Are rated current and voltage required when declaring? Yes, these parameters are key for customs to verify product specifications and classification. Missing them may cause customs clearance delays or classification disputes. Is the code for a thyristor module the same as for a single thyristor? If the module consists only of thyristors, it is still classified under 854130; if it contains other circuits, it may be classified under other headings, depending on the specific structure. If a triac is used in a dimmer, does the code change? The code remains 854130, but the purpose must be declared specifically, such as 'used in dimmer', to assist customs confirmation. Does importing thyristors require 3C certification? Thyristors are generally not within the scope of 3C certification, but must comply with relevant standards for electronic components. For details, consult the catalog of the State Administration for Market Regulation. What is the export tax rebate rate for 854130? Tax rates change, so it is recommended to check the latest export tax rebate rate database or consult the tax authorities. Specific values are not provided here. What are the consequences of misclassifying a thyristor under 854120? It may lead to classification errors, affecting tax rates, regulatory conditions, and even customs penalties. Accurate classification is recommended to avoid risks.