Posts Tagged ‘FR4 PCB’

hs code electronic,What is the HS code for circuit boards?

Friday, August 2nd, 2024

hs code electronic (HS codes) for electronic products involve multiple categories and specific commodities, including but not limited to laptops, tablets, portable devices, phones, electronic watches, smartphones, electronic game consoles, electric toys, electronic cigarettes, etc. The HS codes for these commodities are as follows:

The HS code for laptops and tablets is 8471301000.
The HS code for portable devices is 8471309000.
The HS code for phones is 8517129000.
The HS code for electronic watches is 9102190000.
The HS code for smartphones is 8517130000.
The HS code for electronic game consoles is 9504901000.
The HS code for electric toys is 8501101000.
The HS code for electronic cigarettes is 8516799000. ‌
The HS code for PCB (printed circuit board) is 8534001000.
PCBs made of FR-4 material (i.e. silicon tetrachloride fiberglass board) are classified under HS code 8534.00.00
HS code for integrated circuit and microelectronic component parts is 8542900000
Electronic circuit boards: HS code is 8534.00.00
Capacitors: HS code is 8532.10.00
Resistors: HS code is 8533.10.00
Transistors: HS code is 8541.10.00
Integrated circuits: HS code is 8542.31.00
Connectors: HS code is 8536.69.00

These HS codes are the standards used by customs to classify and count goods in international trade. Each commodity has a specific HS code to facilitate customs management and statistics of imported and exported goods. ‌Knowing these codes is very important for companies and individuals engaged in international trade, as it can help them declare goods correctly and avoid mistakes in tariffs or customs declarations.

How do I find an HS code?

You’ll often find HS codes on invoices and shipping documents around the world. HTS codes are like Schedule B numbers, but for importing goods into the United States instead. They’re also made up of 10 digits, and they help the US government to track imports and apply the right tariffs to different products.

HS code is a coding system consisting of six digits, each of which represents specific information in order to accurately define and classify goods. The following is the basic structure of HS code:

The first digit (chapter): represents the major category of goods, usually describing the general nature of the goods, such as raw materials, machinery and equipment, electronic products, etc.

The second digit (section): further subdivides the major category of the first digit to provide more specific information.

The third digit (subsection): continues to refine the classification of goods, usually including the materials and uses of goods.

The fourth digit (group): describes the specific characteristics and attributes of the goods.

The fifth digit (subgroup): provides more specific information related to the characteristics of the goods.

The sixth digit (item): the most specific code, used to identify specific goods.

What is the HS code for circuit boards?

he HS code for circuit boards is a standard international commodity code, the full name of which is “HS code for printed circuit boards”, which is part of the customs coding system. The coding system was formulated by the World Customs Organization (WCO) to uniformly identify the classification and classification of international goods.

The role of the HS code for circuit boards

The HS code for circuit boards is an important voucher in international trade, which can help customs to quickly and accurately count and classify imported or exported goods. At the same time, it is also an important basis for customs to determine tariff rates, levy import tariffs, supervise trade measures, and implement regional protectionist policies.

Classification of HS codes for circuit boards

According to WCO regulations, the HS code for circuit boards is divided into 16 chapters, Chapters 1 to 5 are industrial product codes, Chapters 6 to 14 are agricultural product codes, Chapter 15 is unlisted commodity codes, and Chapter 16 is supplementary codes for machinery and equipment. Among them, the HS code classification of circuit boards is in Chapter 85, which belongs to machinery and electrical equipment.

Application of HS code of circuit boards

HS code of circuit boards is one of the key points in international trade. Reasonable coding will have an important impact on trade costs and trade efficiency. When conducting import and export trade activities of circuit boards, relevant HS codes must be correctly declared, otherwise they may face customs control, return, fines and other consequences. Therefore, the correct understanding and application of HS code of circuit boards is of great significance to the commercial success of enterprises.

As a basic work in international trade, HS code of circuit boards not only plays an important role in facilitating and smooth trade, saving costs and improving efficiency, but also is a key link in the import and export trade of circuit boards. Therefore, enterprises should attach great importance to the correct understanding and application of HS code of circuit boards, making it a powerful tool to promote the development of enterprises.

Electrical-Related Safety Spacings

Wire Spacing

As far as the processing capability of the mainstream PCB manufacturer is concerned, the spacing between the wires shall not be less than 0.075mm. The minimum line distance refers to line to line, line to pad space. From a production perspective, the larger the better, and the more common wire spacing is 0.25mm by far.

Diameter and Width of Pad

From the processing capability of mainstream PCB manufacturers, the minimum diameter shall not less than 0.15mm if the holes on pad requires mechanically drilled. If used laser drilling, then hole diameter must greater or equal than 0.10mm. At the same time, the tolerance of hole diameters varies slightly according to different substrates. Generally, it can be controlled within 0.05mm, and the minimum width of the pad should not be less than 0.2mm.

Spacing between Pad to Pad

The spacing between pads must be at least 0.2mm as far as the processing capacity of mainstream PCB manufacturers concerned.

Copper and Edge of the Board Spacing

The spacing between electronic copper and edge of the board should be no less than 0.30mm, and it can be set spacing rule on the “Design – Rules – Board outline” page.

If it requires a larger area of copper, it is generally needs to set 0.5mm as a retraction spacing from the edge of board. In the PCB design and manufacturing industries, engineers often shrink the large area of copper coating to the edge of the board by 20mil for mechanical considerations of the finished circuit board, or to avoid the occurrence of curling or electrical short circuit caused by the exposure of copper on the edge of the board, rather than coating whole copper to the edge of the board.

There are many methods to handle such shrink problems, such as drawing a keepout layer and then set a distance between copper and the keepout. As a professional PCB manufacturer that have rich experience over 16years, there is a much easy way to set different safety spacings for copper objects. For example, the safety spacing of the whole board set as 0.25mm, then we can set copper to 0.5mm, which can achieve a shrink distance of 0.5mm, and the dead copper that may cause in some devices also can be removed as well.

Non-Electrical-Related Safety Spacing

Width, Height and Spacing of Legends

We can’t make any changes during the processing of text legend film, except that the line width of legend with D-CODE less than 0.22mm (8.66mil) is enlarged to 0.22mm, that is, the line width of legends L=0.22mm (8.66mil).

The width of the whole charact legends W=1.0mm, the height of the whole legends H=1.2mm, the spacing between the legends D=0.2mm. When the text is less than the above standard, the text legends after printing will be blurred.

Spacing between Via to Via

The spacing between vias to vias is preferably not less than 8mil.

Spacing between Legend to Pad

Legends/Silkscreens are not allowed on the pads, otherwise, the covered area can’t be tinned and which will affect the assembly process finally. Generally, manufacturer requires a 8mil space to convenient for silkscreen printing, but if your PCB is small and limited in area, it is barely acceptable to leave a 4 mil safety space.

If some legends accidentally over the pads in your design, Best Technology will remove or move to another area when get your approval to ensure good tinned.

Of course, design on a case-by-case situation. Sometimes the screen printing is deliberately close to the pad, because when the two pads are very close, the screen printing in middle can effectively prevent the short circuit of the solder connection during soldering, and this is another case.

Mechanical 3D height and Horizontal Spacing

When mounting the components on the PCB surface, it is necessary to consider whether there will be conflicts with other mechanical structures in horizontal direction and spatial height. Therefore, in the PCB design, the compatibility between components, finished products and product outer house and spatial structure should be fully considered, and the safety spacing should be reserved for each target object to ensure there is no conflicts occur in space.

In summary, there are many data and key points should be pay highly attention to while in PCB designing, Best Technology manufactures varies of good quality PCBs for our customers, so please do not hesitate to contact us when you have PCB design, we can help to evaluate it freely for you.

Form factor and flexibility: Does your PCB have a strict form factor requirement? Thinner boards tend to be used in smaller devices and can flex more than a thicker board. A more flexible board may be unusable with a pick & place machine. Electrical connections in flexible boards can also break unless they have some mechanical support.

Components and connections: Will the device have any components that require the Printed Circuit Board to have a specific thickness? Components like USB edge connectors and some through-hole components require PCB in correct thickness. BGA connectors generally require thicker boards.

Impedance matching: Traces on adjacent layers in multi-layer boards form a capacitor, and the layer thickness and its dielectric constant determines the equivalent capacitance. Impedance matching is critical, and the capacitance must be taken into consideration when designing the board. This is especially true in HDI PCB.

High-speed devices: If you are working with a high-speed device, FR4 is always not the best option, and some other material should be used instead. FR4 PCB could be used in high-speed devices when the layers are coated with high-speed laminates. These laminates offer significantly improved electrical performance over standard FR4, and generally a combination of FR4 and a high-speed laminate may be preferable to an alternative material.

RF losses: FR4 tends to have higher losses than other PCB materials that are specialized for RF applications. Traces on FR4 will have larger attenuation at RF frequencies than other specialized materials for a given board thickness. The board thickness also changes the effective dielectric constant of the board, which then changes the required impedance matching in RF circuits.

Thermal and Reliability Considerations

All materials expand at higher temperatures, and the thermal expansion coefficient must be taken into consideration when choosing the board thickness. The thermal expansion coefficient of FR4 changes drastically above the materialâ€™s glass transition temperature (140â„ƒ). The board can become electrically and mechanically unstable when the board operates above the glass transition temperature.

The reliability of the trace materials, laminate materials, and solder joints on a PCB laminate are determined by the resistance to thermal cycling. When the thermal expansion coefficients of the different materials are mismatched, fatigue occurs after repeated thermal cycling. Copper plating in vias and solder balls are especially vulnerable to damage under thermal cycling.

This is a greater problem in thick FR4 PCB with high aspect ratio vias. Plating damage in through-hole vias, lifted pads, and cracked surface resin can occur under the stress caused by thermal cycling. A thicker board will have a larger expansion magnitude for a given via aspect ratio, resulting in more damage to the board and the electronic components. Thermal stresses can be huge when an FR4 PCB runs above the glass transition temperature.

Volumetric expansion is also critical in rigid-flex FR4 PCB. Thermoplastic adhesives with low glass transition temperatures and high Z-direction expansion coefficients can exhibit very large volume expansion at high temperature. Z-direction expansion in these situations can be as large as 500 ppm/ƒ.

Even though a thicker FR4 PCB has greater thermal mass and can dissipate more heat from electronic components, there is also the potential for more damage due to thermal expansion. Therefore, how to choose between a thick and thin FR4 PCB that satisfies all other requirements, the thinner board may be a better choice if the FR4 PCB will undergo thermal cycling frequently.

If you have any comments. queries or suggestions on this, welcome to contact us.