IC lead free has lead coil tube how to identify

Lead is harmful to the human body and can cause infertility and intellectual disability. Since 2003, the European Union has launched the RoHS environmental protection directive, which has strictly limited the content of harmful substances in electronic products exported to Europe (there are mainly six categories, lead is one of them, as well as chromium, cadmium, mercury, polybrominated biphenyls, etc., which are commonly used raw materials in electronic products in the past). Electronic products that exceed this content will be banned from import by local customs, and many other countries have followed up and put forward requirements in this regard, which has caused certain difficulties in the export of electronic products (the cost of lead-free raw materials** is much higher than that of lead, and the processing is also more difficult). Since 2008, countries such as Japan have issued stricter REACH directives to further regulate the requirements for hazardous substances.

Now for China's electronic product manufacturers, if they want their products to enter the European and North American markets with relatively high profits, they must meet the local environmental protection requirements in terms of the content of harmful substances in the products, otherwise they will be returned or even seized by the customs, so that the loss will be large.

The so-called "leaded" and "lead-free" refers to whether the integrated circuit meets the latest environmental protection standards in the packaging process and materials, the materials and processes used in the packaging of the previous integrated circuits are containing lead and some other components that are not environmentally friendly, and the devices produced by the manufacturers in the past two years have basically been changed to new processes and new materials, all of which belong to the "lead-free" packaging products. There is no difference in the internal functions and parameters of the same model of lead-free packaging products and lead-encapsulated products, but the soldering process is slightly different when installed on the circuit board.

Lead free, certified by SGS Report ROSH Document, can be used in all markets that require environmental protection requirements.

Lead-free is an environmental imperative (RoHS).

The difference between leaded and leadless is whether the tin on the IC pins is leaded. The melting point of the alloy is relatively low, with a lead melting point of 183 degrees and a lead-free melting point of 217 degrees. It doesn't matter if the temperature is a little higher, it doesn't matter if it's welded, it usually won't be welded for a long time.

It is best to treat them as lead-free when they are taken off......In case you drop a point.

View the original post

On the basis of the original, the ones after 05 are environmentally friendly. Of course, if you buy it, it's best to buy it within 2 years.

Rub off the tin dots with white paper, the white paper that changes color is leaded, and the color that does not change is lead-free.

On the most basic PCB, parts are concentrated on one side and wires are concentrated on the other. Because the wires only appear on one side, this type of PCB is called single-sided.

Because single-sided boards have many strict limitations in designing the circuits (because there is only one side, the wiring cannot cross each other and must go around their own paths), so only early circuits use this type of board.

The main advantages of PCB boards are:

1. Due to the repeatability (reproducibility) and consistency of the graphics, the errors of wiring and assembly are reduced, and the maintenance, debugging and inspection time of the equipment are saved;

2. The design can be standardized, which is conducive to interchangeability;

3. High wiring density, small size, light weight, conducive to the miniaturization of electronic equipment;

4. It is conducive to mechanized and automated production, improves labor productivity and reduces the cost of electronic equipment. In particular, the bending resistance and precision of FPC flexible board are better applied to high-precision instruments.

Wipe the tin surface with white paper, and the black one of the white paper is a leaded PCB.

The PB of the PCB is mainly distinguished on the coating layer of the pad, in general:

1.Tin Plating - The common process is to coat a 63 37 tin-lead alloy on the pad, so there is a lead PCB (although the latest process has made it possible to make a lead-free tinned PCB).

2.Nickel Gold A layer of nickel gold is plated on copper foil, and the plating is lead-free.

On the surface of the copper foil, the coating layer is lead-free.

4.Pre-applied flux Flux is applied to the surface of the copper foil (generally used on single-sided sideboards) and the coating layer is lead-free.

In addition, whether the PCB is leaded or lead-free also depends on the lead content of the components that make up the PCB, such as the base material and copper foil, and the lead content is generally less than 1000ppm.

Lead-free PCBs are now mainly used on products that comply with the RoHS directive, and it is best to consider other hazardous substances together.

1.Look at the logo:

Lead-free glasses generally contain potassium, mostly high-end handicrafts and are marked on the outer packaging; Leaded glasses, on the other hand, contain lead, which is a common crystal glassware in some supermarkets and street stalls, and its lead oxide content can reach 24%.

2.Look at the color:

Lead-free glass has better refractive property than traditional leaded crystal glass, and more perfectly demonstrates the refractive performance of metallic glass; For example, some ornaments of various shapes, crystal wine glasses, crystal lamps, etc. are made of leaded glass. Look at heat resistance: glasses can generally withstand very high temperatures, but generally have poor resistance to extreme cold and heat.

Lead-free crystal glass is a glass with a high coefficient of expansion, and its resistance to extreme cold and heat is a little worse, and it is easy to burst if you make tea with boiling water in a particularly cold lead-free glass.

3.Weigh the weight:

Leaded crystal glass products are slightly heavier than lead-free crystal glass products.

4.Listen to the sound:

Beyond the metallic sound of the leaded crystal glass, the sound of the lead-free glass is more pleasant to the ear, rich in the reputation of the "**" cup.

5.Look at resilience:

Lead-free glasses are tougher than leaded crystal glasses, i.e. impact resistance.

The glass containers circulating in the market can be divided into ordinary glass containers and crystal glass containers according to the material. There are two types of crystal glass containers: lead-free crystal glass and lead-containing crystal glass. When we see lead-free glass, we usually refer to lead-free crystal glass.

Features of crystal glass.

Crystal glass is relatively bright in color, strong in refractive index, exquisite in workmanship, good in hand, looks like it is made of crystal, and there is a crisp metal sound when gently tapped, which is because of the addition of lead, so it is also called lead-containing glass. It is widely used in glass crafts and decorations.

Compared with lead-containing crystal glass products, lead-free glass crystal glass products are slightly lighter and thinner, and its characteristics are that it inherits the appearance quality of lead-containing crystal glass, and does not contain lead, so it is also called non-toxic glass. It is widely used in high-end porcelain, tableware and wine utensils.

Features of ordinary glass.

Ordinary glass products have dull color, poor refractive index, rough workmanship, poor hand feel, and even bubbles in some places, and the sound of light tapping is dull, and its advantage is that it is lead-free and non-toxic. It is widely used in food glass containers and medical devices.

Indicates lead-free, - indicates leaded, and t indicates tray-packed. For example, MAX3232CSA+This is the model, such as the Yuguo is MAX3232CSA+, which means lead-free Heng Rent Rock, non-disc type, if it is MAX3232CSA+T, it means lead-free disk.

Green Times Tin Industry thinks:

1. Judging from the appearance of tin:

The surface with lead solder appears bright white;

Lead-free solder, on the other hand, is brighter and yellowish in color. 2. From the composition of metal alloys:

Leaded solder refers to alloy products containing other metal elements, and the commonly used solder for electronic soldering contains two main metal elements, tin and lead (such as: SN63 PB37, SN50 PB50, etc.);

Lead-free solder is the environmentally friendly solder currently used in the industry, which is basically lead-free solder, generally made of tin-copper, tin-silver, tin-silver-copper as the main metal elements.

The EU RoHS standard is less than 1000ppm of lead, and the Sony standard is less than 100ppm).

Leaded solder is used for the welding of leaded products that do not require environmental protection, and the tools, plates and components used in it are not environmentally friendly.

Lead-free solder is used for the welding of products that require environmental protection and lead-free, and the tools, plates and components used in it are required to be environmentally friendly and lead-free. 4. Detection method: The metal direct reading spectrometer can be used to detect the main metal elements and trace metal elements contained in it.