Intercept Packaging Technology to Control Corrosion
Engineered Materials, Inc. Keith W. Donaldson
TEC-HUB Asia Ltd Andy Lim
Precise mechanical equipment and high-tech electronic equipment all face problems such as corrosion, oxidation, static electricity, and mold. Engineers and technicians have exhausted various methods and expect a complete solution. Lucent Technologies Bell Labs has developed Intercept Technology packaging technology that combines long-term anti-corrosion and permanent anti-static functions.
Intercept packaging can effectively prevent metal corrosion.
High-precision mechanical equipment and components have long been adopting a variety of passive corrosion protection methods, and the quality of various electronic devices and circuit boards often presents non-device failures. It is generally considered to be the damage caused by an electrostatic accident. An in-depth study by Bell Labs found that the failure of the circuit board was actually caused by the corrosive gas in the atmosphere, causing oxidation, corrosion, mold, and static electricity. The "invisible killer" in the atmosphere is also widespread and there are regional differences. These corrosive gases include: hydrogen chloride (HCI), hydrogen sulfide (H2S), sulfur dioxide (SO2), carbon sulfide (COS), ozone (O3), nitrous acid mixture (NOx), and the like.
Traditional anti-static technology
Electrostatic discharge (ESD) can have destructive consequences for the quality and reliability of electronic products. Electrostatic discharge is usually caused by over-voltage (EOS) caused by improper material selection or surface corrosion.
General electronic devices have circuit systems that control the susceptibility to electrostatic discharge, but this protection is usually not enough. The standard practice in the industry is to ensure that sensitive electronic components and components are only exposed to energy-dissipating materials during manufacture, transportation, and storage.
Carbon-containing polymers are materials that are often used for static dissipation. Carbon black has good electrical conductivity. The amount of carbon black dispersed in the polymer can achieve the desired static dissipative range. Only this conductive mechanism is limited by the percolation threshold. If the percolation threshold is not reached, the plastic will not have a continuous conduction path. If the weight exceeds the percolation threshold, many random conductive paths will be generated, which will greatly reduce the resistance. It is not easy to fabricate carbon black-containing conductive plastics with a resistance in the static dissipative range, because the resistance is not only sensitive to the amount of activated carbon black added, but also affected by the manufacturing process. In addition, polymers containing carbon black tend to emit carbon black and are generally not acceptable for use in cleanrooms.
The coating of organic compounds on the surface of the polymer is also a way of making static dissipative conductive materials. These compounds are usually amines or acyl groups. When it adsorbs water in the air, the polymer surface will form a conductive function. This method of controlling electrostatic discharge has three shortcomings. First, these organic compounds are volatile. After months or years, most of the coating will evaporate and disappear, making the material an insulating polymer. From the surface can not see if it has lost anti-static function. Another drawback is that volatile organic compounds may be deposited on the protected object, creating a layer of film that may be corrosive or insulative. The third drawback is that the organic compound coating needs to absorb the moisture to exert its anti-static effect, so it will lose its function in a low relative humidity environment. Therefore, when the relative humidity is lower than 30% in a relatively dry environment or in combination with certain moisture-proof bags, the polymeric material becomes an insulator.
For electronic products, the corrosion of conductor surfaces due to trace gases in the atmosphere is an important aspect that is often overlooked. For example, copper and silver can easily react with gases such as hydrogen sulfide, carbon-based sulfur, sulfur dioxide, and hydrogen chloride. These gases also have the most serious problems. And these trace gases are everywhere.
In the case of hydrogen sulfide, the concentration in the North American atmosphere is generally between 1 and 10 billion parts per million, but in Asia, due to a large increase in the consumption of fossil fuels, poor control of pollution, air quality As a result, it is even worse, resulting in a significant increase in hydrogen sulfide concentration.
Laboratory test results show that the thickness of the corroded body film produced by hydrogen sulfide corrosion of copper, silver and bronze is proportional to the concentration of hydrogen sulfide. If copper is exposed to hydrogen sulfide at a concentration of 1 billion parts per million, a 50-nanometer-thick copper sulfide film will be grown in one year.
U.S. Military Department's Comparison of Intercept's Corrosion Resistance with Other Materials
In order to overcome the corrosive gas attack, a complete solution for corrosion, oxidation, static electricity, and mold problems that satisfies all the following requirements should be developed and a multifunctional composite material should be created:
1) No matter how the atmospheric environment changes, it can protect iron and non-ferrous metals from corrosive gases in the long term;
2) Provide permanent anti-static function, which is important for electronic devices;
3) It can inhibit the growth and spread of mold and similar microorganisms;
4) Non-volatile residue and contains only trace amounts of contaminating ions;
5) Particles measured in the liquid state at a lower content relative to existing materials;
6) The material itself has no volatile poisonous gas (NO Out-gassing);
7) No physical damage to the operator;
8) No infringement of the products in the protective packaging;
9) Environmental protection and safety, materials can be biodegradable, and can also be recycled;
10) The use of materials is simple and convenient while at the same time being highly cost-effective.
Intercept Technology
Lucent's Bell Labs evaluated the industry's long-term anti-corrosion needs for cleanliness, permanent anti-electrostatic discharge, and non-pollution. After years of research and development, it has developed a new material with patented Intercept Technology to replace moisture-proof bags and traditional shielding. Bags, "Pink Polymers" are even anti-corrosion materials such as volatile corrosion inhibitors, oil films and most desiccants.
Intercept Technology uses high-quality copper raw materials and inert plastic-polyethylene film to neutralize and neutralize all the corrosive gases and make it ineffective, resulting in a clean, durable, superior, corrosion-resistant polymerization. Substrate.
Commonly used anti-corrosion methods include the use of soft metal foils or oils (VCI, VPI, etc.), oil-impregnated films and paper and other anti-corrosion methods. Metal foil bags and all common flexible packaging also require tight closure and complete packaging. However, when the items to be protected are loaded or removed from the pouch, harmful gases can enter and remain in the pouch to erode the items to be protected. Intercept's Interceptor Corrosion Protection uses a patented technology that prevents copper gas from entering the polyethylene bag. It can provide two types of anti-corrosion functions at the same time: on the one hand, to prevent corrosive gas from intruding into the bag from the outside (every 1 mil = 0.0254 mm The thickness of the film is sufficient to prevent the corrosive gas from invading from the outside for more than 10 years; on the other hand, it reacts with the corrosive gas in the packaging bag, and after a few hours or minutes, it can clean all the corrosion sealed in the packaging bag. gas. The interception type anti-corrosion packaging bag does not require vacuum treatment, does not require grease, and does not require tight sealing. After the entire bag opening is simply folded, the use of a clean sealing film or heat sealing port can provide sufficient protection. Also, the use of interception products will not have oil or particulates precipitated from the surface of the package, and there will be no other residues contaminating the protected items. This is exactly why the U.S. military has tested and approved this technology and replaced the VCI foil bag series.
The U.S. Army conducted a series of tests at the Bikantinni arsenal in New Jersey. From the comparison of the effects of Intercept Technology and other traditional protective materials, it can be seen that the Intercept insulation material has a significantly longer duration of anti-corrosion than other traditions. Protection technology.
Antistatic Research Group at Bell Labs, Maree Hills, New Jersey, Anti-Static Research Group of DuPont, Wilm, Dillawa, and Antistatic Research Group, Buster Pharmaceuticals Industry Department, Velangsiya, California The test results are consistent.
In recent years, with the improvement of environmental protection requirements, the electronics industry has become an important trend in the development of lead-free solder. At the same time, it also put forward higher requirements for anti-corrosion work. Silver-impregnated printed circuit boards are one of the technological pioneers in this area. Compared with the hot soldering method, the silver dipping does not plug the micro-holes on the circuit board and does not go beyond the printed circuit.
The American Institute of Competitiveness in Philadelphia is an independent laboratory that has tested the packaging of the material to determine the solderability of the underlying silver plating. The test results show that the specimens placed in the Static Intercept bag with the anti-electrostatic bag-protected test piece having lost its weldability can completely maintain the original weldability.
Application area
Intercept Technology was developed in 1992. After more than 10 years of continuous research and improvement, the technology has been widely adopted in aerospace and military equipment protection. It is recognized as an excellent protective packaging material that protects various precision products and parts (including aerospace equipment, aircraft engines, and high-tech electronic products) against corrosion, oxidation, static electricity, and other pollution accidents.
Intercept polymer packaging is used for export transportation, which can not only obtain better protection effect, but also reduce the cost of protective materials. Companies like Lucent Technologies can rely on this material to improve the reliability of electronic and telecommunications products and comply with regulations for hazardous substances at the same time.
In the field of antistatic use in the electronics industry, various options such as packaging bags, film sheets, bubble films, and loading pad packaging films can be used with very thin polyethylene films. Using these Intercept products instead of the normal anti-static packaging material can also preserve the anti-corrosion and reduce the erosion of air pollution in Asia, which is even worse than North America.
Many industries need to protect copper and silver from corrosion. In the electronics industry, electrical interfaces, printed circuit boards, and other components and silver-plated components have been eroded. Decreasing corrosion will reduce the current interruption associated with the interface while improving solderability.
Other industries that rely on clean copper include the power industry and electroplating industry that use a large number of copper conductors. These industries need to ensure that the finished product in transit is properly protected.
Artefacts stored in museum collections, such as bronze ware and silverware, can also benefit from the corrosion protection provided by Intercept Technology.
Source: "China Plastics & Rubber"