PCB(Printed Circuit Board)

PCB(Printed Circuit Board),is important and electronic components, electronic components are support body, the electronic components are the provider of electrical connections. Since it is made by electronic printing, reason is called "print circuit board.

PCB environmental

In earlier years, PCB belongs to the high-tech industry, foreign most companies control technology output, once bound and limits the PCB industry development. But now we PCB enterprise's development were given a place restrictions, the more developed economy place this limitation is greater, why? Because unknowingly, PCB enterprise development governmental eyes pollution of cultivating, energy consumption of cultivating, water users! While paying great attention to environmental protection and sustainable development today, once put on such "hat", PCB enterprise is really to be "everyone Shouting dozen". In fact, we are large, energy dissipation of cultivating, pollution of water users? Of course not! We PCB enterprise is the low energy consumption and low pollution. We can according to the following data to contrast: from the point of view of environmental protection industry enterprise effluent, through the pollution index to be compared, can see:

1. The PCB enterprise's variety of pollutants is relatively concentrated, mainly COD and heavy metal pollution, no copper cyanide/CD/chrome poisonous things emissions, no carcinogenic, teratogenic, cause the genetic mutation induced material three emissions. But the major of heavy metals pollution of component -- copper ions, through conventional processing methods can be easily removed, so not afraid of pollutants PCB.

2. PCB enterprise concentration of pollutants is low. As is known to all, PCB production of water is demanding, the majority is with pure water, emissions of wastewater is mainly smoke board when brought out the wastewater. Can be seen from the table, relative to other pollution industry speaking, PCB enterprise wastewater concentration of pollutants is very low, especially COD, but other pollution industry 1/10.

3. The wastewater discharge circuit enterprise of freshwater less polluted. Because of the high demand for water circuit, and in the process of production, so tightly control circuit enterprise wastewater of salt (namely conductivity) relative to other industries is much lower. From fresh water resources protection, speaking, salt is crucial to the index, any salt of freshwater resources are polluted. So in comparison, PCB enterprise can call low pollution.

To sum up, the PCB industry in government and social status of large eyes pollution is out of line with reality. Why is the situation appears, what is the reason for PCB industry to wear a pollution's hat? Investigate its reason, have the following:

One is part of environmental protection circuit enterprise and cleaner production no great attention.

This paper firstly analyzes PCB enterprise of itself. At present, there are also a few kinds of enterprise did not understand the importance of environmental protection and clean production. Many companies for the wastewater treatment, waste water reuse, and clean production etc. Are all in order to cope with a check, or for the corresponding qualification certificate, without the ascent to the social responsibility of the enterprise and law of height. Some time ago, we participated in a new standard of written work she visited many enterprises, during a large part of the enterprise, found the wastewater treatment facilities still follow five years ago process, only for heavy metals processing, such as COD pollutants and not give special treatment, and gray water recycle system is decoration. Many enterprises of recycling process without thorough understanding, blind pursue low price products, the results a lot of recycling equipment fundamental operation does not rise, became decoration.

These are all hardware facilities, the other is the soft management issues, such as not processing, less dosing and steal row wait for a phenomenon. These behaviors though just a few enterprise's behavior, but once being tracked down to exceed bid, will in PCB industry wastewater pollution density high, fluctuation, difficult to treat such reasons as to examinations, come down for a long time in the public's heart naturally left PCB enterprise is polluting enterprise impression. It is our own give oneself wore pollution "hat."

Second is the peripheral related enterprise bring us trouble.

From the point of view of environmental protection speaking, PCB enterprise peripheral related enterprise is mainly the recycling waste bath enterprise. Everyone knows that waste bath pollution density high, dealing with large difficulty, there are many bad firms will waste away after bath, producing useful heavy metals, but the rest of them useless liquid steal into environment, which caused great pollution, let governments and people think this is PCB enterprise to bring pollution, PCB enterprise eduction of liquid is unable to process, PCB enterprise is polluting enterprises.

Three is publicity, caused a misunderstanding.

PCB company belongs to a high-tech enterprise, which is generally for production adopts confidential situation, so of external circuit board production process don't understand. Such as cyanide use, PCB industry is only in gold-plated and heavy gold thread, use a small amount of cyanide and discharge of wastewater are through online gold recovery processes handle again after discharged workshop, so basically no cyanide wastewater pollution, it and following the alkali copper usage and emission concentrations fundamental [christy feig, but now just see the production line has cyanide use and electroplating use cyanide equivalent.

PCB enterprise washed wastewater pollution concentration is very low, a part of the bath pollution concentration is higher, such as ink liquid and fluffy agent liquid and etching waste liquid etc., because have these high concentrations of wastewater from exist, many people would think these liquid is representative of the PCB enterprise level of pollution. Actually PCB enterprise of waste liquid trough is treasure, except for one of the heavy metal outside, other chemicals for PCB enterprise that is very important cost savings sources. If the government allowed enterprise to waste bath recycle and reuse, then PCB enterprise couldn't is polluting enterprise reason.

Strengthen self-discipline accelerating technological innovations

Based on the above reasons, we PCB industry this to do? We must the initiative to remove our head, "hat", for our industry to create more broad space for development. I think that the primary should from the following several aspects:

Strengthen self-discipline

Self-discipline should be made by us industry association to lead and regularly or irregularly through various channels for PCB enterprise to investigate, for the adoption of cleaner production or energy conservation and emission reduction of new technology, new technology, steadfast to do work of the enterprise, must in the industry to promotion, praise, and in various ministries for such enterprise for providing realistically help. Instead, for forgery, no social responsibility of the enterprise, we must firmly exposure and report to relevant departments for punishment. Only a stitch in time saves nine, our industry can obtain the public extensive approbate, healthy development.

Positive technical innovations

Now our country energetically advocate clean production and energy saving and emission reduction technology, we PCB enterprises should actively response, strive to each member unit do cleaner production, reduce truly, truly, the discharge of wastes, including waste liquid trough etc. Our member unit can through technical innovation to produce economic benefits, then use our actions to affect peripheral enterprises.

After a while, we industry new standards for pollutants discharge upcoming law, all the enterprise should take it as an opportunity, actively adopt advanced wastewater treatment process, return water technology, clean production technology, etc, to the original traditional process for rectification, such ability make our enterprise have more energy and quickly remove polluting enterprise's hat.

In the new standard, new technology popularization process, we industry association member unit can organize study and communication, please industry has experienced experts for enterprises to interpret the new standard, the promotion of new technology, explore new technology, etc. Our association may also organize expert team for the member unit, door to door services for the member unit eliminated uncertainty. Thus, it can not only provides a platform of communication, still can promote the enterprise to adapt the current industrial situation.

Fourthly, we should improve the transparency of waste and go

The 21st century is open era, we have good aspects should be "show" come out. We shall make proper circuit enterprise propaganda work, to make it clear to the public that our production environment, the producing pollution environment, pollutant discharge of pollutants, speculation. Enterprise as long as strictly implementing cleaner production measures, carefully for wastewater treatment, we PCB industry of energy conservation and emission reduction and wastewater treatment work is not difficult. We welcome a society with the government supervision, this also can supervise and promote PCB enterprise better implementation and improvement of clean production and for energy conservation and emissions reduction.

The PCB's history

The inventor of the printed circuit board is Austrian PaulEisler, he in 1936 in a radio device used in printed circuit board. In 1943, americans will use of this technology in military radio inside. In 1948, the United States formally approved the invention used for commercial purposes. Since the 1950s medium-term on, printed circuit edition technology began to be used extensively.

In printed circuit board before the emergence of electronic components of the interconnection between all rely on wires connected directly to realize. And now, circuit panel only as effective experimental tools and exist, Printed circuit board in the electronics industry has occupied a olute dominant position.

Process control block

Process Control PCB (which), Taiwan translation travel Control table, also have translation mission Control list that is an operating system kernel data structures, mainly expresses Process state.

Although each actual situation is endless and same, PCB usually records process related information, including:

Process state: can be new and comments, running,'re or halted, etc. When a new process, the system allocation of resources and PCB to it. And when the completed a specific task, recover the process system accounts for resources and cancel the process of PCB will cancel the process. The program counter: and then be operational instructions address. The CPU registers: such as accumulators, Index registers (Index), receive en: stack pointer and general purpose registers, status code etc, main USES is interrupted to temporarily store data so that later continue to use, The quantity and classes for computer architecture differences. The CPU scheduling method: priority, such as scheduling queue pointer and other parameters. Memory management: such as labelling Page table (en brief table is) etc. : Accounting information: if the CPU and actual time use quantity, time limit, account, work or process number. Input/output state: configuration process using the I/O devices, such as tape. In fact, the PCB as name, not content from all process related information.

PCB design

For both single panel, double panel, produce multilayer prototypes design, before they are designed with protel PADS, useful, now Allegro, such as design.

Printed circuit design based on circuit principle, realize the circuit designer according to the graph is required functions. PCB design mainly refers to the layout design, you need to consider the external connection layout, internal electronic components of optimizing the distribution, metal attachment and hole optimizing the distribution, electromagnetic protection, heat dissipation of various factors. Excellent layout design can save the cost of production, achieve good circuit performance and radiating performance. Simple layout design can use implement manually, complex layout design needs to refer to the computer aided design (CAD) is realized.