Kapper series used in the semiconductor industry
Along with our country the steady growth of the national economy and the innovation development of production technology, production technology is more and more high to the requirement of production. QianHouDao each working procedure in large scale and very large scale Ic production put forward higher requirements on production environment, not only to maintain a certain temperature, humidity, cleanliness, and also to electrostatic protection cause enough attention.
As is known to all, belongs to the whole IC packaging industry in the production of the production process, in the process, for IC and mixed IC or monolithic IC, mainly include the wafer thinning (grinding), wafer cutting (scribing), the core (stick), bonding (bonding), encapsulation (coating) before and after curing, electroplating, printing and after curing, cutting, tubing, sealing test and so on. For different process conditions in each process has different requirements.
The influence of electrostatic factor of IC packaging First of all, the causes of static electricity is everywhere. In the rapid development of science and technology and industrial production of highly automated today, electrostatic hazard in industrial production is obvious, it can cause all sorts of obstacles, restrict the improvement of automation level and affect the quality of the product. Here combined with our factory in integrated circuit encapsulation, the actual situation of the production process to explain the reason with the generation of static electricity, basically has the following several aspects.
3．1 Production workshop building decoration materials with high resistance materials IC production process requires the use of clean workshop or ultra clean workshop. Request dust particle size from past 0.3 microns to 0.1 mu m under quasi, dust density is about 353 / m3. Therefore, in addition to the dust collection equipment installed and using inorganic and organic dust not hair material, to prevent the dust. But not for building materials performance as an index into account. Industrial enterprises has not made clean workshop design norms. IC factory clean workshop mainly used in indoor decoration materials are: polyurethane elastic ground, nylon, hard plastic, polyethylene, plastic wallpaper, resin, wood, white porcelain, enamel, gypsum and so on. Most of the above materials, is high molecular compound or insulators. For example, organic vitreous resistivity for Ω 1012 ~ 1014 cm, polyethylene volume resistivity for n, 1013 ~ 1015 cm, and conductive performance is poor, some reason it is not easy to produce static through them to the earth leakage, thus result in the accumulation of static electricity.
3．2The different actions of human body electrostatic clean workshop operators and walking around, sole and ground keep close contact and separation, all parts of the body also have activities and friction, whether walking, walking, running will produce static electricity, the so-called charged on foot; Human activity after a rise, human body wearing fatigues and chair surface contact again after separation, also can produce static electricity. Human body electrostatic voltage if away not to drop, and to contact IC chip, may cause breakdown of IC unconsciously.
3．3 Air conditioning and air purification caused by static electricity Due to the IC production requirements under the condition of 45-55% RH, so it implements the air conditioning, must carry on the air purification at the same time. Drop in at the beginning of wet air passes through the filter efficiency, effectively filter, high efficiency filter and duct for clean room. General total duct wind speed is 8 ~ 10 m/s, duct wall paint, when the dry air and air duct, dry air filter and make relative motion, will generate static electricity. What should notice is static and humidity are more sensitive. In addition, delivery of semi-finished products and IC products in the process of the packing and shipping will generate static electricity, this is one of the factors of electrostatic electrification. Second, the electrostatic damage to IC are considerable. Generally speaking, the static characteristics with high potential, strong electric field, in the process of electrostatic electrification - discharge, sometimes forming transient high discharge current and electromagnetic pulse (EMP), produced by a wide spectrum of electromagnetic radiation field. In addition, compared with conventional electric energy, electrostatic energy is small, in the process of nature electrification - discharge, electrostatic discharge (ESD) parameter is not to control, is a kind of difficult to repeat random process, so its role is often ignored by people. Especially in the field of microelectronics technology, it gives us the damage is amazing, it is reported that every year because of static electricity caused direct economic losses as high as hundreds of millions of yuan, the electrostatic hazard in order to become a great obstacle for development of the microelectronics industry.
In the semiconductor device production workshop, because the dust adsorption on a chip, IC, especially the very large scale integrated circuit (VLSI) yield will be dramatically reduced. IC production workshop operators wear clean work clothes, if the human body with electrostatic, extremely easy adsorption dust, dirt, etc., if the dust, dirt, was taken to the operating site will affect the quality of our products and degradation product performance, reduce IC yield greatly. If the adsorption of dust particle radius is larger than 100 microns line width of about 100 microns, the film thickness under 50 microns, is most likely to make products to be scrapped.
Again, the electrostatic damage to the IC has certain characteristics.
(1)concealment Unless some electrostatic discharge, the human body can not directly perceive electrostatic, human body electrostatic discharge occurred but also not necessarily can have the feeling of electric shock, this is because the perception of the human body electrostatic discharge voltage of 2 ~ 3 kv, so electrostatic has concealment.
(2)Some potential will be affected by the performance of electrostatic damage after no significant decline, but many times accumulative discharge will cause internal injuries to IC devices and form. So the electrostatic damage in IC with potential.
(3)Randomness electrostatic damage IC what circumstance? You can say that, from an IC chip after until it damaged before, all process are threatened by static electricity, and the randomness of the generation of static electricity also, randomness of its damage.
(4)Complexity of electrostatic discharge damage failure analysis work, because of microelectronics IC product fine, fine, microscopic structure and time consuming, trouble and costs, to demand higher technology and often need to use high precision instruments, even so, some of the electrostatic damage phenomenon can also be difficult to distinguish between with other causes of damage; Makes one mistake electrostatic discharge damage failure as other failure, this before for electrostatic discharge damage did not fully understand, often due to early failure or the failure of the unknown, and thus not consciously conceal the real reason for the failure. So the analysis of electrostatic damage in IC is complex.
packaging production line of electrostatic requirements more stringent. In order to guarantee the normal operation of the production line, its clean workshop is anti-static whole decorate building materials, all the personnel in and out of the clean workshop equipped with anti-static clothing hardware measures, such as packaging companies according to the relevant national standard and the enterprise's actual sui condition to develop the enterprise standards or specific requirements in terms of antistatic, to cooperate with the normal operation of IC packaging production line. With China's IC assembly line expansion, encapsulation ability, encapsulation varieties increased year by year, and higher requirements for product quality and yield, accordingly to the various kinds of hardware and software requirements and to the increased awareness of all employees of electrostatic protection becomes even more important, and it is playing and ACTS as a affect the quality of our products "leading role" and "invisible killer". So, electrostatic protection will be current and a major topic in the IC industry of us in the future.
