资源预览内容
第1页 / 共77页
第2页 / 共77页
第3页 / 共77页
第4页 / 共77页
第5页 / 共77页
第6页 / 共77页
第7页 / 共77页
第8页 / 共77页
第9页 / 共77页
第10页 / 共77页
亲,该文档总共77页,到这儿已超出免费预览范围,如果喜欢就下载吧!
资源描述
ESD Thoughts and theoriesESD things I think about (Rev. 1)Do you have other ESD topics we should clarify better?Graphics I did not create are 1999 New Vision Technologies Inc.dmasonalphalink.com.au1(c) 2000 Doug MasonIntroductionI am a soldering trainer who focuses on the management of the total process that impacts on the quality of the solder joint, from design to delivery.One aspect I cover is the management of ESD. In researching this topic, I am running into explanations that would not satisfy my audience, who are: Process Workers, Stores people, Purchasers, Managers, and so on.They do not want explanations that require an understanding of Laws of Physics or any mathematics, formulae, and so on. Explanations must be clear, simple and obvious, related to their everyday experiences.dmasonalphalink.com.au2(c) 2000 Doug MasonIntroductionI want to know if my explanations make sense and are correct.Even if I am wrong, hopefully I am a catalyst for the generation of more lucid and logical simple explanations that are understandable by the widest community.When such people understand the reasons they need to take such steps, this should surely help them implement the required strategies.dmasonalphalink.com.au3(c) 2000 Doug MasonIntroductionI am interested in hearing from people who want to make positive contributions.When you write, please tell me the Revision number (see the first Title Slide)If you can make a useful contribution to my knowledge, please do so. My address is dmasonalphalink.com.au Many thanks, Dougdmasonalphalink.com.au4(c) 2000 Doug MasonFirst, some basic principles . . .dmasonalphalink.com.au5(c) 2000 Doug MasonAtomic TheoryBasic Principles (1)dmasonalphalink.com.au6(c) 2000 Doug MasonAn atom is made up of chargesAn atom is made up of charges.In its stable state, the size of the positive charge at the centre (nucleus) of an atom is balanced by the size of all the negative charges of the electrons, making it neutral overall.The electrons whirl around the centre like planets.dmasonalphalink.com.au7(c) 2000 Doug MasonCreating a charge imbalanceWhen an atom loses an electron, it has a charge imbalance.Since this atom has lost an electron, which is a negative charge, the atom is now a positive charge.When it gains an extra electron, an atom becomes a negative charge.Electron “lost”dmasonalphalink.com.au8(c) 2000 Doug MasonA dischargeThis movement of charges is called a discharge. When something which has When something which has a charge imbalance is a charge imbalance is brought close to or touches brought close to or touches something else, a stream of something else, a stream of charges might move, to try charges might move, to try to bring the atoms back to to bring the atoms back to their stable balanced their stable balanced condition.condition.This powerful, rapid movement of charges can damage electronic components.Lets see it again!dmasonalphalink.com.au9(c) 2000 Doug MasonTriboelectric generationBasic Principles (2)dmasonalphalink.com.au10(c) 2000 Doug MasonWhen materials are in contactdmasonalphalink.com.au11(c) 2000 Doug MasonWhen materials are in contactdmasonalphalink.com.au12(c) 2000 Doug MasonWhen two materials are in intimate contact, they share electrons which are at their surfaces.When materials are in contactdmasonalphalink.com.au13(c) 2000 Doug MasonWhen two materials are in intimate contact, they share electrons which are at their surfaces.When materials are in contactIt is possible for electrons to be “stolen” from one material by nuclei in the other material, because they have a stronger forcedmasonalphalink.com.au14(c) 2000 Doug MasonIt is possible for electrons to be “stolen” from one material by nuclei in the other material, because they have a stronger forceWhen materials are in contactSince the contacting surfaces still have an equal number of positive and negative charges, there is no overall charge imbalance on them.dmasonalphalink.com.au15(c) 2000 Doug MasonWhen the materials are separateddmasonalphalink.com.au16(c) 2000 Doug MasonWhen these materials are separated, electrons are removed from one material and are transferred to the other material.When the materials are separatedElectrons “lost”Electrons “gained”dmasonalphalink.com.au17(c) 2000 Doug MasonWhen the materials are separatedElectrons “lost”Electrons “gained”When these materials are separated, electrons are removed from one material and are transferred to the other material.This action takes place with all types of materials. With insulators, the charges remain at the points of contact. A charge spreads all over an ungrounded conductor.dmasonalphalink.com.au18(c) 2000 Doug MasonThis action takes place with all types of materials. With insulators, the charges remain at the points of contact. A charge spreads all over an ungrounded conductor.When the materials are separatedElectrons “lost”Electrons “ga
收藏 下载该资源
网站客服QQ:2055934822
金锄头文库版权所有
经营许可证:蜀ICP备13022795号 | 川公网安备 51140202000112号