The properly and electrostatically measured taping materials are used for the components, but attention should be paid to the fact that there is some danger the parts absorb on the top
tapes to cause a failure in the mounting and the parts are destructed by static electricity (more than 1kV : 1J, 2A, 2B, 2E 0.5kV : 1E, Human Body Model 100pF 1.5kΩ) to change the
resistance in the conditions of an excessive dryness or after the parts are given vibration for a long time as they are packaged on the tapes. Similarly, care should be given not to apply the
excessive static electricity when mounting on the boards.
●
Ionic impurities such as flux etc. that are attached to these products or those mounted onto a PCB, negatively affect their moisture resistance, corrosion resistance, etc. The flux may
contain ionic substances like chlorine, acid, etc. while perspiration and saliva include ionic impurities like sodium (Na
＋
), chrorine (Cl
−
) etc. Therefore these kinds of ionic substances may
induce electrical corrosion when they invade into the products. Either thorough washing or using RMA solder and flux are necessary since lead free solder contains ionic substances.
Washing process is needed, before putting on moisture proof material in order to prevent electrical corrosion.
●
Please pay attention that the top of an iron does not direct touch to the components. There is a risk that may cause a change in resistance. Take care that another risk may happen that
the protecting coat is carbonized in an instant when touched directly by the top of the iron, also climatic-proof for electric corrosion or insulation of protecting coat may be dropped down.
Be sure not to give high temperature on the top of the iron as it will degrade the protecting coat.
●
Avoid storing components under direct sun rays, high temperature/humidity. Direct sun rays will cause quality change of taping and difficulty of keeping appropriate peeling strength. 5∼
35℃/35∼75%RH, there is no deterioration of solderability for 12 months, but take special care for storing, because condensation, dust, and toxic gas like hydrogen sulfide, sulfurous acid
gas, hydrogen chloride, etc. may drop solderability.
[p=24, null, left][color=#4c4c4c][font=tahoma, Verdana, Arial, 宋体]Do cars also have electromagnetic radiation problems? Some time ago, news about a car with excessive electromagnetic radiation made ca...
Although I have been exposed to some FPGA designs before, they were just to implement some interface protocols or as customized FIFOs. I have never been exposed to SOC, so I would like to thank the fo...
I'm in urgent need of a graduation thesis on "FPGA-based digital clock design" that needs to display hours, minutes, and seconds, accurately time, set alarms, and reset the time. Literature review and...
[size=14px]In PCB design and processing, OZ (ounce) is often used as the unit of copper thickness. 1OZ copper thickness is defined as the weight of copper foil in an area of 1 square inch is 1 ounce, ...
At present, the traffic congestion in cities is quite serious. According to relevant news reports: In China, the traffic congestion has expanded from megacities such as Beijing, Shanghai, and Guang...[Details]
1. Introduction
This design was made for participating in an electronic design competition. It effectively solved the problem of the operation and control of an electric car on a seesaw. The s...[Details]
With the advent of increasingly powerful processors, image sensors, memory, and other semiconductor devices, as well as the algorithms that enable them, computer vision can be implemented in a wide...[Details]
1. With the development of modern industry and the continuous improvement of automation, some medium and large control systems have been greatly facilitated, which not only makes control easier, bu...[Details]
The potentiometer is an adjustable electronic component. The main functions of the potentiometer in the circuit are as follows:
1. Used as a voltage divider
A potentiometer is a continuou...[Details]
With the advocacy and implementation of the government's Safe City Plan, the security market has increasingly higher requirements for the clarity of surveillance images. Imagine that after a case o...[Details]
Experimental tasks
A DS18B20 is used to form a temperature measurement system. The temperature measurement accuracy reaches 0.1 degrees. The temperature range is between -20 degrees and +50 de...[Details]
Continuity test
A variety of devices need to be checked for continuity, including cable assemblies, printed circuit boards, and connectors to ensure that these components have the expected contin...[Details]
As people's requirements for safety and comfort in the process of driving cars continue to increase, automotive radars are widely used in the car's adaptive cruise system, collision avoidance syste...[Details]
In 2012, more than half of the cars in the European, Japanese and American car markets will be equipped with color displays, navigation systems, satellite communications and other in-vehicle infota...[Details]
At present, the traffic congestion in cities is quite serious. According to relevant news reports: In China, the traffic congestion has expanded from megacities such as Beijing, Shanghai, and Guangzho...[Details]
Introduction
Nowadays, people pay more and more attention to the security alarm system, and people have higher and higher requirements for the functions and performance of the alarm. This paper prop...[Details]
Traditional
virtual instruments
consist of a data acquisition
board
based on PCI bus and
corresponding software. However, with
the rapid development of
computer
network techno...[Details]
Analysis of the three core aspects of digital TV transmission standards
According to the differences in regionality, transmission method and modulation method, the transmission method needs to...[Details]
1 Battery technology determines the fate of energy vehicles
Regardless of whether new energy vehicles are hybrid or pure electric vehicles, they cannot do without the core technology of batter...[Details]
Automotive Electronics
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