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.
I want to make a remote real-time monitoring system that can realize parameter setting function and data access operation through C52 without using USB camera. When searching on the Internet, I found ...
Speaking of test calibration,
The first thing that comes to mind for the "Siege Lions" is
Calibration of network analyzers.When you use a network analyzer for testing,
Calibration is a mandatory actio...
[i=s]This post was last edited by nwx8899 on 2014-7-14 20:03[/i] [font=Verdana][align=left]Follow the user manual step by step, here[/align][align=left][color=#ff0000] [/color][/align][align=left][col...
PI understands fast charging needs better. Download product information to win gifts!Click to enter the eventEvent time: From now until March 20, 2020
How to participate:1. Enter the product informati...
Emergency hand-held lamps powered by 6V maintenance-free batteries are widely used in rural areas. The charger used is a transformer step-down and single diode half-wave rectifier, and the charging...[Details]
There are three types of mobile TV: one is based on analog TV broadcasting network, another is based on mobile communication network, and the other is based on digital broadcasting network. The f...[Details]
As LEDs continue to improve in almost every aspect of performance and cost, LED lighting is being used in an increasingly wide range of applications, among which LED street lights are a focus of in...[Details]
Introduction
Power subsystems are becoming more and more integrated into the overall system. Power systems have moved from being separate "essential dangerous devices" to being monitorable...[Details]
1. Introduction to CIF Board
Fieldbus integration based on PC system
Whether it is a master or a slave, fieldbus has won unanimous praise in the field of PC-based automation. For more...[Details]
Toyohashi University of Technology demonstrated electric field coupled wireless power supply technology using life-size car tires and roads at the wireless technology exhibition "Wireless Technolog...[Details]
1. When the slip speed regulating motor is undergoing frequency conversion and energy saving transformation, the original excitation box (referred to as the speed regulating box) and the original s...[Details]
1. Disadvantages of choosing too high a voltage level
Choosing too high a voltage level will result in too high an investment and a long payback period. As the voltage level increases, the...[Details]
D5026A is a driver IC designed by Shanghai Debei Electronics for energy-saving LED display screens. Its design concept is energy-saving and compatible with existing solutions, that is, it can be ...[Details]
Fruit planting is an important part of China's agricultural development, and fruit tree pest control operations are becoming more and more important. At present, the overall level of pesticide applica...[Details]
Portable power applications are broad and varied. Products range from wireless sensor nodes with average power consumption of only a few microwatts to in-vehicle medical or data acquisition systems...[Details]
The installation locations of DC-DC converters are relatively scattered. DC-DC converters can be found on the power board, main board, logic control board and other circuit boards of PDP color TVs....[Details]
0 Introduction
In the design and construction of communication systems,
communication power supply
is called the heart of the communication system. The power supply system will dire...[Details]
UDN2916LB is a two-phase stepper motor bipolar driver integrated circuit launched by SANKEN. It can drive dual-winding bipolar stepper motors and is particularly suitable for controlling dual-step ...[Details]
1 Introduction
In order to cope with the energy crisis and slow down global warming, many countries have begun to pay attention to energy conservation and emission reduction and the de...[Details]
Embedded System
京公网安备 11010802033920号
EEWORLD
