What are the damages of electronic components caused by ESD failure?

Date：2022-07-20 14:57:51Views：1163

Static electricity and electrostatic discharge (ESD) are everywhere in our daily life, especially when handheld electronic devices are developing in the direction of lightweight and compact, and product functions are increasing, their input / output ports are also increasing, resulting in electrostatic discharge entering the system and interfering with or damaging integrated circuits. Semiconductor materials and devices have higher and higher requirements for electrostatic control in the process environment of production, assembly and maintenance. The harm of electrostatic discharge to the reliability of devices has become more and more significant. In order to help you understand in depth, the following contents are sorted out by Chuangxin testing network for your reference.

1、 ESD infringes on electronic devices in the following ways:

1) Electrostatic source discharges electronic devices directly

ESD events often occur during the discharge of ESDs by live conductors (including human body). The general electrostatic hazard is caused by the discharge of ESDs directly by human body or charged conductor.

2) Electrostatic discharge of charged devices on other conductors

When electrostatic discharge sensitive devices are in operation, or in contact with packaging materials and machine surfaces, electrostatic charges will accumulate. Electrostatic discharge will occur when the device moves or vibrates in the packaging box. The capacitance and energy involved in this discharge are different from the discharge of ESDs devices by human body. In some cases, CDM events are more harmful than hBN events.

3) Electric field induced discharge

The inductive field can directly or indirectly cause harm to the ground. Because there is an electrostatic field around any charged body. If ESDs devices enter the range of electrostatic field, they will be charged due to induction. If the device is grounded in the electric field area, the process of charge transfer to ground is called CDM event.

2、 Two failure modes of ESD electrostatic damage

1) Hard damage: also known as "sudden complete failure" and "one-time damage", accounting for about 10%. It shows that the electrical parameters of the device suddenly deteriorate and lose their original functions. The main reason is that the overvoltage caused by electrostatic discharge causes the dielectric to be broken down, or the overcurrent causes the internal circuit metal wire to fuse, and the silicon chip to partially melt, etc. Hard damage can be found in time by conventional performance testing methods, and the harm is much smaller than that of soft failure.

2) Soft damage: also known as "potential slow failure", "failure after multiple damage accumulation", accounting for about 90%. Although all kinds of electrical parameters of soft damaged devices were still qualified at that time, their service life was greatly shortened. Products or systems containing these devices have poor reliability and may continue to suffer from ESD soft damage or other over stress damage accumulation and premature failure in the subsequent process (until the end user). Because the soft damage is potential, it is difficult to prove or detect it by using the current technology, especially after the device is loaded into the whole product, so it has greater harm. The maintenance costs and other losses caused by these products after they enter the market will be dozens or even hundreds of times larger than the direct losses in production! Most components without protective measures have low electrostatic discharge sensitivity, many of which are in the range of hundreds of volts, such as MOS single tubes between 100-200v, and these single tubes cannot add protective circuits; Some circuits, especially CMOS.

IC adopts electrostatic protection design. Although the anti ESD level is significantly improved, most of them can only reach 2000-4000v, while the electrostatic voltage generated in the actual environment may reach tens of thousands of volts. Therefore, components without protection are vulnerable to electrostatic damage. As the size of components decreases, this kind of damage will increase. Therefore, the vast majority of components are electrostatic sensitive devices, which need to take anti-static protection measures in the process of manufacturing, transportation and use.