PCB Technical - Vibration test and shock test of PCB board

Vibration test and shock test of PCB board

Vibration test is to assess the product's ability to withstand the vibration environment (with different vibration levels), to check and analyze the product's vibration resistance defects in design and manufacturing, so as to improve the design and manufacturing, and ensure the reliability of the product in use and transportation. An important part of PCBA testing.

The vibration test is performed in the laboratory to simulate various vibration environments and fasten the samples on the special fixture of the PCB vibration table. The test can be divided into a fixed frequency vibration test called a fixed frequency vibration test; the other is based on The frequency conversion vibration test is a frequency conversion vibration test or called a scanning vibration test. The fixed frequency vibration test is carried out according to the vibration test standards specified in the product technical conditions, and the frequency, vibration acceleration, vibration direction (can be one or two or three directions) and vibration time are carried out. Vibration time can be extended when fatigue damage occurs under vibration stress.

The frequency conversion vibration experiment changes from low frequency to high frequency, and then from high frequency to low frequency (its frequency changes continuously in a logarithmic manner) for a cycle, which is called a scan. The cycle time and number of times, frequency range and vibration direction are specified in the technical conditions according to the requirements of the product. During the scanning vibration test, it is necessary to observe whether the test sample has resonance phenomenon and the damage effect on the product structure during resonance.

The impact test is a test to test the product's ability to withstand impulse impact and non-repetitive impact during use and transportation. It is used to determine the adaptability of the product when subjected to mechanical impact and the firmness of its structure.

When the impact is applied, the time for the kinetic energy to be transmitted to the product is the shortest. The magnitude of the impact force can be expressed in terms of impact acceleration, and it can also be expressed in units of gravitational acceleration g. The shorter the impact time and the greater the impact acceleration, the greater the damage to the product. When the waveforms are different, they correspond to different frequency spectra, and different frequency spectra will have different effects on the product. Duration describes the length of the impact time. Under the same conditions, the longer the duration, the greater the impact on the product.

The simulated impact test in the laboratory is carried out by fastening the product on the special fixture of the PCB impact test bench (in a non-working state). The shock pulse generated by the shock machine can be a terminal peak sawtooth wave, semi-sine wave and trapezoidal wave. For various shock pulse waves used in the test, the pulse peak acceleration and pulse width (duration) are specified by relevant standards. During the test, the three mutually perpendicular axes of the sample were continuously impacted three times in the forward and reverse directions, a total of 18 times.

The free drop test is also the simplest impact test. It is generally used to test the strength of the packaging structure by raising the packaging to a height of 0.5 to 0.8 meters above the ground. Then allow it to fall freely and impact on the rigid cement floor. The impact position and number of samples of the sample are specified in accordance with the product technical requirements in the PCBA program.

ipcb is a high-precision, high-quality PCB manufacturer, such as: isola 370hr PCB, high-frequency PCB, high-speed PCB, ic substrate, ic test board, impedance PCB, HDI PCB, Rigid-Flex PCB, buried blind PCB, advanced PCB, microwave PCB, telfon PCB and other ipcb are good at PCB manufacturing.