Laser seal welding method for oxygen-free copper shell and oxygen-free copper cover plate

Abstract

The invention discloses a laser seal welding method for an oxygen-free copper shell and a cover plate. Green laser with the wavelength of 515nm is adopted to conduct laser seal welding on the oxygen-free copper shell and the cover plate adopting a lock bottom self-centering joint in a glove box filled with high-purity nitrogen in an output mode of pulse or continuous laser light emission. The technological parameters of pulse mode laser seal welding are as follows: the laser pulse peak power ranges from 1200 W to 1400 W, the pulse waveform is a rectangular wave, the pulse width ranges from 5 ms to 7 ms, the pulse repetition frequency ranges from 5 Hz to 10 Hz, the welding speed ranges from 18 mm / min to 36 mm / min, and the defocusing amount ranges from 0 mm to 2 mm. The technological parameters of the continuous mode laser seal welding are as follows: the laser power ranges from 700W to 900W, and the welding speed ranges from 6000 mm / min to 8000 mm / min. According to the pulse or continuous laser seal welding method for the oxygen-free copper shell, the stable welding process can be obtained, splashing and holes in the laser welding seam of the oxygen-free copper shell are effectively eliminated, and the packaged microwave assembly oxygen-free copper shell has the advantages of being attractive in appearance of the welding seam, high in air tightness, high in reliability and the like.

Description

technical field [0001] The invention relates to a laser welding method, in particular to a laser sealing welding method for an oxygen-free copper shell and an oxygen-free copper cover plate. Background technique [0002] With the rapid development of modern advanced integrated circuits and microwave technology, the packaging quality of electronic devices and components has an increasing impact on the performance of the overall system. According to statistics, among the factors currently limiting the performance of microwave devices, about 30% of device failures are related to packaging. Packaging not only has the function of mechanical support and environmental protection for the chip, but also prevents it from being polluted and eroded by moisture, impurities and various chemical atmospheres in the atmosphere, so that the internal chip of the device can stably perform normal electrical functions. And the thermal performance and even the reliability of the circuit also play...

AI Technical Summary

Problems solved by technology

Due to the characteristics of high thermal conductivity, high reflectivity (about 98%) for lasers in the infrared band (such as 1064nm, 1030nm) at room temperature, high melting point and boiling point, infrared laser sealing welding of oxygen-free copper shell and cover plate exists. It is difficult to form a stable molten pool, the depth of fusion is shallow, it is easy to produce large particle splashes and holes, it has a high tendency to thermal cracks, it is easily affected by the surface state of the workpiece, the welding process is extremely unstable, and the reflected laser may damage the laser, etc., which limit the use of oxygen-free copper. Applications in the field of microwave component housing packaging

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