Yan Yongda

Processing technique of target capsule's micro inflation hole with a scanning probe

To resolve inflation of inertial confinement fusion (ICF) target and encapsulation of micro inflation hole with adhesive, a scanning probe microscope (SPM) diamond microprobe was used as the cutting tool with SPM in contact mode. Some parameters influencing the quality of micro inflation hole, such as the scanning direction of the diamond tip, the scanning rate and the contact force are discussed. Accurate taper hole was achieved whose climension and precision could meet the requirements of inflation and encapsulation technique of micro hole. The experimental results show that using SPM diamond microprobe as the cutting tool and with special processing technique, the precision machining of target capsules taper inflation hole can be realized. A novel operative technology for filling high Z gas to target is provided.

Research advances of electrochemical micro/nanofabrication based on confined etchant layer technique

Compared with mechanical machining, ECM has several advantages, such as avoiding tool wear, none thermal or mechanical stress on machining surfaces, as well as high removal rate. Moreover, ECM is capable of making complex three-dimensional structures and is appropriate for flexible, fragile, or fissile materials even materials harder than the machining tool. Thus, ECM has been widely used for various industrial applications in the fields of aerospace, automobiles, electronics, etc. ECM methods can be classified usually as electrolytic machining based on anodic dissolution and electroforming based on cathodic deposition of metallic materials. Recently, high technology industry, such as ultralarge scale integration (ULSI) circuits, microelectromechanical systems (MEMS), miniaturized total analysis systems (μ-TAS) and precision optics, has developed more and more rapidly, where miniaturization and integration of functional components are becoming significant. Nowadays, the feature size of interconnectors in ULSI circuits has been down to 20 nanometers, predicted by Moore’s law. Confined etchant layer technique (CELT) was proposed in 1992 to fabricate three-dimensional micro- and nanostructures (3D-MNS) on different metals and semiconductors, which has been developed an effective machining method with independent intellectual property rights. Generally, there are three procedures in CELT: (1) generating the etchant on the surface of the tool electrode by electrochemical or photoelectrochemical reactions; (2) confining the etchant in a depleted layer with a thickness of micro- or nanometer scale; (3) etching process when the tool electrode is fed to the workpiece, which applicable for 1D milling, 2D polishing, and 3D microfabrication with an accuracy at micro or nanometer scale. External physical-field modulations have recently been introduced into CELT to improve its machining precision. In this review, the advances of CELT in principles, instruments and applications will be addressed as well as the prospects.