Non-adhesive direct bonding of tiny parts by means of ultraprecision trapezoid microgrooves

The study proposes a new method of bonding two small parts without the use of any adhesive by making use of ultraprecision trapezoid microgrooves on the surfaces of each part. These trapezoid microgrooves allow small parts to be bonded together with high positioning accuracy due to a wedge effect and an adhesion phenomenon between the mating surfaces. Ultraprecision trapezoid microgrooves are created by using an ultraprecision machining center having 1 nm positioning resolution and a diamond milling cutter. From experimental and simulated results, it is found that the bonding strength in general increases with decreasing wedge angle. The effect of the wedge length on bonding strength varies with the wedge angle where the strength increases with increasing length for wedge angles greater than 8 degrees but increases with decreasing length for wedge angles less than 8 degrees.