First, the alignment of second-hand Yamaha mounter circuit board

Due to the different sizes of the substrates used for flip chips, different degrees of problems can be caused in the alignment of the circuit boards. Some mounters' substrates are fixed by vacuum clamping. The use of thinner substrates is quite questionable. The requirements for flatness of thin substrates are difficult to achieve. Although the substrates are quite flat while the vacuum system is operating, the substrates will return to their original state when the vacuum is removed. In addition, if the component is temporarily fixed by the viscosity of the flux, the component will be easily displaced after the substrate is moved. Although a hard board can be added to strengthen the substrate, this way the vacuum system will No longer useful. Part of the vacuum system will cooperate with a special tool, the relative price will increase.

Adjustable placement pressure of second-hand Yamaha placement machine

The downward pressure of the placement nozzle is also a very important parameter of the placement machine. For the component, a sufficient downward pressure is required to accurately place it on the welding pad, but it cannot be too large to make the component the welding Slide off the mat. The general downward pressure is 3 to 10 g per bump.

Vision system of second-hand Yamaha mounter

Vision system is one of the most important units in the chip mounter. In addition to identifying solder joints, the vision system also has the function of inspecting the component size to confirm whether the component sucked by the nozzle is correct. The parameters that affect the quality of the vision system are gain, offset, threshold, vision tools. The placement machine manufacturer can effectively handle components with fine pitches with this part. When the pitch of the components is reduced, the solder contacts are also relatively forced to shrink. For example, the height of the solder contacts of a component with a pitch of 0.004 ″ is about 0.002 ″. When the solder contacts are narrowed to be close to the chip, even the image Zooming in out is still quite difficult, because the color of the passivation on the chip surface is quite close to the color of the solder joints.

Another problem is the fiducial on the substrate. Because the size of the flip chip is quite small, in some cases, some standard fiducials are actually larger than the chip. To solve this problem It is necessary to control the search area of the vision system.