Sensitive drilling machine

The main elements of a typical sensitive drilling machine are shown in Fig. 8.1. 

The transistor film is then mechanically processed by a numerically controlled (NC) cutting plotter or drilling machine to form the net-shaped structures, as shown in Figure 6.3.8. In a similar way, a pressure-sensitive rubber sheet and a copper electrode suspended by a polyimide film are cut separately to form net-shaped structures. These two films are laminated on the top of the transistor fihn to complete the pressure sensor network. The periodicity is 4 mm, and the width of the struts is 0.3-0.5 mm. 

A trip device is any device which, as the operator approaches the dangerous part, automatically trips the safety circuit. A simple flap trip is shown in Figure 4.3.13 but trip devices can include trip bars and wires, sensitive probes (on drilling machines), photoelectric devices, pressure sensitive strips and mats, and emergency stop switches. Figure 4.3.14 shows a pull trip switch on a conveyor. It is important that trip devices are properly adjusted and that the machine s brake is in good working order. 

Kraft paper is widely used as a reinforcement. When saturated with phenolics, it is made into a common printed wiring board. When combined with melamine, it becomes a decorative high-pressure laminate used in furniture, countertops, and wall panels. Paper reinforcement is inexpensive and easy to machine, drill, and pxmch. It imparts good electrical properties, but it is sensitive to moisture and cannot withstand high temperatures. 

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