Circuit assembly device for programmably controlling placement force and method thereto

A robotic placement device, comprising:

• a programmable end-effector for picking and placing component parts, the programmable end-effector including a cylinder having a piston, the piston including a first and second shafts coupled together, the first shaft being larger than the second shaft;
• an O-ring seal coupled to and dividing the cylinder into a first and second chambers wherein the first shaft is moveably coupled between the O-ring seal;
• a controlling means for controlling a pressure applied to the first chamber for establishing a predetermined placement force at the programmable end-effector while placing component parts;
• an air-bearing moveably coupled to the second shaft for providing substantially friction-free coupling therebetween as the piston moves vertically;
• means for sensing the pressure in the first chamber and in response thereto generating a signal;
• a processing means, coupled to the controlling means, for processing the signal and in response thereto varying the pressure in the first chamber for maintaining a substantially constant placement force being exerted by the programmable end-effector on a circuit assembly, said processing means controls the placement force when the programmable end-effector moves vertically while in contact with the circuit assembly.