Pressure control mechanism for adhesive thermal compression bonding machines

A method for joining together two superimposed and mated parts of a case or housing of an electronic device which parts have contacting portions that abut one another over a predetermined contact area, which comprises:

• (a) providing a fixture having a contact surface that abuts against an exterior surface of one of the parts of the case or housing of the electronic device during the compression of the parts against one another;
• (b) providing a plurality of powered pistons carried on the fixture for movement with the fixture, wherein each piston comprises a cylinder and a head that is extensible and retractable from the cylinder, wherein the heads of the cylinders are extensible through the contact surface of the fixture to directly engage against the exterior surface of the one part of the case or housing of the electronic device to help push the parts together and close any gaps occurring over the contact area therebetween;
• (c) applying pressure to the superimposed and mated parts using a powered actuator that is separate from the powered pistons;
• and
• (d) actuating the powered pistons during the pressure applying step to cause the heads of the powered pistons to extend in a direction that pushes the parts together with a force that is additive to whatever force is applied by the powered actuator to the parts.