Abstract: A method and apparatus for component to substrate assembly permits in situ reflow of a flip chip (or other suitable component) in a manner which promotes proper settling of the component as solder begins to flow at the contact points between the component and the substrate. The pick-up head of a placement machine heats the component while applying up to several grams of downward force that serves to level the component. The downward force (downforce) is accurately measured using an electronic force sensor such as a strain gauge, force sensitive resistor, or any other suitable type of force sensor. The initiation of solder reflow can be detected with the pick-up head by sensing a decrease in the downforce.

Abstract: A method and apparatus for component to substrate assembly permits in situ reflow of a flip chip (or other suitable component) in a manner which promotes proper settling of the component as solder begins to flow at the contact points between the component and the substrate. The component is heated and held by a pick-up head while applying downforce that serves to level the component. The initiation of solder reflow can be detected with the pick-up head by sensing a decrease in the downforce. Downforce applied to the component with the pick-up head is then decreased and the retention mechanism holding the component is released, freeing the component from the pick-up head and permitting the component to properly self-center using the liquid solder's surface tension.

Abstract: A placement robot includes a micro alignment pick-up head (MAP) to hold a component for placement on a substrate. The MAP includes a retention member that may be a vacuum pick-up nozzle for component retention and has two main parts: an upper body and a lower body. The upper body and the lower body are separated from one another by an air bearing which provides near-frictionless performance and allows the lower body a range of motion relative to the upper body. The MAP is either “attached” or “loose.” Micropositioning actuators provide fine positioning in the X and/or Y directions.

Abstract: An electronic imaging system for component to substrate alignment utilizes a single imager and a moveable reflector mounted together in an imager body. The imager body can move into and out of position between a pick-up head of a placement machine, rework machine or similar device, and a target substrate. The imager moves into position for performing alignment tasks. The moveable reflector moves to a first position to image a component held by the pick-up head and a second position to image the substrate. This may be accomplished by mounting the reflector for rotational movement. The imager then moves out of position to permit the pick-up head to perform its placement tasks once alignment is determined. The component can thus be imaged while the pick-up head carries the component from the pick-up position to the place position.

Abstract: A method and apparatus for component to substrate assembly permits in situ reflow of a flip chip (or other suitable component) in a manner which promotes proper settling of the component as solder begins to flow at the contact points between the component and the substrate. The pick-up head of a placement machine heats the component while applying up to several grams of downward force that serves to level the component. The downward force (downforce) is accurately measured using an electronic force sensor such as a strain gauge, force sensitive resistor, or any other suitable type of force sensor. The initiation of solder reflow can be detected with the pick-up head by sensing a decrease in the downforce.