Layer thickness control for stereolithography utilizing variable liquid elevation and laser focal length
First Claim
1. An apparatus for providing at least an underfilled encapsulant structure for a flip-chip configured semiconductor device having a plurality of external conductive elements projecting from an active surface thereof, the apparatus comprising:
- a reservoir;
a platform disposed in the reservoir and having an upper surface for supporting at least one semiconductor die thereon;
a drive assembly operably configured for tilting the platform to at least one selected acute angle to the horizontal within the reservoir;
a liquid displacement structure for selectively varying a surface level of a curable liquid material contained in the reservoir; and
a source of electromagnetic radiation configured to generate, focus and traverse a substantially vertical beam of electromagnetic radiation over the platform.
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Abstract
An apparatus and method for controlling the surface level of a liquid residing within a relatively vertically stationary workpiece support platform disposed within a reservoir for use in stereolithographic processes wherein a layered object or structure is formed by selectively curing portions of the liquid to at least a semisolid state in multiple, at least partially superimposed layers. Providing precise control of liquid depth over the vertically stationary platform as well as focusing of a laser beam for curing the liquid at the varying surface levels thereof relative to the vertically stationary platform is effected using a laser range finder system controlled by a computer used to control the stereolithographic process in a closed loop fashion.
90 Citations
10 Claims
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1. An apparatus for providing at least an underfilled encapsulant structure for a flip-chip configured semiconductor device having a plurality of external conductive elements projecting from an active surface thereof, the apparatus comprising:
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a reservoir; a platform disposed in the reservoir and having an upper surface for supporting at least one semiconductor die thereon; a drive assembly operably configured for tilting the platform to at least one selected acute angle to the horizontal within the reservoir; a liquid displacement structure for selectively varying a surface level of a curable liquid material contained in the reservoir; and a source of electromagnetic radiation configured to generate, focus and traverse a substantially vertical beam of electromagnetic radiation over the platform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification