Accurate relative alignment and epoxy-free attachment of optical elements
AssigneeNorthrop Grumman Corporation
InventorNicholas Bosco
Life of this patent
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Abstract
A method for accurately positioning and aligning multiple components, such as optical components, on a common substrate. A separate pattern of solder bumps is formed on the substrate for each of the components to be mounted. Congruent patterns of solder pads are formed on the respective components. The components are placed and positioned on the substrate as accurately as possible using manual or other means, and then the assembly is heated sufficiently to reflow the solder bumps beneath each component. During reflow, the solder pads on the components move into accurate alignment with the solder bumps on the substrate. On cooling, the components are attached and remain in the automatically aligned configuration.
Claims21
A method for alignment and attachment of multiple components on a common substrate, comprising:
- applying, to a surface of each component to be attached to the substrate, a plurality of metal pads, the plurality of pads being arranged in a selected pattern;
- applying, to a surface of the substrate, a plurality of patterns of solder bumps, each pattern of solder bumps being congruent with a corresponding pattern of metal pads on a component;
- placing each component on the substrate with the pattern of metal pads on the component in congruence with the corresponding pattern on the substrate;
- heating the substrate and the components, thereby reflowing the solder bumps;
- as a result of the reflowing of the solder bumps, automatically aligning each component on the substrate, wherein each component is allowed to move laterally and rotationally to align the corresponding patterns of solder bumps and metal pads;
- and
- allowing the substrate and the components to cool and the solder bumps to return to a solid state, accurately attaching the components to the substrate in their desired positions.
A method for alignment and attachment of multiple optical components on a common substrate, comprising:
- applying, to a glass surface of each optical component to be attached to the substrate, a plurality of metal pads, the plurality of pads being arranged in a selected pattern;
- applying, to a surface of the substrate, a plurality of patterns of solder bumps, each pattern of solder bumps being congruent with a corresponding pattern of metal pads on a component;
- placing each optical component on the substrate with the pattern of metal pads on the component as closely as possible in congruence with the corresponding pattern on the substrate;
- heating the substrate and the optical components, thereby reflowing the solder bumps;
- as a result of the reflowing of the solder bumps, automatically aligning each optical component on the substrate, wherein each optical component is allowed to move laterally and rotationally to align the corresponding patterns of solder bumps and metal pads;
- and
- allowing the substrate and the components to cool and the solder bumps to return to a solid state, accurately attaching the components to the substrate in their desired positions.
Dependencies are inferred from the claim text.