Self-aligning optical sensor package

• US 7,567,235 B2
• Filed: 12/12/2005
• Issued: 07/28/2009
• Est. Priority Date: 12/12/2005
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Spurlock, Brett A., Carlisle, Clinton B., Sanders, Steven
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US11/301,833
• Publication Number:
  US 20070131946A1
• Time in Patent Office: 1,324 Days
• Field of Search: 345/166, 257/680, 438/116
• US Class Current: 345/166
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/0312 for tracking the rotation of a spherical or circular member, e.g. optical rotary encoders used in mice or trackballs using a tracking ball or in mouse scroll wheels tracking relative movement in co-operation with a regularly or irregularly patterned surface, e.g. as in optical mice G06F3/0317; constructional details of scroll or thumb-wheels G06F3/0362; optical rotary encoders G01D5/3473
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/03549 Trackballs G06F3/03541 takes precedence

Abstract

One embodiment relates to an optical navigation device. The device includes a lead frame having reference features, a laser, a detector array, and an optical component having alignment features. The laser is attached to the lead frame and positioned in reference to the reference features of the lead frame. The detector array is attached to the lead frame and positioned in reference to the reference features of the lead frame. The optical component is coupled to the lead frame so that its alignment features register to the reference features of the lead frame. In this way, the molded optical component is passively aligned to the laser and the detector array. Other embodiments are also disclosed.

Claims

1. An optical navigation device comprising:

a lead frame having reference features;

a laser attached to the lead frame and positioned in reference to the reference features;

a detector array attached to the lead frame and positioned in reference to the reference features;

an optical component coupled to the lead frame and having alignment features registered to the reference features of the lead frame such that the optical component is passively aligned to the laser and the detector array; and

an optical aperture art between the lead frame and the optical component and having an emitter aperture configured to restrict a diameter of a beam of coherent light from the laser, the optical aperture part having reference features registered to the alignment features of the optical component and the reference features of the lead frame.

2. The optical navigation device of claim 1, wherein the optical component includes collimation optics for collimating light emitted by the laser.

3. The optical navigation device of claim 2, wherein the optical component further includes collection optics for collecting light onto the detector array.

4. The optical navigation device of claim 3, wherein the optical aperture part is between the collection optics and the detector array.

5. The optical navigation device of claim 4, wherein the optical aperture part is registered to a molding compound that covers at least a portion of the lead frame.

6. The optical navigation device of claim 5, wherein the optical component comprises said molding compound.

7. The optical navigation device of claim 1, wherein the optical aperture part includes a baffle that blocks a light path within the device between the laser and the detector array.

8. The optical navigation device of claim 1, wherein the reference features comprise holes in a substrate of the lead frame, and the alignment features comprise posts fitting into said holes.

9. The optical navigation device of claim 8, wherein the holes are formed by etching of the substrate of the lead frame.

10. An optical sensor comprising:

a lead frame having reference features;

an optical detector which is positioned in reference to the reference features on the lead frame;

an optical component for collecting light onto the detector,

wherein the optical component is passively aligned to the detector by mechanical registration of alignment features of the optical component with the reference features of the lead frame; and

an optical aperture art between the lead frame and the optical component and having an emitter aperture configured to restrict a diameter of a beam of coherent light, the optical aperture part having reference features registered to the alignment features of the optical component and the reference features of the lead frame.

11. The optical sensor of claim 10, wherein the optical aperture part is aligned to the detector by registration of the reference features of the optical aperture part with the alignment features of the optical component.

12. The optical sensor of claim 10, wherein the reference features comprise holes, and the alignment features comprise posts fitting into said holes.

13. The optical sensor of claim 12, wherein the holes are formed by etching.

14. An apparatus to passively align an external lens to one or more packaged die, the apparatus comprising:

a lead frame;

a reference feature on the lead frame;

the external lens;

an alignment feature of the external lens, where the alignment feature mechanically engages and passively registers to the reference feature of the lead frame; and

a die mounted to the lead frame at a position precisely referenced to the reference feature of the lead frame.

15. The apparatus of claim 14, wherein the reference features comprise holes, and the alignment features comprise posts fitting into said holes.

16. The apparatus of claim 15, wherein the holes are formed by etching.

17. A method of passively aligning an external lens to a light source and a detector array, the method comprising:

providing a lead frame;

etching reference features in the lead frame;

attaching the light source to the lead frame at a position in reference to the reference features of the lead frame;

attaching the detector array to the lead frame at a position in reference to the reference features of the lead frame;

providing a molded optical component including the external lens and having alignment features; and

mechanically coupling the molded optical component to the lead frame such that the alignment features of the molded optical component mechanically engage and register with the reference features of the lead frame.

18. The method of claim 17, further comprising:

providing an aperture part having reference features; and

coupling the aperture part to the lead frame in such a way that the alignment features of the molded optical component mechanically and register with the reference features of the aperture part.