Optical transmitter package assembly including lead frame having exposed flange with key

• US 5,808,325 A
• Filed: 06/28/1996
• Issued: 09/15/1998
• Est. Priority Date: 06/28/1996
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Webb, Brian A.
• Primary Examiner(s): Jackson, Jerome
• Assistant Examiner(s): Kelley, Nathan K.
• Application Number:
  US08/671,864
• Time in Patent Office: 809 Days
• Field of Search: 257/79, 257/80, 257/81, 257/98, 257/99, 257/100, 257/680, 257/666, 257/787
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01S 5/02234 Resin-filled housings; the housings being made of resin
• CPC Class Codes: H01S 5/0232 Lead-frames

Abstract

A package assembly (31) has a leadframe (10) including a locating flange (30), an optical transmitter (22) such as a laser diode mounted to the leadframe, and a package (32) enclosing both the optical transmitter and a portion of the leadframe so that the locating flange of the leadframe is disposed outside of the package. The locating flange is used as a reference datum to align the optical transmitter'"'"'s relative height and lateral position during manufacture. Also, the locating flange is used as a reference datum in mating the package assembly to other, standard optical components when mounting to other components in an optical end product.

Claims

1. A package assembly comprising:

a leadframe comprising a flag and at least three leads, wherein a first lead of said at least three leads is integral with said flag and said flag further includes a locating flange disposed around a periphery of said flag and having at least one key formed in said locating flange;

an optical transmitter mounted to said flag at a height and lateral alignment determined in response to said locating flange and said at least one key;

a package enclosing said optical transmitter and a portion of said leadframe so that said locating flange and said at least one key are disposed outside of said package; and

an optical element mounted to said package above said optical transmitter and optically coupled to said optical transmitter.

2. The package assembly of claim 1 wherein said package is a transparent plastic.

3. The package assembly of claim 1 wherein said at least three leads extend outward from said package and are substantially parallel.

4. The package assembly of claim 1 wherein said optical element is selected from the group consisting of a hologram and a lens.

5. The package assembly of claim 1 wherein said optical transmitter is a laser diode.

6. The package assembly of claim 5 wherein said laser diode is a vertical cavity surface emitting laser.

7. The package assembly of claim 1 wherein said leadframe has an elevated platform and said optical transmitter is mounted on said elevated platform.

8. The package assembly of claim 1 further comprising a pedestal mounted to said leadframe, wherein said optical transmitter is mounted on said pedestal.

9. The package assembly of claim 8 wherein said pedestal includes a stake that connects said pedestal to said leadframe.

10. The package assembly of claim 1, further comprising an optical receiver mounted to said leadframe.