Proximity sensor having light-blocking structure in leadframe and method of making same

Patent metadata

Field	Value
Publication number	US-9608158-B2
Application number	US-201615336566-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Oct 1, 2012
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A method for fabricating a semiconductor proximity sensor includes providing a flat leadframe with a first and a second surface. The second surface is solderable. The leadframe includes a first and a second pad, a plurality of leads, and fingers framing the first pad. The fingers are spaced from the first pad by a gap which is filled with a clear molding compound. A light-emitting diode (LED) chip is assembled on the first pad and encapsulated by a first volume of the clear compound. The first volume outlined as a first lens. A sensor chip is assembled on the second pad and encapsulated by a second volume of the clear compound. The second volume outlined as a second lens. Opaque molding compound fills the space between the first and second volumes of clear compound and forms walls rising from the frame of fingers to create an enclosed cavity for the LED. The pads, leads, and fingers connected to a board using a layer of solder for attaching the proximity sensor.

First claim

We claim:

1. A semiconductor proximity sensor comprising:
a flat leadframe having a first and a second surface, the second surface being solderable, the leadframe including a first and a second pad, a plurality of leads, and fingers framing the first pad, the fingers spaced from the first pad by a gap;
clear molding compound filling the gap;
a light-emitting diode (LED) chip assembled on the first pad and encapsulated by a first volume of the clear compound, the first volume outlined as a first lens;
a sensor chip assembled on the second pad and encapsulated by a second volume of the clear compound, the second volume outlined as a second lens;
opaque molding compound filling the space between the first and second volumes of clear compound and forming walls rising from the frame of fingers to create an enclosed cavity for the LED; and
a layer of solder on the second leadframe surface of the pads, leads, and fingers.

2. The proximity sensor of claim 1 wherein the fingers framing the first pad are designed to leave a gap between the finger tips for placing a lead.

3. The proximity sensor of claim 1 wherein the fingers framing the first pad are designed to encircle the first pad as well as the lead carrying the LED stitch bond.

Assignees

• Texas Instruments Inc

Inventors

• Tran Andy Quang
• Wright Lance

Classifications

• H10W74/10

  characterised by their shape or disposition · CPC title

• H10W90/00 Primary

  Package configurations · CPC title

• H01L31/101

  Electricity · mapped topic

• H01L31/02002

  Electricity · mapped topic

• H01L31/09

  Electricity · mapped topic