Semiconductor packages having light-sensitive chips

• US 6,583,444 B2
• Filed: 02/18/1998
• Issued: 06/24/2003
• Est. Priority Date: 02/18/1997
• Status: Expired due to Term

• Current Assignee: Tessera, Inc. (Adeia Inc.)
• Original Assignee: Tessera, Inc. (Adeia Inc.)
• Inventors: Fjelstad, Joseph
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): Chambliss, Alonzo
• Application Number:
  US09/025,558
• Publication Number:
  US 20020001869A1
• Time in Patent Office: 1,952 Days
• Field of Search: 257/778, 257/779, 257/780, 257/784, 257/787, 257/788, 257/684, 257/81, 257/82, 257/88, 257/99, 257/100, 257/723, 257/724, 257/730, 257/431, 257/432, 257/433, 257/434, 438/113, 438/114
• US Class Current: 257/82
• CPC Class Codes: H01L 21/4832 Etching a temporary substrate after encapsulation process to form leads
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 21/561 Batch processing
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 2221/68377 with parts of the auxiliary support remaining in the finished device
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48228 the bond pad being disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/4824 Connecting between the body and an opposite side of the item with respect to the body
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/48475 connected to auxiliary connecting means on the bonding areas, e.g. pre-ball, wedge-on-ball, ball-on-ball
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/85001 involving a temporary auxiliary member not forming part of the bonding apparatus, e.g. removable or sacrificial coating, film or substrate
• CPC Class Codes: H01L 2224/85051 Forming additional members, e.g. for "wedge-on-ball", "ball-on-wedge", "ball-on-ball" connections
• CPC Class Codes: H01L 2224/92 : Specific sequence of method steps
• CPC Class Codes: H01L 2224/92247 : the second connecting process involving a wire connector
• CPC Class Codes: H01L 2224/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01009 : Fluorine [F]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/18165 : of a wire bonded chip
• CPC Class Codes: H01L 31/0203 : Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80

Abstract

A method of making a microelectronic package includes providing a sacrificial layer having a first surface and providing an optoelectronic element having a front face including one or more contacts and a rear surface and securing the rear surface of the optoelectronic element over the first surface of the sacrificial layer. The one or more contacts are then electrically interconnected with one or more conductive pads on the sacrificial layer and a curable and at least partially transparent encapsulant is provided over the first surface of the sacrificial layer so as to encapsulate the optoelectronic element and the conductive pads. The encapsulant is then cured the sacrificial layer is at least partially removed so as to leave said one or more conductive pads on a bottom surface of the encapsulant, the bottom surface of the encapsulant defining the bottom of the package. The optoelectronic element may include a light sensitive chip such as an ultraviolet-erasable programmable read-only memory (UV EPROM) or a light emitting chip, such as a light emitting diode (LED).

Claims

1. A microelectronic package comprising:

an electrically conductive base having a cavity formed in a top surface thereof;

a conductive pad adjacent said conductive base;

an optoelectronic element disposed in said cavity, said optoelectronic element having a front face including a first contact and a rear surface including a second contact, said second contact being electrically connected to said conductive base by a conductive layer overlying said cavity, wherein said conductive layer aids in reflecting light emitted from the optoelectronic component;

a flexible lead having a first end connected to said first contact and a second end connected to said conductive pad;

an at least partially transparent encapsulant covering said optoelectronic element, said base, said lead and said conductive pad, said conductive base and said conductive pad being exposed on a bottom surface of said encapsulant, the bottom surface of said encapsulant defining the bottom of said package.

2. A package as claimed in claim 1, said cavity including a bottom and side walls extending therefrom and said optoelectronic element having an optical area for emitting light, wherein the side walls of said cavity reflect light transmitted to or from said optical area.

3. The package as claimed in claim 1, said package further comprising an at least partially transparent lid over a top surface of said encapsulant and overlying the front face of said optoelectronic element.

4. The package as claimed in claim 1, wherein said lid includes a material selected from the group consisting of glass, quartz, and rigid polymeric materials.

5. The package as claimed in claim 3, wherein said lid includes a lens for focusing light.

6. The package as claimed in claim 1, wherein said package includes two or more optoelectronic elements.