Light-emitting unit and method for producing same as well as lead frame used for producing light-emitting unit

• US 7,317,181 B2
• Filed: 08/22/2005
• Issued: 01/08/2008
• Est. Priority Date: 12/07/2001
• Status: Expired due to Fees

• Current Assignee: Hitachi Cable Limited (Proterial Ltd.), Stanley Electric Company Limited
• Original Assignee: Hitachi Cable Limited (Proterial Ltd.), Stanley Electric Company Limited
• Inventors: Saito, Tetsuya, Morikawa, Toshiaki, Otaka, Atsushi, Aoki, Dai, Abe, Tomoaki, Murakami, Gen
• Primary Examiner(s): Epps; Georgia
• Assistant Examiner(s): Lee; Patrick J.
• Application Number:
  US11/208,961
• Publication Number:
  US 20060054912A1
• Time in Patent Office: 869 Days
• Field of Search: 250/239, 250/214.1, 257 79-103, 438106-127
• US Class Current: 250/214.1
• 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 2224/45015 being circular
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 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 2224/73265 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 2224/85203 Thermocompression bonding
• CPC Class Codes: H01L 2224/85207 Thermosonic bonding
• 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 24/45 of an individual wire connector
• 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 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• 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 2924/01078 : Platinum [Pt]
• 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 2924/12042 : LASER
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/20751 : larger or equal to 10 microns less than 20 microns
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• CPC Class Codes: H01L 33/60 : Reflective 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

Abstract

A surface mount type light-emitting unit includes a light-emitting device. A first lead is connected electrically to a first electrode of the light-emitting device. A second lead is connected electrically to a second electrodc of the light-emitting device. A clear insulator seals the light-emitting device, a section connecting the first electrode to the first lead and a section connecting the second electrode to the second lead. An end of the first lead, forming a reflecting section, is molded into a cup-shaped portion having a flat bottom. The light-emitting device is bonded to the flat bottom. A surface of the reflecting section opposed to the flat bottom is exposed to a surface of thc insulator.

Claims

1. A method for producing a light-emitting unit of a surface mount type including:

a lead frame forming step for opening a tape-like conductive plate into a predetermined profile to form a lead frame involving a first lead and a second lead;

a light-emitting device mounting step for bonding a light-emitting device to a predetermined position in the lead frame formed in said lead frame forming step to connect electrically a first electrode of said light-emitting device with said first lead as well a to connect electrically a second electrode of said light-emitting device with said second lead;

a sealing step for sealing said light-emitting device, wherein a connecting section of said first electrode of the light-emitting device and said first lead, and a connecting section of said second electrode of the light-emitting device and said second lead are sealed with a clear insulator after conducting said light-emitting device mounting step, and wherein a surface of said first lead is exposed to a surface of said insulator, said surface of said first lead exposed to said insulator is opposite a surface of the first lead onto which said light emitting device is bound; and

a fragmenting step for cutting off portions of said first lead and said second lead, which have been protruded from said insulator, to fragment them;

comprising said lad frame forming step involving a step for opening and conductive plan to define said first lead and said second lead, and

a step for molding an extreme end of said first lead to form a cup-shaped reflecting section having a flat bottom;

said light-emitting device mounting step involving a step for bonding said light-emitting device to the bottom inside of said reflecting section of said first lead;

wherein;

the step for forming said first lead and said second lead includes the step of forming the first lead and the second lead to have protrusions in a region to be sealed with said insulator, and

said lead frame forming step includes a step for folding said protrusions in a direction towards the surface on to which said light-emitting device is to be bonded and forming the first lead and second lead protrusions so the protrusions are separate from said reflecting section.

2. A method for producing a light-emitting unit as claimed in claim 1, wherein:

said fragmenting step includes a step for cutting off said first lead and said second lead so as to protrude from said insulator by a predetermined length, respectively; and

a step for folding portions of said first lead and said second lead, which have been protruded from said insulator, to be in contact with said insulator.

3. A method for producing a light-emitting unit of a surface mount type including:

a light-emitting device mounting step for bonding a light-emitting device to a predetermined position in the lead frame formed in said lead frame forming step to connect electrically a first electrode of said light-emitting device with said first lead as well as to connect electrically a second electrode of said light-emitting device with said second lead;

a sealing step for sealing said light-emitting device, wherein a connectin section cf said first electrode of the light-emitting device and said first lead, and a connecting section of said second electrode of the light-emitting device and said second lead are sealed with a clear insulator after conducting said light-emitting device mounting step, and wherein a surface of said first lead is exposed to a surface of said insulator, said surface of said first lead exposed to said insulator is opposite a surface of the first lead onto which said light emitting device is bonded; and

a fragmenting step for cutting off portions of said first lead and said second lead, which have been protruded from said insulator, to fragment them;

comprising;

said lead frame forming step involving a step for opening said conductive plate to define said first lead and said second lead, and

a step for molding an extreme end of said first lead to form a cup-shaped reflecting section having a flat bottom; and

said light-emitting device mounting step involving a step for bonding said light-emitting device to the bottom inside of said reflecting section of said first lead;

wherein;

the step for forming said first lead and said second lead includes the step of forming the first lead and the second lead to have protrusions in a region to be sealed with said insulator and said lead frame forming step includes a step for folding said protrusions in a direction towards the surface on to which said light-emitting device is to be bonded;

the step for forming said reflecting section is implemented in such that a thickness of the bottom in said reflecting section is thinner than that of a region other than said reflecting section of the first lead and wherein said step for forming said first lead and said second lead includes forming said first lead and second lead protrusions so the protrusions are separate from said reflecting section.

4. A method for producing a light-emitting unit as claimed in claim 3, wherein:

the step for forming said first lead and said second lead is a step for forming the first lead and the second lead involving protrusions in a region to be sealed with said insulator, respectively; and

said lead frame forming step includes a step for folding said protrusions in a direction towards a surface onto which said light-emitting device is to be bonded, respectively.

5. A method for producing a light-emitting unit as claimed in claim 3, wherein:

said fragmenting step includes a step for cutting off said first lead and said second lead so as to protrude from said insulator by a predetermined length, respectively; and

a step for folding portions of said first lead and said second lead, which have been protruded from said insulator, to be in contact with said insulator.

6. A method for producing a light-emitting unit as claimed in claim 4, wherein:

said fragmenting step includes a step for cutting off said first lead and said second lead so as to protrude from said insulator by a predetermined length, respectively; and

a step for folding portions of said first lead and said second lead, which have been protruded from said insulator, to be in contact with said insulator.