Electronic device encapsulated directly on a substrate

• US 6,617,786 B1
• Filed: 04/04/2000
• Issued: 09/09/2003
• Est. Priority Date: 12/10/1996
• Status: Expired due to Term

• Current Assignee: ITT Manufacturing Enterprises LLC (ITT, Inc.)
• Original Assignee: ITT Industries (ITT, Inc.)
• Inventors: Centofante, Charles A.
• Primary Examiner(s): Day, Michael H.
• Assistant Examiner(s): HAYNES, MACK NELSON
• Application Number:
  US09/542,194
• Time in Patent Office: 1,253 Days
• Field of Search: 313/500, 313/506, 313/510, 313/511, 313/512, 313/513, 445/24, 264/255, 264/272.16, 264/272.17, 264/1.7, 340/762, 340/786, 361/1, 228/6.2, 250/577, 257/99, 257/433, 257/81-82, 257/88, 257/680-681, 257/787, 438/5, 438/123, 425/116
• US Class Current: 313/512
• CPC Class Codes: B29C 45/14311 using means for bonding the coating to the articles B29C45/14795 takes precedence
• CPC Class Codes: B29C 45/14655 connected to or mounted on a carrier, e.g. lead frame
• CPC Class Codes: B29C 45/2708 Gates B29C45/2703 takes precedence
• CPC Class Codes: B29C 70/74 Moulding material on a relatively small portion of the preformed part, e.g. outsert moulding B29C70/845 takes precedence
• CPC Class Codes: G09F 9/3023 Segmented electronic displays
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: H01L 21/565 Moulds
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence

Abstract

A method and apparatus for encapsulating one or more small electronic devices, including for example light-emitting diodes, mounted directly on a substrate by providing a three-dimensional formation on the substrate adjacent to the device and injection molding a thermoplastic encapsulating material to cover the device and extend over the three-dimensional formation on the substrate and wherein the encapsulating material mechanically bonds to the three-dimensional formation. A gate plate for use in injection molding a thermoplastic encapsulating material over a small electronic device mounted directly on a substrate including a cavity formed to enclose the device, and a short gate formed entirely within the gate plate having an input for receiving an encapsulating material and an output communicating with the cavity. One or more encapsulated electrical devices mounted directly on a substrate, including for example, an LED or an array of LEDs, wherein the device is fully and individually encapsulated by an encapsulating material which is injection molded onto and mechanically bonded to the substrate.

Claims

1. An electronic device, comprising:

a printed circuit board; and

a plurality of encapsulated light emitting devices, each of the light emitting devices having been separately formed and mounted directly on the printed circuit board, wherein each of the light emitting devices consists of a single light emitting element and is separately and fully encapsulated by an encapsulating material molded onto and mechanically bonded to an area of the printed circuit board local to each individual light emitting device, and wherein the encapsulating material is a thermoplastic resin covering less than the entire surface of the printed circuit board and encapsulating each individual light emitting device and all of its electrical contacts.

2. The device of claim 1, wherein each of the light emitting devices is a light emitting diode.

3. The device of claim 1, further comprising:

a three-dimensional formation extending above a surface of the printed circuit board and disposed adjacent to at least one of the light emitting devices, wherein the encapsulating material extends over the three-dimensional formation and forms the mechanical bond to the printed circuit board at the three-dimensional formation.

4. The device of claim 1, further comprising a hole through the printed circuit board adjacent to at least one of the light emitting devices, wherein the encapsulating material fills the hole and forms the mechanical bond to the printed circuit board at the hole.

5. The device of claim 1, further comprising a recess extending below a surface of the printed circuit board and disposed adjacent to at least one of the light emitting devices, wherein the encapsulating material fills the recess and forms the mechanical bond to the printed circuit board at the recess.

6. An electronic device, comprising:

a printed circuit board; and

a plurality of encapsulated light emitting devices, each of the light emitting devices having been separately formed and mounted directly on the printed circuit board, wherein each of the light emitting devices consists of a single light emitting diode and is separately and fully encapsulated by an encapsulating material molded onto and mechanically bonded to an area of the printed circuit board local to each individual light emitting device, and wherein the encapsulating material is a thermoplastic resin covering less than the entire surface of the printed circuit board and encapsulating each individual light emitting device and all of its electrical contacts.