Surface acoustical wave flip chip

• US 6,448,635 B1
• Filed: 08/30/1999
• Issued: 09/10/2002
• Est. Priority Date: 08/30/1999
• Status: Expired due to Term

• Current Assignee: Amkor Technology Singapore Holding Pte., Ltd. (Amkor Technology Incorporated)
• Original Assignee: Amkor Technology Incorporated
• Inventors: Glenn, Thomas P.
• Primary Examiner(s): Abraham, Fetsum
• Application Number:
  US09/385,696
• Time in Patent Office: 1,107 Days
• Field of Search: 257/671-684, 257/777-786, 257/700, 257/730, 257/734
• US Class Current: 257/676
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/056 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 24/05 of an individual bonding area
• 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 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H03H 9/059 consisting of mounting pads or bumps

Abstract

A die mounting apparatus that includes: 1) a die including a bottom surface having an active region is located among the bottom surface and a first and second bond pads provided on the bottom surface outside of the active region; 2) a substrate including a top surface and protruding electrical contacts that are electrically coupled to the first and second bond pads; and 3) a first encapsulant circumscribing a periphery of the die, where the first encapsulant, the bottom surface of the die, and the top surface of the substrate define a free space. The first encapsulant extends inwards from the periphery of the die towards the active region but does not contact the active region. Advantageously, the first encapsulant forms a seal around the die to protect its active region from the environment. A further advantage is that the first encapsulant provides added security that bond pads of the die will remain in contact with contacts formed among the substrate even after distortion of the shape of the die.

Claims

1. A mounting for a surface acoustical wave (“

SAW”

) device comprising;

a SAW device including a first surface having an active region, a first conductive pad, and a second conductive pad, wherein said first and second conductive pads are located on said first surface and on opposite ends of said active region;

a substrate including a continuous first surface, said first surface having conductive contacts thereon;

a first conductive connection between said first conductive pad and a corresponding contact on said first surface of said substrate;

a second conductive connection between said second conductive pad and a corresponding contact on said first surface of said substrate; and

a first encapsulant contacting and circumscribing a periphery of said SAW device, wherein said first encapsulant, said first surface of said SAW device, and said continuous first surface of said substrate define a free space, and said first encapsulant extends inwards along said first surface of said SAW device from the periphery of said SAW device towards said active region but does not contact said active region or said first and second conductive connections.

2. The mounting of claim 1, wherein

said SAW device includes a second surface opposite said first surface, said second surface having a peripheral portion adjacent to the periphery of said SAW device and a central area within said peripheral portion and opposite said active region of said first surface; and

said first encapsulant contacts said peripheral portion of said second surface, but does not cover said central portion.

3. A mounting for a surface acoustical wave (“

SAW”

) device comprising;

a SAW device in a flip chip electrical connection with a substrate, said SAW device having a first surface with an active region juxtaposed with a first, continuous surface of said substrate; and

a hardened first encapsulant on the substrate and contacting and circumscribing a periphery of said SAW device, wherein said first encapsulant, said first surface, and said substrate define a free space adjacent said active region, said flip chip electrical connection includes electrical connections between the first surface and the substrate, with the active region being between the electrical connections, and said first encapsulant extends inward from said periphery between said first surface and said substrate without contacting said electrical connections.

4. The mounting of claim 3, wherein said SAW device includes a second surface opposite said first surface, and said first encapsulant covers a peripheral portion of said second surface without covering a central portion of the second surface.