Method and apparatus for making encapsulated electronic circuit devices

• US 4,872,825 A
• Filed: 07/13/1987
• Issued: 10/10/1989
• Est. Priority Date: 05/23/1984
• Status: Expired due to Fees

• Current Assignee: Internal Revenue Service (Government of the United States of America), Inovent
• Original Assignee: Milton I. Ross
• Inventors: Ross, Milton I.
• Primary Examiner(s): Hoag, Willard
• Application Number:
  US07/072,510
• Time in Patent Office: 820 Days
• Field of Search: 425/116, 425/117, 425/122, 425/126.1, 425/127, 425/397, 425/346, 264/272.14, 264/272.17, 264/257, 264/258, 249/83, 249/85, 249/78, 249/79, 249/81
• US Class Current: 425/117
• CPC Class Codes: B29C 43/18 incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles B29C43/206 takes precedence
• CPC Class Codes: B29C 43/203 Making multilayered articles
• CPC Class Codes: H01L 21/50 Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 23/057 the leads being parallel to the base
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01039 Yttrium [Y]
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding

Abstract

Encapsulated electronic circuit devices as well as methods and molding apparatus for making same are disclosed. For example, an integrated circuit "die" (or "chip") and the lead frame (or frames) to which it is physically affixed and electrically connected are positioned in a mold between stacks of resin impregnated fibrous layers of predetermined shape and size. The layers are then compressed under heat and pressure causing them to fuse together about the die and its lead frame(s). This forms a laminated protective sealed encapsulation for the die and adjacent portions of the lead frame(s), without causing undue damage to the delicate lead wires electrically connecting the die to the lead frame. Such multiple laminated layers of resin and fibers, which preferably include woven glass cloth or similar materials, provide a strong, resilient integrated circuit chip "carrier" (of either the "leaded" or "leadless" variety) which may conveniently include multiple lead frames, heat conductive members, strengthening members and the like. A window may be provided in the layers to provide a space for the chip. Also, metallic layers may also be provided to enhance performance of the package.

Claims

1. A molding apparatus for producing an encapsulated electronic circuit device, said mold comprising:

an upper press member disposed above a lower press member, said upper and lower press members being relatively movable toward each other;

heated molding means disposed between said upper and lower press members and having at a parting plane thereof ledge means for holding at least one planar conductive lead frame therein and having upper and lower mold cavity means, and

means for placing plural sheets of prepreg, a planar conductive lead frame, and plural sheets of prepreg, in that order, between said upper and lower mold cavity means.

2. A molding apparatus as in claim 1 wherein said molding means includes slot means for inserting said sheets of prepreg therethrough into at least one of said upper and lower mold cavity means after said lead frame is held therein.

3. A molding apparatus as in claim 1 wherein said molding means includes an upper portion and a lower portion each having a stepped end face for supporting between said upper portion and said lower portion the vertically spaced and horizontally offset leads of plural conductive lead frames.

4. A mold for use in producing an encapsulated electronic circuit device having plural planar arrays of conductive beam leads extending therefrom, said mold comprising:

an upper mold member having an end face which is stepped about at least a part of its periphery; and

a lower mold member having an end face which is stepped about at least part of its periphery and mated with that of said upper mold member, said stepped end faces being spaced and dimensioned to simultaneously support plural planar arrays of conductive beam leads extending from an electronic circuit device during encapsulation thereof in said mold; and

means for placing plural sheets of prepreg, a planar conductive lead frame, and plural sheets of prepreg, in that order, between said upper and lower mold members.

5. An apparatus for encapsulating an electronic circuit device comprising:

an upper mold defining an upper mold cavity;

a lower mold defining a lower mold cavity;

first holding means for holding fiber resin prepregs for deposition in said lower mold cavity;

first transporting means for transporting prepregs from said first holding means to a point intermediate said upper mold cavity and said lower mold cavity for placement in said lower mold cavity;

means for conveying electronic circuit devices to be encapsulated to a point intermediate said upper mold cavity and said lower mold cavity;

second holding means for holding fiber resin prepregs for placement on top of an electronic circuit device disposed intermediate said upper and lower mold cavities; and

second transporting means for transporting prepregs from said second holding means to a point intermediate said upper mold cavity and said lower mold cavity for placement on an electronic circuit device to be encapsulated.

6. An apparatus as in claim 5, wherein said first transporting means and said second transporting means each comprise a plurality of arm elements coupled for movement relative to said first and second holding means and said upper and lower mold cavities and having at a second end thereof auction cup means for coupling said arms to said fiber resin prepregs to thereby transport said fiber resin prepregs from said first and second holding means to said mold cavities.

7. An apparatus as in claim 5, further comprising means for removing an encapsulated circuit device from said upper and lower mold cavities after encapsulation therein.

8. An apparatus as in claim 5, further comprising means for heating said fiber resin prepregs during transport from said first and second holding means, respectively to said point between said upper molding cavity and lower mold cavity.

9. An apparatus as in claim 8, wherein said means for heating comprise hot air blowers mounted intermediate said first holding means and said lower mold cavity and said second holding means and said lower mold cavity.

10. An apparatus as in claim 5, further comprising first and second rollers mounted for rotation on opposite ends of said molding cavities and a non-stick film material mounted to said rollers so as to extend between said upper mold cavity and said lower mold cavity.

11. An apparatus as in claim 10, wherein there are two sets of rollers to thereby provide two sheets of non-stick film extending between said upper and lower mold cavities to thereby prevent sticking of said encapsulated electronic device to said mold cavities.

12. An apparatus as in claim 5, wherein said first holding means and said second holding means each comprise a plurality of bins, each said bin holding a plurality of fiber resin prepregs.

13. An apparatus as in claim 12, wherein there are six bins for said first holding means and six bins for said second holding means.

14. An apparatus as in claim 12 further comprising hot air blowers heating said fiber resin prepregs during transport disposed intermediate each said plurality of bins and said lower mold cavity.