Method of attaching conductive traces to an encapsulated semiconductor die using a removable transfer film

• US 5,200,362 A
• Filed: 09/09/1991
• Issued: 04/06/1993
• Est. Priority Date: 09/06/1989
• Status: Expired due to Term

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Sato, Takehi, Uchida, Sugio, McShane, Michael B., Lin, Paul T.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Graybill, David E.
• Application Number:
  US07/756,952
• Time in Patent Office: 575 Days
• Field of Search: 437/206, 437/211, 437/220, 437/207, 264/272.17, 29/841, 29/855
• US Class Current: 29/841
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• 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 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/73257 Bump and wire connectors
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 2224/97 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 23/49855 for flat-cards, e.g. credit cards cards per se G06K19/00
• CPC Class Codes: H01L 24/48 of an individual wire 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 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 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01076 : Osmium [Os]
• 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 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19105 : in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H05K 3/3431 : Leadless components
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.

Abstract

A semiconductor device and a method for its fabrication are disclosed. In a preferred embodiment, a pattern of conductive traces is formed on a film of transfer material. A semiconductor device die is interconnected to the pattern of conductive traces and a resin body is formed around the die, one side of the conductive traces, and the interconnecting means. The film of transfer material forms, at this stage of the process, one side of the package. The film of transfer material is then peeled from the pattern of conductive traces and the resin body to expose the other side of the pattern of conductive traces. Contact to the other side of the pattern provides electrical contact to the senmiconductor device die.

Claims

1. A process for fabricating a semiconductor device comprising the steps of:

providing a transfer film;

providing a pattern of conductive traces on said transfer film;

providing a semiconductor device die;

forming electrical interconnections between said pattern of conductive traces and said semiconductor device die;

providing a resin material on one side of said transfer film to encapsulate said semiconductor device die, said electrical interconnections, and a portion of said pattern of conductive traces; and

removing said transfer film to expose one side of said pattern of conductive traces.

2. The process of claim 1 further comprising the step of forming a layer of insulating material over portions of said one side and leaving contact areas of said pattern exposed.

3. The process of claim 1 further comprising the step of laminating said semiconductor device die and said resin material between two sheets of plastic material.

4. The process of claim 3 wherein said step of laminating leaves exposed a portion of said one side.

5. The process of claim 4 further comprising the step of plating contact metal onto said exposed portion.

6. The process of claim 1 wherein said step of forming a pattern of conductive traces comprises the steps of:

forming a continuous layer of conductive material on said transfer film; and

selectively etching said continuous layer to form said pattern of conductive traces.

7. The process of claim 6 wherein said step of forming a continuous layer comprises laminating a layer of conductive foil to said transfer film.

8. The process of claim 6 wherein said step of forming a continuous layer comprises evaporating a layer of metal onto said transfer film.