LOC semiconductor assembled with room temperature adhesive

• US 20020090751A1
• Filed: 02/04/2002
• Published: 07/11/2002
• Est. Priority Date: 08/14/1997
• Status: Active Grant

• Current Assignee: Ford B. Grigg, Warren M. Farnworth
• Original Assignee: Ford B. Grigg, Warren M. Farnworth
• Inventors: Farnworth, Warren M., Grigg, Ford B.
• Granted Patent: US 6,534,342 B2
• Time in Patent Office: Days
• US Class Current: 438/106
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32014 the layer connector being smaller than the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/4824 Connecting between the body and an opposite side of the item with respect to the body
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/4826 Connecting between the body and an opposite side of the item with respect to the body
• 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 2224/73215 Layer and wire connectors
• CPC Class Codes: H01L 2224/743 Apparatus for manufacturing layer connectors
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/83101 as prepeg comprising a layer connector, e.g. provided in an insulating plate member
• CPC Class Codes: H01L 2224/83192 wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/92 Specific sequence of method steps
• CPC Class Codes: H01L 2224/92147 : the second connecting process involving a wire connector
• CPC Class Codes: H01L 2224/92247 : the second connecting process involving a wire connector
• CPC Class Codes: H01L 23/4951 : Chip-on-leads or leads-on-chip techniques, i.e. inner lead fingers being used as die pad
• CPC Class Codes: H01L 23/49513 : having bonding material between chip and die pad
• CPC Class Codes: H01L 24/27 : Manufacturing methods
• CPC Class Codes: H01L 24/28 : Structure, shape, material or disposition of the layer connectors prior to the connecting process
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/743 : Apparatus for manufacturing layer connectors
• CPC Class Codes: H01L 24/83 : using a layer connector
• 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 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/078 : Adhesive characteristics other than chemical
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: Y10T 428/24207 : with strand[s] or strand-portion[s] between layers [e.g., upholstery trim, etc.]

Abstract

A semiconductor device assembly has a lead frame and a semiconductor device configured to be attached to each other. An adhesive is applied at room temperature through a stencil to the lead frame. The semiconductor device is urged against the adhesive to effect the attachment between the semiconductor device and the lead frame. The adhesive preferably is from about 75 percent to about 95 percent isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent, respectively, of titanium oxide.

Claims

1. A method for attaching a semiconductor die having an active surface to a portion of a lead frame having a plurality of lead fingers thereon, at least one lead finger having an attaching surface, said method comprising:

selecting an adhesive from a group of adhesives comprising tacky and compliant polymer adhesives at room temperature, said polymer adhesive including a first material from a group that includes isobutyl acetal diphenol copolymer and a second material that is from a group including metal oxides;

applying said polymer adhesive in one of at least one line of polymer adhesive and a plurality of beads of polymer adhesive on one of at least a portion of said active surface of said semiconductor die and the attaching surface of at least one lead finger, said polymer adhesive at room temperature; and

urging said active surface of said semiconductor die with said attaching surface of said at least one lead finger of said plurality of lead fingers of said lead frame while at room temperature for attaching the attaching surface of said at least one lead finger of said plurality of lead fingers of said lead frame and said active surface of said semiconductor device.

2. The method of claim 1, wherein a portion of said polymer adhesive has a first copolymer material from a group of copolymers that includes isobutyl compounds.

3. The method of claim 1, wherein a first portion of said polymer adhesive is isobutyl acetal diphenol copolymer.

4. The method of claim 1, wherein said polymer adhesive includes a group of metal oxides that includes titanium dioxide.

5. The method of claim 4, wherein said polymer adhesive has from about 75 percent to about 95 percent by weight of isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent by weight, respectively, of titanium dioxide.

6. A method of attaching a semiconductor die to at least a portion of a lead frame, said method comprising:

providing a lead frame having at least one lead having at least one attaching surface thereon;

providing a semiconductor die having an active surface and having at least one bond pad thereon;

selecting an adhesive which includes a first material from a group that includes an isobutyl acetal diphenol copolymer and a second material that is from a group including titanium dioxide;

applying said polymer adhesive in one of at least one line of adhesive and a plurality of beads of adhesive on at least a portion of said active surface of said semiconductor die, said adhesive at room temperature; and

urging said active surface of said semiconductor die and said attaching surface of said lead frame together to attach said semiconductor die and said lead frame together connecting said attaching surface of said lead frame and said active surface of said semiconductor die having a portion of said at least one lead located adjacent said at least one bond pad on said active surface of said semiconductor die.

7. A method of attaching a portion of a semiconductor die to a portion of a lead frame for use in a semiconductor device assembly, said method comprising:

providing a lead frame having a plurality of lead fingers, each lead finger of said plurality of lead fingers having an attaching surface and an end portion;

providing a semiconductor die having an active surface and having a plurality of bond pads thereon;

selecting an adhesive that includes from about 75 percent to about 95 percent of isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent, respectively, of titanium dioxide;

applying said adhesive in one of a line of adhesive and a plurality of beads of adhesive to at least a portion of said active surface of said semiconductor die, said adhesive at room temperature; and

urging said active surface of said semiconductor die and said attaching surfaces of said plurality of lead fingers of said lead frame together at room temperature to attach at least a portion of said semiconductor die and said lead frame together connecting said attaching surfaces of said lead fingers of said plurality of lead fingers of said lead frame and said portions of active surface of said semiconductor die at least some lead fingers of said plurality of lead fingers having the end portion thereof located adjacent a bond pad of said plurality of bond pads of said semiconductor die.

8. A method of attaching at least a portion of a semiconductor die to a portion of a lead frame for use in a semiconductor device assembly, said method comprising:

providing a lead frame having at least one lead having at least one attaching surface;

providing a semiconductor device having an attaching surface and having at least one bond pad;

providing a stencil having a pattern therein;

selecting a polymer adhesive from a group that is tacky and compliant at room temperature for application to a substrate using a stencil;

applying said polymer adhesive in one of at least one line of adhesive and a plurality of beads of adhesive to a portion of said attaching surface of said semiconductor device through said stencil, said adhesive at room temperature;

positioning said at least one attaching surface of said lead frame and said attaching surface of said semiconductor device relative to each other; and

urging said attaching surface of said semiconductor device and said at least one attaching surface of said lead frame together to attach said semiconductor device and said lead frame together having a portion of said at least one lead of said lead frame located adjacent said at least one bond pad of said semiconductor die.

9. A method of attaching at least a portion of a semiconductor die to a portion of a lead frame for use in a semiconductor device assembly, said method comprising:

providing a lead frame having at least one lead having at least one attaching surface;

providing a semiconductor device having an attaching surface and having at least one bond pad;

providing a stencil having a pattern therein;

selecting an adhesive including a first material from a group that includes isobutyl acetal diphenol copolymer and a second material that is from a group that includes titanium dioxide;

applying said polymer adhesive in one of at least one line of adhesive and a plurality of beads of adhesive through said stencil to at least a portion of said attaching surface of said semiconductor device, said adhesive at room temperature;

positioning said at least one attaching surface of said lead frame and said attaching surface of said semiconductor device relative to each other; and

urging said attaching surface of said semiconductor device and said at least one attaching surface of said lead frame together at room temperature to attach said semiconductor device and said lead frame together having a portion of said at least one lead of said lead frame located adjacent said at least one bond pad of said semiconductor die.

10. A method of attaching at least a portion of a semiconductor die to a portion of a lead frame for use in a semiconductor device assembly, said method comprising:

providing a lead frame having at least one lead having at least one attaching surface;

providing a semiconductor device having an attaching surface and having at least one bond pad;

providing a stencil having a pattern therein;

selecting an adhesive including from about 75 percent to about 95 percent of isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent, respectively, of titanium dioxide;

applying said adhesive through said stencil in one of at least one line adhesive and a plurality of beads of adhesive to said attaching surface of said semiconductor device, said adhesive at room temperature;

positioning said lead frame and said semiconductor device relative to each other; and

urging said semiconductor device and said lead frame together to attach said semiconductor device and said lead frame using said adhesive having a portion of said at least one lead located adjacent said at least one bond pad of said semiconductor die.