Semiconductor device including plateless package fabrication method

• US 4,631,805 A
• Filed: 07/22/1985
• Issued: 12/30/1986
• Est. Priority Date: 03/23/1981
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Olsen, Dennis R., Spanjer, Keith G.
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): QUACH, TUAN N
• Application Number:
  US06/757,584
• Time in Patent Office: 526 Days
• Field of Search: 29/588, 29/589, 29/590, 29/591, 228/121, 228/122, 228/123, 228/208, 357/67, 357/70, 357/71
• US Class Current: 438/123
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05666 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/29111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45014 Ribbon connectors, e.g. rectangular cross-section
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/4823 connecting the wire to a pin of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/48647 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48666 Titanium (Ti) as principal constituent
• CPC Class Codes: H01L 2224/48747 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48766 Titanium (Ti) as principal constituent
• CPC Class Codes: H01L 2224/48847 : Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48866 : Titanium (Ti) as principal constituent
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/83101 : as prepeg comprising a layer connector, e.g. provided in an insulating plate member
• CPC Class Codes: H01L 2224/83191 : wherein the layer connectors are disposed only on the semiconductor or solid-state body
• 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 2224/85099 : Ambient temperature
• CPC Class Codes: H01L 2224/85205 : Ultrasonic bonding
• CPC Class Codes: H01L 23/045 : the other leads having an insulating passage through the base
• CPC Class Codes: H01L 23/3107 : the device being completely enclosed
• CPC Class Codes: H01L 23/4924 : characterised by the materials
• CPC Class Codes: H01L 23/49562 : for devices being provided for in H01L29/00
• 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 24/45 : of an individual wire connector
• 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 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01051 : Antimony [Sb]
• CPC Class Codes: H01L 2924/01072 : Hafnium [Hf]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• 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 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/0133 : Ternary Alloys
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/1305 : Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/20102 : Temperature range 0 C=<T<60 C, 273.15 K =<T< 333.15K
• CPC Class Codes: H01L 2924/206 : Length ranges
• CPC Class Codes: H01L 2924/2075 : larger or equal to 1 micron less than 10 microns
• CPC Class Codes: H01L 2924/20752 : larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/20753 : larger or equal to 30 microns less than 40 microns
• CPC Class Codes: H01L 2924/20754 : larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/20755 : larger or equal to 50 microns less than 60 microns
• CPC Class Codes: H01L 2924/20756 : larger or equal to 60 microns less than 70 microns
• CPC Class Codes: H01L 2924/20757 : larger or equal to 70 microns less than 80 microns
• CPC Class Codes: H01L 2924/20758 : larger or equal to 80 microns less than 90 microns
• CPC Class Codes: H01L 2924/20759 : larger or equal to 90 microns less than 100 microns
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device

Abstract

A semiconductor device including a metallurgically compatible unplated package is provided. The package includes a plateless copper alloy die mount area to which a semiconductor die is attached. The semiconductor die is metallized on its mounting surface to provide electrical contact. A metallic solder which is compatible with both the copper alloy and the die metallization joins the die to the die mount area. The package further includes a plateless copper alloy lead portion which is physically joined to the die mount area. The top surface of the semiconductor die is provided with a patterned metallization making electrical contact to selected portions of the die. Electrical contact is made between the top surface die metallization and the lead portion of the package by ultrasonically bonded copper ribbon. The die and interconnecting ribbon is then enclosed by an epoxy encapsulant or by a welded metal cover.

Claims

1. A method for packaging a semiconductor device which comprises the steps of:

providing a semiconductor die;

providing a plateless copper alloy package bonding portion;

providing a plateless copper alloy package lead portion;

said bonding portion positioned with respect to said lead portion;

applying a metal layer to a first side of said semiconductor die;

bonding said metal layer to said bonding portion using a metal solder metallurgically compatible with said copper alloy and said metal layer;

applying a patterned metal to a second side of said semiconductor die;

ultrasonically bonding copper ribbon between said patterned metal and said package lead portion; and

encapsulating said semiconductor die.

2. The method of claim 1 further comprising the step of applying a die coat over said semiconductor die.

3. The method of claim 2 wherein said die coat comprises a polyimide.

4. The method of claim 1 wherein said step of encapsulating comprises injection molding.

5. A method for packaging a semiconductor device which comprises the steps of:

providing a semiconductor die and a copper alloy package having a plateless bonding portion and a plateless lead portion;

forming a first metallization on a first surface of said semiconductor die;

forming a second patterned metallization on a second surface of said semiconductor die;

soldering said semiconductor die to said plateless bonding portion with a solder which is metallurgically compatible with both said first metallization and said copper alloy;

ultrasonically bonding electrical conductors between said plateless lead portion and said second patterned metallization; and

encapsulating said semiconductor die, said electrical conductors and interior portions of said package in a protective enclosure.

6. The method of claim 5 wherein said step of forming a first metallization comprises the steps of sequentially applying to said first surface layers of titanium, nickel, and silver.

7. The method of claim 6 wherein said step of soldering comprises the step of melting a solder comprising tin, silver, and antimony in contact with said first metallization and said plateless bonding portion.

8. The method of claim 7 wherein said melting is done in a reducing ambient.

9. The method of claim 5 wherein said step of forming a first metallization comprises the steps of sequentially applying to said first surface layers of chromium and silver.

10. The method of claim 5 wherein said step of forming a patterned metallization comprises forming a copper surface layer.

11. The method of claim 10 wherein said step of forming a second patterned metallization comprises forming a contact layer making electrical contact to portions of said semiconductor die, a barrier layer, and a surface layer.

12. The method of claim 11 wherein said contact layer comprises titanium.

13. The method of claim 11 wherein said barrier layer comprises nickel.

14. The method of claim 10 wherein said step of forming a second patterned metallization comprises forming sequential layers of titanium, nickel, and copper.

15. The method of claim 10 wherein said step of forming a second patterned metallization comprises forming sequential layers of aluminum, titanium tungsten, and copper.

16. The method of claim 10 wherein said step of ultrasonically bonding comprises bonding a copper conductor between said plateless lead portion and said copper surface layer.

17. The method of claim 16 wherein said copper conductor comprises a copper ribbon.

18. The method of claim 5 wherein said step of encapsulating comprises coating said semiconductor die with a die coat.

19. The method of claim 18 wherein said die coat comprises a polyimide.

20. The method of claim 18 wherein said step of encapsulating comprises forming a plastic housing.

21. The method of claim 5 wherein said step of encapsulating comprises forming a plastic housing.

22. The method of claim 5 wherein said step of encapsulating comprises welding a cover member to said plateless bonding portion.