Substrate-less stackable package with wire-bond interconnect

• US 9,953,914 B2
• Filed: 02/11/2016
• Issued: 04/24/2018
• Est. Priority Date: 05/22/2012
• Status: Active Grant

• Current Assignee: Invensas Corporation
• Original Assignee: Invensas Corporation
• Inventors: Mohammed, Ilyas
• Primary Examiner(s): ARMAND, MARC ANTHONY
• Application Number:
  US15/042,034
• Publication Number:
  US 20160163639A1
• Time in Patent Office: 803 Days
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76892 modifying the pattern
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45139 Silver (Ag) 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 2224/45155 Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/45565 Single coating layer
• CPC Class Codes: H01L 2224/45624 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45655 Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/45664 Palladium (Pd) as principal constituent
• CPC Class Codes: H01L 2224/45669 Platinum (Pt) as principal constituent
• CPC Class Codes: H01L 2224/4569 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/48 : of an individual wire connector
• CPC Class Codes: H01L 2224/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 2224/73267 : Layer and HDI connectors
• CPC Class Codes: H01L 2225/06524 : Electrical connections formed on device or on substrate, e.g. a deposited or grown layer
• CPC Class Codes: H01L 2225/06548 : Conductive via connections through the substrate, container, or encapsulation
• CPC Class Codes: H01L 2225/06558 : the devices having passive surfaces facing each other, i.e. in a back-to-back arrangement
• CPC Class Codes: H01L 2225/1035 : the device being entirely enclosed by the support, e.g. high-density interconnect [HDI]
• CPC Class Codes: H01L 2225/1052 : Wire or wire-like electrical connections
• CPC Class Codes: H01L 2225/1058 : Bump or bump-like electrical connections, e.g. balls, pillars, posts
• CPC Class Codes: H01L 23/5226 : Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/5389 : the chips being integrally enclosed by the interconnect and support structures
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• CPC Class Codes: H01L 24/18 : High density interconnect [HDI] connectors; Manufacturing methods related thereto interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 24/19 : Manufacturing methods of high density interconnect preforms
• CPC Class Codes: H01L 24/20 : Structure, shape, material or disposition of high density interconnect preforms
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/46 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/96 : the devices being encapsulated in a common layer, e.g. neo-wafer or pseudo-wafer, said common layer being separable into individual assemblies after connecting
• CPC Class Codes: H01L 25/0657 : Stacked arrangements of devices
• CPC Class Codes: H01L 25/105 : the devices being of a type provided for in group H01L27/00
• 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 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/18162 : of a chip with build-up interconnect
• CPC Class Codes: H01L 2924/182 : Disposition
• CPC Class Codes: H01L 2924/191 : Disposition
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H05K 2201/10287 : Metal wires as connectors or conductors
• CPC Class Codes: H05K 2203/1461 : Applying or finishing the circuit pattern after another process, e.g. after filling of vias with conductive paste, after making printed resistors
• CPC Class Codes: H05K 3/4046 : using auxiliary conductive elements, e.g. metallic spheres, eyelets, pieces of wire

Abstract

A method for making a microelectronic unit includes forming a plurality of wire bonds on a first surface in the form of a conductive bonding surface of a structure comprising a patternable metallic element. The wire bonds are formed having bases joined to the first surface and end surfaces remote from the first surface. The wire bonds have edge surfaces extending between the bases and the end surfaces. The method also includes forming a dielectric encapsulation layer over a portion of the first surface of the conductive layer and over portions of the wire bonds such that unencapsulated portions of the wire bonds are defined by end surfaces or portions of the edge surfaces that are unconvered by the encapsulation layer. The metallic element is patterned to form first conductive elements beneath the wire bonds and insulated from one another by portions of the encapsulation layer.

Claims

1. A method for making a microelectronic unit, comprising:

forming a plurality of wire bonds on a conductive bonding surface of a metallic structure, the wire bonds having bases joined to the conductive bonding surface and end surfaces disposed away from the conductive bonding surface;

forming a dielectric layer over at least a portion of the conductive bonding surface and over first portions of the wire bonds, the first portions including the bases thereof having the dielectric layer formed thereover for covering the first portions of the wire bonds, second portions of the wire bonds including the end surfaces thereof not covered by the dielectric layer; and

patterning the metallic structure to form conductive elements separated from one another by the dielectric layer for having the bases of the wire bonds disposed on the conductive elements.

2. The method of claim 1, wherein at least some of the wire bonds are formed with the end surfaces thereof displaced in one or more lateral directions away from the bases thereof.

3. The method of claim 1, wherein:

the bases are in a first pattern having a first minimum pitch; and

the second portions of the wire bonds are in a second pattern having a second minimum pitch greater than the first minimum pitch.

4. The method of claim 1, wherein:

the bases are in a first pattern having a first minimum pitch; and

the second portions of the wire bonds are in a second pattern having a second minimum pitch less than the first minimum pitch.