# US 9,437,566 B2 · Conductive connections, structures with such connections, and methods of manufacture

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- Number: US 9,437,566 B2
- Document ID: US9437566B2
- Status: Granted
- Kind: B2
- Application number: 14/275,514
- Filed: 2014-05-12
- Published: 2015-11-12
- Granted: 2016-09-06
- Earliest claimed: 2014-05-12
- Assignees: Invensas Corporation
- Applicants: Invensas Corporation
- Inventors: Rajesh Katkar; Cyprian Emeka Uzoh
- Web page: https://patentgrep.com/patent/US9437566B2

## CPC

- H05K 3/341: Surface mounted components
- B23K 1/0016: {Soldering of electronic components}
- B23K 3/0623: {for shaped solder piece feeding, e.g. preforms, bumps, balls, pellets, droplets}
- B23K 35/0244: {Powders, particles or spheres; Preforms made therefrom}
- B23K 35/0266: {flux-cored}
- H05K 1/115: {Via connections; Lands around holes or via connections (H05K1/112 takes precedence)}
- H05K 1/144: {Stacked arrangements of planar printed circuit boards}
- H10P 14/63: {characterised by the formation processes}
- H10W 70/099: {Connecting interconnections to insulating or insulated package substrates, interposers or redistribution layers}
- H10W 70/652: Cross-sectional shapes
- H10W 72/0112: {Apparatus for manufacturing bump connectors}
- H10W 72/071: {Connecting or disconnecting}
- H10W 72/90: Bond pads, in general
- H10W 74/01: Manufacture or treatment
- H10W 74/016: {using moulds}
- H10W 74/121: {by multiple encapsulations, e.g. by a thin protective coating and a thick encapsulation}
- H10W 74/129: {forming a chip-scale package [CSP]}
- H10W 90/00: Package configurations
- H10W 90/701: {characterised by the relative positions of pads or connectors relative to package parts}
- B23K 2101/40: Semiconductor devices
- H05K 2201/09572: Solder filled plated through-hole in the final product
- H10W 70/63: Vias, e.g. via plugs
- H10W 72/012: {of bump connectors, dummy bumps or thermal bumps}
- H10W 72/01204: {using temporary auxiliary members, e.g. using sacrificial coatings or handle substrates}
- H10W 72/01212: {at a different location than on the final device, e.g. forming solder preforms}
- H10W 72/01223: {in liquid form, e.g. by dispensing droplets or by screen printing}
- H10W 72/01225: {in solid form, e.g. by using a powder or by stud bumping}
- H10W 72/01257: {by reflowing}
- H10W 72/019: {of bond pads}
- H10W 72/01923: {in liquid form, e.g. by dispensing droplets or by screen printing}
- H10W 72/01925: {in solid form}
- H10W 72/07141: {Means for applying energy, e.g. ovens or lasers}
- H10W 72/072: {of bump connectors}
- H10W 72/07227: {involving guiding structures, e.g. spacers or supporting members}
- H10W 72/07232: {Compression bonding, e.g. thermocompression bonding}
- H10W 72/07234: {Using a reflow oven}
- H10W 72/07235: {Applying EM radiation, e.g. induction heating or using a laser}
- H10W 72/07236: {Soldering or alloying}
- H10W 72/07252: {changes in structures or sizes}
- H10W 72/07253: {changes in shapes}
- H10W 72/07254: {changes in dispositions}
- H10W 72/07255: {changes in materials}
- H10W 72/07337: {using a polymer adhesive, e.g. an adhesive based on silicone or epoxy}
- H10W 72/221: {Structures or relative sizes}
- H10W 72/222: {Multilayered bumps, e.g. a coating on top and side surfaces of a bump core}
- H10W 72/224: {Bumps having multiple side-by-side cores}
- H10W 72/227: {Multiple bumps having different sizes}
- H10W 72/228: {Multiple bumps having different structures}
- H10W 72/231: {Shapes}
- H10W 72/234: {Cross-sectional shape, i.e. in side view}
- H10W 72/241: {Dispositions, e.g. layouts}
- H10W 72/242: {relative to the surface, e.g. recessed, protruding}
- H10W 72/245: {of outermost layers of multilayered bumps, e.g. bump coating being only on a part of a bump core}
- H10W 72/247: {Dispositions of multiple bumps}
- H10W 72/252: {comprising solid metals or solid metalloids, e.g. PbSn, Ag or Cu}
- H10W 72/253: {not comprising solid metals or solid metalloids, e.g. polymers or ceramics}
- H10W 72/255: {of outermost layers of multilayered bumps, e.g. material of a coating}
- H10W 72/257: {Multiple bump connectors having different materials}
- H10W 72/287: {Flow barriers}
- H10W 72/354: {comprising polymers}
- H10W 72/923: {Bond pads having multiple stacked layers}
- H10W 72/9415: {relative to the surface, e.g. recessed, protruding}
- H10W 72/944: {Dispositions of multiple bond pads}
- H10W 72/952: {comprising metals or metalloids, e.g. PbSn, Ag or Cu}
- H10W 74/012: {of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills}
- H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills
- H10W 90/722: {between stacked chips}
- H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL}
- H10W 99/00: Subject matter not provided for in other groups of this subclass
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

In some embodiments, to increase the height-to-pitch ratio of a solder connection that connects different structures with one or more solder balls, only a portion of a solder ball's surface is melted when the connection is formed on one structure and/or when the connection is being attached to another structure. In some embodiments, non-solder balls are joined by an intermediate solder ball (140i). A solder connection may be surrounded by a solder locking layer (1210) and may be recessed in a hole (1230) in that layer. Other features are also provided.

## Claims

### Claim 1

A method for attaching a first conductive component to a second conductive component, the method comprising:
(1) melting a first portion of a surface of the first conductive component without melting a second portion of the surface of the first conductive component even though the second portion's melting temperature is no higher than the first portion's melting temperature, wherein the second portion is continuous with the first portion;
(2) bringing the melted first portion into physical contact with the second conductive component and cooling the first portion to form a conductive attachment between the first and second conductive components;
wherein the second portion is not melted in operations (1) and (2); and
wherein the first conductive component comprises a core having a higher melting temperature than the first portion of the surface of the first conductive component.

### Claim 2 (depends on 1)

The method of claim 1 wherein in operation (2), the melted first portion is brought into physical contact with the second conductive component when the second conductive component is unmelted.

### Claim 3 (depends on 1)

The method of claim 1 wherein a maximum pre-melted dimension of the first portion does not exceed 700 μm.

### Claim 4 (depends on 1)

The method of claim 1 wherein the first portion is melted to a depth not exceeding 500 μm.

### Claim 5 (depends on 1)

The method of claim 1 wherein the pre-melted volume of a melted portion of the first conductive component does not exceed 50% of the first conductive component.

### Claim 6 (depends on 1)

The method of claim 1 wherein the second conductive component is a contact pad of a semiconductor integrated circuit or of a substrate attachable to a semiconductor integrated circuit, or the second conductive component is a connection component that has been attached to such contact pad before operation (1).

### Claim 7 (depends on 1)

The method of claim 1 wherein the melting is performed by a beam of electromagnetic radiation.

### Claim 8

A method for fabricating an electrical connection, the method comprising:
providing a first structure which comprises a first contact pad;
forming a first portion of the electrical connection on the first contact pad, the first portion comprising a first component comprising a first surface;
providing a second component of the electrical connection, the second component comprising a second surface comprising solder;
providing a third component of the electrical connection, the third component comprising a third surface;
attaching the second component to the first and third surfaces, wherein said attaching comprises melting the solder to obtain melted solder in physical contact with the first and third surfaces, and re-solidifying the solder to attach the solder to the first and third surfaces, wherein at least one of the first and third surfaces has an unmelted area which is not melted in said attaching even though a melting temperature of the unmelted area is not higher than a highest temperature of the solder in said attaching.

### Claim 9 (depends on 8)

The method of claim 8 wherein the first and third surfaces are not melted in said attaching.

### Claim 10 (depends on 8)

The method of claim 8 wherein at least one of the first and third surfaces has the same melting temperature as the solder.

### Claim 11 (depends on 8)

The method of claim 8 wherein the third component is a solder ball which has the same melting temperature as the second component's solder but which is not melted in said attaching.

### Claim 12 (depends on 8)

The method of claim 8 wherein the first structure comprises at least one of a semiconductor integrated circuit or a substrate attachable to a semiconductor integrated circuit.

### Claim 13 (depends on 8)

The method of claim 8 wherein the melting is performed by a beam of electromagnetic radiation.

### Claim 14 (depends on 8)

The method of claim 8 wherein the solder surrounds a core that does not melt in said attaching.

### Claim 15 (depends on 8)

The method of claim 8 wherein the melting is performed only once during said attaching.

### Claim 16 (depends on 1)

The method of claim 1 wherein the first conductive component does not physically contact the second conductive component during operation (1).

### Claim 17 (depends on 1)

The method of claim 1 wherein the entire surface of the first component is the same material.

### Claim 18 (depends on 7)

The method of claim 7 wherein the beam of electromagnetic radiation arrives at the first portion without first passing through the second portion.

### Claim 19 (depends on 7)

The method of claim 7 wherein the beam of electromagnetic radiation arrives at the first portion without first passing through the first conductive component.

### Claim 20 (depends on 8)

The method of claim 8 wherein the unmelted area physically contacts the melted solder in said attaching.