# US 12,120,818 B2 · Printed circuit board

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- Number: US 12,120,818 B2
- Document ID: US12120818B2
- Status: Granted
- Kind: B2
- Application number: 17/910,528
- Filed: 2021-03-03
- Published: 2023-05-18
- Granted: 2024-10-15
- Earliest claimed: 2020-03-10
- Assignees: LG Innotek Co., Ltd.
- Applicants: LG Innotek Co., Ltd.
- Inventors: Myung Gu Kang
- Web page: https://patentgrep.com/patent/US12120818B2

## CPC

- H05K 1/111: {Pads for surface mounting, e.g. lay-out}
- H05K 3/3452: Solder masks
- H05K 3/341: Surface mounted components
- 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
- H05K 3/3436: {having an array of bottom contacts, e.g. pad grid array or ball grid array components}
- H05K 3/3494: Heating processes for reflow soldering
- H05K 2201/0989: Coating free areas, e.g. areas other than pads or lands free of solder resist
- H05K 2201/099: Coating over pads, e.g. solder resist partly over pads
- H05K 2201/09909: Special local insulating pattern, e.g. as dam around component
- H05K 2201/10977: Encapsulated connections
- H05K 2201/10984: Component carrying a connection agent, e.g. solder, adhesive
- H05K 2201/2081: Compound repelling a metal, e.g. solder
- H05K 2203/041: Solder preforms in the shape of solder balls
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Disclosed is a printed circuit board according to an embodiment. The printed circuit board comprises: a base board; a metal layer, including a pad and a metal line formed in the base board; a solder resist layer that is formed on the base board on which the metal layer is formed and has an opening through which the surface of the metal line is exposed; and an underfill that is formed between the solder resist layer and a semiconductor chip electrically connected to the pad and includes a blocking area formed in the opening.

## Claims

### Claim 1

A printed circuit board comprising: a base board; a metal layer including a pad and a metal line formed on the base board; a solder resist layer formed on the base board on which the metal layer is formed and formed with an opening through which a surface of the metal line is exposed; and an underfill formed between the solder resist layer and a semiconductor chip electrically connected to the pad, and including a blocking area formed in the opening, wherein the blocking area is formed to surround a portion of the semiconductor chip along an edge of the semiconductor chip, and wherein the blocking area is formed in an area where the metal line is formed among the entire edge of the semiconductor chip.

### Claim 2 (depends on 1)

The printed circuit board of claim 1, wherein the blocking area is formed to surround an entire semiconductor chip along an edge of the semiconductor chip.

### Claim 3 (depends on 1)

The printed circuit board of claim 1, wherein the opening is formed within a predetermined distance from the pad.

### Claim 4 (depends on 1)

The printed circuit board of claim 1, further comprising a solder ball formed on the pad of the metal layer.

### Claim 5 (depends on 1)

The printed circuit board of claim 1, wherein: the opening includes a plurality of openings which are formed in parallel; and the blocking area includes a plurality of blocking areas respectively formed in the plurality of openings.

### Claim 6 (depends on 1)

The printed circuit board of claim 1, wherein a width of the opening ranges from 0.2 mm to 0.3 mm.