Semiconductor Wire Bonding via Bump Electrodes

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Solution Overview

Problem

Multi-chip package semiconductor devices face challenges in connecting semiconductor chips with different-sized electrode pads due to the risk of wire short-circuits and deformation during molding, especially when using wires with diameters suited to either large or small pads.

Innovation Solution

The solution involves using a configuration where wide width wires connect to larger electrode pads via bump electrodes smaller than the pads, and the other ends of the wires connect to smaller pads via these bump electrodes, reducing the risk of short-circuits and allowing for thicker wires to be connected at a narrower pitch, thereby improving reliability and miniaturizing the wiring substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wires with large diameters are used to connect large electrode pads, then connection reliability is improved, but the wires become easily deformed on molding and wire short-circuit risk increases

Engineering Contradiction:

Improveconnection reliabilityVSAvoidwire deformation and short-circuit risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the wire structure into two distinct parts: a first wire with large diameter for connecting large electrode pads, and a second wire with small diameter for connecting small electrode pads. This segmentation allows each wire to be optimally sized for its specific connection task, preventing the deformation and short-circuit issues that would occur if a single wire size were used for both large and small pads.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If wires with small diameters are used to connect small electrode pads, then bonding is improved, but the wires become easily deformed on molding and wire short-circuit risk increases

Engineering Contradiction:

Improvebonding qualityVSAvoidwire deformation and short-circuit risk

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent segments the wire system into two types: small-diameter wires optimized for bonding to small electrode pads, and large-diameter wires with wide width parts for enhanced mechanical stability. This allows small wires to be used where needed for good bonding while the wide width parts provide protection against deformation and short-circuits during molding.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by giving different wire structures to different locations: small-diameter wires are used specifically at the bonding interface with small electrode pads to ensure good electrical contact, while wide width parts are positioned in areas subject to molding stress to prevent deformation and short-circuits.

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If multiple semiconductor chips with different sized electrode pads are assembled in the same package, then device functionality is improved, but wire short-circuit risk due to resin flow increases

Engineering Contradiction:

Improvedevice functionalityVSAvoidwire short-circuit risk

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the wire population into two categories based on the size of electrode pads they connect: one group of wires for large pads and another group for small pads. This segmentation allows the package to accommodate multiple chips with different pad sizes while maintaining wire integrity and preventing short-circuits during molding.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by positioning wide width parts of wires specifically in regions where resin flow during molding could cause short-circuits. This localized structural enhancement protects the wire connections in the most vulnerable areas while allowing the rest of the wire structure to remain optimized for electrical connection.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP2557594B1Semiconductor device reducing risks of a wire short-circuit and a wire flow

Publication Date: 2023.01.11 LONGITUDE LICENSING LTD

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AI summary

A semiconductor device includes a wiring substrate (12) having first (124) and second (125) connection pads on a main surface thereof, a first semiconductor chip (14) having first electrode pads (141), a second semiconductor chip (16) having second electrode pads (161) each of which has a size smaller than that of each of the first electrode pads (141), first wires (22) connecting the first electrode pads (141) with the first connection pads(124), and second wires (24) connecting the second electrode pads (161) with the second connection pads (125). The second wires (24) have wide width parts at first ends (241). The wide width parts (241) are connected the second connection pads (125) and the second wires (24) have second ends connected to the second electrode pads (161) via bump electrodes (30) which are smaller than the second electrode pads (161).