Wedge Wire Bonding Tail Alignment to Prevent Lead Short Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wire bonding processes using a capillary, the long wire tails formed after bonding can protrude and potentially contact adjacent leads, especially as the distance between leads narrows and wire directions change, leading to short circuits.
Innovation Solution
A wire bonding apparatus that calculates the extending direction of wire tails based on the shape of the lead and adjusts the cutting mechanism to align the wire tails with the lead direction, using a bending station to shape the wire tails to prevent protrusion and contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wedge bonding is performed using a capillary with a rotationally symmetric front end, then bonding can be performed without rotating the bonding head, but long wire tails are formed that may protrude and contact adjacent leads causing short circuits
Solution Approach 1:
The patent applies preliminary action by forming the wire tail in a specific direction along the lead extending direction before the bonding process completes. The calculating part computes the lead extending direction in advance, and the cutting part forms the wire tail accordingly, preventing future contact with adjacent leads while maintaining high bonding speed without rotation
2Reliability
If the wire tail is formed along the lead extending direction, then contact with adjacent leads is prevented, but additional calculation and control functions are required
Solution Approach 1:
The control part serves multiple functions: it acts as both the shape acquisition part that obtains lead shape information and the calculating part that computes the lead extending direction. This multi-functionality reduces overall system complexity while achieving reliable wire tail orientation along the lead direction
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents contact between adjacent wire tails by aligning them with the lead direction, ensuring reliable bonding without short circuits and allowing for faster wedge bonding without rotating the bonding head.
Implementation Method 1
an ultrasonic vibration is applied and the wire and the lead are joined to perform first bond (1st bond)
Data Source
AI summary
A wire bonding apparatus connecting a lead of a mounted member with an electrode of a semiconductor die through a wire comprises a capillary through which the wire is inserted, a shape acquisition part which acquires the shape of the lead to which the wire is connected, a calculating part which calculates an extending direction of a wire tail extending from the end of the capillary based on the shape of a lead to which the wire is connected next, and a cutting part which moves the capillary in the extending direction and cuts the wire to form the wire tail after the lead is connected with the electrode through the wire. Thus, in the wire bonding using wedge bonding, joining part tails (183a, 283a, 383a) formed in continuation to a first bonding point can be prevented from coming into contact with each other.