Semiconductor Wire Bonding Double Joint Thermal Shock
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Solution Overview
Problem
Conventional semiconductor devices face disconnection issues due to thermal shock and temperature cycles during mounting, particularly in the second bonding section where the wire is stitch-bonded to an island, leading to reduced bonding strength and increased process time due to capillary displacement during the wire bonding process.
Innovation Solution
A semiconductor device with a double bonding section formed by wire-bonding a second wire onto the second bonding section of the first wire bonded to the island, increasing the thickness and bonding strength of the junction, and eliminating the need for capillary movement in the X-Y direction between bonding steps, thereby preventing disconnection and reducing process time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wire is stitch-bonded to an island in the second bonding section, then the wire connects the semiconductor chip electrode to the island, but the bonding strength is insufficient and disconnection occurs due to thermal shock and temperature cycles
Solution Approach 1:
A bump is formed on the island before wire bonding in advance. This preliminary action creates a robust bonding target that can withstand thermal shock and temperature cycles, preventing disconnection issues that would occur with direct stitch bonding to the island surface.
2Reliability
If a bump is formed on the island before wire bonding, then the bonding strength is improved, but the process time is increased due to additional manufacturing steps and capillary movement
Solution Approach 1:
The bump formation process is merged with the wire bonding process by using the same capillary for both operations. The capillary forms the bump and then immediately performs wire bonding without moving in the X-Y direction, combining two separate processes into one continuous operation that reduces total process time.
Solution Approach 2:
The capillary maintains its position and continues the bonding action without interruption or repositioning. The wire bonding follows immediately after bump formation in a continuous sequence, eliminating idle time and maintaining continuous useful action throughout the process.
3Reliability
If the capillary moves from above the bump to above the electrode and returns for double bonding, then the bonding strength is improved, but the capillary displacement increases and yield deteriorates
Solution Approach 1:
The bump formation and wire bonding operations are merged into a single continuous process using the same capillary position. The capillary forms the bump and then bonds the wire to the same location without moving in the X-Y direction, eliminating positioning errors and improving manufacturing precision.
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
The double bonding section enhances the bonding strength, preventing wire disconnection from thermal shocks and temperature cycles, while streamlining the manufacturing process by maintaining capillary position, thus improving yield and efficiency.
Implementation Method 1
an electric blowpipe 103 is opposed to the forward end thereof to discharge between the electric blowpipe 103 and the wire 102, thereby heating and melting the forward end of the wire 102
Implementation Method 2
the ball 104 is pressed against and bonded to the electrode 105 by the capillary 101, thereby forming a first bonding section 109... the ball 104 is thermocompression-bonded to the electrode 105
Implementation Method 3
At this time, ultrasonic waves may be applied simultaneously with the pressing by the capillary 101
Data Source
AI summary
The present invention aims at providing a semiconductor device capable of reliably preventing a wire bonded to an island from being disconnected due to a thermal shock, a temperature cycle and the like in mounting and capable of preventing remarkable increase in the process time. In the semiconductor device according to the present invention, a semiconductor chip is die-bonded to the surface of an island, one end of a first wire is wire-bonded to an electrode formed on the surface of the semiconductor chip to form a first bonding section and the other end of the first wire is wire-bonded to the island to form a second bonding section, while the semiconductor device is resin-sealed. A double bonding section formed by wire-bonding a second wire is provided on the second bonding section of the first wire wire-bonded onto the island.