Thin Film Probe Sheet with Quadrangular Pyramid Probes
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Solution Overview
Problem
The challenge is to miniaturize semiconductor integrated circuit devices while maintaining the quality of probe testing, particularly in densely packed test pad arrangements, where existing technologies face difficulties in reducing the pitch between pads and preventing breakage of thin film probes and wafers during testing.
Innovation Solution
The solution involves a thin film probe sheet with a multilayer structure, including a metal film and a polyimide film, where the probes are formed with a quadrangular pyramid shape and anisotropically etched to increase the depth of holes, allowing for a higher probe height and improved contact without omitting pads, and using a copper film to enhance the probe height without increasing the pad size, thus enabling better contact and reducing foreign matter attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pitch between test pads is decreased to miniaturize semiconductor devices, then the area of each chip is reduced and more chips can be produced from one wafer, but the arrangement of probes becomes difficult and probe testing quality deteriorates
Solution Approach 1:
The patent introduces a vertical dimension by forming probes with a quadrangular pyramid shape having an inclined surface. This three-dimensional structure allows the probe tip to make contact with the pad surface while the base remains elevated, enabling probe arrangement at smaller pitch distances without compromising contact quality or probe integrity.
2Reliability
If the height of probes is increased to improve contact with densely packed pads, then probe testing reliability is improved, but the risk of probe breakage and wafer damage from foreign matter increases
Solution Approach 1:
The patent forms an insulating film layer between the probe base and the pad surface. This insulating film acts as a cushioning layer that prevents direct metal-to-metal contact, reducing the risk of probe breakage and wafer damage when foreign matter is present, while still allowing effective electrical contact through the insulated tip.
Solution Approach 2:
The probe structure combines multiple materials: a conductive metal film for electrical contact, an insulating film for protection and isolation, and a polyimide film for structural support. This composite structure provides both the necessary electrical conductivity and mechanical protection against breakage and damage.
3Manufacturing precision
If a dummy metal film is inserted to adjust probe height, then probe height can be controlled, but the manufacturing process becomes more complex and additional materials are required
Solution Approach 1:
The patent controls probe height by adjusting the thickness parameters of the insulating film and polyimide film layers during the manufacturing process. This approach allows precise height control through film thickness deposition parameters rather than adding complex dummy structures, simplifying the overall manufacturing process.
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
This approach allows for efficient miniaturization of semiconductor devices, improves production yield, and prevents breakage of probes and wafers during testing by maintaining consistent contact with densely packed pads, enhancing the reliability of probe testing.
Implementation Method 1
a thin film probe sheet having a plurality of contact terminals which can be brought into contact with the plurality of electrodes of the semiconductor wafer
Implementation Method 2
portions in which probes are to be formed are anisotropically etched into a plurality of quadrangular pyramid holes having a side surface inclined at an angle of about 70.5° relative to the bottom surface
Data Source
AI summary
A probe having a sufficient height is manufactured by selectively depositing, over the main surface of a wafer, a copper film in a region in which a metal film is to be formed and a region which will be outside an adhesion ring when a probe card is fabricated; forming the metal film, polyimide film, interconnect, another polyimide film, another interconnect and a further polyimide film; and then removing the wafer and copper film. According to the present invention, when probe testing is performed using a prober (thin film probe) having the probe formed in the above-described manner while utilizing the manufacturing technology of semiconductor integrated circuit devices, it is possible to prevent breakage of the prober and a wafer to be tested.