IC Chip Package Sealing Resin Thermal Expansion Control
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Solution Overview
Problem
The existing IC chip mounting packages face challenges with sealing reliability due to thermal expansion and contraction issues, as well as insufficient resin filling, particularly when using an interposer substrate, which can lead to cracking and air bubbles.
Innovation Solution
The package design includes an IC chip connected to a package base member via an interposer with specific sealing resin properties: a coefficient of linear expansion not exceeding 80 ppm/°C, viscosity between 0.05 Pa·s and 0.25 Pa·s, and filler particles no larger than 1 μm, ensuring reliable resin sealing and filling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an interposer substrate is used to connect IC chip to package base member, then fine pitch connections are achieved, but sealing reliability deteriorates due to thermal expansion mismatch and resin cracking
Solution Approach 1:
The patent changes the physical parameters of the sealing resin by strictly controlling its coefficient of linear expansion to be 80 ppm/°C or less, and specifying viscosity range (0.05-0.25 Pa·s) and filler particle size (≤1 μm). These parameter changes enable the resin to match thermal expansion characteristics of the interposer and package base member, preventing resin cracking while maintaining fine pitch connection reliability
Solution Approach 2:
The patent uses a composite sealing resin formulation containing filler particles with specific size constraints (1 μm or less). This composite material approach allows the resin to achieve both the required mechanical properties for fine pitch sealing and the thermal expansion characteristics needed to prevent cracking during temperature cycling
2Productivity
If device hole size is reduced to improve package density, then packaging efficiency improves, but resin filling completeness deteriorates due to insufficient resin flow
Solution Approach 1:
The patent changes the rheological parameters of the sealing resin by controlling viscosity to 0.05-0.25 Pa·s and filler particle size to 1 μm or less. These parameter changes enable the resin to flow completely into smaller device holes while maintaining proper sealing characteristics, thus achieving both high package density and complete resin filling
3Manufacturing precision
If copper foil thickness is reduced to achieve finer wire pitch, then wire pitch precision improves, but mechanical strength deteriorates
Solution Approach 1:
While the patent does not directly address copper foil thickness, it enables finer wire pitch implementations by providing a reliable sealing system that can accommodate thinner copper foils. The controlled resin parameters ensure proper stress distribution and protection, allowing the use of reduced thickness copper foil for fine pitch applications without compromising overall package strength
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 configuration effectively suppresses resin cracking and ensures complete filling between the IC chip and interposer, enhancing sealing reliability and reducing costs by allowing for a smaller device hole size and stable package base member design.
Implementation Method 1
the inner leads on a tape carrier are bonded to bumps on an IC chip by the application of heat and pressure so that the tape carrier is brought into conduction with the IC chip
Implementation Method 2
the sealing resin having a coefficient of linear expansion of not more than 80 ppm/° C.
Implementation Method 3
the inner leads on a tape carrier are bonded to bumps on an IC chip by the application of heat and pressure so that the tape carrier is brought into conduction with the IC chip
Data Source
AI summary
In one embodiment of the present invention, an IC chip mounting package is arranged such that an IC chip and a film base member are connected via an interposer, and a section in which the IC chip, the film base member, and the interposer are connected is sealed with sealing resin. The sealing resin is provided by potting sealing resin around the interposer via a potting nozzle, or is provided by potting the sealing resin around the IC chip, that is, via a device hole. Moreover, the sealing resin has a coefficient of linear expansion of not more than 80 ppm/° C., a viscosity of not less than 0.05 Pa·s but not more than 0.25 Pa·s, and also includes filler having a particle size of not more than 1 μm.