Interposer Through-Hole Staggered Arrangement Laser Etching
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Solution Overview
Problem
Conventional methods for manufacturing interposers struggle to produce smaller devices while maintaining high reliability and accuracy in forming through holes, leading to defects in insulating films and increased aperture sizes.
Innovation Solution
The method involves forming through holes with a staggered arrangement and using modified regions to control the etching process, ensuring precise formation and preventing aperture size increase, with laser processing and anisotropic etching to achieve a target thickness and uniform insulating films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If through holes are arranged in a staggered pattern to increase density, then the interposer size can be reduced, but the manufacturing precision of through holes may deteriorate
Solution Approach 1:
The patent applies preliminary action by forming a modified region in the object before etching the through holes. This modified region serves as a pre-prepared guide that controls the etching process, ensuring that even when multiple through holes are arranged densely in a staggered pattern, each hole maintains its intended aperture size and position. The modified region is created by irradiating the object with laser light at specific positions corresponding to where through holes will eventually form.
Solution Approach 2:
The patent introduces an intermediary element - the modified region - that mediates between the laser irradiation step and the final etching process. This modified region acts as a bridge that transfers the positional information from the laser processing step to the etching step, ensuring that the etching follows the intended pattern accurately even when through holes are arranged in a complex staggered configuration for miniaturization.
2Ease of manufacture
If conventional laser irradiation is used to form precursory holes, then the process is simple, but the aperture size of through holes increases due to etching progression
Solution Approach 1:
The patent improves upon conventional methods by performing a preliminary laser irradiation step that creates a modified region with different properties than the surrounding material. This modified region has reduced etchability, which prevents the etching process from excessively enlarging the aperture. The laser irradiation parameters are carefully controlled to create this modified region without completely removing material, thus maintaining process simplicity while gaining aperture control.
Solution Approach 2:
The patent applies parameter changes by utilizing the laser irradiation to fundamentally alter the physical or chemical properties of the material in the modified region. This change in material parameters (such as crystalline structure, density, or chemical composition) makes the modified region resistant to etching, thereby controlling the final aperture size of the through holes while maintaining the simplicity of the laser-based approach.
3Volume of moving object
If through holes are formed with tilted directions for dense packing, then the interposer can be made smaller, but insulating films may develop defects due to projections on inner faces
Solution Approach 1:
The patent applies preliminary action by creating the modified region before etching, which pre-determines the shape and surface characteristics of the through hole inner faces. By controlling the laser irradiation parameters and the geometry of the modified region, the patent ensures that the subsequent etching produces smooth inner surfaces without projections, even when through holes are tilted for dense staggered packing. This preliminary preparation prevents insulating film defects before they can occur.
Solution Approach 2:
The patent utilizes parameter changes in the laser irradiation process to create modified regions with specific geometric properties that translate into smooth inner surfaces after etching. By adjusting laser parameters such as power, pulse duration, and scanning speed, the patent controls the formation of the modified region to eliminate surface irregularities that would otherwise cause insulating film defects in tilted through holes.
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 the creation of smaller interposers with high reliability and accurate through holes, suppressing defects in insulating films and enabling dense packaging, thus enhancing the manufacturing process.
Implementation Method 1
converges a laser light into a object to be processed, so as to form a modified region
Implementation Method 2
the etching step may advance the etching selectively along the second modified region and then along the first modified region while thinning the object to a target thickness
Data Source
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AI summary
A method for manufacturing an interposer equipped with a plurality of through-hole electrodes comprises a laser light converging step of converging a laser light at a sheet-like object to be processed made of silicon so as to form a modified region in the object; an etching step of anisotropically etching the object after the laser light converging step so as to advance etching selectively along the modified region and form a plurality of through holes in the object, each through hole being tilted with respect to a thickness direction of the object and having a rectangular cross section; an insulating film forming step of forming an insulating film on an inner wall of each through hole after the etching step; and a through-hole electrode forming step of inserting a conductor into the through holes so as to form the through-hole electrodes after the insulating film forming step; wherein the plurality of through holes are arranged such that the through holes aligning in the tilted direction are staggered in a direction perpendicular to the tilted direction as seen from a main face of the object.