Package Substrate Laser Grooving to Prevent Molten Resin Sticking

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing methods for machining package substrates with LEDs or other chips result in molten material sticking to the device packages, degrading chip quality, as the molten material accommodated in grooves on the ceramic substrate side faces becomes stuck during division.

Innovation Solution

A package substrate machining method involving first and second laser-machined groove formation steps, where the first grooves are formed in a resin coating layer and the second grooves in the ceramic substrate, with a cleaning step using ultrasound to remove the molten material, preventing it from sticking to the device packages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If laser beam machining is performed on the package substrate, then division along scheduled lines is achieved, but molten material is produced and sticks to device packages

Engineering Contradiction:

Improvemachining efficiencyVSAvoidmolten material sticking

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

Grooves are formed in advance in both the coating layer and ceramic substrate before the actual division machining is performed. This preliminary groove formation creates containment structures that will capture any molten material generated during the subsequent laser beam division process, preventing the molten material from sticking to device packages.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The molten material, which is normally a harmful byproduct of laser machining, is converted into a beneficial contained substance by directing it into pre-formed grooves. The grooves act as receptacles that capture and contain the molten material, transforming it from a contaminant into a controlled element that does not adhere to device packages.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Manufacturing precision

If grooves are formed to accommodate molten material, then machining can proceed, but cleaning becomes more difficult due to molten material remaining in grooves

Engineering Contradiction:

Improvemachining precisionVSAvoidcleaning difficulty

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The groove structure is segmented into two distinct layers - grooves in the coating layer and grooves in the ceramic substrate. This segmentation creates a configuration where molten material is contained in accessible grooves that can be easily cleaned, rather than being trapped in deep, inaccessible cavities within a single thick substrate.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The coating layer acts as an intermediary layer between the laser machining process and the ceramic substrate. The grooves formed in this intermediate coating layer provide easy access for cleaning operations, allowing molten material to be removed without requiring complex cleaning procedures to access deep substrate grooves.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method effectively prevents the sticking of molten material to device packages by accommodating it in the first laser-machined grooves, allowing for easy removal during cleaning, thus maintaining chip quality.

Implementation Method 1

irradiating a laser beam at a wavelength absorbable by the coating layer from the coating layer side of the package substrate

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

wavelength absorbable by the coating layer

Methodology Applied

Scientific EffectAbsorption of electromagnetic radiation: Absorption (EM radiation)

Implementation Method 3

irradiating a laser beam at a wavelength absorbable by the ceramic substrate from the ceramic substrate side of the package substrate

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 4

wavelength absorbable by the ceramic substrate

Methodology Applied

Scientific EffectAbsorption of electromagnetic radiation: Absorption (EM radiation)

Implementation Method 5

immerse the package substrate in a liquid subjected to ultrasound for cleaning

Methodology Applied

Scientific EffectUltrasonic cleaning: Ultrasound

Data Source

PatentUS9831381B2Package substrate machining method

Publication Date: 2017.11.28 DISCO CORP

AI summary

A package substrate machining method is provided. The package substrate includes a ceramic substrate, a plurality of device chips arranged on one face of the ceramic substrate, and a coating layer made of a resin that covers the entire one face of the ceramic substrate. The package substrate machining method includes a first laser-machined groove formation step adapted to form, in the coating layer, first laser-machined grooves along scheduled division lines set up on the package substrate by irradiating a laser beam at a wavelength absorbable by the coating layer from the coating layer side of the package substrate; and a second laser-machined groove formation step adapted to form, in the ceramic substrate and after the first laser-machined groove formation step, second laser-machined grooves along the scheduled division lines by irradiating a laser beam from the ceramic substrate side of the package substrate.