Semiconductor Laser Test Pads for Alignment Protection

Solution Overview

Problem

In semiconductor lasers used for heat assisted magnetic recording, existing assembly and testing methods risk damaging the solder pads and alignment features during testing, leading to potential alignment issues and reduced manufacturing yield due to the need for direct contact with sensitive electrical and mechanical coupling junctions.

Innovation Solution

Incorporating test pads on the junction surface that are separate from and electrically coupled to the cathode and anode junctions, allowing for electrical testing without contacting the solder pads or stripe, thus avoiding damage and ensuring proper alignment during bonding with the integrated optics slider.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If test probes directly contact the cathode and anode electrical junctions for testing, then electrical testing can be performed, but the solder pads and alignment features are at risk of damage

Engineering Contradiction:

Improveelectrical testing capabilityVSAvoidalignment precision

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The junction surface is segmented into distinct functional zones: electrical junctions for electrical coupling, test pads for testing, and solder pads for mechanical bonding. This segmentation allows test probes to contact only the test pads without interfering with the electrical junctions or solder pads, thereby enabling testing while preserving alignment precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Test pads serve as an intermediary element between the test probes and the electrical junctions. The test pads are electrically coupled to the electrical junctions through conductive pathways, allowing electrical testing to be performed indirectly without direct probe contact with the sensitive electrical junctions or solder pads.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If test probes contact the solder pads for testing, then electrical testing can be performed, but the solder pads may be damaged leading to manufacturing yield reduction

Engineering Contradiction:

Improveelectrical testing capabilityVSAvoidmanufacturing yield

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The junction surface is segmented into distinct functional zones: electrical junctions for electrical coupling, test pads for testing, and solder pads for mechanical bonding. This segmentation allows test probes to contact only the test pads without interfering with the electrical junctions or solder pads, thereby enabling testing while preserving alignment precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Test pads serve as an intermediary element between the test probes and the electrical junctions. The test pads are electrically coupled to the electrical junctions through conductive pathways, allowing electrical testing to be performed indirectly without direct probe contact with the sensitive electrical junctions or solder pads.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If test probes contact the stripe for testing, then electrical testing can be performed, but alignment features may be compromised

Engineering Contradiction:

Improveelectrical testing capabilityVSAvoidalignment accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The junction surface is segmented into distinct functional zones: electrical junctions for electrical coupling, test pads for testing, and solder pads for mechanical bonding. This segmentation allows test probes to contact only the test pads without interfering with the electrical junctions or solder pads, thereby enabling testing while preserving alignment precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Test pads serve as an intermediary element between the test probes and the electrical junctions. The test pads are electrically coupled to the electrical junctions through conductive pathways, allowing electrical testing to be performed indirectly without direct probe contact with the sensitive electrical junctions or solder pads.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8532156B2Semiconductor laser with test pads

Publication Date: 2013.09.10 SEAGATE TECH LLC

AI summary

A laser diode includes a junction surface configured to interface with an integrated optics slider. Cathode and anode electrical junctions are disposed on the junction surface. The cathode and anode electrical junctions are configured for electrical and mechanical coupling to the integrated optics slider. At least one test pad is disposed on the junction surface that is physically separate from and electrically coupled to one of the cathode and anode electrical junctions. The test pad is configured to be contacted by a test probe and is not configured for electrical or mechanical coupling to the integrated optics slider.