Laser Welded Contacting Arrangement for Ceramic Substrates

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Solution Overview

Problem

Current methods for connecting Low Temperature Cofired Ceramics (LTCC) and High Temperature Cofired Ceramics (HTCC) substrates to connecting wires are limited by insufficient printed layer thickness, making laser welding impossible and requiring cost-intensive stamped grids or inserts, unlike Direct Bonded Copper (DBC) substrates.

Innovation Solution

A contacting arrangement and method that utilize a metal filling in through-openings of printed circuit board substrates to create a thick enough metallization for laser welding connections between the substrate and connecting wires, allowing for direct laser welding of LTCC, HTCC, and standard ceramics to connecting wires, enabling connections at any point on the substrate and using various wire types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If bonded connections are used for LTCC/HTCC substrates, then connections can be made, but the connection cost is high due to requiring stamped grids/inserts with specially prepared connections

Engineering Contradiction:
Improveconnection costVSAvoidconnection structure
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention extracts the metal filling material from the through-opening and uses it as the contact surface for laser welding. By removing the need for separate stamped grids or inserts with prepared connections, the solution eliminates complex additional components while maintaining connection functionality, thereby reducing both cost and structural complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The metal filling acts as an intermediary element between the ceramic substrate and the connecting wire. It provides a sufficiently thick metallization layer that enables direct laser welding without requiring complex stamped grids or inserts, thus simplifying the connection structure and reducing costs

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If laser welding is attempted on standard LTCC/HTCC substrates, then welding speed would be high, but the printed layer thickness is insufficient for laser welding

Engineering Contradiction:
Improvewelding speedVSAvoidmetallization thickness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The metal filling is preliminarily introduced into the through-opening before the laser welding process. This preliminary metallization ensures that sufficient thickness is available for the subsequent laser welding operation, enabling high-speed welding without compromising metallization quality

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the metallization parameter by introducing metal filling material into the through-opening. This increases the effective metallization thickness from the insufficient printed layer thickness to a sufficient thickness that enables laser welding, thereby achieving high welding speed while maintaining manufacturing precision

Inventive Principle:
Principle #35Parameter changes

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 solution allows for efficient, cost-effective direct connections between ceramic substrates and connecting wires, eliminating the need for expensive stamped grids, enabling flexible wire configurations, and simplifying handling and installation by allowing connections at any point on the substrate.

Implementation Method 1

a laser welded connection forms an electrical contact between the first contact area and the second contact area

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 2

the laser beam can introduce the welding energy via the second contact area or via a rear side of the metal insert opposite the second contact area

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP3375263A1Contacting arrangement for a circuit board substrate, and method for contacting a circuit board substrate
Publication Date: 2018.09.19 ROBERT BOSCH GMBH

AI summary

The invention relates to a contacting arrangement (1A) for a circuit board substrate (20), comprising at least one connecting wire (10A) that has a first contact zone (12) and is in electric contact with a corresponding second contact zone (32) on the circuit board substrate (20). Also disclosed is a corresponding method for contacting a circuit board substrate (20). According to the invention, a metal filler (30) in a through-hole (26) of the circuit board substrate (20) forms the second contact zone (32), and a laser-welded joint forms the electric contact between the first contact zone (12) and the second contact zone (32).