Plastic Hollow Rivet Bulging for Stronger PCB Connections

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rivet connection methods, such as blind rivets and plastic rivets, often result in insufficient attachment of the rivet head to the remaining pipe, leading to weakened strength, appearance, and function due to low melt layer thickness and high shear rates, particularly when connecting components like printed circuit boards with electronic components.

Innovation Solution

A riveted joint and method where lateral energy is introduced into the tubular component's side wall using lasers to plasticize the material, allowing it to form a bulged portion without generating shear edges, while minimizing heat input to the second component, thereby reducing stress and enhancing attachment quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the rivet end is heated and deformed to form a rivet head, then the components are connected together, but the rivet head may not be sufficiently attached to the remaining pipe due to low melt layer thickness and high shear rate

Engineering Contradiction:
Improveattachment strength of rivet headVSAvoidmelt layer thickness
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies local quality by heating only the side wall of the tubular rivet in a localized region above the workpiece using a laser, rather than heating the entire rivet end uniformly. This creates a localized plasticized zone with controlled melt layer thickness, allowing the material to flow and form a bulged portion with adequate attachment strength while avoiding the uniform heating limitations that cause insufficient attachment in conventional methods.

Inventive Principle:
Principle #3Local quality

2Temperature

If infrared heating is used to heat the rivet end, then the rivet head can be formed, but the second component receives excessive heat input causing thermal stress

Engineering Contradiction:
Improverivet end temperatureVSAvoidthermal stress on second component
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The laser heating method applies local quality by directing energy specifically at the side wall of the tubular rivet above the workpiece, creating a localized heating zone. This prevents heat from being transferred to the second component through the rivet end, thereby forming the rivet head at the required temperature while avoiding thermal stress on the second component that would result from conventional infrared heating of the rivet end.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The side wall of the tubular rivet acts as an intermediary medium. By heating the side wall laterally rather than the rivet end directly, the patent uses the rivet material itself as a heat transfer medium that can be plasticized and formed while isolating the second component from excessive heat input, thus resolving the contradiction between achieving sufficient rivet head temperature and protecting the second component from thermal damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If the rivet is inserted through openings in components and deformed by pulling, then the two components are connected, but the deformation may create weld lines that negatively affect strength and appearance

Engineering Contradiction:
Improveconnection strengthVSAvoidrivet head surface quality
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The patent changes the fundamental parameter of how the rivet head is formed - instead of mechanical deformation by pulling (which creates weld lines), the method uses laser heating to plasticize the material followed by compression forming. This parameter change from mechanical deformation to thermal-plastic forming eliminates weld line formation while maintaining connection strength and improving surface quality.

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 approach ensures a stronger, more reliable riveted connection with reduced thermal stress on the second component, particularly beneficial for attaching electromechanical components to printed circuit boards, by allowing the plasticized material to form a stable bulged portion without penetrating into the cavity, thus improving the connection's strength and appearance.

Implementation Method 1

the side wall of the rivet is heated laterally above the workpiece to be connected from the side on its circumference by means of at least one laser until it is plasticized

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

heated laterally above the workpiece to be connected from the side on its circumference by means of at least one laser until it is plasticized

Methodology Applied
Scientific EffectPlasticization: Melting

Data Source

PatentEP3685052B1Rivet connection and method for producing a rivet connection
Publication Date: 2023.02.22 CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
  • EP3685052B1 patent drawingFigure 1~2
  • EP3685052B1 patent drawingFigure 3~4
  • EP3685052B1 patent drawingFigure 5~6

AI summary

The invention relates to a rivet connection comprising a hollow rivet, the hollow rivet consisting of plastic and connecting a first component (100) to a second component (200), the first component having a first surface (101) and the second component having a second and a third surface (202, 203), the first surface (101) of the first component (100) and the second surface (202) of the second component (200) abutting one other and the second component (200) having a first opening (201) between the second and the third surface (202, 203), the hollow rivet having a tubular component (300) comprising a sidewall (310), a hollow chamber (350), and a first end (301) and a second end (302), a part of the tubular component (300) being located in the first opening (201) of the second component (200), and the tubular component (300) projecting with its second end (302) beyond the second component (200). According to the invention, the sidewall (310) of the tubular component (300) is heated and compressed along its periphery adjacent to the first opening (201) above the third surface (203) of the second component (200) and forms a bulged region (320) such that a portion of the bulged region (320) contacts the third surface (203) of the second component (200).