Mother Daughter Circuit Board Assembly With Cavity

Solution Overview

Problem

The existing mother/daughter circuit board configuration is not space-efficient due to the need to account for the entire length and width of the daughter board, limiting optimal component placement on the mother board and resulting in suboptimal packaging.

Innovation Solution

A circuit board assembly where the daughter board has a cavity on its bottom surface that encloses a portion of the mother board's electronic components, allowing for reduced size requirements on the mother board and enabling more efficient component placement, with conductive pads on both boards for direct soldering and castellated vias for electrical connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the entire length and width of the daughter board is designated as a keep out zone on the mother board, then the daughter board can be directly attached to the mother board with all components mounted on the top surface, but the mother board size increases and component placement flexibility is reduced

Engineering Contradiction:

Improveease of manufacturingVSAvoidmother board area

Core Design Contradiction:

Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent applies nesting by creating a cavity in the daughter board that accommodates mother board components. Specifically, a cavity is formed in the daughter board substrate beneath the keep-out zone, allowing selected mother board components to be mounted in this cavity and electrically connected to traces on both boards. This nested configuration allows the keep-out zone to be smaller than the entire daughter board area, as portions of the daughter board can extend over and enclose mother board components without preventing their electrical connection.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of manufacture

If the entire length and width of the daughter board is designated as a keep out zone on the mother board, then the daughter board can be directly attached to the mother board with all components mounted on the top surface, but component placement flexibility and packaging efficiency are reduced

Engineering Contradiction:

Improveease of manufacturingVSAvoidpackaging efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies nesting by creating a cavity in the daughter board that accommodates mother board components. Specifically, a cavity is formed in the daughter board substrate beneath the keep-out zone, allowing selected mother board components to be mounted in this cavity and electrically connected to traces on both boards. This nested configuration allows the keep-out zone to be smaller than the entire daughter board area, as portions of the daughter board can extend over and enclose mother board components without preventing their electrical connection.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Productivity

If the mother board size is reduced to improve packaging efficiency, then space utilization improves, but the structural rigidity and mounting stability may be compromised

Engineering Contradiction:

Improvepackaging efficiencyVSAvoidstructural rigidity

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The patent applies nesting by creating a cavity in the daughter board that accommodates mother board components. Specifically, a cavity is formed in the daughter board substrate beneath the keep-out zone, allowing selected mother board components to be mounted in this cavity and electrically connected to traces on both boards. This nested configuration allows the keep-out zone to be smaller than the entire daughter board area, as portions of the daughter board can extend over and enclose mother board components without preventing their electrical connection.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 configuration allows for a smaller mother board size, improved packaging efficiency, and reduced manufacturing costs by enabling thinner conductive traces and smaller components on the daughter board, while maintaining structural rigidity and easy mounting using standard surface mount techniques.

Implementation Method 1

The daughter board may include conductive pads on the bottom surface of the daughter board that are soldered directly to corresponding conductive pads on the mother board

Methodology Applied

Scientific EffectSoldering: Soldering

Data Source

PatentUS9693459B2Circuit board assembly and method of manufacturing same

Publication Date: 2017.06.27 APTIV TECHNOLOGIES AG

AI summary

The circuit board assembly includes a first circuit board having a first plurality of electronic components attached to a major surface of the first circuit board. The first plurality of electronic components is electrically interconnected to a first plurality of conductive pads defined on the major surface of the first circuit board. A second circuit board has a second plurality of electronic components attached to a first major surface of the second circuit board. The second plurality of electronic components is electrically interconnected to a second plurality of conductive pads defined on a second major surface of the second circuit board. The first and second circuit board are attached by coupling the first and second plurality of conductive pads. A portion of the first plurality of electronic components on the first circuit board are disposed within a cavity defined by the second major surface of the second circuit board.