Hybrid PCB Lead Frame Package for Moisture Resistance

Solution Overview

Problem

Existing circuit packaging systems, such as micro lead frame packages and system in packages, are limited in their ability to incorporate both integrated circuit dice and surface mount components effectively, leading to increased component count, assembly complexity, and vulnerability to moisture infiltration, while also being inefficient in terms of size and manufacturing cost.

Innovation Solution

A MiniCircuits System in Package (MSiP) that uses a printed circuit board with surface mount components and integrated circuit dice, attached to a lead frame, with wire bonding for electrical connections and encapsulated with a molding compound, allowing for a compact, environmentally sealed, and cost-effective packaging solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lead frame is used to hold integrated circuit dice, then moisture resistance is improved, but the ability to incorporate surface mount components is worsened

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent merges the advantages of lead frames (moisture protection, thermal dissipation) with printed circuit boards (surface mount component compatibility) by attaching the PCB to the lead frame, creating a hybrid structure that supports both IC dice and surface mount components while maintaining environmental protection

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If a printed circuit board is used to hold integrated circuit dice and surface mount components, then component integration is improved, but moisture protection is worsened

Engineering Contradiction:

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The PCB is attached to the lead frame which provides moisture and environmental protection, combining the component integration capabilities of PCBs with the protective properties of lead frames to achieve both high integration and reliable protection

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If multiple external components are used to realize circuit designs, then circuit flexibility is improved, but board area and assembly expense are worsened

Engineering Contradiction:

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines multiple components (IC dice, surface mount components, passive components) into a single integrated package, reducing the number of external components needed and minimizing board area while maintaining circuit flexibility through the hybrid PCB-lead frame structure

Inventive Principle:

Principle #5Merging (Combining)

4Ease of manufacture

If a micro lead frame package is used, then manufacturing simplicity is improved, but the ability to support multiple component types is worsened

Engineering Contradiction:

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent maintains the manufacturing simplicity of lead frames while adding PCB capabilities to support multiple component types, creating a hybrid structure that can be manufactured using existing lead frame processes plus standard PCB assembly techniques

Inventive Principle:

Principle #5Merging (Combining)

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 MSiP enables the integration of a wide range of components in a small, surface mountable package, enhancing operating frequency and reducing manufacturing costs, while being robust and flexible, with exposed terminals for easy attachment and improved thermal dissipation.

Implementation Method 1

The entire structure is encapsulated with molding compound, leaving the bottom surface of the lead frame exposed

Methodology Applied

Scientific EffectEncapsulation: Physical Containment

Implementation Method 2

Wire bonds provide electrical connections from the integrated circuit to some of the pads

Methodology Applied

Scientific EffectWire bonding: Welding

Implementation Method 3

Surface mount components including active, passive and fully packaged circuit devices are typically attached per step C2 using a conductive attachment material 32 which can be solder or conductive adhesive

Methodology Applied

Scientific EffectSoldering: Soldering

Implementation Method 4

conductive attachment material 32 which can be solder or conductive adhesive

Methodology Applied

Scientific EffectConductive adhesive bonding: Adhesive

Implementation Method 5

a central die pad 28 which typically also serves as a thermal pad to provide improved heat dissipation for the integrated circuit

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 6

uses a printed circuit board with surface mount components and integrated circuit dice, attached to a lead frame

Methodology Applied

Scientific EffectMechanical support: Mechanical Force

Data Source

PatentUS8994157B1Circuit system in a package

Publication Date: 2015.03.31

AI summary

A circuit packaging system allows a combination of integrated circuit dice and surface mount electronic components to be mounted on a printed circuit board which is in turn mounted on a lead frame and encapsulated, thus providing an environmentally sealed package which is manufactured using standard circuit fabrication methods and machinery.