Substrate-Free SIP Design for Z-Height Reduction

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Solution Overview

Problem

Legacy system in package (SIP) manufacturing methods using strip level bismaleimide triazine substrates are unreliable and costly, limiting assembly efficiency and component integration due to thick substrates and complex assembly processes.

Innovation Solution

A substrate-free SIP design utilizing a wafer or panel carrier with pre-defined circuit traces, where solder balls are coupled to the traces and embedded in molding, with the tops exposed through grinding, allowing for thinner packages and increased component integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If strip level BT substrate is used in legacy SIP manufacturing, then structural support is provided, but Z-height is increased and assembly cost increases

Engineering Contradiction:

ImproveZ-heightVSAvoidassembly process complexity

Core Design Contradiction:

Length of moving objectVSDevice complexity

Solution Approach 1:

The patent removes the BT substrate layer from the SIP structure, extracting the problematic thick substrate that increased Z-height. The carrier becomes the primary structural element, eliminating the need for the separate BT substrate layer and its associated assembly complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of building up from a thick substrate and adding components, the patent inverts the approach by using a thin carrier as the base and building components directly upon it. This reversal of the traditional build-up sequence enables thinner overall packaging.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If film assisted molding process is used to define through-mold via, then via structure is created, but manufacturing reliability decreases and assembly cost increases

Engineering Contradiction:

Improvemanufacturing reliabilityVSAvoidmanufacturing process simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical film assisted molding process with a direct wafer-level molding approach. By eliminating the film layer and using direct molding on the wafer, the process becomes more reliable and easier to manufacture while achieving the same through-mold via structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If laser ablation process is used to define through-mold via, then via opening is achieved, but manufacturing cost increases and precision may be compromised

Engineering Contradiction:

Improvevia opening precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the laser ablation process with a mechanical punching or drilling process performed at the wafer level. This substitution reduces manufacturing cost while maintaining adequate precision for via opening, eliminating the need for expensive laser equipment and processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If wafer or panel level molding is implemented with thin film material, then components are secured, but Z-height increases and throughput decreases

Engineering Contradiction:

Improveassembly throughputVSAvoidZ-height

Core Design Contradiction:

ProductivityVSLength of moving object

Solution Approach 1:

The patent removes the thin film material layer from the molding process, extracting the source of additional Z-height. By performing direct wafer-level molding without the intermediate film layer, the overall package height is reduced while maintaining component security.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the component attachment and molding operations into a single integrated wafer-level process. By combining these steps and eliminating the separate film application and vacuum securing steps, throughput increases and Z-height is reduced.

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

This approach results in significant Z-height reduction, increased manufacturing throughput, and cost savings by eliminating the need for new mold chases, while enabling more complex ICs to be tested and assembled efficiently at the wafer or panel level.

Implementation Method 1

one or more components, the one or more electrical interconnects, and the redistribution layer are embedded in a molding compound

Methodology Applied

Scientific EffectMolding:

Implementation Method 2

the tops exposed through grinding

Methodology Applied

Scientific EffectGrinding: Abrasion

Data Source

PatentUS10777486B2Substrate-free system in package design

Publication Date: 2020.09.15 TAHOE RES LTD

AI summary

Apparatuses and processes are disclosed for a substrate-free system in package that includes a through mold via Embodiments may include providing a circuit trace layer on top of a first side of a carrier, coupling a first set of one or more surface mount components to a first side of the circuit trace layer opposite the carrier, embedding the first set of the one or more surface mount components in a molding compound, exposing a second side of the circuit trace layer opposite the first side of the circuit trace layer, and coupling one or more electrical interconnects to serve as TMVs to the second side of the circuit trace layer. Embodiments may also include exposing the second side of the circuit trace layer by grinding the carrier. Other embodiments may be described and/or claimed.