Electronic Package Molding Supports to Prevent Die Pad Flash
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Solution Overview
Problem
Existing electronic package manufacturing methods often result in thick flashes of molding compound forming under die pads and package contacts, which can obstruct electrical contacts and reduce the effectiveness of die pads as heatsinks, leading to potential manufacturing inefficiencies and performance issues.
Innovation Solution
The method involves using conductive mechanical supports that are either integrally connected to or separately fixedly connected to die pads and electrical contacts, with the second mold portion contacting these supports during molding to prevent compound accumulation and form part of the package terminals, allowing for singulation without cutting through the die pads, thereby preventing thick flashes and maintaining heatsink functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a molding compound is injected into the molding cavity to encapsulate semiconductor dies, then the semiconductor dies are protected and encapsulated, but thick flashes of package material form under die pads and package contacts, obstructing electrical contacts and reducing heatsink effectiveness
Solution Approach 1:
The patent applies preliminary action by providing mechanical supports (such as pins or protrusions) on the mold that contact the die pads or package contacts before the molding compound is injected. These supports pre-position and stabilize the electrical contacts, preventing the molding compound from forming thick flashes underneath them. The supports are removed after molding, leaving clean electrical contacts without obstructing material.
Solution Approach 2:
The patent uses mechanical supports as intermediary elements between the mold and the electrical contacts during the molding process. These intermediaries (pins or protrusions) temporarily hold the die pads or package contacts in place, allowing the molding compound to flow around them without forming thick flashes. After the molding is complete, the intermediaries are removed, leaving clean electrical contacts.
2Reliability
If package material covers die pad to encapsulate semiconductor die, then encapsulation is achieved, but the effectiveness of die pad as heatsink is decreased
Solution Approach 1:
The mechanical supports are positioned in advance to prevent molding compound from accumulating under the die pads. By stabilizing the die pads before injection, the supports ensure that the molding compound forms a thin, uniform layer rather than thick flashes, thereby maintaining thermal contact between the die pad and the underlying substrate for effective heat dissipation.
Solution Approach 2:
The patent converts the potential harm of molding compound accumulation into a benefit by using mechanical supports to control the flow and distribution of the compound. Instead of allowing harmful thick flashes to form, the supports guide the compound to form a protective encapsulation layer that maintains thermal conductivity while providing mechanical protection.
3Ease of manufacture
If mold is removed after solidification, then the encapsulated structure is formed, but thick flashes of package material remain obstructing electrical contacts
Solution Approach 1:
The mechanical supports are installed before molding to prevent flash formation during the injection process. By pre-positioning these supports, the patent ensures that when the mold is removed, the electrical contacts are already free of thick flashes, eliminating the need for additional cleaning or trimming operations.
Solution Approach 2:
The mechanical supports serve as temporary intermediaries during the molding process that are removed after encapsulation. Their presence during injection prevents flash formation, and their removal leaves clean electrical contacts without obstructing material, simplifying the overall manufacturing process.
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 effectively prevents molding compound from obstructing electrical contacts and die pad heatsinks, ensuring reliable electrical connections and efficient heat dissipation while reducing manufacturing time by avoiding unnecessary cutting through the die pads.
Implementation Method 1
applying a molding compound in the molding cavity and allowing the molding compound to solidify to thereby form a body
Data Source
Figure 1
Figure 2A
Figure 2B~2D
AI summary
Aspects of the present disclosure generally relate to an electronic package and a method for manufacturing such electronic packages. The method includes providing a frame including a plurality of die pads, each die pad having arranged thereon a semiconductor die, the semiconductor die having a first electrical contact on a first side of the semiconductor die facing and electrically contacting the die pad, and a second electrical contact on a second side of the semiconductor die opposite to the first side, providing a first conductive mechanical support that is fixedly connected to the die pad and/or providing a second conductive mechanical support that is fixedly connected to the second electrical contact, and providing a mold comprising a first mold portion on which the frame is arranged, and a second mold portion that is brought into contact with the frame opposite to the first mold portion, the mold forming a molding cavity around the plurality of semiconductor dies, wherein the second mold portion contacts at least one of the first conductive mechanical support and the second conductive mechanical support while applying the molding compound and allowing said molding compound to solidify.