Spring-Contact Molded Package for Adhesive-Free Die Connection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Molded electronic packages face issues with inconsistent conductive adhesive volume leading to substrate tilting and incomplete flux residue removal, affecting reliability and potentially causing electronic component failure due to ionic contamination.
Innovation Solution
A molded electronic package design incorporating a spring member between the second substrate and the electronic component, which is deformed and pressed against the component during manufacturing to form a thermal and/or electrical connection without adhesive, and is fixated by a conductive adhesive or mechanical features within the substrate, ensuring accurate positioning and encapsulation by a solidified molding compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive adhesive is used to attach the substrate to the electronic component, then electrical connection is achieved, but the adhesive volume inconsistency causes substrate tilting and positioning errors
Solution Approach 1:
A spring member is introduced as an intermediary element between the substrate and the electronic component. The spring member serves as a mediator that transmits electrical connection while accommodating positioning variations, eliminating the direct adhesive bond that causes tilting issues.
Solution Approach 2:
The spring member's elastic properties allow it to deform and adapt to slight positioning variations, changing its physical state from rigid to flexible. This parameter change enables the system to tolerate manufacturing tolerances without compromising electrical connection or substrate positioning.
2Reliability
If conductive adhesive is applied during manufacturing, then electrical connection is established, but flux residue remains incompletely removed affecting package reliability
Solution Approach 1:
The adhesive material is completely removed from the system and replaced with a spring member mechanism. This extraction eliminates the source of flux residue contamination entirely, as no adhesive application or flux cleaning process is required for the electrical connection.
3Strength
If adhesive is used to secure the substrate, then mechanical attachment is achieved, but inconsistent adhesive volume leads to substrate tilting
Solution Approach 1:
The spring member introduces dynamic flexibility to the mechanical attachment system. Instead of relying on precise adhesive volume control for static bonding, the spring member dynamically adapts to positioning variations through elastic deformation, maintaining both attachment strength and substrate flatness.
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 solution mitigates the drawbacks of adhesive inconsistencies and flux residue, enhancing the reliability and stability of the electronic package by maintaining a secure physical and electrical connection without the need for conductive adhesives, thus preventing potential failures.
Implementation Method 1
the spring member, which, during manufacturing, is deformed and pressed against the electronic component
Implementation Method 2
a body of solidified molding compound configured to encapsulate the electronic component and the spring member and to mutually fixate the first substrate, the second substrate, the electronic component and the spring member
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A molded electronic package (1a, 1b) comprises a first substrate (2), a second substrate (3), an electronic component (4) arranged on the first substrate (2), a spring member (5) arranged between the second substrate (3) and the electronic component (4), the spring member (5) comprising a first contact portion (5a) being fixed relative to the second substrate (3) and a second contact portion (5b) physically contacting the electronic component (4), and a body of solidified molding compound (6) encapsulating the electronic component (4) and the spring member (5) and mutually fixing the first substrate (2), the second substrate (3), the electronic component (4) and the spring member (5). The spring member (5) may be fixed to the second substrate (3) by an adhesive layer (e.g., solder). Alternatively or in addition, the spring member (5) may be fixed to the second substrate (3) by a recess in the second substrate (3) in which the first contact portion (5a) is arranged, the recess being configured to mechanically lock a position of the spring member (5) in a direction parallel to the second substrate (3); and/or the spring member (5) may be fixed to the second substrate (3) by one or more protrusions extending from the second substrate (3) and surrounding the first contact portion (5a), the one or more protrusions being configured to mechanically lock a position of the spring member (5) in a direction parallel to the second substrate (3). The second substrate (3) and the spring member (5) may be thermally conductive, wherein at least a portion of a surface of the second substrate (3) is exposed to an outside of the molded electronic package (1a, 1b), the second substrate (3) forming a heatsink for the electronic component (4). The second substrate (3) and the spring member (5) may be electrically conductive, wherein the second substrate (3) comprises: a planar portion (3a), the spring member (5) being arranged in between the planar portion (3a) and the electronic component (4); and a first lead (3b) integrally connected to the planar portion (3a) and extending from said planar portion (3a) and out of the body of solidified molding compound (6), wherein the first lead (3b) is electrically connected to a terminal of the electronic component (4) via the planar portion (3a) and the spring member (5), and forms a package contact of the molded electronic package (1a). Alternatively, the second substrate may comprise a printed circuit board, PCB, comprising a dielectric layer and a circuit arranged on the dielectric layer, wherein the circuit is electrically connected to the electronic component (4) through the spring member (5). The first substrate (2) may be electrically conductive and electrically connected to a terminal of the electronic component (4), wherein the first substrate (2) comprises a pad portion (2a) on which the electronic component (4) is arranged, and wherein the pad portion (2a) comprises a surface that is exposed to an outside of the molded electronic package (6), said surface forming a package contact of the molded electronic package (6), and/or wherein the first substrate (2) further comprises a second lead (2b) integrally formed with the pad portion (2a), said second lead (2b) extending from said pad portion (2a) and out of the body of solidified molding compound (6), wherein the second lead (2b) forms a package contact of the molded electronic package (1a); and/or wherein the electronic component (4) comprises a semiconductor die having a circuit integrated thereon, wherein the circuit comprises a plurality of terminals corresponding to terminals of the electronic component (4), wherein the first substrate (2) preferably comprises a die pad. The molded electronic package (1b) may further comprise: a further package contact (9), a first end thereof being external to the body of solidified molding compound (6), and a second end thereof being encapsulated by the body of solidified molding compound (6); a further spring member comprising a first further contact portion (8a) contacting the second substrate (3), and a second further contact portion (8b) contacting the further package contact (9), wherein the further spring member is electrically conductive, wherein the further spring member is preferably integrally connected to the spring member (5). In a method for manufacturing the molded electronic package (1a, 1b), a molding compound is applied and allowed to solidify to thereby form the body of solidified molding compound (6) upon applying a force (P1, P2, P3) to the second substrate (3), said force (P1, P2, P3) allowing the second contact portion (5b) of the spring member (5) to deform and press against the electronic component (4). At least part of a surface of the second substrate (3) may be kept clear of molding compound, wherein the force (P1) is applied to said part of the surface of the second substrate (3); and/or a first end portion and an opposing second end portion of the second substrate (3) are kept clear of molding compound, wherein the force (P2, P3) is applied to said first end portion and second end portion.