Strip-Shaped Substrate Anchoring Edge for Thin Chip Carriers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing strip-shaped substrates for producing chip carriers have a minimum film thickness requirement that limits the overall thickness of electrical modules, making it difficult to reduce the module thickness without compromising the secure anchoring of the potting compound and stability of the chip carrier.
Innovation Solution
A strip-shaped substrate with units featuring a chip island, electrodes, and openings, where the surface section adjoining the opening is folded to create a beveled anchoring edge that protrudes beyond the foil side, allowing for secure mechanical connection with the encapsulation compound, regardless of the substrate thickness, using a hard-rolled austenitic stainless steel foil with a thickness of 15 µm to 35 µm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the film thickness is reduced to decrease module thickness, then the overall thickness of the electrical module is reduced, but the anchoring effect of the potting compound is compromised
Solution Approach 1:
The anchoring edge is formed by folding the surface section of the foil, creating a three-dimensional protruding structure that extends beyond the foil surface. This dimensional transformation allows the anchoring edge to provide sufficient mechanical interlocking for the potting compound without requiring increased film thickness, thus resolving the contradiction between thin module design and reliable anchoring.
Solution Approach 2:
The invention changes the geometric parameters of the anchoring structure by folding the surface section to create a protruding anchoring edge. This parameter change enables effective anchoring with thinner foil, as the folded structure provides the necessary depth and surface area for potting compound adhesion without increasing the base film thickness.
2Reliability
If the film thickness is increased to improve anchoring, then the anchoring effect is enhanced, but the overall thickness of the electrical module increases
Solution Approach 1:
Instead of increasing film thickness in the vertical dimension, the invention creates anchoring depth by folding the surface section to form a protruding anchoring edge. This approach achieves enhanced anchoring through geometric transformation rather than material thickness increase, thereby maintaining thin module overall dimensions while improving anchoring reliability.
3Length of stationary object
If the foil is made thinner to reduce module thickness, then the module becomes more compact, but the stability of the chip carrier is reduced
Solution Approach 1:
The folding of the surface section creates a three-dimensional anchoring edge that provides mechanical stability without requiring increased foil thickness. This geometric transformation compensates for the reduced material thickness by creating structural depth and rigidity through the folded configuration, thereby maintaining chip carrier stability in thin-module designs.
Solution Approach 2:
The invention creates a composite structure where the folded surface section forms an integrated anchoring feature combined with the potting compound. This composite configuration enhances the mechanical stability of the chip carrier by combining the foil structure with the encapsulating compound, achieving robust stability without increasing base material thickness.
4Reliability
If the anchoring edge is formed by undercut through embossing, then the anchoring effect is achieved, but a minimum film thickness is required which limits module thinness
Solution Approach 1:
Instead of creating an undercut by removing or recessing material (embossing), the invention inverts the approach by folding the surface section outward to create a protruding anchoring edge. This inverted methodology achieves anchoring through material addition to the surface profile rather than material removal, eliminating the minimum film thickness constraint associated with embossing techniques.
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 reduces the overall thickness of the electrical module to approximately 200 µm while maintaining secure anchoring and stability, allowing for thinner and more robust chip carriers without increasing mechanical stresses.
Implementation Method 1
A surface section of the foil adjoining the opening is folded to form the anchoring edge
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
The invention relates to a strip-shaped substrate made from a film (1) comprising a plurality of units (2) for producing chip carriers, wherein each unit has a chip island (3) for fixing a semiconductor chip, electrodes (4) for electrical connection of the semiconductor chip, and through openings (7, 8, 9, 10) for structuring the unit (2), wherein at least one through opening (7, 8, 9, 10) forms an anchoring edge (11) for a casting compound for encapsulating the semiconductor chip, wherein a surface section (12) of the film (1) abutting the through opening (7, 8, 9, 10) is chamfered to form the anchoring edge (11), wherein the anchoring edge (11) protrudes past the side of the film (1) on which the chip island (3) is arranged.