Lead Terminal Clamp Portions for Insert Molding Stress Reduction
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Solution Overview
Problem
Existing semiconductor device manufacturing methods using insert molding apply stress to lead terminals, potentially deforming them and affecting wire bonding properties and reliability, particularly in vibration and heat cycle tests.
Innovation Solution
The method involves using clamp portions with notch portions on lead terminals, which are inserted between molds during resin molding, allowing for precise positioning and reduced stress, ensuring accurate bonding without deformation and maintaining wire bonding integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If unnecessary parts of external lead-out terminals are cut off after insert molding, then the lead terminal thickness is reduced, but stress is applied to the external lead-out terminals causing deformation and gaps between terminals and resin layer
Solution Approach 1:
The patent applies preliminary action by forming clamp portions with clamp protrusions on the lead terminals before the insert molding process. These clamp protrusions engage with the mold during molding to prevent deformation during subsequent cutting operations, thus preserving wire bonding properties while allowing thickness reduction.
Solution Approach 2:
The clamp portions with clamp protrusions provide preliminary anti-action by counteracting the stress that will be applied during the cutting process. The clamp protrusions are positioned to prevent deformation of the external lead-out terminals before the harmful cutting stress is applied, thereby maintaining manufacturing precision.
2Stability of the object's composition
If fixation pins are used to fix the lead frame during molding, then the lead frame is secured, but the places where the lead frame is fixed by the fixation pins are deformed as the thickness of lead terminals is reduced
Solution Approach 1:
The patent applies segmentation by dividing the lead frame into multiple regions with different functions: clamp portions with clamp protrusions for stress prevention during cutting, fixation pin insertion portions for stable positioning during molding, and bonding portions for wire bonding. This segmentation allows each region to optimize its function without interfering with others.
Solution Approach 2:
The patent applies local quality by providing different structural features at different locations of the lead terminals. The clamp portions have clamp protrusions for stress prevention, the fixation pin insertion portions have recesses for positioning, and the bonding portions have smooth surfaces for wire bonding. This localized differentiation resolves the contradiction between stable positioning and deformation prevention.
Data Source
AI summary
A resin casing is insert-molded while clamp protrusions of clamp portions formed in bonding portions of lead terminals are put between an upper mold and a lower mold. An insulating substrate which has a wiring pattern mounted with semiconductor elements is fitted into an opening portion of the resin casing and adhesively bonded to the resin casing. Electric connection between the semiconductor elements and the bonding portions of the lead terminals and between the wiring pattern on the insulating substrate and the bonding portions of the lead terminals is made by bonding wires. Thus, it is possible to provide a method for manufacturing a semiconductor device and the semiconductor device, in which stress applied to lead terminals of a lead frame formed by insert molding can be suppressed, and wire bonding properties and reliability can be improved even when the thickness of each of the lead terminals is reduced.