Semiconductor Leadframe Land Grid Array I/O Configuration
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Solution Overview
Problem
Conventional semiconductor devices have limitations in providing increased I/O capacity with reduced size and weight, as existing leadframe structures are unsatisfactory for high-frequency applications and consumer electronics.
Innovation Solution
The semiconductor device incorporates a leadframe with an increased number of lands in a prescribed arrangement, exposed within the package body, fabricated using standard forming techniques like sawing, punching, or etching, to enhance electrical isolation and protect the semiconductor die from moisture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional leadframe structures are used, then manufacturing cost is reduced, but I/O capacity is limited and size cannot be reduced further
Solution Approach 1:
The patent transitions from conventional peripheral lead arrangements to a land grid array configuration where multiple lands are distributed across the bottom surface of the package body. This spatial reorganization in the third dimension (bottom surface area) enables significantly increased I/O capacity without proportionally increasing package dimensions, resolving the contradiction between I/O quantity and device complexity.
Solution Approach 2:
The leadframe is segmented into multiple discrete lands (first lands, second lands, third lands, fourth lands) arranged in specific patterns around the die pad. This segmentation allows each land to function as an independent I/O terminal, enabling high I/O capacity while maintaining manufacturability through standardized formation processes for each segmented element.
2Quantity of substance
If the number of lands is increased, then I/O capacity is improved, but fabrication complexity increases
Solution Approach 1:
The patent employs universal formation techniques (sawing, punching, etching) that can create multiple land configurations from a single leadframe blank. These standardized processes can fabricate different land patterns (first, second, third, fourth lands) using the same equipment and methods, maintaining ease of manufacture while enabling increased land quantity through process versatility rather than requiring specialized fabrication for each additional land.
3Reliability
If lands are exposed within the package body, then electrical isolation is improved, but protection from moisture is worsened
Solution Approach 1:
The patent uses a plastic encapsulant material that forms a protective shell over the semiconductor die and leadframe structure. This encapsulant provides moisture barrier protection while allowing specific regions (lands) to remain exposed for electrical connection purposes. The flexible nature of the encapsulant enables it to conform to the complex leadframe geometry and provide selective coverage, maintaining both electrical isolation and moisture protection.
Data Source
AI summary
In accordance with the present invention, there is provided a semiconductor package or device including a uniquely configured leadframe sized and configured to maximize the available number of exposed lands or I/O's in the semiconductor device. More particularly, the semiconductor device of the present invention includes a die pad (or die paddle) defining multiple peripheral edge segments. In addition, the semiconductor device includes a plurality of lands which are provided in a prescribed arrangement. Connected to the top surface of the die pad is at least one semiconductor die which is electrically connected to at least some of the lands. At least portions of the die pad, the lands, and the semiconductor die are encapsulated by the package body, with at least portions of the bottom surfaces of the die pad and the lands being exposed in a common exterior surface of the package body.