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STRUCTURE AND METHOD OF FORMING A NOVEL FLAT LEAD SINGLE SIDED SEMICONDUCTOR PACKAGE MOLD

IP.com Disclosure Number: IPCOM000021452D
Publication Date: 2004-Jan-19
Document File: 3 page(s) / 51K

Publishing Venue

The IP.com Prior Art Database

Abstract

Key Words: Semiconductor Package, Flat Lead, Package Mold, De-gate, Chipping, Defects Background: A problem one sided mold designs used to produce flat lead semiconductor packages have is their high defect rate. Defects like chipping are costly as the finished semiconductor package does not meet customer expectations for fit, finish, and integrity. Chipping is induced during de-gating from placing the mold gate on the mold parting or break line (refer to Figure 1). Particularly deleterious are chips that propagate along the topside of the finished package as this area is used to mark the finished package. Moreover, these topside chipping impair effective pattern recognition equipment used during assembly due to their effect on the topside package dimensions. Thus, it would be an advantage in the art to produce a mold and method of using that produced flat lead semiconductor packages without defects.

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STRUCTURE AND METHOD OF FORMING A NOVEL FLAT LEAD SINGLE SIDED SEMICONDUCTOR PACKAGE MOLD

Key Words: Semiconductor Package, Flat Lead, Package Mold, De-gate, Chipping, Defects

Background:

A problem one sided mold designs used to produce flat lead semiconductor packages have is their high defect rate. Defects like chipping are costly as the finished semiconductor package does not meet customer expectations for fit, finish, and integrity. Chipping is induced during de-gating from placing the mold gate on the mold parting or break line (refer to Figure 1). Particularly deleterious are chips that propagate along the topside of the finished package as this area is used to mark the finished package. Moreover, these topside chipping impair effective pattern recognition equipment used during assembly due to their effect on the topside package dimensions. Thus, it would be an advantage in the art to produce a mold and method of using that produced flat lead semiconductor packages without defects.

Detailed Description of the Drawings:

Chipping during the de-gate process can be eliminated by moving the mold gate inwards away from the mold parting line (refer to Figure 2). Moreover, in a one sided mold, introduction of a mold gate bump to shift the mold gate location inwards provides a low cost, easy means of shifting the mold gate away from the mold parting line as shown below in the figures. The small bump has a small draft angle.

 
 

FIGURE 1

 
 

 
 

FIGURE 2

 
 

           
 

Breaking Guide after Using New Gate...