Bare die tray with flat datum surface

Abstract

In one embodiment of the present invention, a component tray includes a component housing portion having a plurality of component pockets, with each pocket opening to a component housing top surface. The tray has a flange around the component housing portion defining a perimeter of the tray. A flange top surface in one embodiment is below the component housing top surface. A plurality of bosses extend downward from a flange bottom surface, and are designed to be positioned in dis-alignment with burrs caused by contact of mold ejector pins with flange bottom and top surfaces. The height of the bosses is designed to exceed the height of burrs, and therefore avoid contact of the burrs with any surface upon which the tray is set. A bottom cavity provides clearance for a tray component housing.

Description

RELATED APPLICATIONS [0001] This application is related to U.S. application entitled Tray With Flat Bottom Reference Surface filed on the same date as this application, having attorney reference 0067810 / 0303882 which is expressly incorporated by reference herein.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to trays for use in carrying components such as semiconductors, and more particularly to a tray having flat datum surfaces and configured to avoid calibration variations due to mold injector pin burrs imposed on the tray during manufacture. [0004] 2. Description of the Related Art [0005] Small components such as semiconductors are often stored or shipped in molded plastic trays similar to tray 10 shown in FIGS. 1A and 1B. In the molding production operation, ejector pins are used to push / eject the tray from the mold casing. Burrs are caused from molten plastic filling the circumferential gap between the ejector pin and the ejector pin ...

AI Technical Summary

Benefits of technology

[0007] It is an advantage of this invention in that it provides a component tray that has improved reference surfaces.

[0008] It is a further advantage in this invention in that it adds bosses to a bottom surface of a tray so as to avoid uncertain contacts due to burrs.

[0009] It is a still further advantage of this invention in providing a tray that in use maximizes the accuracy of calibration of automated equipment.

[0010] It is another advantage of this invention in providing a tray that can be stacked accurately.

[0011] It is another advantage of this invention in providing a tray wherein ejector pin blemishes do not affect stacks and calibration.

[0012] In one embodiment of the present invention, a component tray includes a component housing portion having a plurality of component pockets, with each pocket opening to a component housing top surface. The tray has a contacting surface which makes contact with a mating surface upon which the tray is placed, such as an equipment handling base, or a contacting surface of another tray if trays are stacked. In one embodiment the contacting surface is on a flange surrounding the component housing portion defining a perimeter of the tray. A flange top surface in one embodiment is below the component housing top surface. A plurality of bosses extend downward from a flange bottom surface, and are designed to be positioned in dis-alignment with burrs caused by contact of mold ejector pins with flange bottom and top surfaces. The height of the bosses is designed to exceed the height of burrs, so as to avoid contact of the burrs with any surface upon which the tray is set. A bottom cavity in each tray provides clearance for a tray component housing of another tray upon which it is stacked.

Problems solved by technology

Part ejection is a forceful process, and the pressure of the pins on the tray leaves burrs / marks / blemishes on the tray surfaces.

These burrs cause variations in the effective tray thickness and as a result trays cannot be stacked with a consistent height or degree of flatness.

The burrs cause errors in calibration of automated tray handling equipment, and equipment for picking and placing components in tray component packets.

Removal of burrs would involve additional and expensive machining or manual processes, and generally is not practical.

These distorted / inaccurate reference surfaces limit the ability of automatic machines to accurately pick and place components in the tray.

The burrs 12 and / or 14 also cause an uncertainty in the height and straightness of a stack of trays 10, causing problems with automatic stack handling equipment, as well as problems with shipping containers and clips.

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