Browse Prior Art Database

Surface-Mounted Components

IP.com Disclosure Number: IPCOM000044554D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Tate, EA: AUTHOR

Abstract

This article describes a technique for preparing a circuit board so that surface-mounted components may be placed on opposite sides of a circuit board in such a manner as to minimize land patterns for interconnecting circuits. The technique requires (1) mirror imaged component pin patterns and (2) that the orientation of the mounting pads, on either side of the circuit board, be 360Πout of phase and placed directly opposite each other on front and back sides of the circuit board. Interconnectivity is now accomplished by straight holes bored in the board at the pad locations. This technique is particularly useful for the design of memory circuit boards and any other highly bus-oriented designs. Fig. 1 shows a side view of a lead chip carrier (LCC) component as it is currently manufactured and mounted to a circuit board. Fig.

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Surface-Mounted Components

This article describes a technique for preparing a circuit board so that surface- mounted components may be placed on opposite sides of a circuit board in such a manner as to minimize land patterns for interconnecting circuits. The technique requires (1) mirror imaged component pin patterns and (2) that the orientation of the mounting pads, on either side of the circuit board, be 360OE out of phase and placed directly opposite each other on front and back sides of the circuit board. Interconnectivity is now accomplished by straight holes bored in the board at the pad locations. This technique is particularly useful for the design of memory circuit boards and any other highly bus-oriented designs. Fig. 1 shows a side view of a lead chip carrier (LCC) component as it is currently manufactured and mounted to a circuit board. Fig. 2 represents the modified LCC plastic package. The notable difference is that in the modified version the top half (A) of the component is basically cast the same as the bottom half (B). The difference between the two is that the orientation corner for the bottom half (B) must be a mirror image, as shown in Fig. 3. Additionally, the leads have been reformed to go up and over the top half (A). This solution provides a manufacturer with the option of vendoring preformed, leaded components for surface mounting of either or both versions or providing the package with straight (unformed) leads which a user might form t...