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Pad Reference Orienting Nest Manufacture Via Coining

IP.com Disclosure Number: IPCOM000046960D
Original Publication Date: 1983-Sep-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Donald, GW: AUTHOR [+2]

Abstract

This arrangement solves the problem of manufacturing pad reference orienting nests (PRONs) with consistent nest uniformity, finish and accuracy. The precise orientation and location of a chip prior to pick and place on a ceramic substrate is critical to the final placement accuracy of chip-placement systems. Present technology utilizes a device called a PRON. The PRON's locating accuracy is dependent on a precisely machined tapered wall nest 10 which locates the chip 12 via the ball 14 pattern at the base of the chip (Fig. 1). The following is a description of a manufacturing process which is capable of producing PRONs with nest dimensions consistently within dimensional tolerance requirements. The key element in producing a nest 10 consistently within tolerance is found in a manufacturing technique known as coining.

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Pad Reference Orienting Nest Manufacture Via Coining

This arrangement solves the problem of manufacturing pad reference orienting nests (PRONs) with consistent nest uniformity, finish and accuracy. The precise orientation and location of a chip prior to pick and place on a ceramic substrate is critical to the final placement accuracy of chip-placement systems. Present technology utilizes a device called a PRON. The PRON's locating accuracy is dependent on a precisely machined tapered wall nest 10 which locates the chip 12 via the ball 14 pattern at the base of the chip (Fig. 1). The following is a description of a manufacturing process which is capable of producing PRONs with nest dimensions consistently within dimensional tolerance requirements. The key element in producing a nest 10 consistently within tolerance is found in a manufacturing technique known as coining. This technique has been utilized to produce the tapered nest 10 in the top surface of the PRON in order to avoid the less accurate and time consuming process of machining the nest configuration. When the coining technique is utilized, the nest configuration will be duplicated exactly in each PRON as it is in the manufacture of coins, and its accuracy is dependent on the original accuracy and finish of the coining hob. First, a coining hob 18 must be fabricated (Fig. 2). The material must be a high-grade tool steel capable of heat treatment to obtain a minimum hardness of Rockwell 55-60. Prior to heat treatment, the hob 18 is rough finished to dimensions slightly larger than those required. After heat treatment, the hob is finish ground so that it is absolutely square and has the clearance between the hob and hob block required. The 30OE angles are finish ground and lapped to a !2 finish after the hob has been squared, leaving a flat square area. It is absolutely necessary to maintain the tapered surfaces equidistant from the center of the hob. This will enable the coining of a perfectly symmetrical tapered nest....