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Multi-Layer Circuit Green Sheet Carrier and Misplacement Detection Device

IP.com Disclosure Number: IPCOM000034984D
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 61K

Publishing Venue

IBM

Related People

Brown, ME: AUTHOR [+3]

Abstract

A technique is described whereby a multi-layer circuit (MLC) green sheet carrier is capable of holding up to four green sheets in position for punching via holes, as used in the fabrication process of printed circuit boards. A misplacement detection device is used in conjunction with a positioning mechanism to accurately locate and hold the sheets in place while loading. (Image Omitted) The carrier consists of five basic elements; carrier mechanism, riser, pneumatics, controller and the software required to operate the device. The five elements are as follows: - Carrier - The carrier is used to locate and hold up to four green sheets in proper position for punching of via holes.

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Multi-Layer Circuit Green Sheet Carrier and Misplacement Detection Device

A technique is described whereby a multi-layer circuit (MLC) green sheet carrier is capable of holding up to four green sheets in position for punching via holes, as used in the fabrication process of printed circuit boards. A misplacement detection device is used in conjunction with a positioning mechanism to accurately locate and hold the sheets in place while loading.

(Image Omitted)

The carrier consists of five basic elements; carrier mechanism, riser, pneumatics, controller and the software required to operate the device. The five elements are as follows: - Carrier - The carrier is used to locate and hold up to four

green sheets in proper position for punching of via holes.

The sheets are held in place by a chuck which is made of a

material which will provide long term stability and will

minimizes thermal expansion. The carrier is cantilevered,

using three opposing springs so as to maintain a flatness of

+ -.0005".

- Riser - The riser is a mechanism attached to the carrier and

consists of four floating grills to hold the green sheets in

place prior to application of vacuum. This prevents the

sheets from becoming deformed during the loading operation.

When the sheets are loaded, the riser drops away before the

carrier moves the sheets to the punching area. During the

punching operation, the risers are positioned to act as a

safety shield to prevent the operator from reaching into the

punching area.

- Pneumatics - The pneumatics consist of four double-acting

three position solenoids which are used to provide either

pressure to float the sheet, or vacuum to the chuck to hold

the sheet, or to shut both pressure and vacuum to the off

position when the device is not in use. Eight vacuum switches

are used to detect the sheets for orientation at the various

operating locations.

- Controller - The controller utilizes an industrial personal

computer which incorporates a digital input/output circuit

interface connected to the detection switches and solenoids.

An operator console is equipped with a start/stop switch,

ON/OFF indicator light, an advance switch, four indicator

lights for each green sheet position, and a ready indicator

light.

- Software - The software is designed to operate in conjunction

with the industrial personal computer and follows the flow

chart, as shown in the figure. The sequence of operation is as

follows:

1

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1) The riser advances upward when the carrier stage is at the

home position. A sliding door is unlatched when the riser

is in the up position, so as to enable the operator to load

the sheets into position.

2) The operator places the first sheet onto the carrier, using

orientation holes in accordance with...