Browse Prior Art Database

MULTIPLE BOARD LOAD SENSING SYSTEM

IP.com Disclosure Number: IPCOM000009678D
Original Publication Date: 2000-Jan-01
Included in the Prior Art Database: 2002-Sep-10
Document File: 2 page(s) / 71K

Publishing Venue

Motorola

Related People

Tracy Chan: AUTHOR [+3]

Abstract

On occasion, two boards enter a part placement machine, when only one board should enter the placement machine at one time as shown in Figure 1 on next page. The placement machine will only place parts on the first board, and will ignore the second. The part placement machine does not have the ability to sense the second board entering. Also, with two boards being close together in the part placement machine, sensors throughout the line will not detect the extra board. As a result, the second board will proceed through the rest of the surface mount process without any parts being placed on it.

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0 M MOTVROLA Technical Developments

MULTIPLE BOARD LOAD SENSING SYSTEM

by Tracy Chan, Ted Hutson and William Kanizar

  On occasion, two boards enter a part placement machine, when only one board should enter the placement machine at one time as shown in Figure 1 on next page. The placement machine will only place parts on the first board, and will ignore the second. The part placement machine does not have the ability to sense the second board entering. Also, with two boards being close together in the part placement machine, sensors throughout the line will not detect the extra board. As a result, the second board will proceed through the rest of the surface mount process without any parts being placed on it.

  The second board will not be found until after the reflow process, and it will have to be scrapped because the board will have undergone the reflow process without its parts, and adequately repairing such a board manually will be next to impossible.

  The present invention proposes adding an auxil- iary sensor and logic relay to the part placement machine and incorporating the auxiliary sensor out-

put via the logic relay to the part placement machine's controller as shown in Figure 2. If the auxiliary sensor is triggered, the part placement machine halts operation and sounds an audible alarm in addition to placing an error message on the controller's monitor.

  In essence, the auxiliary sensor and logic relay make the part placement machine think there is a load...