Browse Prior Art Database

AIR LEVEL ASSISTED COATING PROCESS

IP.com Disclosure Number: IPCOM000008559D
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2002-Jun-24
Document File: 1 page(s) / 51K

Publishing Venue

Motorola

Related People

Roger Freeston: AUTHOR

Abstract

The conformal coating process consists of two spray booths, primer and coating. Both sides of the PC8 are primed and coated. The bottom side of the PCB is only populated with chip components which are low profile and easily covered in one pass of the spray gun. The top side of the board consists of larger components, these contribute to a more complicated profile.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 77% of the total text.

Page 1 of 1

0 M

MOTOROLA Technical Developments

AIR LEVEL ASSISTED COATING PROCESS

by Roger Freeston

BACKGROUND

  The conformal coating process consists of two spray booths, primer and coating. Both sides of the PC8 are primed and coated. The bottom side of the PCB is only populated with chip components which are low profile and easily covered in one pass of the spray gun. The top side of the board consists of larger components, these contribute to a more complicated profile.

  A programmed robotic arm carries a spray gun through a predetermined spray pattern across the surface of the printed circuit board in order to ensure coating coverage. The system is passed through with a "flip over" mechanism to enable both sides of the printed circuit board to be confor- ma1 coated.

PROBLEM

  Current cycle time to spray conformal coating onto a printed circuit board to ensure adequate cover of the board surface and the components is

37 seconds, this is too long to support the future manufacturing requirements,

SOLUTION

  In order to speed up delivery of the coating and ensure that the printed circuit board and the compo- nents are still adequately covered, two low velocity air knives (one for each lane of the coating machine) should be located at the entrance to the cure tunnel. The air knives should be as wide as the printed circuit board for maximum effect.

  The speed at which the robotic arm carries the spray gun can be increased so that the coating can be sprayed onto the (top side) surfa...