Design rules Glass

Ref no.TVR-225-03-CS-D087Date2003-10-21Page4/5 = -1 + \* MERGEFORMAT 4

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Screen design rules

from screenprocessing

TVR-225-03-CS-D087

2003-10-21

Product and Process Development

Screen Processing Group

C.J. Selten

Table of contents

32.1 GLASS ROUGHNESS (STIPPLE).

2.1.1 Inside picture area.32.1.2 Upstanding wall.32.2 R/R TRANSITION.32.2.1 Position R/R transition.32.3 CORNER DESIGN.32.3.1 Angle inside upstanding wall in the corner.32.3.2 Horizontal radius in the corners.32.3.3 Heel radius in the corners.42.4 PIN.42.4.1 Pin diameter.42.4.2 Pin insertion.42.4.3 Connection pin ball.42.5 UPSTANDING WALL AROUND SHORT AND LONG SIDES OF THE SCREEN.42.5.1 Angle.4

1. Introduction

The screen design rules, which are important for screen processing, are described in TVB-657-99-CS-D1673, C. Selten, 1999-11-08.

In this report the design rules are updated with the Dreux experiences (Eric Abgrall).

2. Design rules

2.1 GLASS ROUGHNESS (STIPPLE).

2.1.1 Inside picture area.

Hibri screens

: Hibri stipple

: 0.4 m ( Ra ( 1.0 m

CMT screens

: Low matrix stipple

: 0.03 m ( Ra ( 0.09 m

TVT screens

: Medium matrix stipple: 0.1 m ( Ra ( 0.2 m

2.1.2 Upstanding wall.

Till minimal 15 mm under mould match line: 1.5 m ( Ra ( 4.0 m

2.2 R/R TRANSITION.

2.2.1 Position R/R transition.

The R/R transition must be outside the picture area.

If the transition is within the picture area this results in Pencil marks in the matrix pattern.

2.3 CORNER DESIGN.2.3.1 Angle inside upstanding wall in the corner.

Minimal 3.0 degrees. The larger the better to prevent wet corners (flow back) in the flowcoat process.

There should be no transition at the upstanding wall from a nominal angle to a steeper angle.

This reduces the flow of the phosphor suspension out of the corner, or even can build a thick difficult to dry wet phosphor layer.

2.3.2 Horizontal radius in the corners.The larger the better.

Minimal value for TVT types is 14.0 mm.

There must be no space under the pin from which the phosphor suspension cannot flow around the pin out of the screen.

If the radius is not large enough a pad can be designed in the corner. The pad should be wide enough because of the already described reason. In most cases, a flat surface perpendicular to the diagonal makes a good corner pad:

For wide screen panels with pins oriented at 29, it assures the wall angle is low at the place where the pin is inserted, preventing the phosphor suspension from flowing towards the pins

For 4:3 panels, the flat surface widens the suspension layer in the corner and avoids accumulation around the pin.

The larger the difference between wall angle in the corner (ISAD/IJAD) and pad angle (PDA), the more effective the corner pad.

2.3.3 Heel radius in the corners.The larger the better.

The smallest heel radii ever measured in the screen processing group are for CMT

screens is 6.5 mm and for TVT screens minimal 7 mm.

The absolute minimal heel radius is not only valid for the diagonal, but also for the

short and long sections: too low heel radius (6mm or below), especially when

combined with high wall angle (> 5), can lead to overflow problem (also called

Narrenkappe/Moustache).

2.4 PIN.2.4.1 Pin diameter.

The smaller the better.

If the pin diameter is smaller there is less space under the pin to collect the phosphor

suspension more space around the pin for flow of the phosphor suspension around the

pin.

2.4.2 Pin insertion.

The smoother the pin is inserted in the glass the easier the phosphor suspension flows

around the pin.

2.4.3 Connection pin ball.

As smooth as possible.

If the connection is smooth it is easier to remove the phosphor suspension by the corner

cleaning process out of the connection.

2.5 UPSTANDING WALL AROUND SHORT AND LONG SIDES OF THE SCREEN.

2.5.1 Angle.

The smaller the better.

If this angle is too big the phosphor suspension flows already along this sides out of the

screen (Narrenkappe/Moustache) in stead of through the corners.

2003 LG.Philips Displays Netherlands B.V.from screenprocessing STYLEREF DocSubtitle \* MERGEFORMAT Product and Process Development, Screen Processing Group IF ="" "" "Screen Processing Group, "

STYLEREF "DocDepartment" Screen Processing Group,

STYLEREF DocAuthor \* MERGEFORMAT C.J. Selten