Print head investigation

Print Head Investigation 2013

Print Head Investigation

AnalysisPrepared By: Joanne de Guzman

I. INTRODUCTION

Research and Development (Joanne R&D)


Print head defect problems is the most common defect that we often encountered in the inspection stage of head type cartridges. The defect can range 30 to 40% per remanufacturing stage, too high percentage where in we can produce 60% only to our main output. Prior to our kaizen suggestion, we refined some of the processes that can cause defect B, result seems quite good but however, It will be a hard time to eradicate Defect A for which the only weapon that we use in inspecting those cartridges was only our naked eye. In this investigation, come with me to analyze what and how the print head was.

II. TECHNICAL ANALYSIS

HOW THE PRINT HEAD LOOKS LIKE?

Print Head with Enlarged View of Nozzle Configuration

The distance between wires in column may give us vertical printing resolution. For example: 9 wire print head with distance 0.35 mm between adjacent wires will result in 25.4/0.35=72.5 dots/inch vertical printing resolution for one pass printed line of characters. 24 wires print heads has 2 columns, 12 wires each, with a vertical displacement of ½ step. So if the distance between adjacent wires is 0.21 mm, then one column will print with 25.4/0.21=120.9 dots/inch vertical resolution, but since the second column print between the dots printed from the first one, the overall vertical resolution will be 240 dots/inch.

Achieving smaller droplet sizes and faster print speeds requires high-precision fabrication technologies to enable the placement of a greater number of nozzles over a wider area. Print heads are made by integrating the heaters and nozzles into a single unit on a wafer using a process that makes the most of the company's expertise in semiconductor production, as well as its original material technologies and innovative processing technologies. The ability to fabricate nozzles with high precision over large areas without using bonding processes makes it possible to arrange 6,000 or more nozzles within an area measuring a mere 20 mm x 16 mm, roughly the size of a thumbprint.

An ink-jet drop on a plain paper during printing.



This is the drop of ink that the print head sprayed on the paper, look at the size of your hair strand, just by seeing that you can and imagined the real size of the print head and the ink flows from it.

III. CURRENT STATUS

As of the current situation there is huge quantity of print head damages especially Defect A that was disposed and cannot be used. This is the everyday problem that we often encountered in our head type production.

We do several methods till we found this new technology that can help us to finally have a criteria on head type damage inspection; this is through microscope inspection. The microscope magnifies the print head 100x seeing the fine heads where the ink drops.

IV. INSTRUMENT FOR HEAD INSPECTION



This piece of instrument can determine and check the damage on the print head area. It is purchased in China that having the same specification that is comparable to Keyence Camera.

V. CURRENT STATUS

The damage that you seen above were automatically judge as NG and that particular cartridge was subject for disposal.

This is the daily scenario that inspection encountered every day.

How can we improve it?

VI. SOLVING ISSUES


Specification:2,000,000 pixels100x magnifying powerPrice: RMB1, 250

Small Damage


VII. BUILDING A CRITERIA


Damage seen by naked eye

Damage seen using microscope

Printing result OK


VIII. OTHER DAMAGES THAT IS OK


The center portion is qualified to have damage.

Print head area, very sensitive to have damage.

Chip probe area.

Good Printing result based from actual


To unify, the purpose of this investigation was to have an inspection criteria upon the usage of this inspection camera. Now that we can determine the delicate part we can make a criterion based form this report for us to use this in near future.


Good Printing result based from actual

Print head investigation

Technology

Transcript of Print head investigation