Specific Process Knowledge/Back-end processing/Disco Saw

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Disco Automatic dicing saw, model DAD321 and DAD3241

DTU nanolab have 2 saws available for dicing substrates into separate chips. Both tools offer versatile processing capabilities, high precision and reliability.

The dicers at DTU Nanolab is placed in room 157 on the first floor in bldg. 346. Please notice that this room is not under filter. Generally speaking the dicing process is very dirty, and you should expect particle contaminants on your device.

Dicers positioned on 1. floor bldg 346 room 157

In general it is not allowed to bring back your samples into the Cleanroom. You need approval from DTU Nanolab staff to do this, follow the instructions here to apply for approval. Your samples have to be thoroughly cleaned before entry, at a minimum a triton ultrasonic clean followed by a piranha clean. You will only be allowed to use a limited number of tools for the processing after dicing.

Comparison of Disco DAD 321 and DAD 3241 Dicing tools

Machine	Name	DAD 321 (old)	DAD 3241 (new 2021)
	Operation	Keyboard F-key menu driven BW screen	Touch screen Guided menu Color screen
Purpose	Main usage	Borofloat Fused Silica	Silicon wafers
	Substrate type	Pyrex/Borofloat Silicon bonded to Silicon Silicon bonded to Pyrex/Borofloat Silicon	Silicon Pyrex/Borofloat Silicon bonded to Silicon Silicon bonded to Pyrex/Borofloat
		For other materials, contact tool responsible (See Labmanager)
Performance	X-axis cutting range	192 mm	210 mm
	X-axis cut speed	0.1 - 300 mm/sec	0.1 - 800 mm/sec
	Y-axis cutting range	162 mm	210 mm
	Y-axis index step	0.0002 mm	0.0001 mm
	Y-axis single error	0.003 or less	0.002 or less
Substrates	Substrate size	up to 6"	up to 8"
	Layers that can't be diced	Thick metal (>0.75 mm) III-V samples	Thick metal (>0.75 mm) III-V samples
Accessories	Accessories for wafer handling	Manual wafer mounter for blue tape	Manual wafer mounter for tape with backside foil (Powatec P200) Automatic Wafer cleaning station (Disco DCS 1441) UV curing station (Powatec U200)

Wafer mounting table for DAD 321	Wafer mounter for DAD 3241	Wafer cleaning station DCS 1441
UV curing/Tape release for DAD 3241

Process information

The user manual, user APV, technical information and contact information can be found in LabManager:

• DAD 321 Saw in LabManager
• DAD 3241 Saw in LabManager

Dicing layout

The dicer is only capable of cutting straight, uninterrupted lines across the entire substrate. Therefore each the position of each individual die must be carefully considered to maximize yield. Please see the below illustrations for a good and a bad design.

GOOD design - simple	GOOD design - complex	BAD design
GOOD design - simple	GOOD design - complex	BAD design
	drawings by Jesper Hanberg, DTU Nanolab

The simplest design consists of identically sized chips placed at constant pitch across an entire wafer. While it is possible to cut at varying pitches, it requires a more complex program and leaves more room for user errors.

It is not possible to interrupt a cut and continuing further down a line, in order to cut out a large chip surrounded by smaller chips, several mounting-dicing-remounting operations must be done.

Recommended dicing parameters

WIP DTU Nanolab offers 2 different blades for different use cases. See recommended parameters below.

For other materials/blades consult tool responsible.

Material	Tool	Blade	Feed speed	Blade RPM	Max removal per cut*
Si	DAD3241	ZH05	10-40 mm/s	30'000	1mm
Pyrex	DAD321	B1A862	1.5 mm/s	15'000	0.5mm
Fused Silica	DAD321	B1A862	1.0 mm/s	15'000	0.3mm
Bonded Si/Pyrex	DAD321	B1A862	0.5 mm/s	15'000	0.5mm

(*) Multiple cuts at the same location can be done if deeper cuts are needed

Available blades

WIP

Table, max sample thickness, expected cut line width, images of cut

Comparing dicing parameters for different materials DAD 321

Do not mix blades for the DAD 321 with the blades for the DAD 3241. They have different outer diameters

	Silicon	Pyrex or bonded Si/Pyrex
Bladetype	HUB Blade ZH05 (27HEEF)	HUBless Blade B1A862
Blade width	50 µm	150 µm
Cutlinewidth	60 µm	180 - 200 µm
Recommended feed speed	Up to 20 mm/sec	Up to 2 mm/sec (0.5 mm/sec)
Recommended dice depth	Set blade height to 200µm (preferred). This leaves 125µm uncut since blue tape is 75µm. It is possible to cut through the sample.	Do not cut deeper than 500 µm in each pass (for fused Silica and SiC 200 µm). If you have thicker wafers then use several passes decreasing the blade height for each pass. For 500 µm thick wafers set blade height to 200µm (preferred). This leaves 125µm uncut since blue tape is 75µm. It is possible to cut through the sample.
Max. sample thickness	1.5 mm	2.0 mm

Comparing dicing parameters for different materials DAD 3241

Do not mix blades for the DAD 321 with the blades for the DAD 3241. They have different outer diameters

	Silicon	Other materials
Bladetype	HUB Blade	Ask! (HUBless)
Blade width	50 µm	ask
Cutlinewidth	50 µm	ask
Recommended feed speed	Up to 40 mm/sec	ask
Recommended dice depth	We usually cut all way through the wafer with a blade height of 50µm (preferred).	ask!
Max. sample thickness	1.5 mm	2.0 mm

Available blades

THIS CHAPTER IS WORK IN PROGRESS

DISCO provides a wide selection of dicing blades optimized for different materials. There catalogue can be accessed online here DTU Nanolab provides 2 different blades for 2 main use-cases