SELECTING RIGHT DIAMOND DICING BLADE FOR YOUR APPLICATION
the right diamond dicing blade & parameters for your
material/application can be a very time consuming, trial & error
frustrating process. The guide below has been
designed to help you better understand the most important diamond blade
variables, which will play a major role in performance, cutting speed, and
surface finish of your dicing blade
following variable should be considered in selecting the right dicing
blade for your application:
parameters will play a major role in determining and/or limiting the blade
bond/binder to use, blade thickness and diamond particle/abrasive size.
Additional factors to be considered is blade dressing, blade exposure,
feed rate, spindle speed, and supply of adequate amount of coolant in
choosing the best dicing blade specification for your application, we
recommend remaining objective as possible and considering all parameters
discussed in this article. For most dicing blade users, blade life and cut
quality is typically the most important criteria in selecting the right
dicing blade for their needs. However, other factors such as consistency,
unit cost, lead time/availability, technical support may have just as much
priority, if not more importance in the decision making process.
observing dicing blade consistency, we recommend considering the dicing
blades Yield. Average blade that can be measured. Such as number of
packages or wafers cut, linear feet or meters cut. For example, if a
particular vendors dicing blade can cut up to twenty five thousand cuts,
however at eighteen thousand cuts inconsistency surfaces, the yields
deviate. Yield deviation negatively affects production and quality
control. At the same time as dicing blades become more inconsistent,
dicing saw operators must monitor the process more closely and make
necessary parameter changes. These parameter changes may extend dicing
blade life back to twenty five thousand cuts. However, the extra time
spend adjusting could have been better utilized monitoring other machines
cost should be directly correlated to dicing blade life in linear
millimeters. For example if blade X cost eighteen thousand dollars as an
example. And cuts hundred thousand of linear millimeters, then cost is $
.00018 USD per linear millimeter. On the other hand if dicing blade Y
costs twenty two thousand dollars, however cuts one hundred fifty thousand
linear millimeters. Actual cost is $ .00016 USD per linear millimeter. As
you can see the higher cost blade is more economical to use. At first
glance the Y dicing blade appears to cost four dollars more than blade X.
When dicing blade yield has be evaluated, dicing blade Y saves you more
money, as well as reduces operator involvement in blade change and set up
– hard & brittle materials require a softer Dicing Bond Matrix, to
cut faster and freer. While
softer and abrasive materials require a harder bond blade bond matrix, to
Harder bond matrixes hold diamond in place for very long time, providing
longer blade life. This requires use of very hard diamond particles in
order for the dicing blade to maintain its sharp edges for long periods of
time. Material Hardness is defined
as the materials capability to resist deformation. All materials are
classified by their scale of hardness. Material hardness is measured by
many different hardness scales such as Mohs, Vickers, Knoop and
other scales of hardness.
Material Thickness – will determine blade diameter, thickness, blade exposure ratio, dicing blade bond type, diamond size and concentration to use.
Depth of Cut - To optimize a blade's capability in cutting, always take into account the thickness of the blade, and the exposure needed to reach the required depth. Eg: .050" thick Alumina Substrate should not be cut with .0040" mil. thick blade because it is too thin of a blade for such a deep cut, it will result in deflection.
process is used in a large variety of industries and applications.
- dicing process used in semiconductor industry. Where diamond dicing
blade is used for die and package separation.
– process when cutting is not completely through the material. Final
separation is done by breaking.
process is also used for cutting very hard and brittle materials partially
or completely through wide range of materials such as ceramics, optical
glass, composites and many other materials. Dicing creates almost perfect
edges, scribing allows much higher cutting speeds. Blade life is typically
2 to 4 times higher in scribing operation.
DICING BLADES WORK
the diamond dicing blade is a cutting tool
which has exposed diamond particles captured
in a bond matrix each with a small
cutting edge. Diamond particles are hold together with a binder such
as resin bond, sintered (metal bond) or nickel bond (electroplated). The
number of cutting edges which is
determined by the number of diamonds
(or concentration) make up the
structure of the diamond blade, along
with its matrix, (metal or nickel
bond). The size of the diamond particle in
the blade will have a direct result in
on surface finish quality and material surface finish the blade leaves
behind. The thickness of the blade (diamond
particle plus matrix) will determine
the width of the cut. Therefore, blade
selection along with feed rate, cutting
speed, and depth of cut will
ultimately determine the blades success. Each diamond
particles grinds away material on micro level. As the diamond
crystal/particles breaks or shatters an new sharp point is formed, hence
continuing the process until the blade is worn out. Blade performance is
determined by bond/binders ability to retain diamond particles/crystals
and release and orient their sharpest point/edge at right time and place when
Why use Diamond or CBN?
Diamond is the hardest material known to man kind. When used in dicing blades, diamond grinds away material on micro (nano) level. Due to its hardness Diamond will work all types of materials from hardness of 40 on Rockwell scale and up. Diamond Blades will machine hardest material, including those materials that other conventional types of abrasives, carbide and high speed steel will not. Diamond Blades will cut faster, produce smoothes surface finish quality, provide consistent performance, & yield (cost per part) possible. Diamond hardness, wear resistance and high natural strength are unchallenged among conventional abrasives.
Diamond Dicing blades – dicing blade is already mounted on hub,
comes ready to use. Once the blade is used, it is disposed. Typically
these type of blades are use din applications requiring minimal blade
vibration, such as cutting silicon & germanium wafers.
Diamond dicing blade – dicing blade is placed on flange/assembly.
The flange assembly. The same assembly is used all the time. Typically
applications that use hubless type of diamond dicing blades where
effecting cooling of blade during cutting process is very important to
obtain maximum results. For some applications such as cutting silicon
wafers, hubbed dicing blades offer the greatest blade life, require
minimum set up time, and provide better consistency. Hubless dicing blades
are more sensitive to foreign particles such a s slurry accrued from
cutting wafers. Careful attention to detail should be taken in order to
clean the inner and outer flanges when mounting these blades.
diamond dicing blades have the following Advantages:
Hubless dicing blades advantages
SINTERED (METAL BOND) DICING BLADES
They wear evenly, and are known for their long life & consistency. Metal bond matrix does not protrude diamonds very high and hence usually requires lower cutting speeds than electroplated (nickel bond) and resin bond blades. In many dicing applications sintered (metal bond) dicing blades are used in applications which are not super hard or super brittle and with minimum tendency to produce chips or cracks.
RESIN BOND DIAMOND
Another disadvantage of
Resin bond is its high wear rate, lack of stiffness, and thickness
limitation. Resin bond can cut hard & brittle materials fast, but will
provide much shorter life. Thinnest blades that can be produced in resin
bond is .004". Many of the resin bond dicing blade weaknesses and
limitation have been resolved by utilizing different phenolic resin types,
mixtures, fillers, and molding techniques in our New Generation Extended
wear resin bond and Hybrid bond dicing blades. Hence increasing their
field or use in greater amount of applications.
NICKEL BOND DIAMOND DICING
RECOMMENDED DIAMOND SIZES FOR DIFFERENT MATERIALS & APPLICATIONS
Blades & Cutting Speeds
RPM’s of the machine spindle should be noted when selecting the right
dicing blade specification of your application.
Speed/RPM - The RPM of your dicing saw should be variable, ranging
from 10,000 to 40,000 RPM. When using standard dicing blades such as
2" 3" 4" diameter for example, blade the best spindle speed
is usually determined by the hardness of your material and the depth of
your cut. Diamond
may break (fracture) at very high speeds, and fall out at very slow
speeds. An optimum surface speed / RPM's must be selected to balance out
the two disadvantages. Diamond Blade life will usually increase at slower
cutting speeds. However the increase in labor costs, utilities costs,
depreciation of equipment and other overhead expenses. Will usually offset
the saving of diamond blade life and other consumables. Cutting Speed
& Surface Finish Quality is often the most important consideration
when selecting the right diamond blade for your application. The
operator mush choose a balance between life of the blades and their
cutting rate. Diamond has a higher impact strength than the material
being machined. During the dicing operation, the diamond ruptures the
material by impact. Each diamond is able to transfer the electrical power
from your cutting machine, into momentum that breaks the material on nano
/ micro level.
increasing power on your dicing saw, your diamond blade RPM's and surface speed
will increase as well. Hence, each diamond will chip off a smaller amount
of material, reducing its impact force on material being machined. And
reducing cutting resistance. In theory, by increasing surface speed /
RPM's, each diamond should receive a smaller impact force. However,
because impact is supported by a smaller volume, the impact force with
this low volume is actually increased. There is a higher probability that
the diamond particles will break or shatter. Hence, cutting materials at
very low surface speeds, creates a large impact force between diamond and
material being machined. Although the diamond may not break, the risk that
the diamond will be pulled out of diamond blade and causing premature
failure of the blade increases.
Blade General Speed Guidelines and Recommendations
diameter machine spindle. For
cutting silicon substrates with nickel type dicing blades. Recommended RPM’s
range from 30 to 35 KRPM (max speed: 40 KRPM). in
most cases for 4” OD nickel bond dicing blades. Maximum RPM’s are 30
KRPM for resin bond diamond dicing blades 4” OD, maximum RPM depends on
to .015” thickness – 16 KRPM max
to 0.025” thickness – 14 KRPM
to .035” thickness – 12 KRPM
.035” thickness – 10 KRPM
Speed range recommendations for typical applications when using 4" OD dicing blades
DIAMOND / ABRASIVE SELECTION
Diamond is universally recognized as the hardest substance known to man. Diamond is recommended for machining hard & brittle materials, optics, semiconductor packages, advanced materials, composites, ferrous & non ferrous metallic materials from 40 on Rockwell scale and up. Diamond crystals can be synthetically grown in a wide variety of qualities, shapes and sizes. Diamond is grown with smooth crystal faces in a cubo-octahedral shape and the color is typically from light yellow to medium yellow-green. Diamond is also grown to a specific toughness, which generally increases as the crystal size decreases.
Synthetic (Men Made) Diamonds - Most frequently used for most diamond blade manufacturing including sintered (metal bond), resin bond, electroplating (nickel bond). Synthetic diamond is more consistent in particle shape, hardness, and density. Synthetic diamond has replaced natural diamond in most dicing blades applications because of its superior consistency and ability to tailor-make the diamond for the specific application.
Cubic Boron Nitride (CBN) - often used for machining materials with high metallic content.
recommended for cutting
The ability of a diamond to withstand an impact load is typically referred to as diamond impact strength. Other diamond-related factors, such as crystal shape, size, inclusions and the distribution of these crystal properties, play a role in the impact strength as well. Impact strength can be measured and is commonly referred to as Toughness Index (TI). In addition, crystals are also subjected to very high temperatures during manufacturing and sometimes during the cutting process. Thermal Toughness Index (TTI) is the measure of the ability of a diamond crystal to withstand thermal cycling. Subjecting the diamond crystals to high temperature, allowing them to return to room temperature, and then measuring the change in toughness makes this measurement useful to a diamond tool manufacturer.
The manufacturer must select the right diamond based on previous experience or input from the operator in the field. This decision is based, in part, on the tool's design, bond properties, material to be cut and machine power. These factors must be balanced by the selection of diamond grade and concentration that will provide the operator with optimum performance at a suitable cost.
HARDNESS – Ability of the bond matrix to hold diamonds. As the hardness of
the bond is increased, its diamond retention capabilities increase as
well. However the trade off is slower cutting speed. Life of the diamond
blade is usually increased with hardness of its bond matrix. Bonds are
designated on their scale of hardness from Soft, Medium, and Hard. There
are dozens of variations and classification schemes based on bond degree
of hardness or softness. Using diamond dicing blades with optimum bond
hardness for your application is important to successful dicing operation.
Bond matrix that is too soft for the material being cut will release
diamond particles faster than needed, resulting in faster wear and shorter
diamond blade life. On other hand bond matrix that is too hard will result
in much slower cutting speeds and require constant dressing to expose the
next diamond layer. As rule of thumb, harder materials such as sapphire
and alumina generally require a softer bond. Whereas softer and more
brittle materials require a harder bond.
it is very important to use blades of proper bond hardness for your dicing application. For example if dicing blade you are using has too soft of a bond hardness, diamond particles/crystals will be pulled out or fall out prematurely. Hence causing blade failure and loading. On the other hand using very hard bond dicing blade (blade that retains its diamond particles beyond their useful life) may cause burning in the material cutting zone and glazing of blades diamond section. Diamond particle size inside dicing blades bond matrix will also affect blades hardness. Lower diamond concentration will create a softer and more brittle bond. Where high diamond concentration would create more harder bond type.
diamond mesh size in a dicing blade also directly relates to the number of
crystals per carat and the free cutting capability of the dicing blade.
The smaller the mesh size, the larger the diamond crystals, while larger
mesh size means smaller diamond. A 30/40 Mesh blocky diamond has about 660
crystals per carat, while a 40/50 Mesh diamond will have 1,700 crystals
per carat. Specifying the proper mesh size is the job of the dicing blade
manufacturer. Producing the right number of cutting points can maximize
dicing blade life and minimize the machine power requirements. As an
example, a dicing blade manufacturer may choose to use a finer mesh size
to increase the number of cutting crystals on a low concentration blade,
which improves dicing blade life and power requirements.
Diamond Mesh size does have considerable effect on cutting speed. Coarse Diamonds are larger than finer diamonds and will remove more material than finer diamond particles. This means that coarse diamond dicing blades are more aggressive for material removal than the finer size diamond dicing blades and will cut faster. However, the tradeoff is increase in material micro damage. If you are cutting fragile, more delicate materials then finer mesh size diamond dicing blades are recommended. Diamond mesh size (grit size) should provide maximum removal rate at minimal acceptable finish.
Typically finder size diamond particles require more horsepower than finer size diamond particles, as well as provide more heat buildup. A good rule to follow when selecting the right diamond size for your dicing blade is to use the largest diamond size possible for particular dicing blade thickness. And decrease the diamond size until desired surface finish quality is obtained.
DIAMOND CONCENTRATION - The proportion, and distribution of diamond abrasive particles, also known as concentration. has an effect on overall cutting performance and price of precision diamond blades. Diamond concentration, commonly referred to as CON, is a measure of the amount of diamond contained in a diamond section of drill based upon volume. Diamond concentration is usually defined as: Concentration 100 = 4.4 ct per cm layer volume (mesh size + bond). Based on this definition a concentration of 100 means that the diamond proportion is 25% by volume of diamond layer, assuming at diamond density is 3.52 g/cm3 and 1 ct = 0.2g. Nominal diamond concentration in precision diamond blades range from 0.5 ct/cm3 to 6 ct/cm3. This means diamond concentrations are available from 8 to 135). Selecting the Right Diamond Concentration can be critical in optimizing your dicing operation. Selecting Optimum Diamond Concentration for your application will depend on a large number of factors, such as:
Diamond Concentration will play a major role in
determining the life and cutting speed of your dicing blade.
High Diamond Concentration
Higher diamond concentration causes the blade to
act harder and wear slower. Hence, higher diamond concentration is
recommended and usually used for cutting softer and more abrasive types of
materials. However, the trade off is significantly slower cutting speed.
Since there is higher density of diamond particles in bond matrix, there
is not enough space for the debris and fine powder created during dicing
process to escape. Blade overloading is often a result of selecting
improper diamond concentration.
Low Diamond Concentration
Low diamond concentration dicing blade is softer
and faster wearing blade, creating better cut quality and surface finish.
Low diamond concentration is often recommended and widely used for cutting
ultra hard and brittle materials. Lower diamond concentration has larger
spacing between diamond particles and can accept more fine powder debris
generated from dicing. This typically creaster faster and more freer
cutting blades, leas loasing and better surface finish quality. Lower
diamond concentration dicing blades will however wear out faster than
their high concentration counterparts.
Diamond Concentration is usually determined by
the the slowest cutting speed that is acceptable for a specific
performance can be achieved when the diamond tool manufacturer utilizes
their experience and analytical capabilities to balance diamond
concentration and other factors to achieve optimum performance for the
UKAM Industrial Superhard Tools has the experience
& applications laboratory to help you select all the right
diamond blade variables for your unique application.
Diamond Concentration & CBN (cubic boron nitride) blades
For CBN (cubic boron nitride) concentration is defined by volume. For
example V120 = 12% by volume, V180 = 18% by volume.
SLOTTED DICING BLADES
dicing allow for better coolant circulation and chip clearance in the cut.
This provides for an improved washing action of kef, reducing abrasive
action of the slurry which is otherwise confined to the cutting edge area.
Of even greater importance is the reduction of heat because an lager
percentage of the coolant is carried to the point of contact. Excess heat
will shorten the life of the blade and may cause permanent damage to the.
Slots help by eliminating continuous contact between blade and material,
hence proving improved coolant fro both blade and material being cut. As a
blade diameter and cutting depth increase, the advantage of slotted dicing
blade design over continuous rim dicing blades is apparent.
bond slotted/serrated dicing blades are standard product. Slots/serrations
are also available for both resin bond and metal bond diamond dicing
of Slotted/Serrated Blades
contact between edge and material, this provides less loading during
cooling characteristics, serrations/slots allow heat to dissipate
is not accurate as with regular continuous rim dicing blades
vibration will be present with using slotted dicing blades
Dicing Blade life
Dicing blade life is determined by large variety
of factors such as
Diamond mesh size
Material thickness, hardness and density
It is possible to tailor dicing blade hardness
to provide optimum performance under specific combinations of variables
indicated above. When determining the parameters above, a good rule to
remember: higher blade lifer, the lower its wear rate and shorter smaller
self sharpening effect. Self sharpening is correlated to blade wear.
Dicing blade wear typically causes a reduction in OD of dicing blade.
Although it is not possible to accurate predict dicing blade wear. Some
characteristics that can assist you are:
Nickel Bond Dicing Blades
6 to 8 micron
/ 100m – pure Si (scribing)
25 – 30 microns / 100m – Si + Adhesion +
Resin Bond Dicing Blades
70 to 100 micron / 10m Glass
250 to 400 micron /
10mm Al203 (99.6% alumina)
DICING SOLUTIONS FOR PACKAGE SINGULATION
What you should know before your buy your next dicing blade?
UKAM Industrial Superhard Tools Division of LEL Diamond Tools International, Inc.
28231 Avenue Crocker, Unit 80 Valencia, CA 91355 Phone: (661) 257-2288 Fax: (661) 257-3833