In the field of cutting hard and brittle materials such as semiconductors, There are generally 3 bond type of dicing blades.there are resin bond and metal bond diamond dicing blade, as well as hybrid bond diamond dicing blade(metal and resin).
In the cutting process, the function of the bonding agent is to bond diamond abrasive grains to form ultra-thin grinding wheel. Its function is mainly reflected in two aspects: One to enable the abrasive to be formed into grinding tool, and other to enable the dicing blade to grinding and cutting.
Resin Bond Type Of Dicing Blade
Resin bond is composed of thermosetting resin and various fillers. The properties and amounts of various components have significant impact on the physical and mechanical performance of bond and the cutting performance of dicing blade. Therefore, select the bond type of dicing blade according to the performance of materials of workpiece to be processed in order to achieve good cutting results.
The material of bond is mainly phenolic resin, in addition to polyimide resin, epoxy resin, polyurethane, etc.
Resin bond itself has good elasticity and polishing effect. When combined with diamond abrasive to form resin blades, it still has good self sharpness, not block, and less dressing. It is used for cutting packaging substrates, ceramics, glass and other materials. However, resin bonding agent has poor holding force on abrasives and poor heat resistance, resulting in significant blade wear during high-temperature cutting. More hear-resistant polyimide resin is usually used.
Resin diamond dicing blade can only be made into hubless blades, which are installed on the flanges. Before formally cutting materials, resin blades need to be pre cutting by blade dressing borard, and that it reaches a true round state.
Metal Bond Type Of Dicing Blade
Metal bond include bronze and electroplating.
Bronze Sintered Bond Type Of Dicing Blade
The sharpness and accuracy of the grinding wheel may change during using, and regular dressing is required. Improper dressing of the grinding wheel can cause uneven surface, which further affects the grinding effect and surface roughness.
Bronze bonding agent is usually made of copper and tin. To change the properties, add other metal powders such as silver, nickel, zinc, etc. Mix the above metal powder and diamond micro powder thoroughly, then place them in the mold to press and shape them, and sinter them to form metal soft blades.
The bonding strength between the bond and abrasive of the blade is high, and the wear resistance is good, and the life is long, and it can maintain good shape, so it can withstand large loads. But the disadvantage is poor self sharpening, block, high heat, difficult to dressing. It is mainly used for cutting non-metallic materials such as glass, ceramics, and semiconductors.
Bronze metal diamond hubless dicing blade is installed on flanges, and needs the dressing board for cutting. This is similar to pre cutting with resin diamond blade, both aimed at achieving true roundness and sharpening. Moreover, bronze hubless blade requires frequent blade dressing.
The influence of metal bond on the performance of blades is multifaceted. Simply adjusting the tin copper content cannot meet the needs, and should add a certain proportion of other metal powders to adjust. Adding an appropriate amount of lead into the copper tin alloys can improve wear resistance. Adding silver powder can improve the mechanical and electrical properties of the alloy, and greatly enhance its flexural strength. In addition, to achieve good process performance in manufacturing, there are strict requirements for the mixing method, molding pressure, mold structure, firing temperature curve, etc.
Electroplated Bond Type Of Dicing Blade
Electroplated bonding agent is a type of bonding agent with higher bonding strength. Generally, single-layer or multi-layer abrasive particles are plated on the metal substrate by electroplating method.This kind of blade has a thin abrasive layer, high abrasive particle density, sharp cutting surface, high cutting efficiency, and has already reached a true round when leaving the factory without dressing. Electroplated diamond dicing blade is relatively expensive and mainly used for cutting wafers,among which DISCO dicing blade is the best.
Electroplated bonding agent is a type of bonding agent with higher bonding strength. Generally, single-layer or multi-layer abrasive particles are plated on the metal substrate by electroplating method.This kind of blade has a thin abrasive layer, high abrasive particle density, sharp cutting surface, high cutting efficiency, and has already reached a true round when leaving the factory without dressing. Electroplated diamond dicing blade is relatively expensive and mainly used for cutting wafers,among which DISCO dicing blade is the best.
Hybrid Bond Type of Hubless Dicing Blade
The most commonly used hybrid bond is to combine metal bond and resin bond, taking the advantages of both bond-excellent sharpness of resin bond and good shape retention and long cutting life of metal bond. When cutting materials that are soft and ensure the verticality of the cutting surface, such as cutting BK7 optic glass, good results can be achieved. As hubless blade, pre cutting is required to ensure its true roundness and sharpening.
Softness and Hardness of Bond:
The role of bond of diamond dicing blade is to firmly bond diamond abrasives together, and the bond with different hardness have a significant impact on the life of blade.
Soft bonding agent can speed the self sharpening of diamond particles, keeping the dicing blade in a relatively sharp state and reducing the problems of front chipping, delamination, and burrs in cutting materials. Hard bonding agent can better hold diamond particles, increase the wear resistance of the blade, and prolong the life.
The disadvantage of soft bonding agents is the shortened life of diamond saw blades, while that of hard bonding agents is the poor quality of cutting products.
In the wafer saw process, it is not only necessary to choose suitable dicing saw blade, but also to pay attention to the optimization of processing conditions. The suitable wafer dicing blade and good processing conditions play a crucial role in achieving good cutting results. For example, the spindle speed, feed rate, cooling water and other parameters of dicing machine.
Spindle Speed Of Dicing Machine:
According to different cutting objects, need to install the diamond blade with different diameters, either hubless or hub dicing saw blade. By adjusting the spindle speed to obtain the out circular linear velocity,the cutting quality and stability can be ensured.
By increasing the speed of the spindle, the processing load of diamond is reduced, the cutting life of the dicing blade is improved, and the risk of front chipping of product is reduced. By reducing the rotational speed, the self sharpening of the dicing blade can be increased, maintaining high sharpness and reducing the risk of back chipping.
Feed Rate Of Dicing Machine:
Feed speed is achieved by moving the worktable. Increasing the feed rate will increase the load on single diamond particles and chipping, and affect the diamond blade life. By reducing the feed rate, the size of the back chipping will decrease, and the cutting life of dicing blade will increase, resulting in the decrease in the number of workpieces per unit time.
Cooling Water Of Dicing Machine
It not only can cool the dicing blade, but also prevent electric shock and arc by controlling the flow rate of cooling water. At the same time, it can flush away the debris during dicing saw process, prevent secondary scratches, and ultimately reduce chipping and control cutting quality.
