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Semiconductor Packaging / Assembly EquipmentDie Attach EquipmentDie attach machines ordie bonders (Fig. 1) are used to mount orattach the die to the die pad or diecavity of the support structure of the package. A typical die attach machine consists of a system

forholding and indexing the leadframes or packages on which the dice will be mounted, a systemfordispensing the die attach material on the die pad or die cavity, and a pick and place systemforejecting a die from the wafer, picking it, and positioning it on the dispensed die attach material.Alphasem, ESEC, and K&S are examples of manufacturers of die bonders. See alsoDi eAttachprocess.

Figure 1. Examples of Die BondersWirebondersWirebond machines orwirebonders are used to connect electricallythe die of the device to the leads ofthe package using very fine wires. A typical wirebonder consists of a systemforholding and indexing the leadframes or packages for wirebonding, a system for ensuring that theunits are at the right temperature during wirebonding, and a system forconnecting the wires from the die

to the bonding fingers of the leadframe or bonding posts of the package. ESEC, ASM, Kaijo, and K&Sare examples of manufacturers of wirebonders. See alsoWirebondprocess.

Figure 2. Examples of WirebondersMolding EquipmentA typical molding equipment for encapsulating integrated circuits consists of a preheating chamber, aplunger system, a melting pot, runners, and molding cavities.

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The preheating chamberis where the molding compound is preheated prior to being melted.The plungersystem forces the preheated molding compound into the melting pot. The melting pot iswhere the mold compound reaches melting temperature and becomes fluid. The plunger system alsoforces the fluid molding compound from the melting pot into the runners. These runners serve as canalswhere the fluid molding compound travels until it reaches the cavities, which contain the leadframes forencapsulation. Sumitomo, Lauffer, and Towa are examples of manufacturers of moldingequipment. See alsoMold ingprocess.

Figure 3. Example of an Automold systemDeflash/Trim/Form/Singulation (DTFS) MachinesThe Deflash (mechanical), Trim, Form, and Singulation of IC packages may be achieved by employingone dedicated machine for each step, or by using one equipment capable of doing all of these steps.Basically, DTFS is a purely mechanical process, so a DTFS machine consists simply ofan automated system ofpunches, blades, strippers, anvils, etc. See alsoDTFSprocess.

Figure 4. Example of a Trim/Form/Singulation (TFS) MachineSolder Plating MachinesA typical automated solder plating machine used for applying lead finish on semiconductor products hasthe following components: a large non-corroding frame structure for housing the other parts of theequipment, a system orbelt fortransporting the IC's through the various steps of the lead finish process,a channel through which the products pass while being processed, storage tanks for the chemicals usedin the plating process, pumps for effecting the flow requirements of the fluid chemicals,an extractorsystem for extracting all the gases released from the various sections of theequipment, loading and unloading systems, and an elaborate control system that orchestrates theinteraction and operation of these various components.

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The lead finish process starts with the equipment's loading system, which places the products on thebelt. The belt then transports the units through the channel of the machine, which consists of severalsections. It is in these sections that products are subjected to specific electrochemical treatmentsthat deposit the necessary metal layers on the leads of the products.

Pumps are used to bring the chemicals from the storage tanks to the channel sections and to return theused chemicals to the storage tanks through discharge pipes. Gases are continuously released duringthe plating process, so anextractoris used to continuously remove these gases. After the products havegone through the entire solder plating flow, the unloading system of the equipment places the productsback in their appropriate cassettes or carriers. MECO and Technic are examples of manufacturers ofsolder plating equipment. See alsoLead Finishprocess.

Figure 5. Example of an Electroplating Machine for Lead Finish

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Wirebonding Tools

Wirebonding equipment use bonding tools known as capillaries for thermosonic ball bonding. Capillarieshold and control the bonding wire as well as form bonds from it during the ball bonding process.Capillaries are ceramic axial-symmetric tools with vertical feedholes (holes where the bonding wires arefed) through its center.

Fig. 1. Photo of uninstalled capillaries (left)and an installed capillary (right)

The proper choice of capillary depends on many factors: bond pad size, bond pad pitch, wire diameterand hardness, bond pad metallization, bonder speed and accuracy, loop height, loop length, andpackage lay-out.Capillary tips may either have a polished finish or a matte finish. Polished tips are specified forapplications where bondability is very good. Applications with poor bondability require tips with a mattefinish since these have a better coupling with the wire and exhibits better transmission of the ultrasonicenergy to the bond.

Fig. 2. Photo of a capillary andthe ball bond it formedWirebonding equipment use tools known as wedges forultrasonic wedge bonding. Wedges are usuallycomposed oftitanium carbide ortungsten carbide. They are typically 1/16"/1.585mm in diameter, andrange from .437"/11.1mm to 1.225"/31mm long, depending on the type of wedge bonding machine beingused.

Fig. 3. Examples of Wedge Bonding ToolsWedges usually have an entry hole or feedhole at a specified angle from the horizontal, which matchesthe feed angle of the wire clamp system of the bonder. These feed angles range from 30 degrees to 60degrees. The wedge hole diameter typically runs about 1.5X-2X the wire diameter being used. Hole-to-wire ratio may fluctuate slightly due to specific applications, bond loop profiles, or wire materialproperties.

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Fig. 4. Close-up photo of a wedge tip