GAISER TOOL COMPANY

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GAISER CAPILLARY INFORMATION

Figure 45. Fine pitch capillaries usually have small B dimensions in order to capture smaller free-air ball sizes. B dimensions from 0.0019in./48µm to 0.0030in./76µm are common depending on the hole diameter. This photo is of a fine pitch test strip.

(Photo courtesy of Shinkawa Corporation)

Figure 46. This fine pitch application has both low and long loops. Two concerns for bonding long loops are wire sweep and wavy wires. Wire sweep, or lid seep occurs when the device is encapsulated or lid sealed. Wavy wires are most frequently due to the friction of the wire making contact with the edge of the I.C.'s transition to the hole.

(Photo courtesy of ASM Corporation)

Today, wire manufacturers have greater control over the chemical composition of the wire in addition to offering closer tolerances. the tolerance for the wire diameter has been reduced from +/- 0.00005in. to +0.00003in., -0.00001in. by some manufacturers. The percent elongation of the wire is selected based on the type of bonder used and the application. Many wire manufacturers agree the most important criteria for bonding wire is that it be stored in a dry nitrogen box at a constant temperature with the wire coil oriented vertically (the axis of the spool being horizontal). 

Figure 47. Another concerns for bonding longer wires is sagging wires. These bonds demonstrate how an unusual looping profile can keep the wires from sagging at the stitch bond.

(Photo courtesy of ESEC Corporation)

Figure 48. The same device as the one pictured in Figure 47. The density of the device often dictates how much the wires will "fan out" in the corners of the package. This package shows how the leads are angled in the frame to make the loops remain the same length. 

(Photo courtesy of ESEC Corporation)

Figure 49. This lead frame has wires that fan out and span a distance of 3mm. 

(Photo courtesy KME, Kyushu Matsushita Electric Co., LTD) Bonds made by MW- series bonder.

Figure 50. This device incorporates staggered die and lead bonds in order to achieve the 0.0025 in/65µm pitch chip to chip bonding. 

(Photo courtesy KME, Kyushu Matsushita Electric Co., LTD) Bonds made by MW- series bonder.

Figure 51. This test strip leadframe incorporates a two tier lead design. Note that the lower loop lengths even at the corners are less than 0.065in./1.7mm. The upper loop lengths are less than 0.0120in./.305mm.  

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