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Thermo-compression bonder head attachment Disclosure Number: IPCOM000236379D
Publication Date: 2014-Apr-23
Document File: 3 page(s) / 93K

Publishing Venue

The Prior Art Database


Disclosed is a head attachment that has a dimple at a center of the head attachment.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 52% of the total text.

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Thermo-compression bonder head attachment

Typically, when a semiconductor chip is bonded to an organic substrate, a predominant fraction of the total heat energy employed to reflow the solder balls is transmitted through the semiconductor chip. Even if the organic substrate is maintained below 100 degrees Celsius and the heat flow from the semiconductor chip into the organic substrate is constricted at the chip area during the reflow of the solder balls, the thermal expansion of the organic substrate is sufficient to cause warpage of the organic substrate. Such warpage of the organic substrate tends to cause non-contacts between peripheral solder balls within the array of solder balls and bonding pads on the organic substrate, thereby causing electrical opens between the semiconductor chip and the organic substrate across the peripheral solder balls. Also, convection heating in thermo-compression bonder allows for chip center Control Collapse Chip Connections (C4s) to melt first. This becomes a reason of C4s bridging at center and non-wet C4s in chip corner. Fig. 1 shows an example of bridging C4s and non-melting of solders for large dies. Thus, there exists a need to provide a reliable flip chip joining method that can provide reliable solder bonding despite inherent warpage issues due to the thermal expansion of the organic substrate.

Figure 1

Disclosed is a method for providing a head attachment that has a dimple at a center of the head attachment.

In accorda...