Also for most joining techniques with adhesives, working temperatures of up to 250 °C and also increased pressure are necessary. With Flip Chip applications all three of the adhesive types mentioned above in brackets are increasingly being used.
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ICA (isotropic conductive adhesive) describes a polymer filled with conductive particles. With Flip Chip processes it is applied to the bond pads and thus creates the contact between bumps and substrate. |
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NCA (non-conductive adhesive) is a non-conductive polymer. The adhesive is applied to the substrate across the whole surface under the component. A Flip Chip die is bonded to the substrate under pressure and heat and the bumps are thus pressed onto the substrate. The adhesive ensures that the mechanical and electrical contact is maintained long term. |
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ACA (anisotropic conductive adhesive) is a polymer with enclosed conductive particles (e.g. Ni). The adhesive is also applied across the whole surface. As a result of the pressure applied during bonding, the conducting connections in the adhesive form a connection between bumps and bond pads on the substrate. |
Substrateheating