The present invention relates to a tape-like carrier for mounting of integrated circuit, and more particular to the tape-like carrier used for tape automated bonding in which plural inner leads are automatically bonded to a semiconductor pellet. Further the present invention relates to the tape-like carrier suitable for connection of very multiple terminals of a semiconductor pellet with electronic elements.
Heretofore well known is a longitudinally extending tape-like carrier for mounting of integrated circuit including sets of leads secured to a flexible insulating film having longitudinally spaced apertures which are dimensioned to encompass contact regions of semiconductor pellet, said leads extending from the periphery of the every aperture toward the inside thereof (U.S. Pat. No. 3,689,991).
FIGS. 1 to 2b show one prior illustration of such a tape-like carrier for mounting of integrated circuit, together with a semiconductor pellet having bump electrodes with leads, FIG. 1 being a plan view, FIG. 2a being a cross-sectional view taken on line IIa-IIa of FIG. 1 and FIG. 2b being a cross-sectional view taken on line IIb-IIb of FIG. 1.
With reference to FIGS. 1 to 2b, the conventional tape-like carrier for mounting of integrated circuit comprises a flexible insulating film 5 in the form of tape made of polyimide. The flexible insulating film 5 is provided with sprocket holes 7 at regular intervals along the longitudinal direction in both side regions thereof. Further the flexible insulating film 5 has longitudinally spaced apertures 26 which are dimensioned to encompass contact regions of a semiconductor pellet.
Longitudinally spaced sets of leads 23 and bars 28 in the form of a frame leading to the leads 23 are formed on the flexible insulating film 5. The leads 23 extend within the periphery of a respective aperture 26 for semiconductor pellet. Between the leads 23 and the leads 23 and between the leads 23 and the bars 28, a surface of the flexible insulating film 5 is partially exposed.
Located in the center of the aperture 26 is a semiconductor pellet 1 having plural bump electrodes 2 formed on the contact regions of the pellet 1. The bump electrodes 2 are bonded to the corresponding leads 23 which are arranged at regular intervals so as to be coincident with the bump electrodes 2, by a heat bonding method using a bonding tool, that is, gang bonding.
When bonding of very multiple inner leads 23 with very multiple bumps 2 of the semiconductor pellet is performed using the above tape-like carrier for mounting of an integrated circuit, the heat dissipation characteristic is remarkably worse so that the following inconvenience occurs: i.e., as metal regions which dissipate heat of the leads 23 conducted from the bonding tool are only the surfaces of the bars 28 and the leads 23, the efficiency of heat dissipation is low.
Therefore, when the inner lead bonding is performed by using the above tape-like carrier for mounting the integrated circuit, thermal expansion of the leads 23 and the deformation and contraction of the flexible insulating film 5 occur, which results in the change of pitches between the leads 23. Thereby, an outer lead bonding for mounting the semiconductor pellet 1 to a substrate (not shown) or to an outer lead frame cannot be normally performed in a postprocess, which results in the faulty bonding.