The present invention relates generally to a semiconductor package, and more particularly, to a substrate for a semiconductor package, a method for manufacturing the same, and a semiconductor package having the same, which requires fewer processing steps during the manufacturing process of a substrate and can prevent the delamination of an encapsulant.
In the semiconductor industry, the constant demand for miniaturization and mounting reliability has driven the development of packaging technology for integrated circuits. For example, the demand for miniaturization has accelerated package development to the extent that the size of semiconductor packages is approaching the size of a semiconductor chip itself; and further, the demand for mounting reliability has accelerated the development of techniques for improving the efficiency of a mounting task and mechanical and electrical reliability after mounting.
An exemplary package, which can accomplish miniaturization of a package, is a BGA (ball grid array) package. In the BGA package, the size of the entire package is very close to that of the size of a semiconductor chip. Further, the BGA package utilizes solder balls as a means for making electrical connection with external circuits (for example, as mounting means to a printed circuit board), which further accommodates the trend toward decrease in a mounting area.
Recently, the FBGA (fine pitch ball grid array) package has been mentioned. The FBGA package provides advantages in that the fine pitch of signal and power input and output pins can be accomplished in conformance with the high integration of semiconductor chips, and electrical connections with external circuits are formed by solder balls in such a way as to reduce the mounting area and shorten a signal transmission path.
A substrate used to form the BGA package, including the FBGA package, comprises an insulation layer, conductive patterns formed on one surface or both surfaces of the insulation layer to form electrical connections with a semiconductor chip and external circuits, and solder masks formed on surfaces of the insulation layer to protect the conductive patterns.
Referring to FIG. 1A, in a case where conductive patterns are formed on only one surface of the insulation layer, the substrate is manufactured by a first step (ST1) of attaching a mask film to a conductive layer, which is formed on one surface of the insulation layer, through a twelfth step (ST12) of cutting a strip level substrate into a unit level.
Referring to FIG. 1B, in a case where the conductive patterns are formed on both surfaces of the insulation layer, the substrate is manufactured by a first step (ST1) of defining via holes through the insulation layer, which has conductive layers formed on both surfaces thereof, through a sixteenth step (ST16) of cutting a strip level substrate into a unit level.
As illustrated in FIGS. 1A-1B, the conventional substrate used when manufacturing a BGA package (including the FBGA package) is formed through a number of manufacturing processes, thereby causing a decrease in productivity and an increase in the manufacturing cost.
Moreover, because a solder mask is formed on the surface of the substrate to which the semiconductor chip is to be attached, the thickness of the package increases. Also, when conducting a molding process for completing the manufacture of a semiconductor package, a phenomenon in which an encapsulant such as an EMC (epoxy molding compound) is delaminated, occurs frequently due to contamination of the surface of the solder mask.
When manufacturing the BGA type semiconductor package, it is the norm that, after applying an adhesive on the substrate, a series of processes are conducted to semi-cure the adhesive, attach the semiconductor chip to the semi-cured adhesive and then completely cure the semi-cured adhesive for the complete attachment of the semiconductor chip. In this regard, since the process for applying the adhesive should be separately conducted, there is an additional decline in productivity and increase in the manufacturing cost. Also, contamination can be caused due to streaming of the adhesive while applying the adhesive; and in this case, a cleaning process should be additionally conducted, causing a further reduction in productivity and the quality of the semiconductor package.