Abstract: A substrate strip with warpage-preventive linkage structure is proposed for a BGA (Ball Grid Array) application. The proposed substrate strip is composed of a series of substrates, each being used for the construction of an individual unit of a BGA package, and which is characterized by the provision of a warpage-preventive linkage structure, by which each substrate on the substrate strip is supported by means of no more than two tie bars, i.e., either by a two-point linkage structure or a one-point linkage structure, in contrast to the four-point linkage structure utilized by the prior art. During high-temperature fabrication steps when the substrate is subjected to thermal stresses, the substrate can freely expand toward the corners where no tie bars are provided; and consequently, it can be unwarped by the thermal stresses. This unwarped substrate allows the subsequently implanted ball grid array thereon to have high coplanarity.

Abstract: A substrate strip with warpage-preventive linkage structure is proposed for BGA (Ball Grid Array) application. The proposed substrate strip is composed of a series of substrates, each being used for the construction of an individual unit of BGA package, and which is characterized by the provision of a warpage-preventive linkage structure, by which each substrate on the substrate strip is supported by means of no more than two tie bars, i.e., either by a two-point linkage structure or a one-point linkage structure in contrast to the four-point linkage structure utilized by the prior art. During high-temperature fabrication steps when the substrate is subjected to thermal stresses, the substrate can freely expanded toward the corners where no tie bars are provided; and consequently, it can be unwarped by the thermal stresses. This unwarped substrate allows the subsequently implanted ball grid array thereon to have high coplanarity.