is thereafter formed on the ubm 52 in a case that the solder bump 56 is formed by using electrical plating the existence of the protruding probe tip 36 will create spike discharge during the plating of the solder bump 56 thereby affecting the uniformity of bump array in a worse case bridging of bump array occurs furthermore the protruding portion of the probe mark 36 is naked that is not covered by the ubm 52 without the barrier of the ubm 52 a bump crack phenomenon is observed due to the diffusion of sn of the solder bump 56 and the diffusion of the underlying al pad to solve the above mentioned problems and to make the novel flip chip packaging process flow of this invention practical a novel probe tip design is proposed please refer to fig4 a and fig4 b fig4 a is an enlarged side view of a probe tip 130 in accordance with the present invention and fig4 b is a perspective view of the probe tip 130 of fig4 a as shown in fig4 a and fig4 b the probe tip 130 comprises a needle body 131 and a stop cylinder 132 the stop cylinder 132 has an opening 133 at the bottom of the stop cylinder 132 for accommodating the needle body 131 the needle body 131 is electrically connected to the.