Conductive bump, method for producing the same, and electronic component mounted structure

#This application is the U.S. National Phase under 35 U.S.C. §371 of International Application No. PCT/JP2008/000428, filed on Mar. 4, 2008, which in turn claims the benefit of Japanese Application No. 2007-076317, filed on Mar. 23, 2007, the disclosures of which Applications are incorporated by reference herein.

#The present invention relates to a conductive bump formed on an electrode terminal of a semiconductor element or a connection terminal of a circuit board. More particularly, the present invention relates to a conductive bump allowing narrow-pitched semiconductor elements to be reliably mounted on connection terminals of a circuit board, a method for producing the conductive bump, and an electronic component mounted structure.

#Recently, in mobile electronic devices such as portable telephones, notebook-sized personal computers, PDAs and digital video cameras, technology development for realizing small-size, light-weight and high-performance devices has been rapidly advanced.

#FIG. 1 is a sectional view illustrating a structure of a conductive bump in accordance with a first exemplary embodiment of the present invention.

#FIG. 2A is a plan view illustrating another example 1 of a pattern shape of a first layer of the conductive bump in accordance with the first exemplary embodiment of the present invention.

#FIG. 2B is a plan view illustrating another example 2 of a pattern shape of the first layer of the conductive bump in accordance with the first exemplary embodiment of the present invention.

#1, 81 electronic component 11, 44, 54, 91 semiconductor element 12, 22, 32, 45, 55, 92 electrode terminal 13, 47, 57, 83, 93 conductive bump 13a, 23a, 32a, 47a, 57a, 83a, 93a first layer (low-density conductive filler resin layer) 13b, 23b, 33b, 47b, 57b, 83b, 93b second layer (high-density conductive filler resin layer) 41, 51, 61 container 41a, 51a bottom surface 43, 53 low-density paste (low-density conductive filler resin paste) 46, 56 photomask (liquid crystal panel) 46a, 56a first opening portion 46b, 56b second opening portion 46c, 56c third opening portion 46d, 56d fourth opening portion 46e fifth opening portion 46f sixth opening portion 47b1, 57b1 first-stage layer 47b2, 57b2 second-stage layer 47b3, 57b3 third-stage layer 47b4 fourth-stage layer 47b5 fifth-stage layer 48, 58 high-density paste (high-density conductive filler resin paste) 82 electrode 94 circuit board 95 connection terminal 96 insulating sealing resin 100 electronic component mounted structure

#Hereinafter, exemplary embodiments of the present invention are described with reference to drawings. The same reference numerals are given to the same configurations in the following exemplary embodiments and in each drawing.

#Hereinafter, a structure of a conductive bump in accordance with a first exemplary embodiment of the present invention is described with reference to FIG. 1. Hereinafter, an example in which a semiconductor element is used as electronic component 1 and a conductive bump is formed on the semiconductor element is described. However, the same is true in the case in which a circuit board is used. Furthermore, an electrode of the electronic component is expressed by using an electrode terminal for the semiconductor element and a connection terminal for the circuit board.