JP2005347673A - Method for mounting conductive ball and its mounting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting equipment which can accurately arrange a ball having conductivity in an arrangement location of a body to be arranged and its mounting method, as one example. <P>SOLUTION: In the method which is to mount the ball having conductivity in the arrangement location of the body to be arranged, an adhesive portion smaller than a projected area of the ball is formed in the arrangement location, the ball is mounted on the adhesive portion through a positioning opening of the component to be arranged, where the positioning opening through which the ball can pass, is formed according to the arrangement location. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mounting method and mounting apparatus for mounting conductive balls so as to be arranged in a predetermined pattern on an arrayed object such as an electronic component or a member used for manufacturing the electronic component. It is about.

  As an example of an arrayed body on which conductive balls (hereinafter referred to as conductive balls) are mounted so as to be aligned in a predetermined pattern, for example, a BGA (Ball Grid Array) type or an FC (Frip- There is an electronic component such as a semiconductor device having a protruding connection bump of an area array type such as a (Chip) type, a substrate, or a package thereof.

  In recent years, as mobile terminal devices and notebook computers have become faster, more functional, lighter, smaller, and thinner, electronic components built into them have become smaller and thinner. The contradictory performance of terminalization is required. The area array type electronic component is employed as a means to meet the demand.

  For example, as a method of forming connection bumps using a conductive material such as solder or copper, a paste method in which a paste containing a conductive material is printed on an electrode of an electronic component, a conductive ball method in which a conductive ball is mounted on an electrode, or conductive There are filming methods such as plating or vapor deposition of materials. In order to increase the number of terminals, the arrangement of electrodes is increased in density, and the size of connection bumps tends to be reduced accordingly. When forming small connection bumps, a conductive ball system that is advantageous in terms of alignment accuracy and productivity of the connection bumps is often employed.

  According to the conventional conductive ball method, the connection bump is formed on the electrode through an adhesive portion forming step of forming an adhesive portion made of a connection aid having adhesive properties such as solder paste and flux on the electrode. It is formed through a mounting process for mounting a conductive ball and a bump forming process for forming a connection bump by heating the conductive ball.

As a method of mounting the conductive ball on the electrode in the mounting process, an adsorption method and a mask method are well known, and an example of the latter is disclosed in Patent Document 1 below. Patent Document 1 describes that a mask having an opening corresponding to the arrangement position of conductive balls is positioned on an electronic component, the conductive balls are filled in the openings, and the conductive balls are arranged. . Further, Patent Document 2 describes that the arranged conductive balls are pressed and brought into close contact with the arrangement position so as not to be displaced in the subsequent steps.
JP 2000-49183 A (paragraph numbers 0011 to 0013)

  Recently, the number of bumps has become enormous and the arrangement thereof has been increased in density and pitch, so that conductive particles having a size as small as 100 μm or less have been used. In the mask method described above, the conductive ball is filled in an opening slightly larger than the conductive ball. Therefore, the variation in the position of the arranged conductive balls is reduced by the restriction of the opening, and the excess conductive There is an advantage that the balls are not arranged. However, since the diameter of the opening is slightly larger than that of the conductive ball, the connection aid (solder paste, flux) that forms the adhesive part may adhere to the inner wall of the opening. There is a problem that the conductive balls formed are trapped by the adhering connection aid while passing through the opening and are not arranged on the electrodes. When the conductive ball is pressed in the state of being inserted into the opening as described in Patent Document 2, the connection aid is spread by the pressurized conductive ball and adheres to the opening. It becomes even more prominent.

  Further, when the connection aid adheres to the mask, the mask becomes difficult to be separated from the arrayed body, and if the mask is forcibly removed, the mask may be damaged. These problems can be solved by, for example, forming an adhesive portion with high precision only on the electrodes, or positioning the mask so as to have a predetermined interval with respect to the arrayed body so that the connection aid does not adhere. Increases complexity and costs.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a mounting apparatus and a mounting method capable of accurately arranging conductive balls at the arrangement position of the objects to be arranged. .

  One embodiment of the present invention provides a mounting method and a mounting device for mounting conductive balls on the arrayed positions of the objects to be arrayed. The present invention includes conductive balls mainly composed of metals such as Sn, Cu, Au, Ag, W, Ni, Mo, and Al. Similarly, a conductive ball in which a conductive metal such as solder is coated on the surface of a ball mainly composed of a resin such as polypropylene or polyvinyl chloride, polystyrene, polyamide, cellulose acetate, or polyester is included in the present invention. In addition, electronic components such as semiconductor devices (chips), substrates, packages thereof, and other electronic components that employ conductive balls as connection bumps are included in the arrayed body of the present invention. In addition, a member for forming a connection bump on the electronic component, for example, a member on which the conductive ball is disposed for mounting the conductive ball on the electronic component is also included in the arrayed body referred to in the present invention. Furthermore, in the present invention, the property of the surface of the arrayed body on which the conductive balls are mounted is not particularly limited, and a flat surface, a curved surface, an uneven surface, or the like is targeted.

  The mounting method according to an embodiment of the present invention is the mounting method described above, wherein an adhesive portion smaller than the projected area of the ball is formed at the array position, and the ball can be inserted corresponding to the array position. The ball is placed on the adhesive portion through the positioning opening of the alignment member in which the opening is formed.

  According to the mounting method of this aspect, since the area of the adhesive portion is smaller than the projected area of the ball when the ball is mounted at the arrangement position and adhered by the adhesive portion, the connection aid constituting the adhesive portion adheres only to the ball. It becomes a state, and the opportunity to adhere to the positioning opening and the non-opening of the alignment member is reduced. Note that the thickness of the adhesive portion is also a factor that affects the chance of adhesion. In order to reduce the opportunity, the thickness is 500 μm or less (more preferably 100 μm or less), and 5 μm or more is required to exhibit sufficient adhesiveness. (More preferably 10 μm or more).

  A mounting device according to an embodiment of the present invention is a mounting device particularly suitable for carrying out the mounting method described above, and the arrayed object in which adhesive portions smaller than the projected area of the ball are formed at the array position. An alignment member positioned with respect to the body is provided, and the alignment member has a positioning opening corresponding to the arrangement position through which the ball can be inserted.

  As described above, according to the embodiments of the present invention, there are provided a mounting method and a mounting apparatus capable of accurately arranging conductive balls at the arrangement positions of the objects to be arranged.

  The present invention will be described based on the embodiments with reference to the drawings. FIG. 1 is a schematic configuration diagram of a mounting apparatus according to an embodiment of the present invention. FIG. 2 is a structural diagram of an arrayed body on which conductive balls are mounted in the mounting apparatus of FIG. FIG. 3 is a diagram for explaining the operation of the mounting apparatus 1 of FIG. FIG. 4 is a diagram for explaining a method of forming an adhesive portion on the arrayed body in FIG.

  As shown in FIG. 2, the substrate 7 that is an implementation target of this aspect has connection bumps 72 b (72) connected to an external device such as a motherboard protruding in one area (lower surface) in an area array shape, Connection bumps 72 a (72) connected to the semiconductor element 8 are projected from the other surface (upper surface) in the form of an area array. The semiconductor element 8 is flip-chip bonded to the upper surface of the substrate 8 to form a package.

  The substrate 7 has a thin plate-like base 73, a pad-like electrode 71a (71) in which the connection bump 72a projects from the upper surface side of the base 73, and a pad shape in which the connection bump 72b projects from the lower surface side. Electrode 71b (71). A conductor pattern is formed on the surface and inside of the base 73 for rewiring. As the substrate 73, a known resin or ceramic substrate or a substrate on which they are laminated is selected as necessary.

  As shown in FIG. 3, the solder ball B is formed so that the solder ball B can be inserted into the substrate 7 on which the adhesive portion F is formed on the electrode 71 which is the arrangement position, corresponding to the position of the electrode 71. The mask 22 having the positioning opening 221 is placed on the adhesive portion F through the positioning opening 221 of the mask 22 that has been aligned (FIG. 3A) (FIG. 3B). Thereafter, the mask 22 is removed from the substrate 7 (FIG. 3C), and the substrate 7 on which the solder balls B are mounted is reflowed to form connection bumps 72 (FIG. 3D).

  Here, as shown in FIG. 1, the adhesive portion F is smaller than the projected area of the solder ball B by using an adhesive flux (connection aid), specifically, the diameter db of the solder ball B. It is formed so that the diameter df of the adhesive part F becomes small. The adhesive portion F has a thickness of 5 μm or more (preferably 10 μm or more) in order to exhibit adhesiveness, and 500 μm or less (in order to prevent the flux from adhering to the positioning opening 221 or the non-opening portion of the mask 22). Preferably, it is 100 μm or less.

  For example, as shown in FIG. 4A, the adhesive portion F described above aligns the print mask 62 having the through hole 63 corresponding to the electrode 71 so that the through hole 63 and the electrode 71 correspond, and the flux f Can be spread with a squeegee 64 and the electrode 71 can be selectively printed with a temporary fixing material f. Further, as shown in FIG. 4B, the flux f may be applied and formed on the electrode 71 using a syringe-like application means 65 that applies paste-like flux f from the lower end.

  As shown in FIG. 1, the mounting apparatus 2 suitable for carrying out the mounting method described above includes a mask 22 that is an alignment member for aligning the solder balls B on the electrodes 71 of the substrate 7.

  The mask 22 includes an upper surface (one surface) 222, a lower surface (the other surface) 223 with respect to the upper surface, a positioning opening 221 that corresponds to the arrangement pattern and can be inserted through the solder balls B, and is open to the upper surface 222 and the lower surface 223. It has. Furthermore, the mask 22 can have a structure in which the protrusion 224 has a lower surface 223 that does not contact the substrate 7 or a structure in which the protrusion 224 does not have the lower surface 223 contacts the substrate 7. . The mask 22 can be aligned so that the positioning opening 221 of the mask 22 corresponds to the electrode 71 of the substrate 7 in the planar direction, and the lower surface of the mask 22 has a predetermined positional relationship with the upper surface of the substrate 7 in the vertical direction. It has a configuration.

  Here, the mask 22 is repeatedly used with a kind of jig, and a plate-like substrate such as a metal plate, a resin plate, a laminated product, or a film-formed product is used. Since the positioning opening 221 must be formed with an accurate shape and size, it is desirable to form the positioning opening 221 on the base material by laser processing, etching processing, or the like. In addition, if the mask 22 is manufactured by electroforming using nickel or the like as a material, the positioning opening 221 is also formed at the same time, which is desirable.

  The present invention is not limited to the above description, and can also be used for applications in which small or irregular powders or granules are mounted on a substrate, for example, in fields such as pharmaceuticals and ceramics.

It is a schematic block diagram of the mounting apparatus of the embodiment of this invention. FIG. 2 is a structural diagram of an arrayed body on which conductive balls are mounted by the mounting apparatus of FIG. 1. It is a figure explaining operation | movement of the mounting apparatus of FIG. It is a figure explaining the method of forming an adhesion part in the to-be-arranged body of FIG.

Explanation of symbols

2 Mounting device 22 Alignment member 7 Substrate 71 Electrode

Claims (2)

A mounting method for mounting conductive balls at an array position of an arrayed object, wherein an adhesive portion smaller than a projected area of the ball is formed at the array position, and the ball can be inserted corresponding to the array position A mounting method in which the ball is placed on the adhesive portion through the positioning opening of the alignment member in which the positioning opening is formed. An apparatus for mounting a conductive ball on an arrayed position of an arrayed body, wherein an alignment member that is positioned with respect to the arrayed body having an adhesive portion smaller than a projected area of the ball formed at the arrayed position is provided. And the alignment member has a positioning opening corresponding to the arrangement position through which the ball can be inserted.

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