JP2010109114A - Solder bump, electronic apparatus using solder bump, method of manufacturing solder bump, and solder bump mounter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solder bump in response to a narrow pitch for an IC chip or an electrode of an electronic component. <P>SOLUTION: A solder bump 101, which connects an IC chip 4 and a substrate 5, includes a column-shaped core part 102 and a coating of its peripheral surface with a solder 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solder bump used for connecting an electronic device such as an IC chip and an electronic component, and is particularly suitable for connecting a surface mount type IC chip such as flip chip mounting and a substrate.

Japanese Patent Laid-Open No. 8-141785 proposes to apply a solder ball having a Cu core to a core portion of a solder bump used for connecting an IC chip and a substrate. Japanese Patent Application Laid-Open No. 10-340980 proposes that a plastic ball is included in a core portion of a solder bump.
JP-A-8-141785 Japanese Patent Laid-Open No. 10-340980

Since the core portion in the prior art has a spherical shape, when the distance between the electrodes of the IC chip is narrow or when it is desired to ensure a large distance between the IC chip and the substrate, the adjacent bumps Since the distance is shortened, the degree of freedom in layout design is restricted and the difficulty in the mounting process is increased. This tendency becomes more prominent as the IC chip is miniaturized and the pitch between the electrodes becomes narrower.
One of the objects of the present invention is to provide a solder bump capable of improving the degree of freedom of design and greatly reducing the difficulty in the mounting process.

The invention of claim 1 is defined by a bottom surface, a side surface perpendicular to the bottom surface, and a top surface parallel to the bottom surface, and a core portion made of a conductor, and a solder covering the entire surface on the side surface. Solder bump provided.
According to a second aspect of the present invention, in the first aspect of the present invention, the core portion is a solder bump having a cylindrical shape.
According to a third aspect of the present invention, in the first aspect of the invention, the core portion is a solder bump having a cylindrical shape having a through hole penetrating the central portion.
Invention of Claim 4 in the invention in any one of Claim 1 thru | or 3 WHEREIN: The electronic component which has a some electrode, The board | substrate which has the some substrate electrode arrange | positioned facing the said some electrode,
The electronic device includes solder bumps that electrically connect the plurality of electrodes and the plurality of substrate electrodes.
According to a fifth aspect of the present invention, in the invention of the third aspect, the electronic component having a plurality of electrodes, a substrate having a plurality of substrate electrodes arranged to face the plurality of electrodes, the plurality of electrodes, and the An electronic device comprising solder bumps for electrically connecting a plurality of substrate electrodes, and having an adhesive means extending from the inner surface of the through hole to the electrode or the substrate electrode.
A sixth aspect of the present invention is the electronic device according to the fifth aspect of the present invention, wherein the bonding means is solder that covers the entire inner surface.
According to a seventh aspect of the present invention, in the method for producing a solder bump having a cylindrical core part according to the second aspect, a step of preparing a metal wire having a cylindrical shape and a step of coating the outer peripheral surface of the metal wire with solder And a step of cutting the metal wire covered with solder into a predetermined length.
According to an eighth aspect of the present invention, there is provided a method for producing a solder bump having a cylindrical core portion according to the third aspect, wherein a step of preparing a wire-shaped resin having a columnar shape and a copper outer peripheral surface of the wire-shaped resin are prepared. The step of plating with copper, the step of plating the outer peripheral surface plated with copper with solder, the step of cutting the copper and solder-plated wire-shaped resin into a predetermined length, and the resin with a solvent And a melting step.
According to a ninth aspect of the present invention, there is provided a method for producing a solder bump having a cylindrical core portion according to the third aspect, wherein the step of preparing a wire-shaped resin having a columnar shape and the outer peripheral surface of the wire-shaped resin are soldered Plating the outer peripheral surface plated with solder with copper, plating the outer peripheral surface plated with copper with solder, and wire-like resin plated with copper and solder. And a step of dissolving the resin with a solvent.
According to a tenth aspect of the present invention, there is provided storage means for storing a plurality of solder bumps according to the second or third aspect, and one of the solder bumps stored in the storage means. And mounting means that are pushed out and disposed on the substrate electrode.
According to an eleventh aspect of the present invention, there is provided storage means for storing a connection solder bump in which a plurality of solder bumps according to claim 2 or claim 3 are connected, and an end portion of the connection solder bump stored in the storage means having a predetermined length. And a mounting means for extruding onto the substrate electrode according to claim 4, separating the end of the extruded solder bump from the connecting solder bump, and disposing it on the substrate electrode.

According to the first to third aspects of the present invention, the side surface is perpendicular to the bottom surface and the top surface, and the entire surface on the side surface is covered with solder. realizable.
According to the invention described in claim 4, in addition to the effects obtained by the inventions described in claims 1 to 3, the distance between the adjacent solder bumps can be increased as compared with the core having a spherical shape. This becomes more remarkable as the IC chip is miniaturized and the pitch between the electrodes is narrowed. Furthermore, in the layout design of the electrodes formed on the IC chip, the influence of adjacent solder bumps is minimized, so that the degree of freedom in design is greatly improved. Furthermore, when the solder bumps are arranged on the electrodes in the mounting process, the distance from the adjacent solder bumps is larger than that in the conventional case, so that the operation can be greatly facilitated.
According to the fifth aspect of the present invention, in addition to the effect obtained by the third aspect of the invention, since the bonding means extending from the inner surface of the through hole to the electrode is formed, the bonding strength between the solder bump and the electrode Can be strengthened.
According to the invention described in claim 6, in addition to the effect obtained by the invention described in claim 5, the bonding means is composed of the solder covering the entire inner surface, so that the solder bump and the electrode are joined to the outer peripheral surface. This can be performed simultaneously with other processes such as the solder connection process, thereby improving workability.
According to the seventh to ninth aspects of the invention, in addition to the effect obtained by the second or third aspect of the invention, the thickness of the layer obtained by plating can be determined by the plating time, the concentration of the plating solution, or the current voltage during electroplating. It can be decided freely by adjusting. Furthermore, since a solder bump having a desired length can be easily cut out from the wire-shaped bump material, it is possible to easily obtain a solder bump having a height suitable for the application.
According to the tenth and eleventh aspects of the present invention, a metal mask for mounting solder bumps, which has been conventionally used, becomes unnecessary, and low-cost solder bumps can be formed on the substrate electrodes. Furthermore, according to the eleventh aspect of the invention, the height setting of the solder bumps can be changed in the step of mounting the solder bumps.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings referred to in the present embodiment, each element is schematically shown for easy understanding of the invention. In this section, the same elements as those described above are denoted by the same reference numerals, and the description thereof may be omitted.

  FIG. 1A shows the solder bump 101 of this embodiment, and FIG. 1B connects the electrode 8 formed on the IC chip 4 and the substrate electrode 7 formed on the substrate 5. A solder bump 101 of this embodiment is shown. In this embodiment, an IC chip is used. However, it is obvious that the present invention can also be applied to an electronic component having electrodes.

  As shown in FIG. 1A, the solder bump 101 includes a cylindrical metal core 102 and solder 3 that covers the outer peripheral surface of the metal core 102. The shape of the metal core is not limited to a cylinder, and may be a shape such as a quadrangular prism. That is, in the solder bump of the present invention, the core portion has a bottom surface, a side surface perpendicular to the bottom surface, and a top surface parallel to the bottom surface, and is made of a conductor. It only has to be prepared. The material of the metal core may be any metal that does not melt at the melting point of the solder outside the core, such as copper, gold, silver, and aluminum.

  In FIG. 1B, the IC chip 4 is mounted on the substrate 5 by flip chip mounting. The electrodes 8 of the IC chip 4 are electrically connected to the electrodes 7 on the substrate 5 by a plurality of solder bumps 101, respectively. Each electrode and the solder bump are joined by a known method.

  FIG. 2 shows adjacent solder bumps in the connection between the IC chip 4 and the substrate 5 when the solder bump 1 having a spherical metal core is used and when the columnar solder bump 101 of the present embodiment is used. The figure which compared the distance between is shown. In FIG. 2, P is the distance between electrodes (electrode pitch), W1 is the distance between bumps of the spherical solder bump 1, W2 is the distance between bumps of the columnar solder bump 101 of this embodiment, and H is the height of the bump. .

  As shown in FIG. 2, the inter-bump distance W2 of the columnar solder bump 101 of this embodiment is longer than the inter-bump distance W1 of the spherical solder bump 1. Since the distance W2 between the bumps can be secured large, the configuration of the present embodiment is suitable for mounting an IC chip with a narrow pitch that is flip-chip mounted. Also, the solder bump itself can be downsized.

Table 1 shows a result of comparison between the spherical solder bump 1 and the columnar solder bump 101 of the present embodiment. For comparison, the electrode size S and the electrode pitch P were set to 1: 0.5.
From this calculation result, it can be seen that at the same height H, the columnar metal core can form bumps with a higher aspect ratio. Further, when the width of the columnar metal core is 20% thinner than the spherical core, the distance between the bumps of the columnar metal core solder bumps can be increased by 40% (= (0.7 / 0.5) × 100).

Next, a method for manufacturing the solder bump 101 of this embodiment will be described with reference to FIG.
In the method of manufacturing a solder bump having a cylindrical core portion as in the present embodiment, the outer peripheral surface of the metal wire 111 having a cylindrical shape as shown in FIG. Wires coated with solder as shown in b) can be easily manufactured. The thickness of the solder 112 can be appropriately set by adjusting the plating time of the solder plating, the concentration of the plating solution, or the current voltage at the time of electroplating.

  Thereafter, the solder bump 101 shown in FIG. 1 can be formed by cutting the wire coated with solder at a predetermined position 113 as shown in FIG. The material of the metal wire 111 is appropriately selected in consideration of the size of the solder bump 101, necessary strength, conductivity, etc., but copper is used in this embodiment.

  FIG. 4 shows mounting machines 114 and 117 for mounting the solder bumps 101 on the IC chip 4. The mounting machine 114 shown in FIG. 4A includes means 116 for storing a plurality of solder bumps 101 therein. After the mounting machine 114 moves onto the electrode 7 of the IC chip 4, the solder bumps 101 are pushed out one by one from the storage means 116 by the extrusion jig 115, and the solder bump 101 is arranged on the electrode 7 of the IC chip 4. The solder bump 101 and the electrode 7 are joined. If solder bumps are mounted using this mounting machine, it is possible to mount the solder bumps without using a metal mask that is used when mounting ball-shaped solder bumps.

  The mounting machine 117 shown in FIG. 4B stores the wire coated with solder shown in FIG. 3B in the storage means 116. After the mounting machine 117 is moved onto the electrode 7 of the IC chip 4, the end of the wire coated with solder is pushed out from the storage means 116 by the pushing jig 115, and the slide cutting part 118 is slid in the horizontal direction and pushed out. Cut the end of the wire. The ends of the cut wires (that is, the solder bumps 101) are arranged on the electrodes 7 of the IC chip 4 and then joined to the electrodes 7. If solder bumps are mounted using this mounting machine, the height of the solder bumps can be freely determined.

  FIG. 5A shows a solder bump 201 according to another embodiment, and FIG. 5B shows a connection between the electrode 8 formed on the IC chip 4 and the substrate electrode 7 formed on the substrate 5. The solder bump 201 of this embodiment is shown. The metal core 202 of the present embodiment has a cylindrical shape and has a through hole that penetrates the central portion. The outer peripheral surface of the cylindrical metal core 202 is coated with the solder 3.

  In FIG. 5B, the IC chip 4 is mounted on the substrate 5 by flip chip mounting. The electrodes 8 of the IC chip 4 are electrically connected to the electrodes 7 on the substrate 5 by a plurality of solder bumps 201, respectively. Each electrode and the solder bump are bonded by a known method. In addition, in this embodiment, the inner surface of the through hole and the electrodes 7 and 8 are connected by an adhesive 203. Thereby, the connection strength between the solder bump 201, the IC chip 4, and the substrate 5 can be increased.

Next, the manufacturing method of the solder bump 201 of this embodiment is demonstrated with reference to FIG.
In the method for manufacturing a solder bump having a cylindrical core portion as in the present embodiment, a wire-shaped resin 211 having a columnar shape as shown in FIG. 6A is prepared, and the outer peripheral surface thereof is shown in FIG. As shown in FIG. In this resin plating method, a copper or nickel film is formed on the resin surface by electroless plating by a general resin plating process. Thereafter, a film formed by electroless plating is electroplated as a plating electrode, and copper is plated to a predetermined thickness.

  Thereafter, similarly to the step of FIG. 3B, solder plating is performed on the copper plating 212, and the solder 112 is coated. The solder-coated structure 213 is cut at a predetermined position 113 as shown in FIG. Thereafter, the resin 211 is dissolved in a solvent, whereby the cylindrical solder bump 201 shown in FIG. 5A can be formed. The solder bump 201 and the solder-coated structure 213 can be mounted on the electrode 7 of the IC chip 4 by a mounting machine shown in FIGS. 4 (a) and 4 (b).

  FIG. 7 shows an application example of another embodiment. FIG. 7A shows the solder bump 301 of this application example, and FIG. 7B connects the electrode 8 formed on the IC chip 4 and the substrate electrode 7 formed on the substrate 5. The solder bump 301 of this application example is shown. The metal core 202 of this application example has a cylindrical shape and has a through-hole penetrating the central portion. The outer peripheral surface and inner surface of the cylindrical metal core 202 are coated with solder 3.

  In FIG. 7B, the IC chip 4 is mounted on the substrate 5 by flip chip mounting. The electrodes 8 of the IC chip 4 are electrically connected to the electrodes 7 on the substrate 5 by a plurality of solder bumps 301, respectively. Each electrode and the solder bump are connected by solder 3 formed on the outer peripheral surface and inner surface of the metal core 202. As a result, the connection strength between the solder bump 301, the IC chip 4 and the substrate 5 can be increased, and the inner surface connection step and the outer surface connection step can be performed simultaneously, thereby improving workability.

  Next, a method for manufacturing the solder bump 301 of this application example will be described with reference to FIG. First, a wire-shaped resin 211 having a cylindrical shape as shown in FIG. 8A is prepared, and the outer peripheral surface thereof is covered with a solder plating 112 as shown in FIG. 8B. In this resin plating method, a copper or nickel film is formed on the resin surface by electroless plating by a general resin plating process. Thereafter, a film formed by electroless plating is electroplated as a plating electrode, and solder is plated to a predetermined thickness. After performing copper plating 212 on the solder plating 112 as shown in FIG. 8C, the solder plating 112 is performed as shown in FIG.

  The structure 311 is cut at a predetermined position 113 as shown in FIG. Thereafter, the resin 211 is dissolved in a solvent, whereby the cylindrical solder bump 301 shown in FIG. 7A can be formed. The solder bump 301 and the structure 311 can be mounted on the electrode 7 of the IC chip 4 by a mounting machine shown in FIGS. 4 (a) and 4 (b).

The figure which shows the solder bump concerning embodiment of this invention Diagram for comparing columnar solder bumps with spherical solder bumps The figure which shows the manufacturing method of the solder bump concerning this embodiment The figure which shows the mounting machine which mounts the solder bump concerning this embodiment on an IC chip. The figure which shows the solder bump concerning other embodiment of this invention. The figure which shows the manufacturing method of the solder bump concerning other embodiment. The figure which shows the solder bump concerning the application example of other embodiment. The figure which shows the manufacturing method of the solder bump concerning the application example of other embodiment.

Explanation of symbols

101 Solder bump 102 Metal core 4 IC chip 5 Substrate 7 Substrate electrode 8 Electrode

Claims (11)

A core portion defined by a bottom surface, a side surface perpendicular to the bottom surface, and a top surface parallel to the bottom surface, and formed of a conductor;
A solder bump, comprising: a solder covering the entire surface of the side surface.   The solder bump according to claim 1, wherein the core portion has a cylindrical shape.   The solder bump according to claim 1, wherein the core portion has a cylindrical shape having a through hole penetrating the central portion. An electronic component having a plurality of electrodes;
A substrate having a plurality of substrate electrodes disposed opposite to the plurality of electrodes;
An electronic device comprising the solder bump according to claim 1, wherein the plurality of electrodes and the plurality of substrate electrodes are electrically connected. An electronic component having a plurality of electrodes;
A substrate having a plurality of substrate electrodes disposed opposite to the plurality of electrodes;
The solder bump according to claim 3, wherein the plurality of electrodes and the plurality of substrate electrodes are electrically connected.
An electronic device comprising an adhesive means extending from an inner surface of the through hole to the electrode or the substrate electrode.   6. The electronic device according to claim 5, wherein the bonding means is a solder covering the entire inner surface. A method for producing a solder bump having a cylindrical core part according to claim 2,
Preparing a metal wire having a cylindrical shape;
Coating the outer peripheral surface of the metal wire with solder;
And a step of cutting the metal wire covered with solder into a predetermined length. A method for producing a solder bump having a cylindrical core part according to claim 3,
Preparing a wire-shaped resin having a cylindrical shape;
Plating the outer peripheral surface of the wire-shaped resin with copper;
Plating the outer peripheral surface plated with copper with solder;
Cutting the wire-shaped resin plated with copper and solder into a predetermined length;
And a step of dissolving the resin with a solvent. A method for producing a solder bump having a cylindrical core part according to claim 3,
Preparing a wire-shaped resin having a cylindrical shape;
Plating the outer peripheral surface of the wire-shaped resin with solder;
Plating the outer peripheral surface plated with the solder with copper;
Plating the outer peripheral surface plated with copper with solder;
Cutting the wire-shaped resin plated with copper and solder into a predetermined length;
And a step of dissolving the resin with a solvent.   A storage means for storing a plurality of solder bumps according to claim 2 or 3, and one of the solder bumps stored in the storage means is extruded onto the substrate electrode according to claim 4, and the substrate electrode A solder bump mounting machine comprising mounting means arranged on the top. 5. A storage means for storing a connection solder bump in which a plurality of solder bumps according to claim 2 or 3 are connected, and an end portion of the connection solder bump stored in the storage means by a predetermined length. A solder bump mounting machine comprising mounting means for extruding onto a substrate electrode, separating an end of the extruded solder bump from the connection solder bump, and arranging the solder bump on the substrate electrode.