JP2007109997A - Method for manufacturing semiconductor module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor module capable of bonding a semiconductor chip to a wiring board by a simple mounting process. <P>SOLUTION: The method for manufacturing the semiconductor module 100 for bonding the semiconductor chip 70 having a cathode electrode 60 and an anode electrode 54 to the wiring board 40 having a first wiring part 12 and a second wiring part 14 by wireless bonding comprises a step of arranging the semiconductor chip to the wiring board so that the cathode electrode faces the second wiring part and the anode electrode faces a first wiring board, irradiating laser beams to a plurality of laser spots 80, 82 and 84, and bonding the cathode electrode to the second wiring part and the anode electrode to the first wiring part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor module.

  In the field of optical communication, research and development of an optical module having a simple structure in which an optical element, a drive driver, and the like are mounted on a transparent substrate are underway. In the mounting process in this case, each element may be damaged due to thermal damage.

  By the way, for example, Japanese Patent Laid-Open No. 9-51016 discloses a technique in which local heating is performed using laser light, and a terminal electrode of a component such as an IC chip and a conductor of a substrate are bonded by a wireless bonding method. It is disclosed.

However, in such a joining method, the heat dissipation and the heat capacity may be different between the cathode electrode and the anode electrode. In such a case, since the amount of irradiation light required for bonding differs between the cathode electrode and the anode electrode, it is necessary to change the irradiation time and the like in order to ensure bonding.
JP-A-9-5016

  An object of the present invention is to provide a method for manufacturing a semiconductor module, in which a semiconductor chip can be bonded to a wiring board by a simple mounting process.

A method for manufacturing a semiconductor module according to the present invention includes:
A method for manufacturing a semiconductor module in which a semiconductor chip having a cathode electrode and an anode electrode is joined to a wiring board having a first wiring portion and a second wiring portion by wireless bonding,
(A) disposing the semiconductor chip on the wiring substrate such that the cathode electrode faces the second wiring portion and the anode electrode faces the first wiring portion;
(B) irradiating at least one laser spot with a laser beam in each of the first wiring portion and the second wiring portion;
(C) joining the cathode electrode to the second wiring part and joining the anode electrode to the first wiring part;
Including
The number of laser spots irradiated with the laser beam in the first wiring portion is different from the number of laser spots irradiated with the laser beam in the second wiring portion.

  In this way, by changing the number of laser spots between the first wiring portion and the second wiring portion, it is possible to change the irradiation light amount without changing the irradiation time and irradiation intensity of the laser beam. Therefore, the semiconductor chip can be bonded to the wiring board by a simple mounting process without complicating the laser irradiation apparatus.

In the method for manufacturing a semiconductor module according to the present invention,
The semiconductor chip further includes a semiconductor substrate and a semiconductor element formed on the semiconductor substrate,
Of the cathode electrode and the anode electrode, the number of laser spots irradiated to the wiring portion facing the electrode in contact with the semiconductor substrate may be larger than the number of laser spots irradiated to other wiring portions.

  Since the electrode in contact with the semiconductor substrate has high heat dissipation, a larger amount of irradiation light is required. Therefore, as described above, the laser beam irradiation time and the irradiation intensity are changed by increasing the number of laser spots irradiated to the wiring portion facing the electrode in contact with the semiconductor substrate among the cathode electrode and the anode electrode. Without any problem, it is possible to increase the amount of laser light applied to the wiring portion facing the electrode in contact with the semiconductor substrate.

In the method for manufacturing a semiconductor module according to the present invention,
The first wiring portion and the second wiring portion each have a land disposed so as to face the cathode electrode or the anode electrode, and a wiring electrically connected to the land,
The land area facing the electrode in contact with the semiconductor substrate may be larger than the land area of another wiring portion.

In the method for manufacturing a semiconductor module according to the present invention,
The first wiring portion and the second wiring portion each have a land that is an area irradiated with the laser beam, and a wiring that is electrically connected to the land,
The number of lands included in the wiring portion facing the electrode in contact with the semiconductor substrate may be greater than the number of lands included in the other wiring portions.

In the method for manufacturing a semiconductor module according to the present invention,
The first wiring portion and the second wiring portion each have a protrusion for bonding to the cathode electrode or the anode electrode,
In the step (b), in the first wiring portion and the second wiring portion, a laser beam can be irradiated to the projection portion and a region other than the projection portion.

In the method for manufacturing a semiconductor module according to the present invention,
In the step (b), one laser beam can be branched into a plurality of laser beams and irradiated to the first wiring portion and the second wiring portion.

In the method for manufacturing a semiconductor module according to the present invention,
In the step (b), one laser beam can be branched into a plurality of laser beams and irradiated onto a two-dimensional matrix laser spot.

In the method for manufacturing a semiconductor module according to the present invention,
The wiring board further includes a transparent substrate that transmits the laser beam,
The first wiring part and the second wiring part are formed on the transparent substrate,
In the step (b), the laser beam can be irradiated from below the transparent substrate.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1-7 is a figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment.

  (1) First, the wiring board 40 and the semiconductor chip 70 are prepared. FIG. 1 is a plan view schematically showing the wiring board 40, and FIG. 2 is a cross-sectional view schematically showing the wiring board 40. The wiring substrate 40 includes a first substrate 10, and a first wiring unit 12 and a second wiring unit 14 formed on the first substrate 10. The first substrate 10 can be made of a transparent substrate such as a glass substrate that transmits laser light. The first substrate 10 can be made of, for example, ceramics such as quartz, sapphire, zirconia, barium fluoride, calcium fluoride, and aluminum nitride, and resins such as polyimide and acrylic. The first wiring part 12 and the second wiring part 14 are made of a conductive material, and can be made of, for example, a laminated film of copper, nickel and gold. The first wiring portion 12 includes a first wiring 21, a first land 20, a first protrusion 16, and a first joint portion 26. The first land 20 is electrically connected to the first protrusion 16. The width of the first land 20 may be larger than the line width of the first wiring 21 as shown in FIG. As shown in FIG. 2, the first protrusion 16 protrudes upward from the first substrate 10 side, and is formed in the first land 20. The first joint 26 is formed on the upper surface of the first protrusion 16. The second wiring part 14 includes a second wiring 25, a second land 24, a second protrusion 18, and a second bonding part 28. The second land 24 is electrically connected to the second protrusion 18. The width of the second land 24 may be larger than the line width of the second wiring 25 as shown in FIG. The second land 24 of the second wiring unit 14 has a larger area than the first land 20 of the first wiring unit 12. As shown in FIG. 2, the second protrusion 18 protrudes upward from the first substrate 10 side and is formed in the second land 24. The second joint portion 28 is formed on the upper surface of the second protrusion 18. The first wiring part 12 and the second wiring part 14 can be formed by a known method, for example, by a plating method. The first protrusions 16 and the second protrusions 18 can be made of a metal having high electrical conductivity such as solder, aluminum, silver, gold, copper, nickel, and alloys thereof. The first joint portion 26 and the second joint portion 28 are made of a metal having a melting point lower than that of the first protrusion portion 16 and the second protrusion portion 18, for example, aluminum, silver, gold, copper, nickel, indium, gallium, bismuth. And alloys thereof.

  FIG. 3 is a plan view schematically showing the semiconductor chip 70, and FIG. 4 is a side view schematically showing the semiconductor chip 70. The semiconductor chip 70 is not particularly limited as long as it has a semiconductor element, a cathode electrode, and an anode electrode. As the semiconductor element, for example, a light emitting element and / or a light receiving element can be applied. In the present embodiment, an example in which a vertical cavity surface emitting laser is applied as the semiconductor chip 70 will be described.

  The semiconductor chip 70 includes a second substrate 50, a resonator 52, an anode electrode 54, a cathode electrode 60, and an insulating layer 58. The second substrate 50 can be made of, for example, an n-type semiconductor substrate. The resonator 52 includes upper and lower mirrors and an active layer, and can emit laser light from the upper surface thereof.

  The anode electrode 54 and the cathode electrode 60 are used to drive a vertical cavity surface emitting laser. The anode electrode 54 is formed on the upper surface of the resonator 52 so as to surround the periphery of the resonator 52. As shown in FIG. 3, the anode electrode 54 has a ring-like planar shape on the upper surface of the resonator 52 and has an opening. Laser light is emitted from the opening of the anode electrode 54. The anode electrode 54 has a first electrode pad 56 that is electrically connected to the upper surface of the resonator 52. Since the first electrode pad 56 is formed on the insulating layer 58 as shown in FIG. 4, the first electrode pad 56 is electrically disconnected from the second substrate 50. The cathode electrode 60 is formed on the upper surface of the second substrate 50.

  (2) Next, as shown in FIGS. 5 and 6, the semiconductor chip 70 is disposed on the wiring board 40. 5 indicates the shape of the semiconductor chip 70. The semiconductor chip 70 is sucked by the bonding tool 90 having the suction holes 92 and aligned with the wiring board 40. First, with a slight gap, the first electrode pad 56 of the anode electrode 54 is positioned immediately above the first protrusion 16 of the first wiring portion 12, and the cathode electrode 60 is the second wiring portion. The semiconductor chip 70 is arranged on the wiring substrate 40 so as to be positioned immediately above the 14 second protrusions 18. Next, the first joint portion 26 is brought into contact with the first electrode pad 56 of the anode electrode 54, and the second joint portion 28 is brought into contact with the cathode electrode 60.

  (3) Next, the semiconductor chip 70 is bonded to the wiring substrate 40 by irradiating the first wiring part 12 and the second wiring part 14 with laser light. The laser light is composed of a plurality of laser beams, and is branched into a plurality of laser beams of equal intensity by, for example, a branch element. As the branch element, for example, a computer generated hologram (CGH) can be used. In the present embodiment, the branch element can turn one light beam into three laser beams.

  Of the three laser beams branched by the branch element, two laser beams irradiate the laser spots 80 and 82 of the second wiring portion 14, and one laser beam is a laser of the first wiring portion 12. The spot 84 is irradiated. The distance between the laser spot 80 and the laser spot 82 may be equal to the distance between the laser spot 82 and the laser spot 84.

  As described above, the second land 24 of the second wiring portion 14 has a larger area than the first land 20 of the first wiring portion 12. Thereby, the number of laser beams irradiated to the 2nd wiring part 14 can be made larger than the number of laser beams irradiated to the 1st wiring part 12. FIG. The laser beam is irradiated to the corresponding laser spot. Here, the laser beam can be applied to the laser spot 80 in addition to the position (laser spot 82) in contact with the cathode electrode 60 of the semiconductor chip 70 in the second land 24. The laser spot 80 is preferably located on the second wiring 25 side of the laser spot 82 in the second land 24.

  Thus, by making the number of laser beams irradiated to the second wiring part 14 larger than the number of laser beams irradiated to the first wiring part 12, the following effects can be obtained. First, as shown in FIG. 6, when the laser light is irradiated onto the wiring substrate 40, the heat generated by the laser light is transmitted to the anode electrode 54 and the cathode electrode 60. As shown in FIG. 4, in the semiconductor chip 70, the anode electrode 54 is formed on the insulating layer 58, whereas the cathode electrode 60 is formed directly on the second substrate 50. Thereby, the heat transmitted to the cathode electrode 60 is easily radiated toward the second substrate 50. In some cases, the area of the cathode electrode 60 is larger than that of the first electrode pad 56, and the cathode electrode 60 has a larger heat capacity than the anode electrode 54. For these reasons, in order to join the second joining portion 28 to the cathode electrode 60, a light amount larger than the amount of light consumed to join the anode electrode 54 to the first joining portion 26 is required. Irradiation time had to be changed between the anode electrode 54 and the cathode electrode 60.

  Therefore, a larger amount of heat is supplied to the second wiring unit 14 by increasing the number of laser beams irradiated to the second wiring unit 14 than the number of laser beams irradiated to the first wiring unit 12. The semiconductor chip 70 can be reliably bonded to the wiring board 40. In addition to the position where the laser beam is in contact with the cathode electrode 60 (laser spot 82), heat is also generated at the position of the laser spot 80 by irradiating the laser spot 80. The generated heat can be prevented from being radiated in the direction of the laser spot 80. In particular, since the laser spot 80 is positioned closer to the second wiring 25 than the laser spot 82, heat generated in the laser spot 82 can be suppressed from being radiated in the direction of the second wiring 25. Therefore, according to the present embodiment, the semiconductor chip 70 can be more reliably bonded to the wiring substrate 40 without changing the irradiation intensity and irradiation time of the laser light between the anode electrode 54 and the cathode electrode 60.

  Note that an appropriate load may be applied to the semiconductor chip 70 in the direction of the wiring substrate 40 while irradiating the laser beam.

  The semiconductor module 100 (see FIG. 7) can be manufactured through the above steps.

  The present invention is not limited to the embodiment described above. A modification according to this embodiment will be described below.

  A method for manufacturing a semiconductor module according to the first modification will be described. In the semiconductor module manufacturing method according to the first modification, the shape of the wiring portion of the wiring board to be used is different from the shape of the wiring portion described above. 8 and 9 are plan views schematically showing the wiring board 140 according to the first modification. The wiring board 140 includes a first board 110, a first wiring part 112, and a second wiring part 114. The first wiring part 112 includes a first wiring 121, a first land 120, and a first protrusion 116. The second wiring part 114 includes a second wiring 125, a second land 124, and a first protrusion 118.

  The first land 120 and the second land 124 are formed in parallel in a planar shape. The shape of the first wiring 121 has a bent planar shape.

  FIG. 9 shows a laser spot irradiated to the wiring board 140. 9 indicates the shape of the semiconductor chip 70. In the first modification, the branch element branches the laser light into a two-dimensional matrix laser beam. That is, as shown in FIG. 9, the branch element can branch the laser beam into a plurality of parts in both the row direction and the column direction in plan view. In this way, by using the branch element that branches the laser light in a two-dimensional matrix, the pattern shape of the first wiring portion 112 and the second wiring portion 114 is appropriately adjusted, thereby generating the laser light generation mechanism. Without changing, it is possible to emit a laser beam having a light quantity suitable for bonding to the wiring board 140.

  Specifically, in the first modification, a 3 × 2 laser spot is formed. By setting the number of laser spots in this way, for example, the second wiring portion 114 is irradiated with laser beams to the three laser spots 180, 182, and 184, and the first wiring portion 112 is irradiated with two laser spots. 186 and 188 can be irradiated with a laser beam. Further, by changing the pattern shape of the first wiring portion 112, only one laser spot can be irradiated with the laser beam.

  Further, by making the shape of the first wiring 121 into a bent planar shape, for example, the laser beam irradiated to the laser spot 190 is prevented from irradiating the first wiring part 112, and an excessive amount of laser light is irradiated. Can be easily prevented. As described above, according to the semiconductor module manufacturing method according to the first modification, the number of laser spots can be easily changed in the semiconductor chip 70 according to the heat capacity and heat dissipation of the anode electrode 54 and the cathode electrode 60. The semiconductor chip can be bonded to the wiring substrate by irradiating with an appropriate amount of laser light.

  The semiconductor module manufacturing method according to the first modification has been described above. However, the processes and configuration of the semiconductor module manufacturing method other than those described above are the same as those of the semiconductor module manufacturing process according to the present embodiment. Description is omitted.

  Next, a method for manufacturing a semiconductor module according to the second modification will be described. The wiring board used in the method for manufacturing a semiconductor module according to the second modification is different in the shape of the wiring portion from the shape of the wiring portion according to the present embodiment described above. FIG. 10 is a plan view schematically showing a wiring board 240 according to the second modification. The second wiring unit 214 according to the second modification has a plurality of second lands 224 and 225. That is, the wiring 226 is formed between the second land 224 and the second land 225, and the line width of the wiring 226 is smaller than the width of the second land 224 and the second land 225. A laser beam is irradiated to the laser spot 80 in the second land 224 and the laser spot 82 in the second land 225.

  Thus, by changing the width of the second wiring portion 214 between the laser spot 80 and the laser spot 82, the heat dissipation from the laser spot 82 can be controlled. Accordingly, the necessary amount of heat can be supplied to the laser spot 82 without excess and deficiency, and the semiconductor chip 70 can be bonded to the wiring substrate 40 with higher accuracy.

  The semiconductor module manufacturing method according to the second modification has been described above. However, the processes and configuration of the semiconductor module manufacturing method other than those described above are the same as the semiconductor module manufacturing process according to the present embodiment. Description is omitted.

  As described above, the embodiments of the present invention have been described in detail. However, those skilled in the art can easily understand that many modifications can be made without departing from the novel matters and effects of the present invention. . Accordingly, all such modifications are included in the scope of the present invention.

  For example, in the above-described embodiment, the p-type and n-type, the cathode electrode, and the anode electrode in each semiconductor layer are interchanged without departing from the spirit of the present invention.

The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning this Embodiment. The figure for demonstrating the manufacturing method of the semiconductor module concerning a 1st modification. The figure for demonstrating the manufacturing method of the semiconductor module concerning a 1st modification. The figure for demonstrating the manufacturing method of the semiconductor module concerning a 2nd modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st board | substrate, 12 1st wiring part, 14 2nd wiring part, 16 1st projection part, 18 2nd projection part, 20 1st land, 21 1st wiring 21, 24 2nd Land, 25 second wiring, 26 first junction, 28 second junction, 40 wiring board, 50 second substrate, 52 resonator, 54 anode electrode, 56 first electrode pad, 60 cathode Electrode, 70 Semiconductor chip, 80, 82, 84 Laser spot, 90 Bonding tool, 92 Suction hole, 100 Semiconductor module

Claims (8)

A method for manufacturing a semiconductor module in which a semiconductor chip having a cathode electrode and an anode electrode is joined to a wiring board having a first wiring portion and a second wiring portion by wireless bonding,
(A) disposing the semiconductor chip on the wiring substrate such that the cathode electrode faces the second wiring portion and the anode electrode faces the first wiring portion;
(B) irradiating at least one laser spot with a laser beam in each of the first wiring portion and the second wiring portion;
(C) joining the cathode electrode to the second wiring part and joining the anode electrode to the first wiring part;
Including
The method of manufacturing a semiconductor module, wherein the number of laser spots irradiated with the laser beam in the first wiring portion is different from the number of laser spots irradiated with the laser beam in the second wiring portion. In claim 1,
The semiconductor chip further includes a semiconductor substrate and a semiconductor element formed on the semiconductor substrate,
Of the cathode electrode and the anode electrode, the number of laser spots irradiated to the wiring portion facing the electrode in contact with the semiconductor substrate is greater than the number of laser spots irradiated to other wiring portions. Method. In claim 2,
The first wiring portion and the second wiring portion each have a land disposed so as to face the cathode electrode or the anode electrode, and a wiring electrically connected to the land,
A method for manufacturing a semiconductor module, wherein an area of a land facing an electrode in contact with the semiconductor substrate is larger than an area of a land included in another wiring portion. In claim 2,
The first wiring portion and the second wiring portion each have a land that is an area irradiated with the laser beam, and a wiring that is electrically connected to the land,
The method of manufacturing a semiconductor module, wherein the number of lands included in the wiring portion facing the electrode in contact with the semiconductor substrate is greater than the number of lands included in the other wiring portions. In any of claims 1 to 4,
The first wiring portion and the second wiring portion each have a protrusion for bonding to the cathode electrode or the anode electrode,
In the step (b), in the first wiring portion and the second wiring portion, a method of manufacturing a semiconductor module, wherein a laser beam is irradiated to the protruding portion and a region other than the protruding portion. In any of claims 1 to 5,
In the step (b), a method of manufacturing a semiconductor module, wherein one laser beam is branched into a plurality of laser beams and irradiated to the first wiring portion and the second wiring portion. In claim 6,
In the step (b), a method of manufacturing a semiconductor module, wherein one laser beam is branched into a plurality of laser beams and irradiated to a two-dimensional matrix laser spot. In any one of Claims 1 thru | or 7,
The wiring board further includes a transparent substrate that transmits the laser beam,
The first wiring part and the second wiring part are formed on the transparent substrate,
In the step (b), a method of manufacturing a semiconductor module, wherein the laser beam is irradiated from below the transparent substrate.

Images