JP2016131986A - Joining device and joining method for semiconductor component to metal member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining device and a joining method which can secure reliability of joining of a semiconductor component to a metal member even when a temperature of a joint part rises while using laser beams for joining of the semiconductor component to the metal member.SOLUTION: A joining device 10 joins a semiconductor component 50 comprising a semiconductor body 51 and a first metal film 52 to a metal member 60 by a laser beam L of infrared wavelength. The semiconductor body comprises a laser transmission material layer 51b is formed of a laser transmission material, and the first metal film is formed of a material which can be fused by absorbing the laser beam L. The joining device 10 makes a laser beam be incident on the surface of the laser transmission material layer where the first metal film is not formed out of the surface of the semiconductor body to make the first metal film absorb the laser beam having transmitted the laser transmission material layer, thereby fusing the first metal film to join the semiconductor component to the metal member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a joining apparatus and joining method for joining a semiconductor component and a metal member by laser light irradiation.

  2. Description of the Related Art Conventionally, when joining a semiconductor component made of, for example, silicon or the like and a metal member, there is a technique for joining using a laser beam having a specific wavelength. For example, Patent Document 1 describes that a semiconductor component (semiconductor chip) and a metal member (base material) are joined (welded) with a laser beam having a predetermined infrared wavelength. Specifically, first, a semiconductor component is placed on a metal member, and a bonding material such as solder is disposed between the metal member and the semiconductor component. At this time, an absorbing resin is disposed around the bonding material, and the bonding material is surrounded by the absorbing resin. In addition, as the absorbing resin, a member having a better absorption rate of the laser beam having the predetermined infrared wavelength described above than the semiconductor component and the bonding material is used. Then, the irradiated laser light passes through the semiconductor component and is absorbed by the absorbing resin. Thereby, the absorption resin is heated and melted, the bonding material is melted by the heat of the heated absorption resin, and the metal member and the semiconductor component are bonded by the molten bonding material.

JP 2014-150130 A

  In the prior art described in Patent Document 1, it is a necessary condition that the material as the bonding material has a melting temperature lower than the melting temperature of the absorbent resin. For this reason, Patent Literature 1 includes lead-free solder, Sn alloy solder, and the like as selection targets for the bonding material.

  However, in recent years, for example, in an electric vehicle or a hybrid vehicle, a PCU (power control unit) that controls electric power has been increased in voltage and current. For this reason, a high voltage is also applied to a semiconductor component used in an inverter constituting the PCU and a large current flows, so that the temperature between the semiconductor component and the metal member, that is, the bonding material may become high. . In such a case, there is a risk that it is difficult to ensure quality with a bonding material made of lead-free solder, Sn alloy or the like having a low melting point as described above.

  The present invention provides a bonding apparatus and a bonding method capable of ensuring the reliability of bonding between a semiconductor component and a metal member even when the bonding portion reaches a high temperature while using a laser beam for bonding the semiconductor component and the metal member. The purpose is to do.

  A bonding apparatus according to the present invention is formed separately from a semiconductor body, a semiconductor component including a first metal film formed on a first surface of the semiconductor body, and the semiconductor component. A joining device that joins a metal member disposed in contact with the first metal film with an infrared wavelength laser beam, wherein the semiconductor body is formed of a laser transmitting material that allows the laser beam to pass therethrough. The first metal film is formed of a material that can be melted by absorbing the laser light, and the bonding device includes a surface of the laser transmissive material layer of the semiconductor body. The laser light is incident on a surface on which the first metal film is not formed, and the laser light transmitted through the laser transmitting material layer is absorbed by the first metal film, Melting the first metal coating to bonding the metal member and the semiconductor parts.

  According to the above aspect, the first metal film is directly heated and melted by the laser beam transmitted through the laser transmitting material layer of the semiconductor body until the melting temperature is reached, and then cooled and solidified to join the semiconductor component and the metal member. Is done. As described above, since the laser light directly irradiates and melts the first metal film, a metal having a melting point temperature much higher than the melting point temperature of the solder can be used as the first metal film. Thereby, the heat resistance of the bonded portion is improved as compared with the bonded portion bonded by solder. As a result, even when the semiconductor component becomes high temperature during use, the reliability of the bonding between the semiconductor component and the metal member is ensured.

  A bonding method according to the present invention includes a semiconductor body, a semiconductor component including a first metal film formed on a first surface of the semiconductor body, and the semiconductor component formed separately from the semiconductor component. A bonding method for bonding a metal member disposed in contact with a metal film by laser light having an infrared wavelength, wherein the semiconductor body is formed of a laser transmitting material capable of transmitting the laser light. A laser transmitting material layer, wherein the first metal film is formed of a material that can be melted by absorbing the laser beam, and the bonding method includes the step of applying the laser beam to the laser transmitting material layer of the semiconductor body. A transmission step of entering and transmitting through the laser transmitting material layer; and the laser light is transmitted through the laser transmitting material layer and then absorbed by the first metal film to melt the first metal film. And a bonding step of bonding the metallic member and the semiconductor component. Thereby, joining similar to the joining obtained with the said joining apparatus with high reliability thermally is obtained.

It is a schematic diagram of a joining device concerning an embodiment. It is a figure explaining the composition of the semiconductor component which concerns on embodiment. It is a figure explaining the dimension of a joining apparatus. It is a figure explaining the joining state in the planar view of a 1st metal membrane | film | coat. It is a flowchart explaining a joining method. FIG. 6 is a diagram corresponding to FIG. 4 in Modification 1; It is a figure corresponding to FIG. 4 in the modification 2.

  A joining apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of the joining apparatus 10. The bonding apparatus 10 includes a laser oscillator 20 (corresponding to an oscillation source of the present invention), a laser head 30 (corresponding to an irradiation angle changing apparatus of the present invention), a reflecting plate 40, and a housing 70. The bonding apparatus 10 is an apparatus for bonding a semiconductor component 50 and a heat spreader 60 (corresponding to a metal member of the present invention) constituting the semiconductor device 100 by laser light (see FIG. 1). For convenience of description of the bonding apparatus 10, first, the semiconductor device 100 to be bonded will be described. In the following description, the upper side of FIG. 1 will be described as the upper side, and the lower side as the lower side.

(1. Configuration of the semiconductor device 100)
As shown in FIGS. 1 and 2, the semiconductor device 100 includes a semiconductor component 50, a heat spreader 60 as a metal member, and a lead frame 62 as another metal member. The semiconductor component 50 is used, for example, in a PCU (power control unit) that controls electric power in an electric vehicle or a hybrid vehicle. Specifically, the semiconductor component 50 shall be used as a semiconductor switching element (IGBT) of an inverter constituting the PCU. In addition to the inverter, the semiconductor component 50 is also used for other devices using a semiconductor switching element. In addition, since IGBT is a well-known technique, detailed description is abbreviate | omitted.

  As shown in FIG. 2, the semiconductor component 50 is formed in a flat plate shape. The semiconductor component 50 includes a semiconductor body 51, a first metal film 52, and a second metal film 53. The second metal film 53 is formed on the second surface of the semiconductor body 51 (the upper surface of the semiconductor body 51 in FIG. 2 and corresponding to the surface of a wide band gap semiconductor layer 51a described later).

  The semiconductor body 51 includes a laser transmitting material layer 51b formed of a laser transmitting material that can transmit laser light having a predetermined infrared wavelength, and a wide band gap semiconductor layer 51a. The laser transmitting material layer 51b is a semiconductor layer formed of a laser transmitting material such as Si. The wide band gap semiconductor layer 51a is a semiconductor layer formed of, for example, GaN, SiC, or the like. The wide band gap semiconductor layer 51a has a wider band gap (forbidden band) than Si. The wide band gap semiconductor layer 51a is not limited to the laser transmitting material layer 51b, and may be formed of a laser transmitting material.

  The first metal film 52 is formed on the first surface of the semiconductor body 51 (the lower surface of the semiconductor body 51 in FIG. 2). The first metal film 52 includes a base bonding layer 52a and a bonding layer 52b in order from the first surface of the semiconductor body 51 downward. The base bonding layer 52a is formed as a base of the bonding layer 52b. Both the base bonding layer 52a and the bonding layer 52b are formed of a metal material having a melting point higher than that of solder. The first metal film 52 can be melted by absorbing laser light having a predetermined infrared wavelength. That is, the first metal film 52 absorbs or reflects the laser beam with almost no transmission. In addition, the energy of the laser beam absorbed becomes large, so that the energy density of the laser beam irradiated to the 1st metal film 52 is large. The first metal film 52 is electronically coupled to the lower surface (second surface) of the laser transmitting material layer 51b.

  The second metal film 53 includes a base electrode layer 53 b and an electrode layer 53 a in order from the second surface of the semiconductor body 51 upward. The base electrode layer 53b is formed as a base of the electrode layer 53a. In the present embodiment, the base electrode layer 53 b and the electrode layer 53 a are formed of the same material as the base bonding layer 52 a and the bonding layer 52 b of the first metal film 52. The wide band gap semiconductor layer 51a is electronically coupled to at least one surface (the upper surface in the present embodiment) of the laser transmitting material layer 51b. That is, the second metal film 53 is electronically coupled to the surface of the wide band gap semiconductor layer 51a.

  From the above, in the second metal film 53 and the first metal film 52, the electrode layer 53a and the bonding layer 52b are electronically coupled to the surfaces of the base electrode layer 53b and the base bonding layer 52a, respectively. That is, the lower surface of the base electrode layer 53b in FIG. 2 is electronically coupled to the wide band gap semiconductor layer 51a, and the upper surface of the base bonding layer 52a in FIG. 2 is electronically coupled to the laser transmitting material layer 51b. Has a structure.

  The heat spreader 60 is a metal member formed of Cu, for example. The heat spreader 60 is formed separately from the semiconductor component 50 and is disposed in contact with the lower surface of the first metal film 52 provided in the semiconductor component 50 in FIG. The heat spreader 60 is bonded to the semiconductor component 50 by melting and then solidifying the first metal film 52. That is, the heat spreader 60 is joined to the first surface of the semiconductor body 51 via the first metal film 52. The heat spreader 60 has a mass larger than a predetermined capacity, and has an action of releasing the heat of the semiconductor component 50 whose temperature has been increased. The predetermined capacity of the mass is arbitrarily set.

  The lead frame 62 is a metal member formed of Cu, for example. The lead frame 62 is formed separately from the semiconductor component 50 and is disposed in contact with the upper surface of the second metal film 53 provided in the semiconductor component 50 in FIG. The lead frame 62 is joined to the semiconductor component 50 so as to be electrically conductive. That is, the lead frame 62 is bonded to the second surface of the semiconductor body 51 via the second metal film 53. The lead frame 62 is a wiring member that supplies power to the semiconductor component 50.

  In the above description, only the lead frame 62 and the semiconductor component 50 are joined so as to be conductive, and the specific method thereof is not described. However, the semiconductor body 51 and the lead frame 62 may be joined using any method. As an example, if possible, similarly to the case where the heat spreader 60 is bonded to the semiconductor component 50, the bonding device 10 irradiates the second metal film 53 with laser light to melt the second metal film 53, and the lead frame 62 and the semiconductor. The component 50 may be joined. In this case, the laser light may be incident from the side surface of the semiconductor component 50 and transmitted through the laser transmitting material layer 51b and the wide band gap semiconductor layer 51a to melt the second metal film 53. Further, the second metal film 53 may be melted by another method, and the lead frame 62 and the semiconductor component 50 may be joined. The lead frame 62 and the semiconductor component 50 may be joined by welding using another joining material having a melting point higher than that of the solder without melting the second metal film 53.

(2. Configuration of the joining apparatus 10)
As shown in FIG. 1, the bonding apparatus 10 includes a laser oscillator 20, a laser head 30, a reflection plate 40, and a housing 70. The laser head 30 and the reflection plate 40 are disposed in the housing 70.

  The laser oscillator 20 generates laser light by oscillating so that the wavelength becomes a predetermined infrared wavelength set in advance. At this time, when the material of the base bonding layer 52a of the first metal film 52 is Ti / Ni and the material of the bonding layer 52b is Au, for example, the predetermined infrared wavelength of the laser light L is 1. It is preferable that it exists in the range of 127 micrometers-6 micrometers. When the infrared wavelength of the laser beam L is in the range of 1.127 μm to 6 μm, the laser beam L is transmitted through the semiconductor body 51 satisfactorily, and is absorbed well by the first metal film 52 and the first metal. The film 52 is melted. Note that when the semiconductor body 51 is replaced with a semiconductor of another material, and when the first metal film 52 is replaced with a metal layer of another material, the infrared wavelength is changed to the infrared of the replaced material. What is necessary is just to change to a predetermined magnitude | size according to a wavelength absorption characteristic.

  Specifically, ErYAG (wavelength: about 3 μm), HoYAG (wavelength: about 1.5 μm), fiber laser, and the like are employed as the laser light L. The laser oscillator 20 includes an optical fiber 22 that transmits the laser light L oscillated from the laser oscillator 20 to the laser head 30.

  As shown in FIG. 1, the laser head 30 is arranged at a distance from the second metal film 53 of the semiconductor component 50 and facing the second metal film 53. The laser head 30 changes the irradiation angle of the laser light L oscillated from the laser oscillator 20.

  The laser head 30 includes a collimating lens 32, a mirror 34, a galvano scanner 36, and an fθ lens 38. As described above, the collimating lens 32, the mirror 34, the galvano scanner 36, and the fθ lens 38 are disposed in the housing 70. The collimating lens 32 collimates the laser light L emitted from the optical fiber 22 and converts it into parallel light.

  The mirror 34 changes the traveling direction of the laser light L so that the collimated laser light L enters the galvano scanner 36. In the present embodiment, the mirror 34 converts the traveling direction of the laser light L by 90 degrees.

  The galvano scanner 36 changes the traveling direction of the laser light L and irradiates the laser light L to any position on the surface of the reflector 40 on the semiconductor component 50 side via the fθ lens 38. As the galvano scanner 36, for example, a known scanner including a pair of movable mirrors (not shown) capable of swinging in two orthogonal directions is used.

  The fθ lens 38 is a lens that condenses the parallel laser light L incident from the galvano scanner 36. The irradiation angle of the laser beam L is an angle toward an arbitrary position outside (outer diameter side) from the second metal film 53, and specifically, an angle toward a reflection surface of the reflection plate 40 described later. .

  The reflector 40 is opposed to the outer peripheral surface (side surface) of the semiconductor component 50 in which the first metal film 52 and the second metal film 53 are not formed among the semiconductor components 50 with a preset angle θ. And it arrange | positions so that the outer peripheral surface of the semiconductor component 50 may be surrounded continuously. The angle θ is an angle formed by the perpendicular line VL1 extending in the direction of gravity and the surface of the reflection plate 40 on the side facing the outer peripheral surface of the semiconductor component 50 (hereinafter referred to as a reflection surface). The reflecting plate 40 is a mirror on the side facing the outer peripheral surface of the semiconductor component 50.

  FIG. 3 shows an example of the dimensional relationship when the laser beam L is incident on the outer peripheral surface (side surface) of the semiconductor component 50 and irradiated to the first metal film 52 using the bonding apparatus 10. In FIG. 3, the upper side is the upper side and the lower side is the lower side. As a precondition for the configuration, the semiconductor component 50 has a prismatic shape, and the length of at least one side of the prism is 5 mm. The thickness t of the semiconductor component 50 excluding the first metal film 52 is 0.5 mm (not shown). Further, the height h (distance) between the upper surface of the first metal film 52 and the irradiation center position C of the laser beam L in the laser head 30 (irradiation angle changing device) is set to 100 mm.

  Under such conditions, the laser beam L is irradiated so that the irradiation angle β of the laser beam L from the laser head 30 is 5 °. Note that the irradiation angle β is an angle between the perpendicular line VL2 hanging from the irradiation center position C of the laser light L of the laser head 30 and the central axis of the optical path of the laser light L. Accordingly, the angle θ of the reflection plate 40 is 31.58 °, the reflection position height h1 of the laser beam L from the first metal film 52 to the reflection plate 40 is 5.07 mm, and the laser beam L from the perpendicular VL2 to the reflection plate 40 is reflected. When the horizontal distance r to the reflection position is 25.38 mm, the laser light L is incident from the upper end P of the side surface of the laser transmitting material layer 51b of the semiconductor body 51 and is transmitted through the laser transmitting material layer 51b. Thus, it is possible to irradiate a substantially central position on the first metal film 52.

  In order to irradiate the entire upper surface of the first metal film 52 with the laser beam L, the galvano scanner 36 is controlled in a state where the angle θ of the reflection plate 40 is fixed at 31.58 °. Specifically, the galvano scanner 36 may be controlled so that the laser beam L is scanned in the direction in which the reflection position height h1 of the laser beam L is smaller than 5.07 mm and in the circumferential direction around the vertical line VL2.

  Thus, although it is the illustration of the dimension of one Example to the last, it turns out that it can fully implement. Thereby, when the first metal film 52 is viewed in a plan view, the semiconductor body 51 and the heat spreader 60 are bonded by the bonding points S distributed over the entire surface of the first metal film 52 as shown in FIG. In FIG. 4, a plurality of junction points S described by circles indicate an example of junction points joined by laser light L irradiation. In FIG. 4, for the convenience of drawing, the intervals between the junction points S are shown in a sparse state, but it is needless to say that a dense state can be achieved depending on the control of the galvano scanner 36. FIG. 4 is a schematic diagram only. Therefore, it is different from the actual bonding shape.

(3. Joining method)
Next, the joining method of the joining apparatus 10 is demonstrated based on the flowchart of FIG. 1 and FIG. As shown in FIG. 5, the joining method includes an irradiation step S10, a transmission step S12, and a joining step S14.

  In the irradiation step S10, the laser oscillator 20 is driven to oscillate the laser light L at a predetermined infrared wavelength. As described above, at this time, the predetermined infrared wavelength of the laser light L is in the range of 1.127 μm to 6 μm. The laser light L oscillated from the laser oscillator 20 is incident on the optical fiber 22 and transmitted to the laser head 30 (see FIG. 1).

  The laser light L emitted from the optical fiber 22 is collimated by the collimator lens 32, reflected by the mirror 34, passes through the galvano scanner 36, and is irradiated toward the reflector 40 through the fθ lens 38. At this time, the galvano scanner 36 changes the angle of the laser light L incident on the fθ lens 38 by swinging a pair of orthogonal movable mirrors (not shown). The angle of the laser beam L to be changed is based on a command value from a control device (not shown).

  As a result, the laser light L is irradiated to a predetermined position on the mirror side of the reflection plate 40 described above via the fθ lens 38, totally reflected by the reflection plate 40, and incident on a predetermined position on the side surface of the semiconductor body 51. (See FIGS. 1 and 3). Here, the side surface of the semiconductor body 51 is a surface on which the semiconductor body 51 is exposed, and is a surface on which the first metal film 52 and the second metal film 53 are not formed. That is, the side surface of the semiconductor body 51 is the side surface of the wide band gap semiconductor layer 51a and the laser transmitting material layer 51b. In the present embodiment, the predetermined position on the side surface of the semiconductor body 51 on which the laser beam L is incident is any position on the side surface of the laser transmitting material layer 51b.

  The fθ lens 38 is a known lens that changes the focal length f according to the incident angle of the laser light L incident from the galvano scanner 36. Therefore, the laser light L that passes through the fθ lens 38 and travels toward the reflecting plate 40 has a cross-sectional diameter (hereinafter referred to as an optical path diameter) of the laser light L that is orthogonal to the central axis of the optical path of the laser light L. It advances while gradually becoming smaller toward the front in the direction of travel (see FIG. 1).

  Next, in the transmission step S12, the laser light L incident on a predetermined position on the side surface of the laser transmission material layer 51b included in the semiconductor body 51 passes through the laser transmission material layer 51b while further reducing the optical path diameter. . In the present embodiment, at this time, most of the energy of the laser light L is transmitted through the laser transmitting material layer 51b. Thereafter, the laser light L reaches a predetermined position on the upper surface of the first metal film 52. At the arrival position of the laser beam L on the upper surface of the first metal film 52, the laser beam L is focused in a focused state. The focused state is a state where the energy density of the laser beam L is increased and the absorption is the best with respect to the first metal film 52.

  In the joining step S14, the first metal film 52 absorbs the energy of the laser light L and is heated. Thereby, the first metal film 52 is heated to reach the melting point and melt. Thereafter, when the first metal film 52 is cooled and solidified again, it is combined with the semiconductor body 51 and the heat spreader 60 that are vertically adjacent to each other, and the semiconductor body 51 and the heat spreader 60 are bonded together. At this time, the first metal film 52 is heated and melted in a very short time by irradiation with the laser beam L. For this reason, the semiconductor main body 51 (laser transmitting material layer 51b) through which the laser light L is transmitted hardly affects the heat.

  In the above description, it has been described that the laser light L is in focus on the first metal film 52. However, even if the laser beam L is not in focus, the first metal film 52 absorbs an energy amount corresponding to each state. For this reason, since the first metal film 52 can be heated and melted, the focused state is not an essential condition.

  In the description of the above process, only one irradiation with one laser beam L has been described for convenience of description. However, actually, in the irradiation step S10, the galvano scanner 36 is intermittently moved while moving a pair of orthogonal movable mirrors in the radial direction and the rotational direction with respect to the perpendicular line VL2 (see arrows Ar1 and Ar2 in FIG. 3). The laser beam L is irradiated. That is, the flowchart shown in FIG. 5 is repeatedly executed.

  As a result, the laser beam L can be scanned at high speed in a short time over the entire upper surface of the first metal film 52 while being totally reflected by the reflector 40 through the fθ lens 38 (see FIG. 4). Therefore, the semiconductor component 50 and the heat spreader 60 are firmly bonded in a short time on the entire surface of the first metal film 52. However, as described above, the semiconductor component 50 and the heat spreader 60 may be joined by only one irradiation with the single laser beam L. This also has a corresponding effect.

  In the above description, it has been described that the irradiation with the laser beam L is a so-called pulse laser that irradiates the laser beam L intermittently. This is based on the knowledge that the absorption efficiency of the laser light L in the first metal film 52 is improved by intermittent irradiation. However, it is not limited to this aspect. The laser beam L may be continuously irradiated by a CW laser (Continuous wave laser) which is not irradiated intermittently and whose energy control is easy. This also provides a reasonable effect.

(Modification)
Next, a joining apparatus according to a modification of the above embodiment will be described with reference to FIGS. The scanning method of the laser light L by the galvano scanner 36 described in the above embodiment is merely an example, and another scanning method may be used. For example, as Modification 1, the irradiation angle of the laser light L is changed with respect to the direction facing the second metal film 53, and the reflection plate 40 is irradiated with the laser light L emitted from the laser head 30 (irradiation angle changing device). May be reflected to absorb the laser beam at different positions of the first metal film 52. That is, the galvano scanner 36 causes the laser light L to scan only in a predetermined radial direction (see the arrow Ar1 in FIG. 3) with respect to the vertical line VL2, thereby causing the laser light to fall within a range of different positions of the first metal film 52. May be absorbed, and the semiconductor component 50 and the heat spreader 60 may be joined (see S in FIG. 6). This also has a corresponding effect. In the first modification, the reflecting plate 40 does not have to be disposed to face the entire outer peripheral surface of the semiconductor component 50.

  Further, as a second modification related to the scanning method of the galvano scanner 36, the laser head 30 (irradiation angle changing device) continuously changes the irradiation position of the laser light L around the second metal film 53 only once. You may make it (refer arrow Ar2 in FIG. 3). As a result, when the laser beam L is irradiated, the first metal film 52 is scanned and bonded not on the entire surface but only on a predetermined circle corresponding to the irradiation position of the laser beam L (see S in FIG. 7). ) The semiconductor component 50 and the heat spreader 60 are joined. In FIG. 7, although it is a single circle, in combination with the first modification, the semiconductor component 50 and the heat spreader 60 may be joined with double or more circles having different diameters. These also have a corresponding effect.

(Effect according to the embodiment)
According to the above embodiment, the bonding apparatus 10 is formed separately from the semiconductor body 50 and the semiconductor component 50 including the first metal film 52 formed on the first surface of the semiconductor body 51, and the semiconductor component 50. The heat spreader 60 as a metal member arranged in contact with the first metal film 52 of the semiconductor component 50 is joined by the laser beam L of infrared wavelength. The semiconductor body 51 includes a laser transmitting material layer 51b formed of a laser transmitting material that can transmit the laser light L. The first metal film 52 is formed of a material that can be melted by absorbing the laser light L. And the joining apparatus 10 makes a laser beam inject into the surface (side surface) in which the 1st metal membrane | film | coat 52 is not formed among the surfaces of the laser transmission material layer with which the semiconductor main body 51 is equipped, and the laser which permeate | transmitted the laser transmission material layer 51b By absorbing the light L in the first metal film 52, the first metal film 52 is melted and the semiconductor component 50 and the heat spreader 60 (metal member) are joined.

  As described above, the first metal film 52 is directly heated to the melting point in a short time and melted by the laser light L transmitted through the laser transmitting material layer 51b of the semiconductor body 51, and the semiconductor component 50 and the heat spreader 60 are bonded. Is done. Thus, since the first metal film 52 having a small capacity due to the film is melted in a short time to join the semiconductor component 50 and the heat spreader 60, the heat capacity held by the melted first metal film 52 is not large. Thus, the first metal film 52 does not have a large thermal effect on the semiconductor body 51. Further, since the semiconductor body 51 is not easily affected by heat, a metal having a melting point higher than the melting point of solder can be used as the first metal film 52 serving as a bonding material. Thereby, the heat resistance of the joint portion between the semiconductor component 50 and the heat spreader 60 (metal member) is improved as compared with the joint portion in the prior art in which the joint is performed by solder.

  Moreover, according to the said embodiment, the semiconductor component 50 is provided with the 2nd metal membrane | film | coat 53 formed in the 2nd surface on the opposite side to the 1st surface of the semiconductor main body 51. FIG. Then, the bonding apparatus 10 causes the laser light L to enter the side surface of the surface of the laser transmitting material layer 51b included in the semiconductor body 51 where the first metal film 52 and the second metal film 53 are not formed. The first metal film 52 is caused to absorb the laser light L transmitted through the laser transmitting material layer 51b and the first metal film 52 is melted. Thus, by providing the second metal film 53, the lead frame 62 and the semiconductor component 50 can be easily joined. Further, at this time, in the semiconductor component 50, the part exposed to the outside can be used as the incident surface of the laser light L to the semiconductor component 50, so that it can be easily handled.

  Further, according to the above embodiment, the laser head 30 (irradiation angle changing device) continuously changes the irradiation position of the laser light L to the outer periphery of the second metal film 53, and the reflection plate 40 is It arrange | positions facing the whole outer peripheral surface of the semiconductor component 50 in which the metal film 52 and the 2nd metal film 53 are not formed. As a result, the laser beam L can be scanned over the entire surface of the first metal film 52 and bonded to the entire surface of the first metal film 52. Thereby, strong joining is obtained between the semiconductor component 50 and the heat spreader 60 (metal member).

  Further, according to the embodiment, the bonding apparatus 10 is disposed at a distance from the second metal film 53 and opposed to the second metal film 53, and the laser oscillator 20 (oscillation source) that oscillates the laser light L. A laser head 30 (irradiation angle changing device) capable of changing the irradiation angle of the laser light L oscillated from the laser oscillator 20 and irradiating the laser light L to an arbitrary position outside the second metal film 53; A reflector that is disposed opposite to the outer peripheral surface of the semiconductor component 50 on which the first metal film 52 and the second metal film 53 are not formed, and reflects the laser light L emitted from the laser head 30 to enter the semiconductor body 51. 40. By providing such an apparatus, the laser light L generated by the laser oscillator 20 can be transmitted and can be favorably incident on the side surface of the small semiconductor body 51.

  Moreover, according to the said embodiment, the bonding | joining method is formed in the semiconductor component 50 provided with the 1st metal membrane | film | coat 52 formed in the semiconductor main body 51 and the 1st surface of the semiconductor main body 51, and the semiconductor component 50 separately. In this method, the heat spreader 60 (metal member) disposed in contact with the first metal film 52 of the semiconductor component 50 is bonded by an infrared wavelength laser beam. The semiconductor body 51 includes a laser transmitting material layer 51b formed of a laser transmitting material (for example, Si or the like) that can transmit the laser light L. The first metal film 52 is formed of a material that can be melted by absorbing laser light. The bonding method includes a transmission step S12 in which the laser beam L is incident on the side surface of the laser transmission material layer 51b of the semiconductor body 51 and transmits the laser transmission material layer 51b, and the laser beam L passes through the laser transmission material layer 51b. And a bonding step of melting the first metal film 52 and bonding the semiconductor component 50 and the heat spreader 60 after being permeated by the first metal film 52. Thereby, joining similar to the joining of the semiconductor component 50 and the heat spreader 60 obtained by the joining apparatus 10 is obtained.

  In the above embodiment, as an example, the semiconductor component 50 has been described as a GaN element including a GaN layer or a SiC element including a SiC layer. However, it is not limited to this aspect. A Si element including a Si layer may be applied as a semiconductor component other than the above. Furthermore, although the laser transmitting material layer 51b has been described as being an Si layer, it may be formed of any material as long as it can transmit the laser light L having a predetermined infrared wavelength.

  In the above embodiment, the laser beam L is incident from the side surface of the semiconductor component 50. However, it is not limited to this aspect. If there is a portion of the semiconductor body 51 of the semiconductor component 50 that is exposed to the outside other than the side surface, the laser light L may be incident from the exposed portion and irradiated to the first metal film 52. The same effect can be expected by this. However, it is needless to say that at this time, all the layers on the path until the laser light L reaches the first metal film 52 must be formed of the laser transmitting material.

  DESCRIPTION OF SYMBOLS 10 ... Joining device, 20 ... Oscillation source (laser oscillator), 30 ... Irradiation angle changing device (laser head), 32 ... Collimating lens, 34 ... Mirror, 36 ... Galvano scanner 38 ... fθ lens, 40 ... reflector, 50 ... semiconductor component, 51 ... semiconductor body, 51a ... wide band gap semiconductor layer, 51b ... laser transmitting material layer, 52. .... First metal film, 52a ... Underlayer bonding layer, 53b ... Underlayer electrode layer, 52b ... Bonding layer, 53a ... Electrode layer, 53 ... Second metal film, 60 ... Metal member (heat spreader), 62 ... lead frame, 70 ... housing, 100 ... semiconductor device, L ... laser light, S10 ... irradiation process, S12 ... transmission process, S 14: Joining step.

Claims (7)

A semiconductor component comprising a semiconductor body and a first metal film formed on a first surface of the semiconductor body;
A metal member formed separately from the semiconductor component and disposed in contact with the first metal film of the semiconductor component;
Is a joining device that joins a laser beam of infrared wavelength,
The semiconductor body includes a laser transmitting material layer formed of a laser transmitting material that can transmit the laser light,
The first metal film is formed of a material that can be melted by absorbing the laser beam,
The bonding apparatus causes the laser light to be incident on a surface of the laser transmissive material layer included in the semiconductor body, on which the first metal film is not formed, and transmits the laser light transmitted through the laser transmissive material layer. A joining apparatus that melts the first metal film and joins the semiconductor component and the metal member by absorbing the first metal film. The semiconductor component includes a second metal film formed on a second surface opposite to the first surface of the semiconductor body,
The bonding apparatus causes the laser light to enter a surface of the surface of the laser transmitting material layer provided in the semiconductor body, on which the first metal film and the second metal film are not formed, and the laser transmitting material layer The bonding apparatus according to claim 1, wherein the transmitted laser light is absorbed by the first metal film. The joining device includes:
An oscillation source for oscillating the laser beam;
Arranged at a distance from the second metal film and opposed to the second metal film, changing the irradiation angle of the laser light oscillated from the oscillation source, and arbitrary outside the second metal film An irradiation angle changing device capable of irradiating the laser beam at a position;
The first metal film and the second metal film are disposed so as to face the outer peripheral surface of the semiconductor component, and reflect the laser light emitted from the irradiation angle changing device to reflect the laser light of the semiconductor body. A reflector that is incident on the laser transmitting material layer;
The bonding apparatus according to claim 2, comprising: The irradiation angle changing device changes an irradiation angle of the laser light with respect to a direction facing the second metal film,
The bonding apparatus according to claim 3, wherein the reflecting plate reflects the laser light irradiated from the irradiation angle changing device and absorbs the laser light at a different position of the first metal film. The irradiation angle changing device continuously changes the irradiation position of the laser light around the outside of the second metal film,
5. The joining device according to claim 3, wherein the reflector is disposed to face the entire outer peripheral surface of the semiconductor component on which the first metal film and the second metal film are not formed.   The said semiconductor body is a joining apparatus as described in any one of Claims 1-5 provided with the wide band gap semiconductor layer whose band gap is wider than Si. A semiconductor component comprising a semiconductor body and a first metal film formed on the first surface of the semiconductor body;
A metal member formed separately from the semiconductor component and disposed in contact with the first metal film of the semiconductor component;
Is a bonding method for bonding with infrared laser light,
The semiconductor body includes a laser transmitting material layer formed of a laser transmitting material that can transmit the laser light,
The first metal film is formed of a material that can be melted by absorbing the laser beam,
The joining method is:
The laser beam is incident on the laser transmitting material layer of the semiconductor body and transmits through the laser transmitting material layer; and
The laser beam is transmitted through the laser transmitting material layer and then absorbed by the first metal film to melt the first metal film and join the semiconductor component and the metal member;
A joining method comprising:

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