JP6690270B2 - Metal member heating method, heated metal member joining method, and metal member heating device - Google Patents

Description

  The present invention relates to a method for heating a metal member by laser light, a method for joining heated metal members, and a heating device for a metal member.

  BACKGROUND ART Conventionally, there is a technique of heating a metal member by irradiating and absorbing laser light on the surface of the metal member (see Patent Documents 1 to 3 below). At this time, there are various purposes for heating the metal member. For example, as one of them, there is one for the purpose of joining two members as shown in Patent Documents 1 and 2. When joining two members, for example, a metal member (for example, a lead wire) that serves as a contact point of an electric circuit is heated to directly join the member to be joined (for example, a semiconductor terminal) and the metal member. At this time, as shown in Patent Documents 1 and 2, the heating part is kept in a solid state without being heated until it is in a liquid state, and a metal member and a member to be joined are pressurized with a predetermined pressure to join (solid phase). Diffusion bonding). Moreover, you may fuse | bond the heating part which is normal welding, and it makes it into a liquid phase state, and it joins. By these, compared with the case where the metal member and the member to be joined are joined by solder, for example, the joining can be made stronger in a high temperature environment.

  In addition, as another example of heating, for example, as shown in Patent Document 3, it is inspected in a non-destructive state whether or not the already joined metal member and the joined member are in contact with each other in a sufficient area and joined. Some are for that purpose. In the technique of Patent Document 3, first, the metal member joined to the member to be joined is irradiated with laser light to heat the metal member to raise its temperature. At this time, if the metal member and the member to be joined are in contact (joined) with each other in a sufficient area, the heat that has risen moves favorably from the metal member toward the member to be joined according to the contact area. Therefore, the temperature rising rate of the metal member becomes gentle. However, if the metal member and the member to be joined are not in sufficient contact with each other and are not sufficiently joined, the heat of the metal member cannot move well toward the member to be joined and the temperature rising rate becomes steep. . The joining state between the metal member and the member to be joined is evaluated based on the difference in the heating rate.

  In the above description, an inexpensive YAG laser or the like is usually applied as the laser light to be applied. The YAG laser is a laser whose laser light has a near infrared wavelength (0.7 μm to 2.5 μm). The laser light from the YAG laser is very low at a low temperature until the absorptance of the metal member made of copper (or aluminum) reaches a predetermined temperature (for example, melting point). Therefore, for example, when copper (or aluminum) is used for the metal member in Patent Documents 1 to 3, even if the metal member is directly irradiated with laser light at low temperature, the absorption rate of the laser light of the metal member is low. Moreover, the temperature rise of the metal member is slow, and a large amount of energy is consumed before reaching a predetermined temperature at which the absorption rate increases.

  On the other hand, according to the technique of Patent Document 3, an oxide film is formed on the surface of the metal member based on known knowledge to improve the absorptivity of laser light to the metal member at low temperatures. The oxide film is formed by irradiating the surface of the metal member with laser light for forming the oxide film. In other words, the surface of the metal member is irradiated with laser light for a predetermined time set in advance in order to make the film thickness of the oxide film a predetermined film thickness that achieves a desired absorption rate. Then, the metal member is irradiated with the heating laser light through the formed oxide film. Then, the temperature of the metal member whose absorption rate of the laser beam is improved by the formation of the oxide film is rapidly raised, and the bonding state is efficiently evaluated. In Patent Document 3, the thickness at which the absorptance is saturated is set based on the known knowledge that the absorptance of laser light is saturated when the thickness of the oxide film exceeds a certain value and becomes large. The irradiation time of the laser light is set so that it can be formed.

Japanese Patent No. 4894528 Japanese Patent No. 5602050 JP, 2014-228478, A

  However, as described in Patent Document 3, it takes too much time to form an oxide film having a certain thickness or more so that the absorptance is saturated, which causes a cost increase. Further, since the oxide film is formed in a short time, when the laser irradiation time is shortened, the film thickness of the oxide film formed becomes thin. At this time, the relationship between the film thickness of the thin oxide film near zero that can be formed by laser irradiation for a short time and the absorptance of the laser light to the metal member is the maximum value in the direction where the film thickness increases beyond zero, and It has a periodicity in which minimum values appear alternately. In this case, even if the formed oxide film has a slight variation in film thickness, the variation in absorptance appears as a large variation. Therefore, stable absorption of laser light is achieved at low cost. Hard to get a rate.

  The present invention has been made in view of the above problems, and improves the absorption rate of laser light by a thin oxide film that can be formed at low cost, and enables stable and highly efficient heating of a metal member. It is an object of the present invention to provide a heating method, a method for joining heated metal members, and a heating device for a metal member.

  In order to solve the above problems, a heating method for heating a metal member by irradiating a heating laser beam according to claim 1 of the present invention is an oxide film forming method for forming an oxide film having a predetermined film thickness on the surface of the metal member. A step of irradiating the heating laser light to the metal member through the oxide film, and the irradiated heating laser light is absorbed by the metal member at an absorption rate according to the predetermined film thickness of the oxide film. And a heating step of heating the metal member to a predetermined temperature, wherein the absorptance has a maximum value with respect to a change in the increasing direction of the film thickness in relation to the film thickness of the oxide film. The minimum value has a periodicity that appears alternately and has the smallest characteristic when the film thickness of the oxide film is zero, and the oxide film formed above the zero in the oxide film forming step The predetermined film thickness has the periodicity In relation to the absorptance, the film thickness of the oxide film exceeds the zero, the first maximum film thickness corresponding to the first maximum value at which the absorptance first appears as the maximum value, and the first maximum value. Next, the absorption rate includes a second maximum film thickness corresponding to the second maximum value that appears as the maximum value, and the absorption rate is next to the second maximum value and the second maximum value. Between the third local maximum film thickness corresponding to the third local maximum value appearing as, and the absorption rate in the first range smaller than the second local minimum film thickness corresponding to the second local minimum value appearing as the local minimum value. Is set.

  As described above, the characteristic of the absorptance of the heating laser light to the metal member has a periodicity in which the maximum value and the minimum value alternately appear in the relationship with the film thickness of the oxide film, and the film of the oxide film is formed. It has a characteristic that the absorptivity becomes the smallest when the thickness is zero. Then, the film thickness of the oxide film of the metal member exceeds zero, and the first maximum film thickness and the second maximum film thickness corresponding to the first maximum value that appears first and the second maximum value that appears next to the first maximum value, respectively. The second minimum film thickness that includes the maximum film thickness and corresponds to the second minimum value that is the minimum value between the second maximum value and the third maximum value that is the maximum value that appears next to the second maximum value. It is set to the smaller first range. As described above, the thickness of the oxide film can be set in a wide range (first range) based on the relationship between the thickness of the oxide film having periodicity and the absorptance. Thereby, even if the film thickness varies slightly during the formation of the oxide film, the absorptance of the heating laser light is surely increased as compared with the case where the heating laser light is applied to the metal member without passing through the oxide film. Therefore, the metal member can be heated stably and highly efficiently. Further, since the film thickness of the oxide film is limited to the first range near zero, it is possible to prevent the film thickness exceeding the first range from being wasted and resulting in cost increase.

  A method for joining metal members according to a fourteenth aspect of the present invention is directed to a first joining surface of the metal member facing the surface of the metal member and a joining target metal member abutting the first joining surface. A bonding method with a second bonding surface, wherein the metal member is heated to the predetermined temperature by the heating method, and the first bonding surface and the second bonding surface are formed at a temperature lower than a liquid state. Then, the solid state is set so that the joining can be performed in a solid state, and the first joining surface and the second joining surface are pressed and joined in the crimping direction.

  In this way, the first joining surface and the second joining surface are joined by raising the temperature to a solid state which is lower than the melting temperature of the metal member. Therefore, the required irradiation amount of the heating laser beam is reduced as compared with the case of melting the metal member. Therefore, an oxide film is provided on the metal member to improve the absorption rate of the heating laser beam, and at the same time, the amount of energy used by the heating laser can be greatly reduced, and the cost of bonding can be reduced. be able to.

  A heating device for a metal member according to a fifteenth aspect of the present invention is a heating device for heating a metal member by irradiating a heating laser beam, wherein the heating device has a predetermined film thickness on a surface of the metal member. An oxide film forming portion for forming an oxide film of the oxide film, and absorption of the heating laser light applied to the metal member through the oxide film having the predetermined film thickness according to the predetermined film thickness of the oxide film. A heating unit that absorbs the metal member at a rate to heat the metal member to a predetermined temperature, and the absorption rate is in the increasing direction of the film thickness in relation to the film thickness of the oxide film. It has a periodicity in which the maximum value and the minimum value appear alternately with respect to the change, and has the smallest characteristic when the thickness of the oxide film is zero, and exceeds the zero in the oxide film forming portion. The predetermined thickness of the oxide film formed is equal to the peripheral thickness. In the relationship with the absorptivity having the property, the film thickness of the oxide film exceeds zero, and the absorptivity first corresponds to the first maximum value that appears as the maximum value, and the first maximum film thickness. The absorptance next to the local maximum includes a second local maximum film thickness corresponding to the second local maximum appearing as the local maximum, and the absorptivity is next to the second local maximum and the second local maximum. Between the third local maximum film thickness corresponding to the third local maximum value appearing as the local maximum value, the absorption rate is smaller than the second local minimum film thickness corresponding to the second local minimum value appearing as the local minimum value. It is set to one range. With this heating device, stable and highly efficient heating similar to that of claim 1 can be performed.

It is a schematic diagram of a heating device concerning a first embodiment. FIG. 3 is an image diagram of irradiation of a metal member with continuous wave laser light and an oxide film formed on the surface by the irradiation. 6 is a graph showing an example of a process in which an oxide film is formed on the surface of a metal member by irradiating an oxide film forming laser beam. It is a figure explaining the state in which the oxide film and the hole were formed in the surface of the metal member by irradiation of the laser beam for oxide film formation. It is an image figure showing the state where a metal member is heated from the surface by irradiation of heating laser light. 7 is a graph showing the relationship between the film thickness of an oxide film and the absorption rate of laser light. It is the flowchart 1 of the heating method which concerns on 1st embodiment. It is an image figure of irradiation to a metal member when the laser beam for oxide film formation is made into a pulse wave in the heating device of a second embodiment. It is a schematic diagram of a heating device concerning a second embodiment. 7 is a graph showing a process in which an oxide film is formed on the surface of a metal member by irradiation with a laser beam for forming an oxide film in the heating device according to the second embodiment. It is the flowchart 2 of the heating method which concerns on 2nd embodiment. It is a schematic diagram of a heating device concerning a third embodiment. It is the flowchart 3 of the heating method which concerns on 3rd embodiment. It is a figure explaining the structure of the modification 1 of 3rd embodiment. It is a figure explaining the structure of the modification 2 of 3rd embodiment. It is a schematic diagram of the joining device to which the heating device of the first embodiment is applied. FIG. 17 is a partially enlarged view of FIG. 16. It is a flowchart of the joining method which concerns on the joining apparatus of FIG.

<First embodiment>
(1. Overview)
A heating device for a metal member according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a heating device 100 according to the present invention. The heating device 100 has a metal member such as copper (lead frame 62) which has a low absorptance and a low temperature raising efficiency for laser light having a near-infrared wavelength typified by a YAG laser at a low temperature below the melting point. ), And causes the metal member to absorb the laser light with a higher absorptivity than that of the prior art to efficiently heat and raise the temperature of the metal member. The purpose of the metal member heated by the heating device 100 is arbitrary. However, in the present embodiment, as an example of application, a mode in which the metal member (lead frame 62) is heated for the purpose of bonding to the metal member to be bonded (metal terminal on the surface of the semiconductor component 50) will be described later.

(2. Configuration of heating device)
First, the heating device 100 will be described. As shown in FIG. 1, the heating device 100 includes an oxide film forming unit 120, a heating unit 130, and a control unit 140. The oxide film forming unit 120 forms an oxide film OM (see FIG. 2) having a predetermined film thickness α on the surface of the lead frame 62 (metal member). At this time, the predetermined film thickness α is an arbitrary film thickness that improves the absorptance of the laser beam to the lead frame 62 as compared with the conventional case.

  At this time, "conventional" means a state in which the oxide film OM is not formed on the surface of the lead frame 62 (metal member). The setting of the predetermined film thickness α will be described in detail later. The oxide film forming unit 120 includes a laser oscillator 121, a laser head 122, and a housing 123. The laser head 122 is arranged in the housing 123. Further, the oxide film forming unit 120 includes a laser light control unit 141a, a laser output adjustment unit 141b, a temperature measurement unit 142, an irradiation time measurement unit 143, a film thickness calculation unit 144, and a film thickness determination unit 145 included in a control unit 140 described later. including.

  The laser oscillator 121 is a laser oscillator capable of emitting continuous waves CW having different outputs (see the image diagram of FIG. 2) by switching operation by the control unit 140. The continuous wave CW is a laser beam that is continuously emitted without interruption. In this embodiment, the continuous wave CW is output in two stages. The continuous wave on the high output side is referred to as a continuous wave CW1, and the continuous wave on the low output side having an output smaller than that of the continuous wave CW1 is referred to as a continuous wave CW2. The continuous wave CW1 on the high output side and the continuous wave CW2 on the low output side are respectively generated by the output adjustment by the laser output adjusting unit 141b. In the present embodiment, the continuous wave CW1 is laser light for forming an oxide film. The continuous wave CW2 is a laser beam for heating, which will be described in detail later.

  When the output of the continuous wave CW1 on the high output side is, for example, 100 W, the output of the continuous wave CW2 on the low output side is, for example, about 20 W. However, this output value is merely an example, and the output value is not limited to this value. The continuous wave CW1 having a large output is generated by the operation of the oxide film forming part 120 when the oxide film OM having a predetermined film thickness α is formed on the surface 62a (upper surface in FIG. 1) of the lead frame 62 (metal member). Is irradiated.

  When heating the lead frame 62 (metal member), the continuous wave CW2 is applied to the surface 62a through the oxide film OM formed on the surface 62a by the operation of the heating unit 130 described in detail later. In the present embodiment, the continuous wave CW1 and the continuous wave CW2 have different outputs but have the same wavelength, and the same device (laser oscillator 121 and laser head 122) irradiates the surface 62a of the lead frame 62. It is the same type of laser light. In the following description, the continuous wave CW1 will be referred to as the oxide film forming laser beam L1 and the continuous wave CW2 will be referred to as the heating laser beam L2.

  The laser oscillator 121 forming the oxide film forming unit 120 oscillates at a predetermined wavelength according to the type of laser light to generate the laser light L1 for forming an oxide film. The wavelength of the oxide film forming laser beam L1 (continuous wave CW1) is preferably in the range of 0.7 μm to 2.5 μm. That is, the oxide film forming laser beam L1 is preferably a laser beam having a near infrared wavelength represented by a YAG laser.

  Thereby, the laser oscillator 121 can be manufactured at low cost. Specifically, as the oxide film forming laser beam L1, HoYAG (wavelength: about 1.5 μm), YVO (yttrium vanadate, wavelength: about 1.06 μm), Yb (ytterbium, wavelength: about 1.09 μm) and A fiber laser or the like can be adopted. Further, the laser oscillator 121 includes an optical fiber 125 that transmits the oxide film forming laser light L1 oscillated from the laser oscillator 121 to the laser head 122.

  As shown in FIG. 1, the laser head 122 arranged in the housing 123 is arranged at a predetermined distance from the surface 62 a of the lead frame 62 and opposite to the surface 62 a of the lead frame 62. The laser head 122 has a collimator lens 132, a mirror 134, and an fθ lens 138. The collimator lens 132 collimates the oxide film forming laser light L1 emitted from the optical fiber 125 and converts it into parallel light.

  The mirror 134 changes the traveling direction of the oxide film forming laser beam L1 so that the collimated oxide film forming laser beam L1 enters the fθ lens 138. In the present embodiment, the mirror 134 changes the traveling direction of the oxide film forming laser beam L1 by 90 degrees. The fθ lens 138 is a lens that collects the parallel laser beam L1 for forming an oxide film, which is incident from the mirror 134.

  In the present embodiment, the oxide film forming laser beam L1 is continuously irradiated with its optical axis orthogonal to the surface 62a of the lead frame 62. The oxide film OM is formed on the surface 62a of the lead frame 62 by the continuous irradiation of the oxide film forming laser beam L1 as shown in the graph of FIG. That is, the oxide film OM gradually grows in the increasing direction of the film thickness as the irradiation time H elapses. For example, the oxide film OM has a diameter of about 200 μm and a film thickness α exceeding zero. It is formed.

  Further, at this time, on the surface 62a (irradiation position) of the lead frame 62 irradiated with the oxide film forming laser beam L1, a hole 62c having a minute diameter and opening to the surface 62a is formed (see FIG. 4). The opening diameter of the hole 62c is, for example, about φ10 μm. The shape (diameter, etc.) of the hole 62c is determined according to the profile of the oxide film forming laser beam L1.

  The profile of laser light refers to a specific irradiation diameter (spot diameter) or spatial intensity distribution of the laser light. When the surface 62a is irradiated with the oxide film forming laser beam L1, a hole 62c corresponding to the profile of the oxide film forming laser beam L1 at that time is formed on the surface 62a. However, depending on the profile specifications, it is possible not to form the holes 62c even if the surface 62a is irradiated with the oxide film forming laser beam L1. The profile of the oxide film forming laser beam L1 can be arbitrarily set by changing the lens configuration such as shape and arrangement.

  Then, when the heating laser beam L2 (continuous wave CW2) is applied to the surface 62a by the heating unit 130 described later, part of the heating laser beam L2 enters the hole 62c. Then, a part of the heating laser beam L2 that has entered the hole 62c collides with the side surface of the hole 62c, is absorbed while being diffusely reflected, is converted into heat, and contributes to the temperature rise of the lead frame 62. Note that, as an example, the opening diameter of the hole 62c that opens in the surface 62a is, for example, about 10 μm and the depth is about 5 μm as described above. However, this is merely an example, and the opening diameter and the depth of the hole 62c are not limited to these dimensions and are arbitrary.

  The heating unit 130 irradiates the laser beam L2 (continuous wave CW2) for heating toward the oxide film OM formed on the surface 62a of the lead frame 62 (metal member) by the oxide film forming unit 120 to expose the lead frame 62. Heat (see FIGS. 2 and 5). As described above, the heating laser light L2 is the same kind of laser light that has a different output (smaller) than the oxide film forming laser light L1.

  Then, the heating laser beam L2 is efficiently absorbed in the surface 62a and the hole 62c of the lead frame 62 while transmitting or reflecting the oxide film OM formed with the predetermined film thickness α, and the lead frame 62 is satisfactorily formed. Heat to. Specifically, heating is performed so that heat is transferred from the front surface 62a to the back surface (corresponding to a first bonding surface 62b described later) facing the surface 62a, and finally the first bonding surface 62b is heated to a desired temperature. To heat.

  Note that the D portion of FIG. 5 represents an image of the lead frame 62 being heated from the surface 62a toward the first bonding surface 62b, and a hatched line showing a cross section of the lead frame 62 showing how heat is transferred. And the diagonal lines with different thicknesses.

  The action of the oxide film OM on the lead frame 62 for improving the absorption rate of the heating laser beam L2 is based on known knowledge. Therefore, the description of the principle of producing the effect is omitted. Further, although the details will be described later, the absorptance of the heating laser beam L2 into the lead frame 62 varies depending on the film thickness of the oxide film OM (see the graph in FIG. 6). Therefore, the predetermined film thickness α formed by the oxide film forming unit 120 is set to a film thickness that allows the heating laser beam L2 to be more efficiently absorbed by the lead frame 62. Is set.

  The heating laser beam L2 applied to the oxide film OM formed on the surface 62a of the lead frame 62 (metal member) by the heating unit 130 is the oxide film forming laser beam L1 (continuous wave CW1) as described above. Is a continuous wave CW2 having a different (small) output. Regarding the heating laser light L2, the laser oscillator 121 changes the output of the oxide film forming laser light L1 to the output for the heating laser light L2 according to a command from the laser output adjusting unit 141b of the control unit 140 described in detail later. Irradiate by. The heating unit 130 has the same configuration as the oxide film forming unit 120 except for the irradiation time measuring unit 143, the film thickness calculating unit 144, and the film thickness determining unit 145 of the oxide film forming unit 120.

  The control unit 140 is a control device that controls the operations of the oxide film forming unit 120 and the heating unit 130. As shown in FIG. 1, the control unit 140 controls the operation of the oxide film forming unit 120 by a laser beam control unit 141a, a laser output adjusting unit 141b, a temperature measuring unit 142, an irradiation time measuring unit 143, and a film thickness. The calculation unit 144 and the film thickness determination unit 145 are provided. As described above, the laser light control unit 141a, the laser output adjustment unit 141b, the temperature measurement unit 142, the irradiation time measurement unit 143, the film thickness calculation unit 144, and the film thickness determination unit 145 are included in the oxide film formation unit 120. .

  The control unit 140 also includes a laser light control unit 141a, a laser output adjustment unit 141b, and a temperature measurement unit 142 for controlling the operation of the heating unit 130. That is, the laser light control unit 141 a, the laser output adjustment unit 141 b, and the temperature measurement unit 142 also serve as the oxide film formation unit 120, and are also included in the heating unit 130.

  The laser light controller 141a controls the laser output adjuster 141b to change the output of the laser light generated by the laser oscillator 121. That is, the laser light controller 141a controls the laser output adjuster 141b so that the oxide film forming laser light L1 (continuous wave CW1) or the heating laser light L2 (continuous wave CW2) is supplied to the lead frame 62 (metal member). The surface 62a is selectively illuminated.

  Specifically, the laser light controller 141a commands the laser output adjuster 141b to set the target output value of the laser light to be emitted. The laser output adjustment unit 141b controls the laser oscillator 121, oscillates the laser oscillator 121 at the target output value designated by the laser light control unit 141a, and emits a desired laser light (for example, the oxide film forming laser light L1). It is generated and continuously irradiated on the surface 62a.

  By this irradiation (see FIG. 2), the temperature rises on the surface 62a of the lead frame 62, and the oxide film OM is formed with a film thickness according to the irradiation time H shown in the graph of FIG. In the graph of FIG. 3, the horizontal axis represents the irradiation time H (or the irradiation duration time) and the vertical axis represents the film thickness of the surface 62a of the lead frame 62. In addition, the graph of FIG. 3 is merely an example, and may have different characteristics.

  As described above, the film thickness α1 of the oxide film OM formed on the surface 62a by the continuous irradiation of the oxide film forming laser beam L1 is equal to the surface temperature T of the surface 62a increased by the irradiation of the oxide film forming laser beam L1. It is formed with a thickness according to the irradiation time H, which is the time during which the irradiation is continued. That is, the film thickness α1 of the oxide film OM can be calculated by the surface temperature T of the surface 62a and the irradiation time H.

  The temperature measuring unit 142 measures the surface temperature T of the surface 62a when the surface 62a is irradiated with the oxide film forming laser beam L1. At this time, the surface temperature T is measured by the non-contact infrared radiation thermometer 39. However, the present invention is not limited to this mode, and the temperature measurement may be performed using any measuring instrument. The data of the measured surface temperature T is transmitted to the film thickness calculation unit 144.

  Further, the irradiation time measuring unit 143 measures the irradiation time H of the continuous irradiation of the surface 62a of the oxide film forming laser beam L1. In this case, the irradiation time H may be actually measured. However, the present invention is not limited to this mode, and preset irradiation time data may be acquired from the laser light controller 141a. The data of the irradiation time H is transmitted to the film thickness calculation unit 144.

The film thickness calculation unit 144 calculates the film thickness α1 of the oxide film OM formed by continuous irradiation of the oxide film forming laser beam L1, the surface temperature T acquired by the temperature measurement unit 142 and the irradiation time measurement unit 143, and The calculation is performed based on the irradiation time H.
The film thickness determination unit 145 determines whether or not the film thickness α1 of the oxide film OM calculated by the film thickness calculation unit 144 has reached within a predetermined film thickness α range set in advance.

At this time, the preset predetermined film thickness α is set to a value at which the heating laser beam L2 is absorbed on the surface 62a of the lead frame 62 with higher efficiency than the conventional one. Actually, as shown in the graph of FIG. 6, the predetermined film thickness α is set between 35 nm and 360 nm which is defined as the first predetermined range Ar1 .

  In order to set the range of the film thickness α in this manner, the inventor repeatedly performed an experiment and found the relationship between the film thickness of the oxide film OM and the absorptance of the laser light L of the metal member. The graph of FIG. 6 is obtained from the experimental result at that time.

  In the graph of FIG. 6, the horizontal axis represents the film thickness (nm) of the oxide film OM formed on the metal surface. The vertical axis represents the absorption rate (%) of the laser beam to the lead frame 62 when the surface 62a of the lead frame 62 (metal member) is irradiated with the laser beam L via the formed oxide film OM.

  Looking at the graph of FIG. 6, the absorption rate has a maximum value (about 60%) and a minimum value (about 20%) with respect to the change in the increasing direction of the film thickness in relation to the film thickness of the oxide film OM. Have a periodicity that alternates. When the thickness of the oxide film OM is 0, the absorption rate is less than 10%. However, in the region where the film thickness exceeds 0 (zero) and the film thickness increases, the absorptance exceeds the absorptance when the film thickness is 0 in all ranges.

  From this, the inventor first absorbs the predetermined film thickness α set to exceed zero in relation to the absorptance having periodicity when the film thickness of the oxide film OM increases beyond zero first. The first maximum film thickness A (85 nm) corresponding to the first maximum value a at which the rate appears as the maximum value (60%), and the absorption rate appears as the maximum value (60%) next to the first maximum value a. It is set within a range including the second maximum film thickness B (265 nm) corresponding to the second maximum value b.

At the same time, a predetermined film thickness α (range) is set to a third maximum value c corresponding to a second maximum value b and a third maximum value c at which the absorptance appears as a maximum value next to the second maximum value b. Between the film thickness C and the second minimum film thickness BB corresponding to the second minimum value bb that appears as the minimum value, the absorption rate is set to be within a range. Then, on this range with the first range.

35nm~360nm Specifically, the inventors, as shown in FIG. 6, the range of the predetermined thickness α of definitive Firstly within range, the practical range in the formation and management of the film thickness, the aforementioned Was set to the range (first predetermined range Ar1) . As can be seen from the graph of FIG. 6, 35 nm and 360 nm are both film thicknesses at which the laser light absorptance is about 40%.

  Note that the metal member is copper under the conditions of the above experiment. The laser light L is generated by a YAG laser and has a near-infrared wavelength. The laser light L is a continuous wave CW laser light. The oxide film OM was formed in the heating furnace. Furthermore, the film thickness of the oxide film OM was measured by the SERA method (continuous electrochemical reduction method). Therefore, in the present embodiment, the thickness of the oxide film OM is the thickness obtained when the measurement is performed by the SERA method. The SERA method is a known film thickness measuring method. Specifically, first, an electrolytic solution is applied to the metal surface, and a minute current is caused to flow from the electrode to cause a reduction reaction. At this time, since each substance has a unique reduction potential, the film thickness can be calculated by measuring the time required for the reduction.

  Next, when the film thickness determination unit 145 determines that the film thickness α1 has reached the range of the predetermined film thickness α, the laser light control unit 141a controls the laser output adjustment unit 141b to control the laser oscillator. The output value of the laser light generated by 121 is changed. That is, the output of the continuous wave CW is switched from the high output side to the low output side. As a result, the oxide film forming laser beam L1 is switched to the heating laser beam L2. In this way, the heating laser beam L2 is applied to the surface 62a of the lead frame 62 through the oxide film OM to heat the lead frame 62 to a predetermined surface temperature Ta.

  At this time, the heating laser beam L2 is absorbed by the lead frame 62 with high efficiency as compared with the case where the oxide film OM is not formed on the surface 62a because the oxide film OM is formed on the surface 62a. It Then, whether or not the lead frame 62 is heated to a predetermined surface temperature Ta may be actually measured by the infrared radiation thermometer 39 described above.

  However, not limited to this mode, the absorptance corresponding to the film thickness (estimated film thickness) of the oxide film OM formed on the surface 62a of the lead frame 62 obtained from the graph of FIG. 6 and the irradiation of the heating laser beam L2 are performed. From the time, the temperature at which the surface 62a may have risen may be estimated by calculation. Then, when the not-shown surface temperature determination unit determines that the preset surface temperature Ta has been reached, the irradiation of the heating laser beam L2 is stopped.

(3. Heating method)
Next, a method of heating the lead frame 62 (metal member) by the heating device 100 will be described based on the flowchart 1 of FIG. The heating method includes an oxide film forming step S110 and a heating step S120. The oxide film forming step S110 includes an oxide film forming laser beam irradiation step S111, a temperature measuring step S112, an irradiation time measuring step S113, a film thickness calculating step S114, and a film thickness determining step S115. Further, the heating step S120 includes a switching step S121, a heating laser beam irradiation step S122, and a surface temperature determination step S123.

  In the oxide film forming laser light irradiation step S111 (oxide film forming step S110), when the operator presses a start button (not shown) of the heating device 100, the oxide film forming laser light L1 (continuous wave CW1) is emitted. The surface 62a of the lead frame 62 (metal member) is continuously irradiated under predetermined irradiation conditions (output, irradiation spot diameter, etc.) under the control of the laser light control unit 141a (laser output adjustment unit 141b). To be done. At this time, the target film thickness α of the oxide film OM formed by the irradiation of the oxide film forming laser beam L1 may be manually input. Further, as the target film thickness α, a value stored in advance in a storage unit (not shown) of the control unit 140 may be acquired.

  By this continuous irradiation, the surface temperature T rises on the surface 62a of the lead frame 62, and as shown in the graph of FIG. 3, an oxide film OM having a film thickness (α1) corresponding to the increased surface temperature T and the irradiation time H. Are formed on the surface 62a.

  In the temperature measuring step S112 (oxide film forming step S110), during irradiation of the oxide film forming laser beam L1 onto the surface 62a, the temperature measuring unit 142 sets the surface temperature T of the surface 62a to the infrared radiation temperature at regular intervals. The measurement is performed by the total 39, and the measurement data is transmitted to the film thickness calculation unit 144 of the control unit 140.

  In the irradiation time measuring step S113 (oxide film forming step S110), the irradiation time measuring unit 143 measures the continuous irradiation time of the oxide film forming laser beam L1 onto the surface 62a, and the film thickness calculation of the control unit 140 is performed. The measurement data is transmitted to the section 144.

  Then, in the film thickness calculating step S114 (oxide film forming step S110), the film thickness calculating section 144 is formed based on the surface temperature T and the irradiation time H acquired in the temperature measuring step S112 and the irradiation time measuring step S113. The estimated film thickness α1 of the oxide film OM is calculated.

  Next, in the film thickness determination step S115 (oxide film formation step S110), the estimated film thickness α1 of the oxide film OM calculated by the film thickness calculation section 144 by the film thickness determination section 145 falls within the predetermined film thickness α range. It is determined whether or not it has been reached. If the estimated film thickness α1 has reached the range of the predetermined film thickness α, the process moves to the switching step S121 (heating step S120). If the estimated film thickness α1 has not reached the range of the predetermined film thickness α, the process moves to the oxide film forming laser beam irradiation step S111 (oxide film forming step S110) again. Then, the steps S111 to S114 are repeatedly performed until it is determined in the film thickness determination step S115 that the estimated film thickness α1 has reached the range of the predetermined film thickness α.

  Next, in the switching step S121 (heating step S120), the laser output adjustment unit 141b (laser light control unit 141a) causes the laser oscillator 121 to change the output of the laser light, and the laser light L1 for oxide film formation is changed. The laser beam L2 for heating is switched (changed).

  Then, in the heating laser light irradiation step S122 (heating step S120), the laser output adjustment unit 141b irradiates the surface 62a of the lead frame 62 with the heating laser light L2 from the laser head 122 through the oxide film OM, The lead frame 62 is heated to a predetermined surface temperature Ta. At this time, as described above, on the surface 62a (irradiation position) of the lead frame 62, a hole 62c having a minute diameter is formed.

  Therefore, when the heating laser beam L2 is applied to the surface 62a, a part of the heating laser beam L2 enters the hole 62c as described above, and one of the heating laser beams L2 that enters the hole 62c. The part is irregularly reflected on the side surface in the hole 62c. As a result, the heating laser beam L2 is absorbed by the side surface inside the hole 62c, and the temperature of the lead frame 62 is raised in a shorter time. Note that, in FIG. 5, an image of how heat is transferred from the surface 62 a of the lead frame 62 to the inside of the lead frame 62 is shown using a cross-sectional display different from the cross-sectional display of the lead frame 62.

  Next, in the surface temperature determination step S123 (heating step S120), the surface temperature determination unit (not shown) determines whether or not the surface temperature T of the surface 62a of the lead frame 62 is heated to a predetermined surface temperature Ta ( Surface temperature T ≧ Ta). Whether or not the surface temperature T of the lead frame 62 has been heated to a predetermined surface temperature Ta may be determined by actually measuring the infrared radiation thermometer 39 described above. Further, the temperature raised from the absorptance corresponding to the film thickness of the oxide film OM formed on the surface 62a of the lead frame 62 and the irradiation time of the heating laser beam L2 may be estimated by calculation.

  Then, when the surface temperature determination unit (not shown) determines that the surface temperature T of the surface 62a has reached the preset predetermined surface temperature Ta, the laser output adjustment unit 141b (laser light control unit 141a) uses The irradiation of the laser beam L2 is stopped and the program ends. However, if it is determined that the surface temperature T of the surface 62a has not reached the preset predetermined surface temperature Ta, the process moves to the heating laser beam irradiation step S122, and the surface temperature determination step S123 determines that the surface 62a is not exposed. The processes of S122 to S123 are continuously performed until the surface temperature T ≧ the surface temperature Ta.

  The surface temperature Ta has a different set value for each purpose of heating the lead frame 62. For example, if the purpose of heating is joining (welding) of the first joining surface 62b facing the surface 62a of the lead frame 62 and another member, the temperature Tb required for joining (welding) the first joining surface 62b. It is necessary to raise the temperature to. Therefore, the surface temperature of the surface 62a of the lead frame 62 when the temperature of the first bonding surface 62b is increased to the temperature Tb necessary for bonding (welding) is previously obtained through experiments or the like as the surface temperature Ta. Set.

  Further, if the purpose of heating is cutting of the lead frame 62, it is not necessary to set the surface temperature Ta. In this case, the heating laser beam L2 may be continuously emitted until the lead frame 62 is cut. Although the description of other examples is omitted, the surface temperature Ta may be sequentially set arbitrarily according to the purpose of heating in this manner.

<Modification 1 of the first embodiment>
In the above-described first embodiment, in the oxide film forming step S110, the film thickness α1 of the oxide film OM to be formed is the surface temperature T measured by the temperature measuring unit 142 and the oxide film forming film measured by the irradiation time measuring unit 143. The calculation was performed based on the irradiation time H from the start of irradiation with the laser beam L1. However, it is not limited to this mode. As a modified example 1 of the first embodiment, the estimated film thickness α1 of the oxide film OM is calculated based on the surface temperature t and the irradiation time h measured at regular intervals, and is added from the previous calculation time point. The film thicknesses αA, αB ... Of the oxide film OM to be formed may be cumulatively obtained. This also provides the same effect as that of the above embodiment.

<Second embodiment>
Next, a second embodiment will be described. In the first embodiment, the oxide film forming laser beam L1 and the heating laser beam L2 are both continuous waves CW. However, it is not limited to this mode. As the second embodiment, the oxide film forming laser light L1 in the first embodiment may be a pulse wave PW (see the image diagram of FIG. 8). At this time, the heating device 200 of the second embodiment (see FIG. 9) differs from the heating device 100 of the first embodiment only in the oxide film forming unit 120 and the control unit 140. Therefore, different parts will be described in detail, and description of other similar parts will be omitted. Further, similar configurations may be described with the same reference numerals.

  FIG. 9 is a schematic diagram of the heating device 200 according to the second embodiment. As shown in FIG. 9, the heating device 200 includes an oxide film forming unit 220, a heating unit 130, and a control unit 240. The oxide film forming part 220 forms an oxide film OM having a predetermined film thickness α (cumulative film thickness) on the surface of the lead frame 62 (metal member). The oxide film forming unit 220 includes a laser oscillator 221, a laser head 122, and a housing 123. Further, the oxide film forming unit 220 includes a laser light control unit 241a, a laser output adjustment unit 241b, a temperature measurement unit 142, an irradiation time measurement unit 143, a film thickness calculation unit 244, and a film thickness determination unit 245 included in a control unit 240 described later. including.

  The laser oscillator 221 is a laser oscillator capable of emitting both a pulse wave PW (see the image diagram of FIG. 8) and a continuous wave CW (see the image diagram of FIG. 2) by switching control of laser light by the control unit 240. The pulse wave PW is laser light emitted intermittently. The pulse wave PW has a predetermined irradiation condition (pulse wave irradiation timing, output when the oxide film OM having a predetermined film thickness α is formed on the surface 62a (upper surface in FIG. 9) of the lead frame 62 (metal member). , And the irradiation spot diameter, etc.). The pulse wave PW is a laser beam suitable for forming the oxide film OM that requires a relatively large output because it easily outputs a large amount of energy instantaneously as compared with the continuous wave CW.

  In the present embodiment, the pulse wave PW and the continuous wave CW have the same wavelength and are the same type of laser light with which the same device (laser oscillator 221 and laser head 122) irradiates the surface 62a of the lead frame 62. . Hereinafter, the pulse wave PW will be referred to as an oxide film forming laser beam L3, and the continuous wave CW will be referred to as a heating laser beam L4. The heating laser light L4 is the same as the heating laser light L2 of the first embodiment.

  The wavelength of the oxide film forming laser beam L3 (pulse wave PW) is preferably a laser beam having a near infrared wavelength represented by a YAG laser, as in the first embodiment. The laser head 122 (collimator lens 132, mirror 134, and fθ lens 138) is the same as that in the first embodiment.

  In the second embodiment, the oxide film forming laser beam L3 is intermittently irradiated (pulse irradiation) with a predetermined number of pulses so as to be orthogonal to the surface 62a of the lead frame 62. By such intermittent irradiation of the oxide film forming laser beam L3, the film thickness of the oxide film OM on the surface 62a of the lead frame 62 becomes, for example, a predetermined film thickness α having a diameter of about 200 μm and a film thickness exceeding zero. Is formed. Further, at this time, on the surface 62a (irradiation position) of the lead frame 62 irradiated with the oxide film forming laser beam L3, a hole 62c having a minute diameter and opening to the surface 62a is formed as in the first embodiment. It The heating unit 130 is the same as the heating unit 130 of the first embodiment.

  The control unit 240 is a control device that controls the operations of the oxide film forming unit 220 and the heating unit 130. The control unit 240 includes a laser light control unit 241a, a laser output adjustment unit 241b, a temperature measurement unit 142, an irradiation time measurement unit 143, a film thickness calculation unit 244, and a film thickness determination unit 245. As described above, the laser light control unit 241a, the laser output adjustment unit 241b, the temperature measurement unit 142, the irradiation time measurement unit 143, the film thickness calculation unit 244, and the film thickness determination unit 245 are included in the oxide film formation unit 220. .

  The control unit 240 also includes a laser light control unit 241a, a laser output adjustment unit 241b, and a temperature measurement unit 142 for controlling the operation of the heating unit 130. That is, the laser light controller 141a, the laser output adjuster 141b, and the temperature measuring unit 142 are shared with the oxide film forming unit 220, and are also included in the heating unit 130.

  The laser output adjusting unit 241b generates an oxide film forming laser beam L3 (pulse wave PW) in response to a command from the laser beam controlling unit 241a, and outputs the oxide film forming laser beam L3 to the surface of the lead frame 62 (metal member). Irradiation is performed on 62a intermittently under predetermined irradiation conditions. As shown in FIG. 10, in the intermittent irradiation of the oxide film forming laser beam L3, the temperature of the surface 62a of the lead frame 62 instantaneously rises by the first irradiation. As a result, the oxide film OM is formed at the irradiation position, and then the temperature is cooled in air at once in a short time. In the graph of FIG. 10, the horizontal axis represents elapsed time, and the vertical axis represents the temperature of the surface 62a of the lead frame 62 and the film thickness of the oxide film OM.

  Each time such intermittent irradiation with the oxide film forming laser beam L3 is performed, an oxide film OM is formed and laminated (accumulated) on the surface 62a of the lead frame 62 (α4 to α7 in FIG. 10). reference). At this time, the film thicknesses α4 to α7 of the oxide film OM formed at each intermittent irradiation with the oxide film forming laser beam L3 are the surface temperature t of the surface 62a increased by the irradiation of the oxide film forming laser beam L3 and the irradiation. Is formed with a thickness corresponding to the irradiation time h (irradiation continuation time). That is, each film thickness of the oxide film OM can be calculated by the surface temperature t of the surface 62a and the irradiation time h (not shown). The temperature measuring unit 142 is the same as that in the first embodiment.

  The irradiation time measuring unit 143 measures each irradiation time h of the intermittent irradiation of the surface 62a of the oxide film forming laser beam L3. In this case, the irradiation time h may be actually measured. However, not limited to this aspect, preset irradiation time data of the oxide film forming laser beam L3 may be acquired from the control unit 240. After that, the irradiation time data is transmitted to the film thickness calculation unit 244 of the control unit 240.

  The film thickness calculator 244 calculates the film thicknesses α4, α5, ..., αn of the oxide film OM formed every time the oxide film forming laser beam L3, which is a pulse wave, is intermittently irradiated, and the temperature measuring unit 142, and The calculation is performed based on the surface temperature t and the irradiation time h acquired by the irradiation time measuring unit 143. Further, the film thickness calculator 244 sequentially accumulates the already calculated film thicknesses α4, α5 ... An to calculate the cumulative film thickness Σ (α4 + α5 + ... + αn) of the oxide film OM.

  In the film thickness determination unit 245, the cumulative film thickness Σ (α4 + α5 + ... + αn) of the oxide film OM, which is the estimated film thickness calculated by the film thickness calculation unit 244, reaches the range of the predetermined film thickness α. Or not.

  When the film thickness determination unit 245 determines that the cumulative film thickness Σ (α4 + α5 + ·· + αn) has reached the range of the predetermined film thickness α, the laser output adjustment unit 141b is instructed by the laser light control unit 141a. The heating laser beam L4 is generated (switched) by adjusting the output of the oxide film forming laser beam L3 to be small and continuously irradiating. Then, the laser output adjusting unit 141b irradiates the surface 62a of the lead frame 62 with the heating laser beam L4 through the oxide film OM to heat the lead frame 62 to a predetermined surface temperature Ta. Thereby, the same effect as the first embodiment can be obtained.

  Next, a method for heating the lead frame 62 (metal member) by the heating device 200 will be described based on the flowchart 2 in FIG. The heating method includes an oxide film forming step S210 and a heating step S120. The oxide film formation step S210 includes an oxide film formation laser beam irradiation step S211, a temperature measurement step S212, an irradiation time measurement step S213, a cumulative film thickness calculation step S214, and a film thickness determination step S215. Further, the heating step S120 includes a switching step S121, a heating laser beam irradiation step S122, and a surface temperature determination step S123. Since the heating step S120 is the same as the heating step S120 of the first embodiment, description thereof will be omitted.

  In the oxide film forming laser light irradiation step S211, which is included in the oxide film forming step S210, when the operator presses a start button (not shown) of the heating device 200, the oxide film forming laser light L3 (pulse wave PW) is emitted. Irradiation is intermittently performed on the surface 62a of the lead frame 62 (metal member) under preset predetermined irradiation conditions (output, irradiation spot diameter, etc.) under the control of the laser light controller 241a and the laser output adjuster 241b. To be done.

  Each of the intermittent irradiations causes the surface temperature t to rise on the surface 62a of the lead frame 62 in a short time as shown in the graph of FIG. 10, and the increased surface temperature t and the irradiation time h of each irradiation. An oxide film OM having a film thickness (α4 to α7) corresponding to the above is formed on the surface 62a, and after each temperature rise, the surface temperature t drops at once in a short time.

  However, the surface temperature t of the surface 62a of the lead frame 62 does not completely return to the initial temperature of room temperature at each intermittent irradiation of the oxide film forming laser beam L3. Therefore, in the second and subsequent intermittent irradiations of the oxide film forming laser beam L3, the oxide film forming laser beam L3 is irradiated with a slight temperature increase at the start of irradiation.

  Therefore, as shown in FIG. 10, even if the output of irradiation is the same each time, the maximum reached temperature of the surface temperature t due to the irradiation of the oxide film forming laser beam L3 gradually increases. Each time such intermittent irradiation of the oxide film forming laser beam L3 is performed, an oxide film OM having a film thickness α4, α5 ... αn is formed and accumulated on the surface 62a of the lead frame 62 (see FIG. 10). ). In the graph of FIG. 10, due to space limitations, only α4 to α7 are shown.

  The temperature measuring step S212 is the same as the temperature measuring step S112 of the first embodiment. Further, in the irradiation time measuring step S213, the irradiation time measuring unit 143 measures each irradiation time h of the intermittent irradiation of the oxide film forming laser beam L3 onto the surface 62a, and the film thickness calculating unit 244 of the control unit 240 is measured. Send measurement data.

  In the cumulative film thickness calculating step S214, the surface temperature acquired in the temperature measuring step S212 and the irradiation time measuring step S213 is calculated by the film thickness calculating section 244 every time the oxide film forming laser beam L3 is intermittently irradiated onto the surface 62a. Based on t and the irradiation time h, the film thicknesses α4, α5, ... αn of the formed oxide film OM are calculated, respectively, and are sequentially accumulated to be the cumulative film thickness Σ (α4 + α5 + ... + Αn) is calculated.

  Next, in the film thickness determination step S215, whether the cumulative film thickness Σ (estimated film thickness) of the oxide film OM calculated by the film thickness calculation unit 244 by the film thickness determination unit 245 has reached the predetermined film thickness α. It is determined whether or not. If it is determined that the cumulative film thickness Σ has reached the predetermined film thickness α, the process moves to the switching step S121 of the heating step S120.

  If it is determined that the cumulative film thickness Σ has not reached the predetermined film thickness α, the process moves to the oxide film forming laser beam irradiation step S211 again. Then, in the film thickness determination step S215, S211 to S214 are repeatedly performed until the film thickness determination unit 245 determines that the cumulative film thickness Σ has reached the range of the predetermined film thickness α. The method of setting the predetermined film thickness α is as described above. The processing content of the heating step S120 is the same as that of the heating step S120 of the first embodiment. Thereby, heating with the same effect as the first embodiment can be performed.

<Modifications 1 and 2 of the second embodiment>
In the second embodiment, the oxide film forming laser light L3 is the pulse wave PW, and the heating laser light L4 is the continuous wave CW. However, it is not limited to this mode. As a first modification of the second embodiment, the oxide film forming laser light L3 may be a continuous wave CW and the heating laser light L4 may be a pulse wave PW. Furthermore, as a second modification, both the oxide film forming laser beam L3 and the heating laser beam L4 may be pulse waves PW. Even with these, a corresponding effect can be obtained.

<Third embodiment>
Next, the heating device 300 of the third embodiment will be described. As shown in FIG. 12, the heating device 300 of the third embodiment is partially different from the heating device 100 of the first embodiment in the oxide film forming unit 120 and the control unit 140. That is, the heating device 300 of the third embodiment includes the oxide film forming unit 320, the heating unit 130, and the control unit 340. In the third embodiment, as in the first embodiment, the oxide film forming laser light L5 and the heating laser light L6 are both continuous waves CW. In the description of the heating device 300, the same components as those of the heating device 100 of the first embodiment will be denoted by the same reference numerals.

  Here, the outline of the heating device 300 according to the third embodiment will be briefly described. The heating device 300 irradiates the surface 62a of the lead frame 62 with the laser light for measuring the absorptance when forming the oxide film OM by the oxide film forming part 320, and reflects the reflected light of the laser light for the absorptivity measurement reflected from the surface 62a. Based on the output, the actual absorption rate Abr, which is the actual absorption rate of the heating laser beam L6 with respect to the lead frame 62, is calculated. Then, the absorption rate difference ΔAb between the calculated actual absorption rate Abr and the estimated absorption rate Abe calculated based on the estimated film thickness calculated by the film thickness calculation unit 144 is calculated. Then, the irradiation condition of the oxide film forming laser beam L5 is set (changed) based on the absorptance difference ΔAb. Note that the calculated estimated film thickness is conditioned on reaching a range of a predetermined film thickness α.

  At this time, the measuring laser beam (the actual absorptivity measuring laser beam L7) for calculating the actual absorptance Abr is the same laser beam as the heating laser beam L6 or the oxide film forming laser beam L5. Is preferred. By setting the measurement laser light to be the same kind as the heating laser light L6 or the oxide film forming laser light L5, the actual absorptance Abr can be obtained more accurately. Therefore, in this embodiment, the actual absorption rate measuring laser beam L7 is also used as the oxide film forming laser beam L5.

  However, it is not limited to this mode. The actual absorption rate measuring laser beam L7 is set to the same irradiation condition as the heating laser beam L6, and the absorption rate when the heating laser beam L6 is irradiated is estimated from the obtained measurement data of the reflected laser beam. May be. Further, the laser light L7 for measuring the actual absorptance is a laser light under irradiation conditions different from the laser light L5 for forming an oxide film and the laser light L6 for heating, and the laser light for heating is obtained from the measurement data of the obtained reflected laser light. You may estimate the absorption rate when L6 is irradiated.

  The oxide film forming unit 320 included in the heating device 300 includes the laser oscillator 121, the laser head 122, the housing 123, and the power meter 330 described above. Further, the oxide film forming unit 320 includes a laser light control unit 141a included in the control unit 340, a laser output adjustment unit 141b (shared with the actual absorption rate measurement laser light irradiation unit), a temperature measurement unit 142, an irradiation time measurement unit 143, and Film thickness calculation unit 144, film thickness determination unit 145, reflected laser light output measurement unit 346, actual absorption rate calculation unit 347, estimated absorption rate calculation unit 348, absorption rate difference calculation unit 349, absorption rate difference determination unit 350, and oxidation. A film forming laser light irradiation condition changing unit 351 is included.

  As shown in FIG. 12, the laser head 122 is arranged at a predetermined angle γ ° with respect to the surface 62 a of the lead frame 62. In the power meter 330, the actual absorption rate measuring laser beam L7 (oxide film forming laser beam L5) is irradiated from the laser head 122 toward the surface 62a, and then reflected laser beam L7A (L5A) reflected by the surface 62a. ) Is arranged on the input surface of the power meter 330 at an arbitrary position and at an angle that enables input. The power meter 330 is connected to the reflected laser light output measurement unit 346 and transmits measurement data to the reflected laser light output measurement unit 346.

  The control unit 340 is a control device that controls the operations of the oxide film forming unit 320 and the heating unit 130. The control unit 340 controls the operation of the oxide film forming unit 320, the laser light control unit 141a, the laser output adjusting unit 141b (shared with the actual absorption rate measuring laser light irradiation unit), the temperature measurement unit 142, and the irradiation time. Measurement unit 143, film thickness calculation unit 144, film thickness determination unit 145, reflected laser light output measurement unit 346, actual absorption rate calculation unit 347, estimated absorption rate calculation unit 348, absorption rate difference calculation unit 349, absorption rate difference determination unit And a laser beam irradiation condition changing unit 351 for forming an oxide film.

  The control unit 340 includes a laser light control unit 141a and a laser output adjustment unit 141b for controlling the operation of the heating unit 130. That is, the laser light controller 141a and the laser output adjuster 141b are shared with the oxide film forming unit 320 and are also included in the heating unit 130.

  The laser light controller 141a included in the controller 340, the laser output adjuster 141b (also serves as the actual absorption rate measuring laser light irradiator), the temperature measuring unit 142, the irradiation time measuring unit 143, and the film thickness calculator 144, the film thickness. The determination unit 145 is the same as the control unit 140 of the first embodiment, and thus the description thereof will be omitted.

  Next, a method of heating the lead frame 62 (metal member) by the heating device 300 will be described based on the flowchart 3 of FIG. The heating method of the heating device 300 includes an oxide film forming step S310 and a heating step S120 similar to the first embodiment. The oxide film formation step S310 includes an oxide film formation laser beam irradiation step S111, a temperature measurement step S112, an irradiation time measurement step S113, a film thickness calculation step S114, a film thickness determination step S115, and an estimated absorption rate calculation step. S311, actual absorption rate measurement laser beam irradiation step S312, reflected laser beam output measurement step S313, actual absorption rate calculation step S314, absorption rate difference calculation step S315, absorption rate difference determination step S316, oxide film And a forming laser beam irradiation condition changing step S317.

  The oxide film forming step S310 of the flowchart 3 is the same as the oxide film forming step S110 of the first embodiment up to the film thickness determining step S115, but the subsequent processing is different. Therefore, in the present embodiment, only the processing after the film thickness determination step S115 will be described and described. Further, the heating step S120 is also the same as that in the flow chart 1, and thus the description thereof is omitted.

  In the third embodiment, the estimated film thickness α1 of the oxide film OM is calculated in the film thickness calculation step S114. Then, in the film thickness determination step S115, it is determined whether or not the calculated estimated film thickness α1 of the oxide film OM has reached the range of the predetermined film thickness α. If the estimated film thickness α1 has reached the range of the predetermined film thickness α, the process proceeds to the estimated absorption rate calculation step S311.

  If it is determined in the film thickness determination step S115 that the estimated film thickness α1 does not reach the range of the predetermined film thickness α, the process moves to the oxide film forming laser beam irradiation step S111 again. Then, in the film thickness determination step S115, the respective steps S111 to S114 are repeatedly processed until it is determined that the estimated film thickness α1 has reached the range of the predetermined film thickness α.

  Next, in the estimated absorption rate calculation step S311, the estimated absorption rate Abe is calculated. In the estimated absorption rate calculation step S311, the estimated absorption rate calculation unit 348 calculates the estimated absorption rate Abe based on the relationship between the film thickness of the oxide film OM having the periodicity shown in FIG. 6 and the absorption rate Ab. That is, the heating laser beam L6 corresponding to the estimated film thickness α1 calculated by the film thickness calculation unit 144 based on the graph of FIG. 6 and determined to have reached the predetermined film thickness α in the film thickness determination step S115 is estimated. The absorption rate Abe is calculated. For example, when the estimated film thickness calculated by the film thickness calculation unit 144 is X1, the estimated absorption rate Abe is Y1 in FIG.

  Next, in the actual absorption rate measuring laser beam irradiation step S312 (oxide film forming step S310), the actual absorption rate measuring laser beam irradiation section (shared with the laser output adjusting section 141b) is operated by the actual absorption rate measuring laser beam L7. The lead frame 62 (metal) (using the same laser beam L5 for forming the oxide film) is passed through the oxide film OM for which the estimated film thickness α1 is determined to have reached the range of the predetermined film thickness α in the film thickness determination step S115. The surface 62a of the (member) is irradiated.

  At this time, the laser beam L5 for forming an oxide film, which has been irradiated until then, may be stopped once and then irradiated again for measuring the actual absorptance. However, without being limited to this aspect, the laser light L5 for oxide film formation may be continuously irradiated without being stopped. However, it is preferable that the irradiation time of the oxide film forming laser beam L5 is short and the irradiation conditions are such that a new oxide film OM is not formed.

  In this embodiment, as the actual absorption rate measuring laser beam L7, not the heating laser beam L6 but the oxide film forming laser beam L5 is adopted. Therefore, a slight difference may occur as compared with the case where the surface 62a is irradiated with the heating laser beam L6 through the oxide film OM and the actual absorption rate Abr is calculated. However, the inventor considered that this difference was very small and decided to calculate the actual absorptance Abr with the oxide film forming laser beam L5.

  The actual absorption rate measuring laser light L7 (oxide film forming laser light L5) irradiated on the oxide film OM on the surface 62a is partly reflected laser light on the surface 62a of the lead frame 62 (metal member). Reflected as L7A. Further, the laser beams other than the reflected laser beam L7A (L5A) among the actual absorption rate measuring laser beam L7 are absorbed in the lead frame 62.

  In the reflected laser light output measuring step S313, the reflected laser light output measuring unit 346 measures the output of the reflected laser light L7A (L5A) by the connected power meter 330. The data measured by the power meter 330 is transmitted to the actual absorption rate calculation unit 347. Since the power meter 330 is a known measuring instrument that measures the output of laser light, detailed description thereof will be omitted. The output of the reflected laser light L7A (L5A) may be measured by a beam profiler, a CCD sensor, a CMOS sensor, or the like, without being limited to the power meter.

  In the actual absorption rate calculation step S314, the actual absorption rate calculation unit 347 calculates the actual absorption rate Abr of the heating laser beam L6 based on the reflected laser beam L7A (L5A). The actual absorption rate Abr is calculated by Abr = ((P1-P2) / P1). At this time, P1 is the initial output of the actual absorption rate measuring laser beam L7 (oxide film forming laser beam L5) with which the surface 62a is irradiated, and P2 is the reflected laser beam L7A (L5A) to be measured. Is the output. Here, the actual absorption rate Abr is Y2 as shown in FIG.

  Next, in the absorption rate difference calculation step S315, the absorption rate difference calculation section 349 calculates the estimated absorption rate Abe calculated in the estimated absorption rate calculation step S311 and the actual absorption rate calculation step S314 to calculate the estimated absorption rate Abe. An absorption rate difference ΔAb (= Abr−Abe = Y2−Y1) between the actual absorption rate Abr corresponding to the oxide film OM formed at the calculated time point is calculated. Then, the calculation result is transmitted to the absorption rate difference determination unit 350.

  In the absorption rate difference determination step S316, the absorption rate difference determination unit 350 determines whether or not the calculated absorption rate difference ΔAb (= Y2-Y1) is within a predetermined range β. If the absorptance difference ΔAb is within the predetermined range β, it is determined that the calculation result of the estimated film thickness is reliable, and the process proceeds to the switching step S121 of the heating step S120. It should be noted that the predetermined range β may be arbitrarily set based on a preliminary experiment or the like.

  Then, in the heating step S120, the laser output adjustment unit 141b irradiates the surface 62a of the lead frame 62 with the heating laser light L6 via the oxide film OM, as in the first embodiment. Thereby, the laser output adjustment unit 141b heats the lead frame 62 to a predetermined surface temperature ta. Next, when the surface temperature determination unit (not shown) determines that the preset surface temperature ta has been reached, the irradiation of the heating laser beam L2 is stopped.

  However, in the determination in the absorption rate difference determination step S316, if it is determined that the absorption rate difference ΔAb is not within the predetermined range β, the process proceeds to the oxide film forming laser light irradiation condition changing step S317. In the oxide film forming laser light irradiation condition changing step S317, for example, the oxide film forming laser light irradiation condition changing unit 351 sets the oxide film forming laser light L5 so that the absorption difference ΔAb falls within the range β in the shortest possible time. Change the irradiation conditions of.

  Here, the oxide film formation laser light irradiation condition changing unit 351 forms the oxide film based on the estimated film thickness X1, the actual absorption rate Abr, and the relationship between the film thickness of the oxide film OM having periodicity and the absorption rate Ab. The predetermined irradiation condition of the laser light L5 for use is changed.

  In other words, the oxide film formation laser light irradiation condition changing unit 351 calculates the estimated absorption rate Abe calculated by the estimated absorption rate calculation section 348 based on the estimated film thickness X1 and the estimated absorption rate calculated by the actual absorption rate calculation section 347. The predetermined irradiation condition of the oxide film forming laser beam L5 is changed based on the actual absorption rate Abr corresponding to the oxide film OM formed when Abe is calculated. The estimated absorption rate Abe is calculated from the estimated film thickness X1 and the relationship between the film thickness of the oxide film OM having periodicity and the absorption rate Ab.

  Further, specifically, the oxide film forming laser light irradiation condition changing unit 351 determines that the absorptance difference determination unit 350 determines that the absorptance difference ΔAb is not within the predetermined range β. In the next determination, according to the magnitude of ΔAb, the predetermined irradiation condition of the oxide film forming laser beam L5 is changed so that the absorptance difference ΔAb falls within the predetermined range.

  For example, when the actual absorptance Abr is smaller than the estimated absorptance Abe and the absorptance difference ΔAb increases in the negative direction, the irradiation condition of the oxide film forming laser beam L5 is set to the oxide film OM. Is changed to an irradiation condition that is more likely to be formed. On the contrary, when the actual absorptance Abr is larger than the estimated absorptance Abe and the absorptance difference ΔAb increases in the positive direction, the irradiation condition of the oxide film forming laser beam L5 is set to the oxide film. Change the irradiation conditions so that OM is not easily formed. This improves the possibility that the absorption difference ΔAb will fall within the predetermined range β at the time of the next determination, so that the desired film thickness α can be obtained for the oxide film OM in a short time, which is efficient.

<Modification 1 of the third embodiment>
In the third embodiment, the actual absorption rate measuring laser beam L7 (oxide film forming laser beam L5) is applied to the surface 62a of the lead frame 62 through the oxide film OM, and then the surface of the lead frame 62 is irradiated. The power meter 330 directly receives the reflected laser light L7A (L5A) reflected by 62a. However, it is not limited to this mode.

  As shown in FIG. 14, as a first modification of the third embodiment, a dichroic mirror 410 may be provided on the optical axis of the oxide film forming laser beam L5 (actual absorption rate measuring laser beam L8). The dichroic mirror 410 is an element that reflects light (laser light) in a specific wavelength range (for example, near infrared wavelength) and transmits light in other wavelength ranges. Any element may be used as long as it has such characteristics, not limited to the dichroic mirror.

  As shown in FIG. 14, the dichroic mirror 410 is about 45 degrees from the surface 62a between the laser head 122 and the surface 62a of the lead frame 62, that is, on the optical axis of the oxide film forming laser beam L5 (L8). They are arranged with a degree of inclination. In the modified example 1 in which the dichroic mirror 410 is arranged in this way, the oxide film forming laser beam L5 (L8) is moved from the laser head 122 arranged so that the optical axis of the oxide film forming laser beam L5 (L8) is horizontal. Is emitted toward the dichroic mirror 410.

  Then, most of the oxide film forming laser beam L5 (L8) reaching the dichroic mirror 410 is reflected by the mirror surface 410a of the dichroic mirror 410 and a part thereof is transmitted. Then, the oxide film forming laser beam L5 (L8) reflected by the mirror surface 410a has its traveling direction changed to a right angle and reaches the surface 62a of the lead frame 62.

  After that, a part of the oxide film forming laser beam L5 (L8) is absorbed by the lead frame 62 from the surface 62a and is converted into heat. Further, the other part is reflected by the surface 62a, travels toward the mirror surface 410a of the dichroic mirror 410 again as the reflected laser light L5A (L8A), and reaches the mirror surface 410a which is inclined with respect to the surface 62a. . At this time, most of the reflected laser light L5A (L8A) is reflected again on the mirror surface 410a of the dichroic mirror 410 that the reflected laser light L5A (L8A) has reached, and is parallel to the optical axis of the oxide film forming laser light L5 (L8). Then, the laser beam moves toward the laser head 122.

  On the mirror surface 410a reached by the reflected laser light L5A (L8A), part of the reflected laser light L5A (L8A) passes through the dichroic mirror 410 and travels upward in FIG. Then, the transmitted laser light L5AA (L8AA) is input to the power meter 330 arranged above, and the output of the transmitted laser light L5AA (L8AA) is measured. As a result, the actual absorption rate Abr of the oxide film OM can be estimated as in the third embodiment. With such a configuration, the same effect as that of the third embodiment can be obtained.

  Further, in the modified example 1 of the third embodiment, unlike the third embodiment, the laser head 122 can be arranged horizontally, and the configuration is simplified. Further, since the output of the transmitted laser light L5AA (L8AA) input to the power meter 330 is small, a small power meter can be used, which can contribute to cost reduction.

<Modification 2 of the third embodiment>
Further, it is not limited to the aspect of the first modification. As a second modification of the third embodiment, as shown in FIG. 15, a dichroic mirror 420, a laser head 122, and a power meter 330 may be arranged. In the modified example 2, the dichroic mirror 420 is located between the laser head 122 having an optical axis in the vertical direction and the surface 62a of the lead frame 62, that is, the oxide film forming laser beam L5 (actual absorption rate measuring laser beam L9). On the optical axis of, the surface 62a is arranged with an inclination of about 45 degrees. It is assumed that the dichroic mirror 420 and the dichroic mirror 410 have different modes of transmitting or reflecting the oxide film forming laser beam L5 (L9).

  In the second modification in which the dichroic mirror 420 is arranged in this way, as shown in FIG. 15, the laser beam L5 (L9) for forming an oxide film is emitted from the laser head 122 arranged so that the optical axis is vertical. It is irradiated toward.

  Then, most of the oxide film forming laser light L5 (L9) reaching the dichroic mirror 420 is transmitted by the mirror surface 420a of the dichroic mirror 420. Then, the oxide film forming laser beam L5 (L9) transmitted through the mirror surface 420a reaches the surface 62a of the lead frame 62.

  After that, a part of the oxide film forming laser beam L5 (L9) is absorbed by the lead frame 62 from the surface 62a and is converted into heat. The remaining part is reflected by the surface 62a, travels toward the mirror surface 420b of the dichroic mirror 420 again, and reaches the mirror surface 420b that is arranged to be inclined with respect to the surface 62a. At this time, part of the reflected laser light L5A (L9A) is reflected at a right angle on the mirror surface 420b of the dichroic mirror 410 with which the reflected laser light L5A (L9A) is in contact, and travels toward the power meter 330. Then, the reflected laser light L5AB (L9AB) is input to the power meter 330 arranged on the left side in FIG. 15, and the output is measured. As a result, the actual absorption rate Abr of the oxide film OM can be estimated as in the third embodiment. With such a configuration, the same effect as that of the third embodiment can be obtained.

  Further, in the second modification of the third embodiment, unlike the third embodiment, the laser head 122 can be vertically arranged, and the configuration is simplified. Further, similarly to the modification 1, since the output of the reflected laser light L5AB (L9AB) input to the power meter 330 is small, a small power meter can be used, which contributes to cost reduction.

<Modification 3 of the third embodiment>
In the third embodiment, the irradiation of the oxide film forming laser beam L5, the heating laser beam L6, and the actual absorption rate measuring laser beam L7 is alternately performed by switching one laser oscillator 121 (output adjustment). I did. However, it is not limited to this mode. As a modified example 3 of the third embodiment, a laser oscillator for the actual absorption rate measuring laser beam L7 may be separately provided (not shown). As a result, the actual absorption rate Abr can be measured at the same time as the irradiation of the oxide film forming laser beam L5, resulting in high efficiency.

<Modifications 4, 5, 6 of the third embodiment>
Further, in the third embodiment, both the oxide film forming laser beam L5 and the heating laser beam L6 are continuous waves CW. However, it is not limited to this mode. As a modified example 4 of the third embodiment, the oxide film forming laser light L5 may be a pulse wave PW and the heating laser light L6 may be a continuous wave CW. As a fifth modification, the oxide film forming laser light L5 may be a continuous wave CW and the heating laser light L6 may be a pulse wave PW. Further, as a modified example 6, both the oxide film forming laser beam L5 and the heating laser beam L6 may be pulse waves PW. Even with this, a corresponding effect can be obtained.

<Modification 7 of the third embodiment>
In the third embodiment described above, in the oxide film forming laser beam irradiation step S111 for forming the oxide film OM, after the irradiation of the oxide film forming laser beam L5 is stopped, the actual absorption rate measuring laser beam is obtained. L7 (L5) was irradiated, and the actual absorption rate Abr was calculated. However, it is not limited to this mode. As a modified example 7, during irradiation of the oxide film forming laser beam L5 for forming the oxide film OM, at the same time, the reflected laser beam L7A of the actual absorption rate measuring laser beam L7 (L5) is acquired by the power meter 330 and actually absorbed. The rate Abr may be calculated.

  In the first to third embodiments, the irradiation of the heating laser beams L2, L4 and L6 is switched by adjusting the output of the oxide film forming laser beams L1, L3 and L5. However, it is not limited to this mode. The control units 140, 240, and 340 each include an irradiation unit that irradiates a laser beam with a preset output, and the control units 140, 240, and 340 each only change the irradiation unit, and the oxide film forming laser beams L1 and L3. , L5 and the heating laser beams L2, L4, L6 may be switched.

(4. Joining device)
Next, a joining device 400 for joining two members to which the heating device 100 of the first embodiment is applied will be described. The joining will be described by taking as an example a mode in which the metal terminal of the semiconductor component 50, which is a metal member to be joined, is joined to the lead frame 62 described above as a heating member by known solid-phase diffusion joining. The solid phase diffusion bonding is performed at a temperature lower than that in the liquid phase by heating the metal member (lead frame 62) and the metal member to be bonded (metal terminal of the semiconductor component 50) and the bonding is performed in the solid state. This is a known joining method in which the first joining surface 62b and the second joining surface 50a are joined together by applying pressure in the pressure-bonding direction in a possible solid state.

  Specifically, the first bonding surface 62b facing the surface 62a of the lead frame 62 and the second bonding surface 50a on the upper surface of the metal layer 51 formed as a terminal on the upper surface of the semiconductor component 50 are bonded (FIG. 17). reference). The metal layer 51 is formed of Au, for example. As shown in FIGS. 16 and 17, before being joined, the first joining surface 62b and the second joining surface 50a are in contact with each other. The lower surface of the semiconductor component 50 is supported by a predetermined support member 52. Further, at the time of bonding, the surface 62a of the lead frame 62 is pressed in the pressure bonding direction between the first bonding surface 62b and the second bonding surface 50a (see the arrow in FIG. 17).

  As shown in FIG. 16, the joining device 400 is a device to which the heating device 100 (the oxide film forming unit 120, the heating unit 130, and the control unit 140) is applied. The joining device 400 includes the heating device 100, a pressurizing unit 430, and a control unit 440. The pressing unit 430 irradiates the surface 62a of the lead frame 62 with the heating laser beam L2 by the heating unit 130 of the heating device 100 and heats the surface 62a of the lead frame 62 to the first bonding surface 62b. And pressure is applied in the direction in which the second bonding surface 50a and the second bonding surface 50a are pressure bonded (see the arrow in FIG. 17).

  At this time, any means may be used for applying pressure. The pressure applied is a pressure that enables solid phase diffusion bonding, and is examined and determined in advance. Further, in the present embodiment, it is assumed that the pressurization in the direction in which the first joint surface 62b and the second joint surface 50a are pressure-bonded is started simultaneously with the operation of the heating device 100. The pressure unit 430 is controlled by the laser light controller 141a of the controller 140.

  The control unit 440 includes a temperature measurement unit 442, an irradiation time measurement unit 443, a bond strength calculation unit 444, and a bond strength determination unit 445. The temperature measurement unit 442 may have a function similar to that of the temperature measurement unit 142 of the control unit 440, and thus may be combined with the temperature measurement unit 142. The measured data of the measured surface temperature t of the surface 62a is transmitted to the bonding strength calculation unit 444 of the control unit 440. The irradiation time measuring unit 443 measures the irradiation time h of irradiation on the surface 62a with the heating laser beam L2. The measured data of the measured irradiation time h is transmitted to the bonding strength calculation unit 444 of the control unit 440.

  The bonding strength calculation unit 444 is provided between the first bonding surface 62b and the second bonding surface 50a calculated based on the surface temperature t and the irradiation time h acquired by the temperature measuring unit 442 and the irradiation time measuring unit 443. The bonding strength F in the solid phase diffusion bonding of is calculated.

  The bonding strength determination unit 445 determines whether or not the bonding strength F calculated by the bonding strength calculation unit 444 has reached a preset predetermined bonding strength F1. That is, it is determined whether the first bonding surface 62b and the second bonding surface 50a are bonded with the bonding strength F (≧ predetermined bonding strength F1).

(5. Joining method)
Next, a joining method using the joining device 400 will be described based on the flowchart 4 in FIG. As shown in the flowchart 4 of FIG. 18, the bonding method includes an oxide film forming step S110 and a heating step S120A. The oxide film forming step S110 is the same as the oxide film forming step S110 of the heating method described above. However, the heating step S120A is partially different from the heating step S120 of the heating method in the first embodiment. Therefore, in the flowchart 4 of FIG. 18, the description of the oxide film forming step S110 is omitted, and only the heating step S120A is described in detail. Also, in the description, only the heating step S120A will be described. The same components and steps as those of the heating method described in the above embodiment will be denoted by the same reference numerals.

  As shown in the flowchart 4 of FIG. 18, the heating step S120A of the bonding method includes a switching step S121, a heating laser beam irradiation step S122, a temperature measurement step S123A, an irradiation time measurement step S124A, a bonding strength calculation step S125A, and a bonding strength. The determination step S126A is provided.

  In the switching step S121, when it is determined in the film thickness determination step S115 of the oxide film formation step S110 that the estimated film thickness α1 has reached (the range of) the predetermined film thickness α, the laser output adjustment unit 141b (laser light control) The part 141a) adjusts the output of the oxide film forming laser beam L1 and changes (switches) to the irradiation of the heating laser beam L2.

  In the heating laser beam irradiation step S122, the surface 62a of the lead frame 62 is irradiated with the heating laser beam L2 through the oxide film OM under the control of the laser output adjusting unit 141b. In the temperature measuring step S123A, the surface temperature t of the lead frame 62 is measured by the infrared radiation thermometer 39, and the measurement data is transmitted to the bonding strength calculation unit 444 of the control unit 440. In the irradiation time measuring step S124A, the irradiation time h of the heating laser beam L2 onto the surface 62a is measured, and the measurement data is transmitted to the bonding strength calculation unit 444 of the control unit 440.

  In the bonding strength calculating step S125A, the bonding strength F between the first bonding surface 62b and the second bonding surface 50a is calculated based on the surface temperature t and the irradiation time h acquired in the temperature measuring step S123A and the irradiation time measuring step S124A. . At this time, the bonding strength calculation step S125A first estimates the temperatures of the first bonding surface 62b and the second bonding surface 50a from the surface temperature t of the surface 62a and the irradiation time h. Then, the estimated temperature is applied to the relationship between the temperature of the first joint surface 62b and the second joint surface 50a and the joint strength F which the control unit 440 has in advance to estimate the joint strength F. However, the present invention is not limited to this mode, and the bonding strength F may be calculated in any way.

  Next, when it is determined in the bonding strength determination step S126A that the estimated bonding strength F does not reach the preset predetermined bonding strength F1, the process returns to the heating laser beam irradiation step S122, and the bonding strength determination is performed. The process is repeated until it is determined in step S126A that the predetermined bonding strength F1 has been reached. However, when it is determined by the bonding strength determination step S126A that the estimated bonding strength F has reached the preset predetermined bonding strength F1, the laser output adjusting unit 141b stops the irradiation of the heating laser beam L2, Exit the program.

  The bonding method described above includes a bonding strength calculation step S125A and a bonding strength determination step S126A, and the heating laser beam L2 is emitted when it is determined that the bonding strength F reaches a predetermined bonding strength F1. I stopped. However, the present invention is not limited to this aspect, and the joining method may not include the joining strength calculation step S125A and the joining strength determination step S126A. In this case, the joining method may determine whether or not the joining is completed only by the measurement data (surface temperature t) of the temperature measuring step S123A. This also has the corresponding effect.

  In addition, regarding the surface temperature ta of the surface 62a which is the criterion for the determination at this time, the first bonding surface 62b and the second bonding surface 50a are in the solid state, and the solid phase diffusion bonding is completed by the pressing in the pressure bonding direction. This is the surface temperature of the surface 62a at that time, which is also studied and set in advance.

  Moreover, in the said joining method, although the aspect which joins the 1st joining surface 62b and the 2nd joining surface 50a by solid phase diffusion joining was demonstrated, it is not restricted to this aspect. As another method of joining, the first joining surface 62b and the second joining surface 50a may be joined to each other in a liquid phase state (molten state). In this case, it is not necessary to apply pressure to the lead frame 62 in the crimping direction with the semiconductor component 50.

  Even in such a case, the completion of bonding may be determined based on the surface temperature t measured in the temperature measuring step S123A or the bonding strength F calculated in the bonding strength calculating step S125A. Similar to the above, the surface temperature ta that is the criterion for the determination at this time is also the surface of the surface 62a that makes it possible to confirm that the first bonding surface 62b and the second bonding surface 50a are bonded in a liquid phase state. Temperature, which is also considered and determined in advance. Also, regarding the determination of the bonding strength F, it goes without saying that the relationship between the surface temperature t and the bonding strength F is acquired in advance and the determination is performed based on the relationship.

(6. Effects of the embodiment)
According to the first to third embodiments described above, the heating method of heating the lead frame 62 (metal member) by irradiating the heating laser beam L2 is the predetermined film thickness α on the surface 62a of the lead frame 62 (metal member). Oxide film forming step S110 for forming the oxide film OM of No. 2 and the surface 62a of the lead frame 62 (metal member) is irradiated with the heating laser light L2 through the oxide film OM, and the irradiated heating laser light L2 is irradiated with the oxide film And a heating step S120 of heating the lead frame 62 (metal member) to a predetermined surface temperature Ta, ta by causing the lead frame 62 (metal member) to absorb the OM at an absorptivity according to a predetermined film thickness α.

In addition, the absorptance has a periodicity in which a maximum value and a minimum value alternately appear with respect to a change in the film thickness in the relationship with the film thickness of the oxide film OM, and the film thickness of the oxide film OM. Has a characteristic that it becomes the smallest when 0 is zero, and the predetermined film thickness α of the oxide film formed in the oxide film forming step S110 is the film thickness of the oxide film OM in relation to the absorptivity having periodicity. The first maximum film thickness A corresponding to the first maximum value a that exceeds zero and the absorption rate first appears as the maximum value, and the second maximum value b that the absorption rate appears as the maximum value next to the first maximum value a. Including the second maximum film thickness B corresponding to the third maximum film thickness b corresponding to the second local maximum value b and the third local maximum value c at which the absorptance appears as the second maximum value. Between C and C, the absorptivity is smaller than the second minimum film thickness corresponding to the second minimum value that appears as the minimum value. It is set to the first range such.

As described above, in the characteristic of the absorptance of the heating laser beam L2 into the lead frame 62 (metal member), the maximum value and the minimum value periodically appear alternately in relation to the film thickness of the oxide film OM. It has a periodicity and has a characteristic that the absorptance becomes the smallest when the film thickness of the oxide film OM is zero. The film thickness of the oxide film OM of the lead frame 62 (metal member) exceeds zero and corresponds to the first maximum value a that appears first and the second maximum value b that appears next to the first maximum value a, respectively. Including the first maximum film thickness A and the second maximum film thickness B, and between the second maximum value b and the third maximum value c which is the maximum value that appears next to the second maximum value b. Is set to the first predetermined range Ar1 (35 nm to 360 nm) within the first range that is smaller than the second minimum film thickness BB corresponding to the second minimum value bb.

As a result, even if the film thickness varies slightly when the oxide film OM is formed, the absorptance of the heating laser beam L2 is obtained when the heating laser beam L2 is applied to the lead frame 62 (metal member) without passing through the oxide film OM. In comparison with, it is possible to surely increase the size, and it is possible to heat the lead frame 62 (metal member) stably and highly efficiently. Further, the thickness of the oxide film OM to limit the first within range near zero, it is possible to prevent the take wasteful time to form a film thickness of more than a first range.

According to the first to third embodiments, the lead frame 62, which is a metal member, is copper, and when the oxide film thickness is measured by the continuous electrochemical reduction method, the oxide film has a predetermined film thickness α. Is set within the first range of 35 nm to 360 nm, so that the absorptance of the heating laser beam L2 on the lead frame 62 (metal member) is surely larger than that in the case where no oxide film is provided. Therefore, the lead frame 62 (metal member) can be heated with high efficiency.

  Further, according to the first to third embodiments, in the oxide film forming steps S110 and S210 in the heating method, the oxide film OM is irradiated on the surface 62a of the lead frame 62 (metal member) based on predetermined irradiation conditions. It is formed by irradiating the oxide film forming laser beams L1, L3 and L5. Accordingly, the same heating device 100, 200, 300 can be used in the oxide film forming steps S110, S210 and the heating step S120, which is efficient.

  Further, according to the first to third embodiments, in the oxide film forming steps S110 and S210 in the heating method, the surface 62a of the lead frame 62 (metal member) is irradiated with the oxide film forming laser beam L1 and the irradiation position. A hole 62c is formed in the. As a result, in the heating step S120, a part of the heating laser beam L2 can be introduced into the hole 62c, and the side surface in the hole 62c can be irradiated and absorbed, so that the lead frame 62 (metal member) with higher efficiency can be obtained. Can be heated.

  According to the heating methods of the first to third embodiments, the oxide film forming laser beams L1, L3, L5 and the heating laser beams L2, L4, L6 are lasers of the same type (near infrared wavelength). Light. Thereby, the heating devices 100, 200, 300 can be manufactured at low cost.

  According to the first and third embodiments, the oxide film forming laser lights L1 and L5 and the heating laser lights L2 and L6 are both continuous waves CW. Thereby, the heating devices 100 and 300 can be manufactured at low cost.

  Further, according to the second embodiment, the oxide film forming laser light L1 is the pulse wave PW, and the heating laser light L2 is the continuous wave CW. As described above, by changing the irradiation mode of the laser light so as to meet the different purposes of oxide film formation and heating, it is possible to efficiently realize the oxide film formation and the heating, respectively.

  Further, according to the first to third embodiments, the oxide film forming steps S110, S210, S310 in the heating method include the surface 62a of the lead frame 62 (metal member) of the oxide film forming laser beams L1, L3, L5. Measuring steps S112 and S212 for measuring the surface temperatures T and t of the surface 62a during irradiation to the surface 62a and irradiation time measuring steps S113 and S213 for measuring irradiation times H and h of the oxide film forming laser beam L1 onto the surface 62a. And film thickness calculation steps S114 and S214 for calculating the cumulative film thickness of the oxide film formed on the surface of the metal member based on the measured surface temperature T, t and irradiation time H, h, and film thickness calculation step S114. , S214, film thickness determination steps S115 and S215 for determining whether or not the film thickness (cumulative film thickness) of the oxide film OM calculated in S214 has reached a predetermined film thickness α.

  Further, in the heating step S120, when the film thickness determination step S115 determines that the cumulative film thickness has reached the predetermined film thickness α, the irradiation of the oxide film forming laser beam L1 is performed and the irradiation of the heating laser beam L2 is performed. A switching step S121 for switching to and a heating laser beam L2 is applied to the surface 62a of the lead frame 62 (metal member) through the oxide film OM to heat the lead frame 62 (metal member) to a predetermined surface temperature Ta. Laser beam irradiation step S122. As a result, the lead frame 62 (metal member) is heated more efficiently, accurately, and stably.

  Further, according to the heating method of the third embodiment, the oxide film forming step S310 measures the surface temperature of the surface 62a when the oxide film forming laser beam L5 is applied to the surface 62a of the lead frame 62 (metal member). Based on the temperature measuring step S112, the irradiation time measuring step S113 for measuring the irradiation time of the oxide film forming laser beam L5 on the surface, and the surface of the lead frame 62 (metal member) based on the measured surface temperature and irradiation time. A film thickness calculation step S114 for calculating the film thickness of the formed oxide film OM as an estimated film thickness, and an actual absorption rate through the oxide film OM on the surface 62a of the lead frame 62 (metal member) on which the oxide film OM is formed. Actual absorption rate measurement laser beam irradiation step S312 of irradiating the measurement laser beam L7 and actual absorption rate measurement laser beam L irradiated in the actual absorption rate measurement laser beam irradiation step S312. Is measured based on the output of the reflected laser beam L7A measured by the reflected laser beam output measuring step S313 for measuring the output of the reflected laser beam L7A reflected by the surface 62a and the reflected laser beam output measuring step S313. Actual absorption rate calculation step S314 for calculating the actual absorption rate Abr of the heating laser beam L6 onto the surface 62a of the lead frame 62 (metal member) on which the OM is formed, the estimated film thickness, the actual absorption rate Abr, and the cycle. A laser beam irradiation condition changing step S317 for changing a predetermined irradiation condition of the laser beam L5 for forming an oxide film based on the relationship between the film thickness and the absorptance of the oxide film having the property. As described above, since the oxide film OM is formed while confirming the estimated film thickness, the actual absorption rate Abr, and the relationship between the film thickness and the absorption rate of the oxide film having periodicity, the oxidation film having the desired absorption rate is formed. The possibility of obtaining the film OM is improved.

  Further, according to the heating method of the third embodiment, the oxide film forming step S310 uses the estimated film thickness calculated in the film thickness calculating step S114 based on the relationship between the film thickness of the oxide film having periodicity and the absorption rate. An estimated absorption rate calculation step S311 for calculating the estimated absorption rate Abe of the corresponding heating laser beam L6 is provided. Then, the oxide film forming laser light irradiation condition changing step S317 corresponds to the estimated absorption rate Abe calculated in the estimated absorption rate calculation step S311 and the oxide film OM formed at the time when the estimated absorption rate Abe is calculated. The irradiation condition of the oxide film forming laser beam L5 is changed based on the actual absorption rate Abr. In this way, since the oxide film OM is formed based on the estimated absorption rate Abe and the actual absorption rate Abr, the possibility of obtaining the oxide film OM having a desired absorption rate is further improved.

  According to the heating method of the third embodiment, the oxide film forming step S310 includes the estimated absorption rate Abe calculated in the estimated absorption rate calculation step S311 and the oxide film formed at the time when the estimated absorption rate is calculated. Absorption rate difference calculation step S315 for calculating the absorption rate difference ΔAb between the actual absorption rate Abr corresponding to the OM and the absorption rate difference for determining whether the calculated absorption rate difference ΔAb is within the predetermined range β. The determination step S316 is provided. Then, in the oxide film forming laser light irradiation condition changing step S317, when it is determined in the absorptance difference determination step S316 that the absorptance difference ΔAb is not within the predetermined range β, the absorptance difference ΔAb is set to the magnitude. Accordingly, the predetermined irradiation condition of the oxide film forming laser beam L5 is changed so that the absorption rate difference ΔAb falls within the predetermined range β. As a result, the oxide film OM having a desired absorptance is reliably formed.

  Further, according to the first to third embodiments, the heating devices 100, 200, and 300 have the oxide film forming unit that forms the oxide film OM having the predetermined film thickness α on the surface 62a of the lead frame 62 (metal member). The lead frame 62 (metal member) is irradiated with the heating laser beams L2, L4, and L6 through 120, 220, 320 and the formed oxide film OM having the predetermined film thickness α, and the irradiated heating laser beam L2. , L4, L6 are absorbed by the lead frame 62 (metal member) at an absorptivity according to the predetermined film thickness α of the oxide film OM, and the lead frame 62 (metal member) is heated to a predetermined surface temperature Ta, ta. And a unit 130.

  In addition, the absorptance has a periodicity in which a maximum value and a minimum value alternately appear with respect to a change in the film thickness in the relationship with the film thickness of the oxide film OM, and the film thickness of the oxide film OM. Has a characteristic that it becomes the smallest when 0 is zero, and the predetermined film thickness α of the oxide film OM formed in the oxide film forming portions 120, 220, 320 is related to the absorptivity having periodicity. The OM film thickness exceeds zero, and the first maximum film thickness A corresponding to the first maximum value a at which the absorption rate first appears as the maximum value, and the absorption rate appears as the maximum value next to the first maximum value a. The second maximum value b corresponding to the second maximum value b and including the second maximum value b and the second maximum value b corresponding to the third maximum value c at which the absorption rate appears as the maximum value. Corresponding to the second minimum value bb at which the absorptance appears as a minimum value between the three maximum film thicknesses C. It is set to a second minimum film thickness smaller first range from BB Ar @ 1. The heating devices 100, 200, and 300 can perform the same efficient heating as the above heating method.

  Further, according to the third embodiment, in the oxide film forming part 320 of the heating device 300, the oxide film OM is formed on the surface 62a of the lead frame 62 (metal member) based on a predetermined irradiation condition. It is formed by irradiation with the laser light L5 for use. Further, the oxide film forming unit 320 measures the surface temperature of the surface when the surface 62a of the lead frame 62 (metal member) is irradiated with the oxide film forming laser light L5, and the oxide film forming laser. An irradiation time measuring unit 143 that measures the irradiation time of the light L5 onto the surface 62a, and the film thickness of the oxide film OM formed on the surface 62a of the lead frame 62 (metal member) based on the measured surface temperature and irradiation time. Is calculated as the estimated film thickness, and the surface 62a of the lead frame 62 (metal member) on which the oxide film OM is formed is irradiated with the actual absorption rate measuring laser beam L7 through the oxide film OM. The absorptance measurement laser light irradiation unit (laser output adjustment unit 141b) and the actual absorptance measurement laser light irradiation unit (laser output adjustment unit 141b) emit the actual absorptance measurement laser light L7. The reflected laser light output measuring unit 346 that measures the output of the reflected laser light L7A reflected by the surface 62a, and the oxide film OM based on the output magnitude of the reflected laser light L7A measured by the reflected laser light output measuring unit 346. An actual absorptance calculator 347 for calculating an actual absorptance of the heating laser beam L6 onto the surface 62a of the lead frame 62 (metal member) on which is formed, an estimated film thickness, an actual absorptance Abr, and oxidation having periodicity. An oxide film forming laser light irradiation condition changing unit 351 that changes a predetermined irradiation condition of the oxide film forming laser light L5 based on the relationship between the film thickness of the film OM and the absorptance Ab. As a result, the heating device 300 can perform heating with the same effect as the heating method of the third embodiment.

  Further, the joining method by the joining apparatus 400 of the above-described embodiment is performed by the first joining surface 62b of the lead frame 62 facing the surface 62a of the lead frame 62 (metal member) and the metal to be joined that abuts the first joining surface 62b. A method of joining the member to the second joining surface 50a, wherein the lead frame 62 (metal member) is heated to a predetermined temperature by the heating method described in the first to third embodiments, and the first joining surface 62b is formed. The second bonding surface 50a is set to a solid state in which it is formed at a temperature lower than the liquid phase state and can be bonded in a solid state, and the first bonding surface 62b and the second bonding surface 50a are pressed in the pressure bonding direction. To join.

  In this way, the first joining surface 62b and the second joining surface 50a are joined by raising the temperature to a solid state which is lower than the melting temperature of the copper lead frame 62 (metal member). The required irradiation amount of the light L2 is reduced as compared with the case where the lead frame 62 (metal member) is melted. Therefore, by the oxide film forming steps S110, S210, and S310, the oxide film OM is provided on the lead frame 62 (metal member) to improve the absorptance of the heating laser light L2, and at the same time, the heating laser light is used. The required energy amount of L2 can be greatly reduced, and the cost for bonding can be reduced.

(7. Others)
In the first to third embodiments described above, the predetermined film thickness α of the oxide film OM formed on the surface 62a of the lead frame 62 (metal member) is determined by the oxide film OM in relation to the absorptivity having periodicity. Of the first maximum film thickness A corresponding to the first maximum value a at which the absorption rate first appears as the maximum value, and the absorption rate appears as the maximum value next to the first maximum value a. The third maximum value c that includes the second maximum film thickness B corresponding to the second maximum value b and that corresponds to the third maximum value c at which the absorption rate appears as the maximum value next to the second maximum value b and the second maximum value b. Between the maximum film thickness C, the absorptance was set to the first range Ar1 smaller than the second minimum film thickness corresponding to the second minimum value that appears as the minimum value.

However, it is not limited to this mode. As shown in the graph of FIG. 6, the predetermined film thickness α of the oxide film OM includes the first maximum film thickness A, and the absorption coefficient is minimum between the first maximum value a and the second maximum value b. includes a first minimum film thickness AA smaller than the second range the second predetermined range of囲内Ar2 or second maximum thickness B, which corresponds to the first minimum value aa appearing as a value, and larger than the first minimum film thickness AA It may be set to the third predetermined range Ar3 within the third range smaller than the second minimum film thickness BB .

That is , in the above embodiment in which the metal member is made of copper and the film thickness of the oxide film OM is measured by the SERA method, the predetermined film thickness α of the oxide film OM is set within the first predetermined range Ar1 of 35 nm to 360 nm. However, not limited to this aspect, the predetermined film thickness α of the oxide film OM is either between 35 nm and 135 nm which is the second predetermined range Ar2 or between 165 nm and 360 nm which is the third predetermined range Ar3. May be set to. As a result, the range of the predetermined film thickness α becomes narrower than the range set in the above embodiment and becomes stable, and the average value of the absorptance is improved, so that a more efficient heating result can be obtained.

  Further, in the first to third embodiments, the metal member is the lead frame 62 made of copper. However, the metal member is not limited to copper and may be a metal such as aluminum or iron. However, when aluminum or iron is applied, the absorptance-oxide film thickness characteristics of the laser light used in the oxide film forming parts 120, 220, 320 and the heating part 130 are different for each metal member. In this case, the predetermined film thickness α may be newly set after grasping the absorptance-oxide film thickness characteristics corresponding to each metal member.

  In the first to third embodiments, the oxide film OM is formed on the surface 62a of the lead frame 62 (metal member) by the oxide film forming laser beams L1, L3, L5 in the oxide film forming steps S110, S210, S310. It was formed by irradiating. However, not limited to this aspect, the oxide film OM may be formed in, for example, a heating furnace. As a result, the efficiency of forming the oxide film OM is reduced, but when focusing only on the heating step S120, the same effect as that of the above embodiment can be obtained.

  Further, the heating method by the heating devices 100, 200, 300 of the first to third embodiments can be applied when cutting and marking members such as copper, iron, and aluminum. Further, in the 3D printer, the above heating method and joining method can be applied when laminating metal members such as copper, iron and aluminum.

  Further, in the second embodiment, the cumulative film thickness Σ of the oxide film does not reach the range of the predetermined film thickness α in S215 of the flowchart 2 of FIG. 11 for explaining the heating method in the embodiment, and the oxide film forming laser is used. When returning (moving) to the light irradiation step S211, the number of irradiation pulses suitable for forming an insufficient film thickness is not merely applied with the same number of pulses as the previous pulse of the oxide film forming laser light L1. The laser light L3 for forming an oxide film may be changed and irradiated.

  Moreover, although the said joining apparatus 400 and the joining method demonstrated that the heating apparatus 100 of 1st embodiment was applied, it is not restricted to this aspect. The heating device 200 or the heating device 300 of the second to third embodiments may be applied to the bonding device 400 and the bonding method.

  50a ... Second bonding surface, 62b ... First bonding surface, 62c ... Hole, 100, 200, 300 ... Heating device, 120, 220, 320 ... Oxide film forming part, 130. ..Heating section, 140, 240, 340, 440 ... Control section, 141a, 241a ... Laser light control section, 141b, 241b ... Laser output adjusting section, 142, 442 ... Temperature measuring section, 143, 443 ... Irradiation time measurement unit, 144, 244 ... Film thickness calculation unit, 145, 245 ... Film thickness determination unit, 330 ... Power meter, 346 ... Reflected laser light output measurement unit 347 ... Actual absorption rate calculation unit, 348 ... Estimated absorption rate calculation unit, 349 ... Absorption rate difference calculation unit, 350 ... Absorption rate difference determination unit, 351 ... Oxide film forming laser Light irradiation condition changed Part, 400 ... Joining device, 430 ... Pressing part, 444 ... Bonding strength calculation part, 445 ... Bonding strength determination part, a ... First maximum value, A ... First Maximum film thickness, aa ... first minimum value, AA ... first minimum film thickness, Abe ... estimated absorption rate, Abr ... actual absorption rate, Ar1 ... first range, Ar2 ... -Second range, Ar3 ... Third range, OM ... Oxide film, L1, L3, L5 ... Oxide film forming laser beam, L2, L4, L6 ... Heating laser beam, L7, L8, L9 ... Laser light for measuring actual absorptance, L7A ... Reflected laser light, S110, S210, S310 ... Oxide film forming step, S111 ... Oxide film forming laser light irradiation step, S112, S123A ... Temperature measurement step, S113, S124A ... Time measurement step, S114 ... Film thickness calculation step, S115 ... Film thickness determination step, S120, S120A ... Heating step, S121 ... Switching step, S122 ... Heating laser light irradiation step, S123 ... Surface temperature determination step, S125A ... Bonding strength calculation step, S126A ... Bonding strength determination step, S311 ... Estimated absorption rate calculation step, S312 ... Actual absorption rate measurement laser beam irradiation step, S313 ... Reflected laser light output measurement step, S314 ... Actual absorption rate calculation step, S315 ... Absorption rate difference calculation step, S316 ... Absorption rate difference determination step, S317 ... Oxide film forming laser Light irradiation condition changing process.

Claims (16)

A heating method for heating a metal member by irradiating a heating laser beam,
The heating method is
An oxide film forming step of forming an oxide film having a predetermined thickness on the surface of the metal member;
Irradiating the heating laser light to the metal member through the oxide film, the irradiated heating laser light is absorbed by the metal member at an absorption rate according to the predetermined film thickness of the oxide film, A heating step of heating the metal member to a predetermined temperature,
Equipped with
The absorptivity has a periodicity in which a maximum value and a minimum value alternately appear with respect to a change in the film thickness in the relation to the film thickness of the oxide film, and the film thickness of the oxide film. Has the smallest property when is zero,
The predetermined film thickness of the oxide film formed above the zero in the oxide film forming step is
In the relationship with the absorptivity having the periodicity, the film thickness of the oxide film exceeds the zero, the first maximum film thickness corresponding to the first maximum value at which the absorptivity first appears as the maximum value, and After the first maximum value, the absorption rate includes a second maximum film thickness corresponding to the second maximum value that appears as the maximum value, and the absorption is next to the second maximum value and the second maximum value. Between the third local maximum film thickness corresponding to the third local maximum value that appears as the local maximum value, the absorption rate from the second local minimum film thickness corresponding to the second local minimum value that appears as the local minimum value. A heating method for a metal member, which is set in a small first range. The predetermined thickness of the oxide film is
Including the first local maximum film thickness, and between the first local maximum value and the second local maximum value, the absorption rate is smaller than the first local minimum film thickness corresponding to the first local minimum value appearing as the local minimum value. The second range, or the third range including the second maximum film thickness and larger than the first minimum film thickness and smaller than the second minimum film thickness, is set to any one of the ranges. Method of heating metal member. The metal member is copper,
When the thickness of the oxide film is measured by a continuous electrochemical reduction method,
The method for heating a metal member according to claim 1, wherein the predetermined film thickness of the oxide film is set within the first range of 35 nm to 360 nm. The metal member is copper,
When the thickness of the oxide film is measured by a continuous electrochemical reduction method,
Wherein the predetermined thickness of the oxide film during the 35nm~135nm is within the second range, or is set to any one between the 165nm~360nm is within the third range, according to claim 2 Method for heating metal member of. In the oxide film forming step,
The said oxide film is formed of the metal member of any one of Claims 1-4 formed by irradiation of the laser beam for oxide film formation with which the said surface of the said metal member is irradiated based on predetermined irradiation conditions. Heating method. In the oxide film forming step,
The method for heating a metal member according to claim 5, wherein the surface of the metal member is irradiated with the laser beam for forming an oxide film to form a hole at an irradiation position.   The method for heating a metal member according to claim 5, wherein the oxide film forming laser light and the heating laser light are the same kind of laser light.   The heating method for a metal member according to claim 5, wherein the oxide film forming laser light and the heating laser light are both continuous waves. The laser light for forming the oxide film is a pulse wave,
The method for heating a metal member according to claim 5, wherein the heating laser light is a continuous wave. In the oxide film forming step,
A temperature measurement step of measuring the surface temperature of the surface when the oxide film forming laser light is applied to the surface of the metal member;
An irradiation time measuring step of measuring the irradiation time of the oxide film forming laser light on the surface,
A film thickness calculating step of calculating the film thickness of the oxide film formed on the surface of the metal member as an estimated film thickness based on the measured surface temperature and the irradiation time;
The estimated film thickness of the oxide film calculated in the film thickness calculation step, a film thickness determination step of determining whether or not to reach the predetermined film thickness,
The heating step,
When the film thickness determination step determines that the estimated film thickness has reached the predetermined film thickness, the switching step of switching the irradiation of the oxide film forming laser light to the irradiation of the heating laser light,
The heating laser light irradiation step of irradiating the surface of the metal member with the heating laser light through the oxide film to heat the metal member to the predetermined temperature. The heating method according to any one of items. In the oxide film forming step,
A temperature measurement step of measuring the surface temperature of the surface when the oxide film forming laser light is applied to the surface of the metal member;
An irradiation time measuring step of measuring the irradiation time of the oxide film forming laser light on the surface,
A film thickness calculating step of calculating the film thickness of the oxide film formed on the surface of the metal member as an estimated film thickness based on the measured surface temperature and the irradiation time;
A film thickness determination step of determining whether or not the estimated film thickness of the oxide film calculated in the film thickness calculation step has reached the predetermined film thickness,
Actual absorptivity measurement by irradiating the surface of the metal member with a laser beam for an actual absorptance measurement through the oxide film determined to have the estimated film thickness reached the predetermined film thickness by the film thickness determination step. Laser light irradiation step for
A reflected laser light output measuring step of measuring the output of the reflected laser light that is reflected by the surface is the actual absorptivity measurement laser light irradiated in the actual absorptance measurement laser light irradiation step,
The actual absorption rate of the heating laser light on the surface of the metal member on which the oxide film is formed is calculated based on the output power of the reflected laser light measured in the reflected laser light output measuring step. Absorption rate calculation process,
The predetermined irradiation condition of the oxide film forming laser light is changed based on the estimated film thickness, the actual absorption rate, and the relationship between the film thickness and the absorption rate of the oxide film having the periodicity. A laser light irradiation condition changing step for forming an oxide film,
The heating method according to any one of claims 5 to 9, further comprising: In the oxide film forming step,
Corresponding to the estimated film thickness of the oxide film determined to have reached the predetermined film thickness in the film thickness determination step based on the relationship between the film thickness of the oxide film having the periodicity and the absorption rate. An estimated absorption rate calculation step of calculating an estimated absorption rate of the heating laser light
The laser beam irradiation condition changing step for forming the oxide film,
Based on the estimated absorption rate calculated in the estimated absorption rate calculation step and the actual absorption rate corresponding to the oxide film formed at the time when the estimated absorption rate is calculated, the oxide film forming laser beam The heating method according to claim 11, wherein the irradiation condition is changed. In the oxide film forming step,
Absorption rate for calculating the absorption rate difference between the estimated absorption rate calculated in the estimated absorption rate calculation step and the actual absorption rate corresponding to the oxide film formed at the time when the estimated absorption rate is calculated. Difference calculation process,
An absorption rate difference determination step of determining whether or not the calculated absorption rate difference is within a predetermined range,
The laser beam irradiation condition changing step for forming the oxide film,
In the absorptivity difference determination step, when it is determined that the absorptivity difference is not within the predetermined range, the predetermined irradiation of the oxide film forming laser beam is performed according to the magnitude of the absorptivity difference. The heating method according to claim 12, wherein the conditions are changed so that the absorption rate difference falls within the predetermined range. A method for joining a first joining surface of the metal member facing the surface of the metal member and a second joining surface of a joined metal member that is in contact with the first joining surface,
The metal member is heated to the predetermined temperature by the heating method according to claim 1, and the first bonding surface and the second bonding surface are formed at a temperature lower than a liquid phase state. Then, a joining method in which the solid state is set so that the joining can be performed in a solid state, and the first joining surface and the second joining surface are pressed together in the crimping direction to join. A heating device for heating a metal member by irradiating a heating laser beam,
The heating device is
An oxide film forming portion for forming an oxide film having a predetermined film thickness on the surface of the metal member,
The metal laser member is made to absorb the heating laser light irradiated to the metal member through the oxide film having the predetermined film thickness by the metal member at an absorption rate according to the predetermined film thickness of the oxide film. A heating unit that heats up to a predetermined temperature,
Equipped with
The absorptivity has a periodicity in which a maximum value and a minimum value alternately appear with respect to a change in the film thickness in the relation to the film thickness of the oxide film, and the film thickness of the oxide film. Has the smallest property when is zero,
The predetermined film thickness of the oxide film formed above the zero in the oxide film forming portion is
In the relationship with the absorptivity having the periodicity, the film thickness of the oxide film exceeds the zero, the first maximum film thickness corresponding to the first maximum value at which the absorptivity first appears as the maximum value, and After the first maximum value, the absorption rate includes a second maximum film thickness corresponding to the second maximum value that appears as the maximum value, and the absorption is next to the second maximum value and the second maximum value. Between the third local maximum film thickness corresponding to the third local maximum value that appears as the local maximum value, the absorption rate from the second local minimum film thickness corresponding to the second local minimum value that appears as the local minimum value. A heating device for a metal member, which is set in a smaller first range. In the oxide film forming part of the heating device,
The oxide film is formed by irradiation of an oxide film forming laser beam with which the surface of the metal member is irradiated under predetermined irradiation conditions,
The oxide film forming portion,
A temperature measuring unit that measures the surface temperature of the surface when the oxide film forming laser light is applied to the surface of the metal member,
An irradiation time measurement unit that measures the irradiation time of the surface of the oxide film forming laser beam,
A film thickness calculation unit that calculates a film thickness of the oxide film formed on the surface of the metal member as an estimated film thickness based on the measured surface temperature and the irradiation time;
A laser beam irradiation unit for actual absorption rate measurement, which irradiates the actual absorption rate measurement laser beam through the oxide film on the surface of the metal member on which the oxide film is formed,
A reflected laser light output measuring unit that measures the output of the reflected laser light that is reflected by the surface of the actual absorptivity measurement laser light emitted by the actual absorptance measurement laser light irradiation unit,
The actual absorption rate of the heating laser light on the surface of the metal member on which the oxide film is formed is calculated based on the output level of the reflected laser light measured by the reflected laser light output measurement unit. Absorption rate calculation unit,
Oxidation for changing the predetermined irradiation condition of the oxide film forming laser beam based on the relationship between the estimated film thickness, the actual absorption rate, and the film thickness of the oxide film having the periodicity and the absorption rate. The heating device according to claim 15, further comprising a film forming laser light irradiation condition changing unit.

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