JP2014120717A - Electronic device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement a structure in which heat conduction is secured, damages of a ceramic plate is prevented, and a metal plate and the ceramic plate are properly joined in an electronic device having a half mold structure.SOLUTION: The electronic device includes: a heater element 20 joined to one surface 11 side of a metal plate 10; an insulation ceramic plate 30 which is provided at the other surface 12 side of the metal plate 10 and is joined with one surface 31 facing the other surface 12 of the metal plate 10; and a mold resin 40 which seals the heater element 20 and the one surface 11 side of the metal plate 10. The other surface 32 of the ceramic plate 30 is exposed from the mold resin 40. The metal plate 10 and the ceramic plate 30 are joined to each other through solder 80 for ceramic plates. The solder 80 directly contacts with both of the other surface 12 of the metal plate 10 and the one surface 31 of the ceramic plate 30 and is ultrasonically joined to them.

Description

  In the present invention, a heating element is mounted on one surface side of a metal plate, the one surface side is sealed with a mold resin, and a ceramic plate is provided on the other surface side of the metal plate. The present invention relates to an electronic device that dissipates heat and a method for manufacturing such an electronic device.

  Conventionally, as this type of electronic device, a metal plate such as a heat sink, a heating element joined to one side of the metal plate, and the other side of the metal plate are provided, with one side facing the other side of the heat sink. An electrically insulating ceramic plate joined in a heated state, and a mold resin that seals one side of the heating element and the metal plate, and radiates heat from the other side of the ceramic plate to the outside of the mold resin. The thing is proposed (refer patent document 1). In Patent Document 1, another metal plate is bonded to the other surface of the ceramic plate with a brazing material, and the other metal plate is exposed from the mold resin, and the other surface is exposed from the other surface of the ceramic plate. External heat dissipation is performed through a metal plate.

  In such an electronic device, the heat of the heating element is radiated from the metal plate to the outside through the ceramic plate, and the ceramic plate has a function of ensuring electrical insulation from the outside. Here, conventionally, the other surface of the metal plate and one surface of the ceramic plate are joined via a brazing material or a resin material containing a heat conductive filler.

JP 2008-41752 A

  However, when the brazing material is used in joining the metal plate and the ceramic plate, the joining temperature is as high as, for example, 600 ° C. or higher, and there is a concern about the occurrence of residual stress in the ceramic plate, damage such as cracking or warping. .

  In addition, in joining with a brazing material, a metallized layer may be provided on one surface of the ceramic plate, and there is a concern that the extra metallized layer may increase the thermal resistance or cause damage such as warpage of the ceramic plate. The

  In particular, in the case of a structure in which the other surface of the metal plate and one surface of the ceramic plate are joined and the other surface of the ceramic plate is directly exposed from the mold resin to dissipate heat, both surfaces of the ceramic plate as described in Patent Document 1 above. The ceramic plate is more likely to warp than when a metal plate is bonded to the plate.

  Moreover, when using the said resin material, since the said resin material contains a heat conductive filler, since it consists of resin with low heat conductivity from the first, the heat conductivity fall by the said resin material Is inevitable.

  The present invention has been made in view of the above problems, and in an electronic device in which heat is radiated through a ceramic plate provided on the other side of a metal plate, ensuring thermal conductivity and damaging the ceramic plate. It aims at realizing the structure by which the metal plate and the ceramic plate were joined appropriately, achieving both prevention.

  In order to achieve the above object, according to the first aspect of the present invention, the metal plate (10) in which the one surface (11) and the other surface (12) are in a front-back relationship and the one surface side of the metal plate are joined. The heat generating element (20) and the ceramic plate (30) made of an electrically insulating ceramic which is provided on the other surface side of the metal plate and joined with the one surface (31) facing the other surface of the metal plate. And a mold resin (40) for sealing one side of the heat generating element and the metal plate, and radiates heat from the other surface (32) of the ceramic plate to the outside of the mold resin. The plate is soldered via a solder (80), and the solder is characterized by being in direct contact with and bonded to both the other surface of the metal plate and one surface of the ceramic plate.

  According to this, the solder is excellent in thermal conductivity as compared with the thermally conductive resin material, and can be joined at a low temperature as compared with the brazing material. In addition, since the solder is directly contacted and bonded to both the metal plate and the ceramic plate, solder bonding between the metal plate and the ceramic plate can be performed without interposing an extra layer such as a metallized layer on one surface of the ceramic plate. Can be formed.

  Therefore, according to the present invention, it is possible to realize a configuration in which the metal plate and the ceramic plate are appropriately joined while ensuring both thermal conductivity and preventing damage to the ceramic plate.

  The invention according to claim 2 is characterized in that, in the electronic device according to claim 1, the ceramic plate and the solder are ultrasonically bonded at the interface between one surface of the ceramic plate and the solder. . According to this, one surface of the ceramic plate and the solder can be firmly bonded while being in direct contact.

  Further, as in the invention according to claim 3, in the electronic device according to claim 2, it is assumed that the metal plate and the solder are ultrasonically bonded also at the interface between the other surface of the metal plate and the solder. Also good. Then, even when the solder wettability on the surface of the metal plate is low, the other surface of the metal plate and the solder can be firmly bonded while in direct contact.

  Here, as in the invention described in claim 4, if the solder contains zinc, it is easy to achieve strong solder bonding in each of the means of claims 1 to 3.

  According to a fifth aspect of the present invention, in the electronic device according to any one of the first to fourth aspects, the plane size of the ceramic plate is slightly smaller than the plane size of the metal plate, and the end portion of the ceramic plate is The entirety is located inside the end portion of the metal plate, and the side surface (33) located at the end portion of the ceramic plate is sealed with mold resin.

  According to this, since the compressive stress of the mold resin is applied to the side surface of the ceramic plate, peeling of the mold resin on the side surface of the ceramic plate can be easily suppressed.

  The invention according to claim 6 is an electronic device manufacturing method for manufacturing the electronic device according to claim 1, wherein an element bonding step of bonding a heat generating element to one surface side of the metal plate, A pre-soldering process in which solder is pre-soldered by applying ultrasonic waves to at least one surface of the ceramic plate among the other surface and one surface of the ceramic plate; and the other surface of the metal plate via the pre-soldered solder A solder reflow step of laminating one surface of the ceramic plate and reflowing the solder by heating to perform solder joining; and then a resin sealing step of sealing one side of the heating element and the metal plate with a mold resin; It is characterized by providing.

  According to this, in the electronic device of claim 1, as in the case of claim 2, it is possible to manufacture a device in which the ceramic plate and the solder are ultrasonically bonded at the interface between the one surface of the ceramic plate and the solder.

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a schematic cross-sectional view of an electronic device according to a first embodiment of the present invention. FIG. 5 is a process diagram showing an element bonding process of the method for manufacturing an electronic device according to the first embodiment. It is process drawing which shows the pre solder process with respect to the ceramic board in the said manufacturing method. It is process drawing which shows the pre solder process with respect to the metal plate in the said manufacturing method. It is process drawing which shows the workpiece | work after the solder reflow in the said manufacturing method. It is process drawing which shows the wire bonding process in the said manufacturing method. It is process drawing which shows the resin sealing process in the said manufacturing method. It is a schematic sectional drawing which shows the assembly | attachment structure to the radiation fin of the electronic device shown by FIG. It is a schematic sectional drawing of the electronic device concerning 2nd Embodiment of this invention. It is a schematic sectional drawing of the electronic device concerning 3rd Embodiment of this invention. It is a schematic sectional drawing of the electronic device concerning 4th Embodiment of this invention. It is a schematic sectional drawing of the electronic device concerning other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
An electronic apparatus according to a first embodiment of the present invention will be described with reference to FIG. This electronic device is mounted on a vehicle such as an automobile, and is applied as a device for driving various electronic devices for the vehicle.

  The electronic device of the present embodiment is roughly composed of a metal plate-like metal plate 10, a heating element 20 joined to the one surface 11 side of the metal plate 10, and a ceramic provided on the other surface 12 side of the metal plate 10. The plate 30 and a mold resin 40 that seals the heat generating element 20 and the one surface 11 side of the metal plate 10 are provided, and the other surface 32 of the ceramic plate 30 is exposed from the mold resin 40.

  The metal plate 10 has a plate shape in which one surface 11 and the other surface 12 are in a front-back relationship, and typically has a rectangular plate shape. The metal plate 10 has conductivity and heat dissipation, and functions as an electrode and a heat dissipation member of the heating element 20. Specifically, the metal plate 10 is made of pure Cu (copper), a Cu alloy, or the like.

  The metal plate 10 may be one having pure Cu or Cu alloy as a base material and Ni plating, Au plating or the like provided on the surface thereof. Here, the metal plate 10 is configured as a heat sink having excellent heat dissipation, but may be configured as an island of a lead frame that is thinner than the heat sink.

  The heating element 20 has a surface 21 and a surface 22 made of silicon semiconductor or the like, and is configured as a plate-like semiconductor chip here. Specifically, the heating element 20 is made of a power element such as an IGBT (insulated gate bipolar transistor) or a power MOS, and has a rectangular plate shape.

  The other surface 22 of the heat generating element 20 and the one surface 11 of the metal plate 10 are joined together via a device solder 50. The element solder 50 is made of a general Pb-free solder material such as Sn—Cu—Ni—P, and is joined by reflow. The heating element 20 and the metal plate 10 are joined via the element solder 50 so as to be electrically, mechanically, and thermally conductive.

  As shown in FIG. 1, lead terminals 60 made of a conductive material such as copper are provided inside the mold resin 40. The inner lead portion of the lead terminal 60 and the one surface 21 of the heating element 20 are connected by a bonding wire 70 and are electrically connected.

  The wire 70 is formed by wire bonding such as gold, aluminum, or copper. The heat generating element 20 and the outside are electrically connected via the outer lead portion of the lead terminal 60.

The ceramic plate 30 is a plate made of an electrically insulating ceramic such as Al ₂ O ₃ (alumina), Si ₃ N ₄ (silicon nitride), AlN (aluminum nitride), and is a solid ceramic plate material with no plating on the surface. is there. Here, the ceramic plate 30 has a rectangular plate shape that is slightly smaller than the metal plate 10.

  The metal plate 10 and the ceramic plate 30 are soldered via a ceramic plate solder 80 with the one surface 31 of the ceramic plate 30 and the other surface 12 of the metal plate 10 facing each other. Here, the ceramic plate solder 80 is joined in direct contact with both the other surface 12 of the metal plate 10 and the one surface 31 of the ceramic plate 30.

  The ceramic plate solder 80 is made of a solder material containing Zn (zinc). The melting point of the ceramic plate solder 80 is preferably equal to or higher than the molding temperature of the mold resin 40 (for example, 175 ° C.) and the melting point of the element solder 50 (for example, 230 ° C. or lower). Specifically, in this embodiment, Sn—Zn—Sb—Al solder having a melting point of 217 ° C. is used as the ceramic plate solder 80.

  In this embodiment, the ceramic plate 30 and the solder 80 are ultrasonically bonded at the interface between the one surface 31 of the ceramic plate 30 and the ceramic plate solder 80. Furthermore, in the present embodiment, the metal plate 10 and the solder 80 are ultrasonically bonded also at the interface between the other surface 12 of the metal plate 10 and the ceramic plate solder 80.

  The mold resin 40 is made of a thermosetting resin such as an epoxy resin, and is molded by a transfer molding method. The mold resin 40 is sealed so as to wrap the heating element 20, the metal plate 10, and the ceramic plate 30, but the outer surface, ie, the other surface 32 of the ceramic plate 30 is exposed from the mold resin 40. Thereby, in this embodiment, heat is radiated from the other surface 32 of the ceramic plate 30 to the outside of the mold resin 40.

  Here, as shown in FIG. 1, the entire side surface 33 located at the end of the ceramic plate 30 is sealed with the mold resin 40, and the surface of the mold resin 40 and the other surface 32 of the ceramic plate 30. Are in the same plane.

  The other surface 32 of the ceramic plate 30 is configured as a heat radiating surface that is exposed to the outside and radiates heat, and the other surface 32 of the ceramic plate 30 is connected to an external housing, a cooler, or the like. It has become. Here, since the ceramic plate 30 is electrically insulating, electrical insulation from the outside is guaranteed.

  Next, a manufacturing method for manufacturing the electronic device will be described with reference to FIGS. 2A to 2C and FIGS. 3A to 3C. In FIGS. 2A and 3A-3C, the work in each process is shown in cross section, and FIGS. 2B and 2C show the work in perspective.

  First, as shown in FIG. 2A, the heating element 20 is bonded to the one surface 11 side of the metal plate 10 (element bonding step). Specifically, in this step, the heating element 20 is mounted on the one surface 11 of the metal plate 10 via the element solder 50, and the element solder 50 is reflowed in this state, whereby the heating element 20 is soldered.

  Next, the pre-solder process shown in FIGS. 2B and 2C is performed. In this pre-soldering process, the solder material containing zinc is used as the ceramic plate solder 80. Then, ultrasonic waves are applied to both the surfaces 12 and 31 of the other surface 12 of the metal plate 10 and the one surface 31 of the ceramic plate 30 to pre-solder the solder 80 for ceramic plate.

  In this ultrasonic soldering method, as shown in FIG. 2B, a solder K1 heated to a melting point of the solder 80 or higher is used, and a solder 80 for a solder plate or a foil is applied to one surface 31 of the ceramic plate 30. This is supplied and spread with a soldering iron K1 that vibrates ultrasonically.

  As a result, the solder 80 spreads over the entire solder joint region of the one surface 31 of the ceramic plate 30 with good wettability, and the solder 80 is ultrasonically bonded at the interface between the ceramic plate 30 and the solder 80. Become.

  On the other hand, as shown in FIG. 2C, the same ultrasonic soldering method is applied to the other surface 12 of the metal plate 10, and the ceramic plate solder 80 is spread with a soldering iron K <b> 1 that ultrasonically vibrates. Accordingly, the solder 80 spreads over the entire solder joint region of the other surface 12 of the metal plate 10 with good wettability, and the solder 80 is ultrasonically bonded at the interface between the metal plate 10 and the solder 80. It becomes.

  Next, a solder reflow process is performed. In this process, the other surface 12 of the pre-soldered metal plate 10 and the one surface 31 of the ceramic plate 30 are opposed to each other, and the other surface 12 of the metal plate 10 is interposed via the pre-soldered ceramic plate solder 80. A surface 31 of the ceramic plate 30 is laminated. Then, the solder 80 is reflowed by heating by a method such as reduced pressure hydrogen reflow to perform solder joining.

  Thereby, as shown in FIG. 3A, the solder joint between the other surface 12 of the metal plate 10 and the one surface 31 of the ceramic plate 30 is completed. Here, after the completion of the joining, the interface between the one surface 31 of the ceramic plate 30 and the solder 80 and the interface between the other surface 12 of the metal plate 10 and the solder 80 are joined by ultrasonic joining. The portion near the center in the thickness direction is a joining form by normal reflow and solidification.

  In this solder reflow step, in addition to the pre-soldered ceramic plate solder 80, in addition to the pre-soldered ceramic plate solder 80, a foil-shaped ceramic plate solder 80 is further added. Reflow may be performed by sandwiching between the metal plate 10 and the ceramic plate 30. Of course, if the amount of solder is sufficiently secured, this foil-shaped solder for ceramic plate 80 is unnecessary.

  After this solder bonding, as shown in FIG. 3B, wire bonding is performed between the heating element 20 and the lead terminal 60 to form a bonding wire 70 (wire bonding step). Note that this wire bonding step may be performed before the solder reflow step as long as it is after the element bonding step.

  Thereafter, as shown in FIG. 3C, the one surface 12 side of the heating element 20 and the metal plate 10 is sealed with the mold resin 40 so that the other surface 31 of the ceramic plate 30 is exposed (resin sealing step).

  Specifically, in this resin sealing step, the other surface 31 of the ceramic plate 30 is brought into close contact with the inner surface of a resin molding die (not shown) so that the resin does not adhere, and the mold resin 40 is molded in this state, The heating element 20, the metal plate 10, the ceramic plate 30, the wire 70, the lead terminal 60, and the like are sealed. Thus, the electronic device shown in FIG. 1 is completed.

  For example, as shown in FIG. 4, the electronic device is used by being assembled to an external heat radiation fin K <b> 2. In this case, the other surface 32 of the ceramic plate 30 which is the heat radiating surface of the electronic device is in contact with the heat radiating fin K2 via the heat radiating gel K3, but the heat radiating surface is the electrically insulating ceramic plate 30. K3 may be conductive. The heat dissipating gel K3 may be heat dissipating grease or the like.

  By the way, according to the present embodiment, the ceramic plate solder 80 is superior in thermal conductivity to a conventional heat conductive resin material and can be joined at a lower temperature than the brazing material. Further, since the solder 80 is in direct contact with and joined to both the metal plate 10 and the ceramic plate 30, the metal plate 10 and the metal plate 10 can be connected to one surface 31 of the ceramic plate 30 without interposing an extra layer such as a metallized layer. A solder joint with the ceramic plate 30 can be formed.

  As described above, according to the present embodiment, the metal plate 10 and the ceramic plate 30 are made compatible with ensuring thermal conductivity between the metal plate 10 and the ceramic plate 30 and preventing damage to the ceramic plate 30. A properly joined configuration is achieved.

  In this embodiment, the ceramic plate 30 and the solder 80 are ultrasonically bonded at the interface between the one surface 31 of the ceramic plate 30 and the ceramic plate solder 80. Usually, the ceramic plate 30 is often low in solder wettability, but by ultrasonic bonding, even if the wettability is poor, the one surface 31 of the ceramic plate 30 and the solder 80 are firmly bonded while in direct contact. Can be made.

  Furthermore, in this embodiment, since the metal plate 10 and the solder 80 are ultrasonically bonded also at the interface between the other surface 12 of the metal plate 10 and the ceramic plate solder 80, the solder wetting on the surface of the metal plate 10 is performed. Even if the property is low, it is advantageous in that the other surface 12 of the metal plate 10 and the solder 80 are firmly bonded while being in direct contact.

  As described above, in this embodiment, the ceramic plate solder 80 is made of a solder material containing zinc, thereby realizing strong ultrasonic bonding as described above at a low temperature. The zinc-containing solder 80 has a melting point lower than that of the element solder 50 (for example, about 230 ° C.) and higher than a molding temperature of the mold resin 40 (for example, about 175 ° C.).

  Therefore, the element solder 50 is not melted during the solder reflow process, and the ceramic plate solder 80 is not melted during the resin sealing process. Is possible.

  In the present electronic device, as shown in FIG. 1, the plane size of the ceramic plate 30 is slightly smaller than the plane size of the metal plate 10, and the entire end portion of the ceramic plate 30 is the end portion of the metal plate 10. Recessed located inside. The mold resin 40 seals up to the side surface 33 located at the end of the ceramic plate 30.

  Here, in the present embodiment, the end of the ceramic plate 30 may protrude beyond the end of the metal plate 10, but the above retracted configuration is more desirable. By adopting such a configuration, the following advantages arise.

  If the end portion of the ceramic plate 30 protrudes from the end portion of the metal plate 10, a tensile stress is applied to the end portion of the ceramic plate 30 by the mold resin 40, and the mold resin 40 is peeled off at the side surface 33 of the ceramic plate 30. It tends to occur.

  In contrast, as in the present embodiment, if the entire end portion of the ceramic plate 30 is located inside the end portion of the metal plate 10 and is retracted, the end portion of the ceramic plate 30 is compressed by the molding resin 40. Therefore, peeling of the mold resin 40 is easily suppressed on the side surface 33 of the ceramic plate 30. Therefore, according to the present embodiment, it is possible to easily suppress peeling of the mold resin 40 on the side surface 33 of the ceramic plate 30.

(Second Embodiment)
An electronic apparatus according to a second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that the metal plate 10 and the ceramic plate 30 are assembled on the one surface 21 side of the heating element 20 as well as the other surface 22 side. Let's focus on the differences.

  As shown in FIG. 5, in the present embodiment, a metal spacer 90 made of Cu or the like is mounted on the one surface 21 of the heating element 20, the metal plate 10 is mounted thereon, and the ceramic plate 30 is mounted thereon. Is installed.

  Here, between the one surface 21 of the heating element 20 and the spacer 90 and between the spacer 90 and the one surface 11 of the metal plate 10 are joined via the element solder 50, and with the other surface 12 of the metal plate 10. The ceramic plate 30 is joined to one surface 31 via a ceramic plate solder 80. The other surface 32 of the ceramic plate 30 is exposed from the mold resin 40 on the one surface 21 side of the heating element 20 as well as the other surface 22 side.

  The spacer 90 has a plate shape (for example, a rectangular plate shape) slightly smaller than the heating element 20 and is made of a material selected from the same metal material as that of the metal plate 10. The spacer 90 plays a role of ensuring a height between the one surface 21 which is a wire bonding surface of the heat generating element 20 and the metal plate 10. Thus, the height of the bonding wire 70 can be maintained when performing wire bonding between the heating element 20 and the lead terminal 60.

  Such an electronic device of this embodiment is manufactured as follows, for example. In the element bonding step in the manufacturing method of the first embodiment, the workpiece shown in FIG. 2A is manufactured, and further a wire bonding step is performed. Thereafter, the spacer 90 and the metal plate 10 are joined to the one surface 21 side of the heating element 20 via the element solder 50.

  Subsequently, a pre-solder process is performed on the other surface 12 of the metal plate 10 on both sides 21 and 22 of the heating element 20 by the same ultrasonic soldering method as described above. On the other hand, pre-soldering is similarly performed on one surface 31 of the ceramic plate 30. Then, the ceramic plate 30 is soldered to the metal plates 10 and 10 by the same solder reflow process as described above.

  Thereafter, sealing is performed with the mold resin 40 so that the other surface 32 of the ceramic plate 30 is exposed on the both surfaces 21 and 22 side of the heating element 20, whereby the electronic device of this embodiment shown in FIG. It ’s done. And according to this embodiment, each effect by the solder 80 for ceramic plates similar to the said 1st Embodiment is exhibited in the both surfaces 21 and 22 side of the heat generating element 20. FIG.

(Third embodiment)
An electronic apparatus according to a third embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that a plurality of heating elements 20 having the same potential are mounted and joined on one surface 11 of one metal plate 10.

  In the example shown in FIG. 6, two heating elements 20 are provided for one metal plate 10, but it is needless to say that three or more heating elements 20 may be provided. Also in this embodiment, the same effects as those in the first embodiment are exhibited.

(Fourth embodiment)
An electronic apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that a plurality of metal plates 10 are mounted and joined on one surface 11 of one ceramic plate 30.

  Such a configuration is effective when the heating elements 20 mounted on the metal plates 10 have different potentials. In the example shown in FIG. 7, two metal plates 10 are provided for one ceramic plate 30, but it is needless to say that three or more metal plates 10 may be used. Also in this embodiment, the same effects as those in the first embodiment are exhibited.

  Furthermore, it is good also as a structure which combined this 4th Embodiment and the said 3rd Embodiment. Specifically, in the configuration shown in FIG. 7, a plurality of heating elements 20 may be further mounted on and joined to one surface 11 of each metal plate 10.

  In addition, each of the third embodiment and the fourth embodiment can be combined with the second embodiment. Specifically, in FIGS. 5A and 5B, the configurations of FIGS. 6 and 7 may be employed on the both surfaces 21 and 22 side of the heating element 20.

(Other embodiments)
As shown in FIG. 8, another metal plate 10 a may be further bonded to the other surface 32 of the ceramic plate 30, and the other metal plate 10 a may be exposed from the mold resin 40. . In this case, the other surface 32 of the ceramic plate 30 and the other metal plate 10a are joined by ultrasonic joining using the ceramic plate solder 80 described above.

  In the case of FIG. 8, heat is radiated from the other surface 32 of the ceramic plate 30 to the outside of the mold resin 40 via the other metal plate 10a, and the ceramic plate 30 ensures electrical insulation from the outside. Further, it is needless to say that the configuration of FIG. 8 can be combined with each of the above embodiments.

  In each of the above embodiments, the metal plate 10 is made of Cu or a Cu alloy. However, as the metal plate 10, other metals such as AL (aluminum), Fe (iron), Mo (molybdenum), Or you may use other metal materials, such as these alloys, or these laminated materials.

  In the pre-soldering process in each of the above embodiments, the ceramic plate solder 80 is pre-soldered by applying ultrasonic waves to both the other surface 12 of the metal plate 10 and the one surface 31 of the ceramic plate 30. . However, this pre-solder process may be performed on at least one surface 31 of the ceramic plate 30.

  In other words, since the metal plate 10 is usually better in solder wettability than the ceramic plate 30, the pre-soldering process by the ultrasonic soldering method is performed only on one surface 31 of the ceramic plate 30, It may not be performed on the other surface 12 of the plate 10. Furthermore, the other surface 12 of the metal plate 10 may be pre-soldered only by normal heating without applying ultrasonic waves, depending on the solder wettability of the metal plate surface.

  When the pre-soldering process by the ultrasonic soldering method is performed only on one surface 31 of the ceramic plate 30, finally, with respect to the ceramic plate solder 80 in the electronic device, only the interface with the ceramic plate 30 is ultrasonic bonded. Thus, the interface with the metal plate 10 is in a joining form by normal reflow.

  In other words, the electronic device is not limited to one that is ultrasonically bonded to the solder 80 at both interfaces of the one surface 31 of the ceramic plate 30 and the other surface 12 of the metal plate 10 and the solder 80 for the ceramic plate, It is sufficient that at least one surface 31 of the ceramic plate 30 and the solder 80 are ultrasonically bonded.

  Further, the ceramic plate solder 80 may not be limited to the zinc-containing solder material as long as the above-described bonding form can be appropriately realized. For example, Sn—Ag—Cu or the like may be used. Other solder materials may be used.

  Further, the joining of the heat generating element 20 and the metal plate 10 is not limited to the element solder 50, but may be, for example, a conductive adhesive or the like, and may be fitted, engaged, and fastened. It may be mechanically fixed.

  Further, the heating element 20 and the metal plate 10 may be at least mechanically joined, and not all electrical, mechanical, and thermal joining is satisfied as in the above embodiments. May be.

  Further, the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims. The above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible, and the above embodiments are not limited to the illustrated examples. Absent.

DESCRIPTION OF SYMBOLS 10 Metal plate 11 One side of metal plate 12 Other side of metal plate 20 Heating element 30 Ceramic plate 31 One side of ceramic plate 32 Other side of ceramic plate 40 Mold resin 80 Solder for ceramic plate

Claims (8)

A metal metal plate (10) in which the one surface (11) and the other surface (12) are in a front-back relationship;
A heating element (20) joined to one side of the metal plate;
A ceramic plate (30) made of an electrically insulating ceramic provided on the other surface side of the metal plate and bonded in a state where one surface (31) is opposed to the other surface of the metal plate;
A mold resin (40) for sealing one side of the heat generating element and the metal plate,
Heat is dissipated from the other surface (32) of the ceramic plate to the outside of the mold resin,
The metal plate and the ceramic plate are soldered via solder (80),
The electronic device is characterized in that the solder is in direct contact with and joined to both the other surface of the metal plate and one surface of the ceramic plate.   The electronic device according to claim 1, wherein the ceramic plate and the solder are ultrasonically bonded at an interface between one surface of the ceramic plate and the solder.   The electronic device according to claim 2, wherein the metal plate and the solder are ultrasonically bonded also at an interface between the other surface of the metal plate and the solder.   The electronic device according to claim 1, wherein the solder contains zinc. The plane size of the ceramic plate is slightly smaller than the plane size of the metal plate, and the entire end portion of the ceramic plate is located inside the end portion of the metal plate,
The electronic device according to any one of claims 1 to 4, wherein the side surface (33) located at an end of the ceramic plate is sealed with the molding resin. An electronic device manufacturing method for manufacturing the electronic device according to claim 1,
An element bonding step of bonding the heat generating element to one surface side of the metal plate;
A pre-soldering process for pre-soldering the solder by applying ultrasonic waves to at least one surface of the ceramic plate among the other surface of the metal plate and the one surface of the ceramic plate;
A solder reflow step of laminating the other surface of the metal plate and one surface of the ceramic plate through the pre-soldered solder, and reflowing the solder by heating to perform solder joining;
Thereafter, a resin sealing step of sealing one side of the heat generating element and the metal plate with the mold resin is provided.   The electronic device according to claim 6, wherein in the pre-soldering step, ultrasonic waves are applied to both the other surface of the metal plate and one surface of the ceramic plate to pre-solder the solder. Production method.   The method for manufacturing an electronic device according to claim 6, wherein a solder containing zinc is used as the solder.

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