Patent Description:
Currently, a power semiconductor module generally uses water cooling to ensure a temperature, but the power semiconductor module needs to have better sealing performance to use water cooling. At present, in some power semiconductor modules, a power device is first connected to a heat sink, and then the power device is packaged. It is difficult to ensure sealing performance of the power semiconductor module, and it is difficult to detect that the power device is properly sealed before use. In some other power semiconductor modules, a heat dissipation medium is filled between a power device and a heat sink, so that the power device is detachably connected to the heat sink. In this case, the power device may be first packaged in plastic. However, a relative position between the power device and the heat sink is not fixed. As a result, heat conduction efficiency of the heat dissipation medium is low, and a gap is likely to appear, thereby reducing heat dissipation efficiency by multiple times.

<CIT> provides a method for manufacturing a cooler for power devices.

This application provides a method for producing a power semiconductor module to seal the power semiconductor module and improve heat dissipation performance of the power semiconductor module.

A first aspect of embodiments of this application provides a method for producing a power semiconductor module in accordance with appended claim <NUM>.

According to the method for producing a power semiconductor module, the power semiconductor module is produced through plastic packaging and then soldering, so that the power semiconductor module has better integrity. When the power device is packaged in plastic, position interference of the first heat sink can be avoided, so that the power semiconductor module has higher waterproof performance. When the first heat sink of the power semiconductor module takes away heat through liquid cooling, a coolant does not easily penetrate into the power semiconductor component of the power semiconductor module, and the power semiconductor component is protected, so that the power semiconductor component can stably work in a water cooling condition. In addition, sealing performance may be detected in advance, to improve reliability.

In the following specific embodiments, this application is further described with reference to the accompanying drawings.

The following describes implementations of this application by using specific embodiments. A person skilled in the art may easily learn of other advantages and effects of this application based on content disclosed in this specification. Although this application is described with reference to an example embodiment, it does not mean that a characteristic of this application is limited only to this implementation. On the contrary, a purpose of describing this application with reference to an implementation is to cover another option or modification that may be derived based on claims of this application. To provide an in-depth understanding of this application, the following descriptions include a plurality of specific details. This application may be alternatively implemented without using these details. In addition, to avoid confusion or blurring the focus of this application, some specific details will be omitted from the description. It should be noted that, when there is no conflict, embodiments in this application and the features in embodiments may be mutually combined.

The following terms "first", "second", and the like are merely used for description, and shall not be understood as an indication or implication of relative importance or implicit indication of a quantity of indicated technical features. Therefore, a feature limited by "first" or "second" may explicitly or implicitly include one or more of the features. In the descriptions of this application, unless otherwise stated, "a plurality of" means two or more than two. Orientation terms such as "up", "down", "left", and "right" are defined relative to an orientation of schematic placement of components in the accompanying drawings. It should be understood that these directional terms are relative concepts and are used for relative description and clarification. These directional terms may vary accordingly depending on an orientation in which the components are placed in the accompanying drawings.

In this application, unless otherwise explicitly specified and limited, a term "connection" should be understood in a broad sense. For example, the "connection" may be a fastened connection, a detachable connection, or an integrated connection; and may be a direct connection or an indirect connection by using an intermediate medium. The term "and/or" used in this specification includes any and all combinations of one or more related listed items.

When the following embodiments are described in detail with reference to schematic diagrams, for ease of description, a diagram indicating a partial structure of a component is partially enlarged not based on a general scale. In addition, the schematic diagrams are merely examples, and should not limit the protection scope of this application herein.

To make the objectives, technical solutions, and advantages of this application clearer, the following further describes implementations of this application in detail with reference to the accompanying drawings.

<FIG> is an exploded view of a power semiconductor module according to an embodiment of this application. <FIG> is a sectional view of a power semiconductor module according to an embodiment of this application.

As shown in <FIG>, the power semiconductor module is a single-faced heat dissipation power semiconductor module that dissipates heat by using a first heat sink <NUM>. The power semiconductor module includes a power semiconductor component and the first heat sink <NUM>. A face that is of the power semiconductor component and that is close to the first heat sink <NUM> forms a first heat dissipation face (a reference numeral is added to a feature in the claims). The power semiconductor component and the first heat sink <NUM> are connected by using a first material <NUM>. Heat generated by the power semiconductor component is transferred to the first heat sink <NUM> by using the first material <NUM>, and then dissipated by using the first heat sink <NUM>.

As shown in <FIG>, the power semiconductor component includes a power device <NUM> and a first substrate <NUM>. A face that is of the power device <NUM> and that faces the first heat sink <NUM> is connected to the first substrate <NUM> by using a second material <NUM>. The first substrate <NUM> enables relative positions of parts of the power device <NUM> to be fixed. The first substrate <NUM> enables the power device <NUM> to have a larger heat dissipation area, thereby improving heat dissipation efficiency of the power device <NUM>. Optionally, a direct bonding copper (Direct Bonding Copper, DBC) ceramic substrate is used as the first substrate <NUM>. The DBC has a high thermal conductivity, and can quickly take the heat generated by the power device <NUM> away from the power device <NUM>.

The power semiconductor component further includes a conductor strip <NUM>. The power device <NUM> includes a first member <NUM> and a second member <NUM>. The first member <NUM> and the second member <NUM> are connected to the conductor strip <NUM> by using a third material <NUM>. The conductor strip <NUM> is disposed on a face that is of the power device <NUM> and that is away from the first substrate <NUM>, to avoid position interference between the conductor strip <NUM> and the first substrate <NUM>. The first member <NUM> and the second member <NUM> are electrically connected by using the conductor strip <NUM>, so that the first member <NUM> and the second member <NUM> may be centrally powered, and a combination of the first member <NUM> and the second member <NUM> can work together to implement some functions. Optionally, the first member <NUM> may be an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor), and the second member <NUM> may be a diode. The diode may protect the IGBT when a voltage or a current in the power device <NUM> suddenly changes.

The first member <NUM> is further electrically connected to a signal pin <NUM>. The signal pin <NUM> is configured to connect to an external device to implement signal transfer with the power semiconductor component.

A first terminal <NUM> and a second terminal <NUM> are respectively connected to two ends of the power semiconductor component. Specifically, the first terminal <NUM> is connected to the first member <NUM>, and the second terminal <NUM> is connected to the second member <NUM>. The first terminal <NUM> and the second terminal <NUM> may implement on/off of the current by using a power semiconductor.

<FIG> is a flowchart of a method for producing a power semiconductor module according to an embodiment of this application. The method is used to produce the single-faced heat dissipation power semiconductor module.

As shown in <FIG>, the method for producing a power semiconductor module includes the following steps.

S110: Package the power device <NUM> in plastic to form the power semiconductor component, and form a first heat dissipation face on a surface of the power semiconductor component. The plastically packaged power semiconductor component implements that the power semiconductor can have better waterproof performance. Heat of the power semiconductor component is taken away from the power semiconductor component by using the first heat dissipation face. After the power semiconductor component is formed through plastic packaging, the power semiconductor component is trimmed, and a surplus material that overflows during plastic packaging is removed.

S120: Place the first heat sink <NUM> on the first heat dissipation face. The first heat sink <NUM> is configured to receive heat of the first heat dissipation face, and dissipate the heat away from the power semiconductor component.

S130: Place the first material <NUM> between the first heat sink <NUM> and the first heat dissipation face. The first material <NUM> is placed between the first heat sink <NUM> and the first heat dissipation face and is configured to connect the first heat sink <NUM> and the power semiconductor component. In addition, the first material <NUM> may further have a heat transfer function, thereby improving heat transfer efficiency of the power semiconductor component and the first heat sink <NUM>. Optionally, the first material <NUM> placed between the first heat sink <NUM> and the first heat dissipation face may be a solder pad or solder paste.

S <NUM>: Heat the first material <NUM>. The first material <NUM> is heated, so that the first material <NUM> is changed into a fluid state or is softened to generate a large intermolecular force, and the first material <NUM> can adhere to the power semiconductor component and the first heat sink <NUM>.

S170: Cool the first material <NUM> on the first heat dissipation face to connect the power semiconductor component and the first heat sink <NUM>. After the first material <NUM> is cooled, the first material <NUM> is changed from the fluid state back to a solid state or is hardened from a softened state, so that the first material <NUM> firmly connects the power semiconductor component and the first heat sink <NUM>.

It may be understood that the S120 may be performed before the S130. For example, the first heat sink <NUM> and the power semiconductor component are first placed close to each other, so that there is a gap between the first heat dissipation face and the first heat sink <NUM>, and then the gap is filled with the sheet-like first material <NUM>. Alternatively, a sequence of the S120 and the S130 may be exchanged. The first material <NUM> is first placed on the first heat dissipation face or on the surface of the first heat sink <NUM>, and then the first heat sink <NUM> is placed close to the first heat dissipation face, so that the first heat dissipation face and the first heat sink <NUM> clamp the first material <NUM>.

Before the S120, the first heat sink <NUM> and/or the power semiconductor component may further be plated, which includes the following steps.

S210: Plate the first heat sink <NUM>. A corrosion-resistant metal is plated on the surface of the first heat sink <NUM>, so that corrosion resistance performance of the first heat sink <NUM> can be improved, and service life of the first heat sink <NUM> is prolonged. A plating layer may completely cover the first heat sink <NUM>, or may cover only a face that is of the first heat sink <NUM> and that faces the power semiconductor component. An oxidized layer is removed after plating, so that heat dissipation efficiency of the first heat sink <NUM> can be maintained.

S220: Plate the power semiconductor component. A corrosion-resistant metal is plated on the surface of the power semiconductor component, so that corrosion resistance performance of the power semiconductor component may be improved, and service life of the power semiconductor component is prolonged.

The metal that is plated on the first heat sink <NUM> and/or the power semiconductor component may be a silver simple substance, a nickel simple substance, a tin simple substance, or a gold simple substance, or may be a composite metal formed by the foregoing metals.

In the step S130, the first material <NUM> needs to be sufficient. To make the first material <NUM> sufficient, an elevation member is disposed on a face that is of the first heat sink <NUM> and that is close to the power semiconductor component.

Optionally, when the elevation member is disposed on the first heat dissipation face, the elevation member includes a metal material that is disposed on the first heat dissipation face, and the metal material protrudes from the first heat dissipation face. Alternatively, the elevation member includes a bump that is disposed on the first heat dissipation face. Alternatively, the elevation member includes a groove that is disposed on the first heat dissipation face.

Optionally, when the elevation member is disposed on the first heat sink <NUM>, the elevation member includes a metal material that is disposed on the surface of the first heat sink <NUM>, and the metal material protrudes from the first heat dissipation face. Alternatively, the elevation member includes a bump that is disposed on the surface of the first heat sink <NUM>. Alternatively, the elevation member includes a groove that is disposed on the surface of the first heat sink <NUM>.

In the step S110, a connection between parts in the power semiconductor component is implemented by using the method for producing a power semiconductor component. The method for producing a power semiconductor component includes the following steps.

S111: Solder the first substrate <NUM> to a face of the power device <NUM> by using the second material <NUM>, and form the first heat dissipation face on a face that is of the first substrate <NUM> and that is away from the power device <NUM>. A melting point of the second material <NUM> is equal to or higher than a melting point of the first material <NUM>. When the first material <NUM> is heated in step S104, the second material <NUM> may remain in a solid state, to maintain stability of the power semiconductor component.

S112: Solder, by using the third material <NUM>, the conductor strip <NUM> to the face that is of the power device <NUM> and that is away from the first substrate <NUM>. The power device <NUM> includes the first member <NUM> and the second member <NUM>. The conductor strip <NUM> connects the first member <NUM> and the second member <NUM>. A melting point of the third material <NUM> is equal to or higher than the melting point of the first material <NUM>. When the first material <NUM> is heated in step S104, the third material <NUM> may remain in a solid state, to maintain stability of the power semiconductor component.

Before the step S110, the method further includes:
S101: Bend the first substrate <NUM> to form a first arc-shaped segment. The first arc-shaped segment is located in a middle part of the first substrate <NUM>.

When the first substrate <NUM> and the power device <NUM> are soldered, the first arc-shaped segment can reduce warpage formed by soldering the first substrate <NUM>, so that the first substrate <NUM> and the power device <NUM> are relatively flat after being soldered.

It may be understood that the first arc-shaped segment may not be formed in a bending manner. For example, when the first substrate <NUM> is formed, heat treatment may be performed to enable the first substrate <NUM> to have an internal stress for forming the first arc-shaped segment.

Before the step S120, the method further includes:
S103: Dispose a second arc-shaped segment on the first heat sink <NUM>. The second arc-shaped segment is at a position that is of the first heat sink <NUM> and that corresponds to the power device <NUM>.

When the step S130 and step S140 are completed, the second arc-shaped segment may reduce a warpage stress of the first heat sink <NUM>, so that the first heat sink <NUM> and the power semiconductor component are relatively flat after being fastened.

When the single-faced heat dissipation power semiconductor module is produced, a relatively complete method for producing a power semiconductor module includes the following steps.

S101: Bend the first substrate <NUM> to form a first arc-shaped segment. The first arc-shaped segment is located in a middle part of the first substrate <NUM>.

S103: Dispose a second arc-shaped segment on the first heat sink <NUM>. The second arc-shaped segment is at a position that is of the first heat sink <NUM> and that corresponds to the power device <NUM>.

S111: Solder the first substrate <NUM> to a face of the power device <NUM> by using the second material <NUM>, and form the first heat dissipation face on a face that is of the first substrate <NUM> and that is away from the power device <NUM>.

S112: Solder, by using the third material <NUM>, the conductor strip <NUM> to the face that is of the power device <NUM> and that is away from the first substrate <NUM>. The power device <NUM> includes the first member <NUM> and the second member <NUM>. The conductor strip <NUM> connects the first member <NUM> and the second member <NUM>.

S110: Package the power device <NUM> in plastic to form the power semiconductor component, and form the first heat dissipation face on the surface of the power semiconductor component. After the power semiconductor component is formed through plastic packaging, the power semiconductor component is trimmed, and a surplus material that overflows during plastic packaging is removed.

S220: Plate the power semiconductor component.

S120: Place the first heat sink <NUM> on the first heat dissipation face.

S130: Place the first material <NUM> between the first heat sink <NUM> and the first heat dissipation face.

S170: Cool the first material <NUM> on the first heat dissipation face to connect the power semiconductor component and the first heat sink <NUM>.

In the foregoing method for producing a power semiconductor module used to produce the single-faced heat dissipation power semiconductor module, the first material <NUM> may be heated by using different processes in the step S160.

Optionally, in the step S160, the first material <NUM> is heated through ultrasonic brazing. A method for heating the first material <NUM> through ultrasonic brazing includes:.

In the step S161a, a material of the ultrasonic tool head may be an aluminum alloy, a titanium alloy, or an alloy steel. All the aluminum alloy, the titanium alloy, and the alloy steel can apply an ultrasonic wave of sufficient amplitude to the power semiconductor or the first heat sink <NUM>, so that a temperature of a soldered end face of the first material <NUM> reaches <NUM>.

In the step S161a, the ultrasonic tool head may be a letter head, a two-claw tool head, or a four-claw tool head. For installation cases of different first materials <NUM> or different IGBTs, a plurality of tool heads may be used to simultaneously emit ultrasonic waves to the power semiconductor or the first heat sink <NUM>.

In the step S161a, the ultrasonic tool head may generate an ultrasonic wave on the first heat dissipation face, a face that is of the first heat sink <NUM> and that is away from the power semiconductor component, a face that is of the first heat sink <NUM> and that faces the power semiconductor component, or a side face of the first heat sink <NUM>. The ultrasonic wave can be kept away from the parts in the power semiconductor component, so that an internal temperature of the power semiconductor component is relatively low, to protect the power semiconductor.

When the first material <NUM> is heated through ultrasonic brazing, before the step S130, the method may further include the following steps:.

The first material <NUM> is ultrasonically pre-coated on the first heat dissipation face and/or the first heat sink <NUM>, so that strength of a connection between the power semiconductor component and the first heat sink <NUM> can be improved, and heat transfer efficiency between the power semiconductor component and the first heat sink <NUM> can also be improved.

In the step S160, when the first material <NUM> is heated through ultrasonic brazing, a first material combination may be used. In the first material combination, the first material <NUM> may be a multi-element alloy solder paste, the second material <NUM> may be sintered silver, and the third material <NUM> may be SAC305. In SAC305, a weight percentage of tin is <NUM>%, a weight percentage of silver is <NUM>%, and a weight percentage of copper is <NUM>%. The multi-element alloy solder paste is a solder paste that is formed by adding a supporting metal material to a Sn-Ag-Cu series solder paste.

In the step S160, the first material combination is used. When the first material <NUM> is heated through ultrasonic brazing, a temperature is controlled between <NUM> and <NUM>. In this case, the ultrasonic brazing concentrates heat at the first material <NUM>, so that the first material <NUM> formed by the multi-element alloy solder paste is heated and melted. The second material <NUM> formed by the sintered silver and the third material <NUM> formed by SAC305 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of the sintered silver and a melting point of SAC305 are higher than that of the multi-element alloy solder paste. When a temperature is controlled between <NUM> and <NUM>, the sintered silver and SAC305 in the power semiconductor component are not melted.

In the step S160, when the first material <NUM> is heated through ultrasonic brazing, a second material combination may also be used. In the second material combination, the first material <NUM> may be SnSb5, the second material <NUM> may be sintered silver, and the third material <NUM> may be SnSb5. In SnSb5, a weight percentage of tin is <NUM>% and a weight percentage of antimony is <NUM>%.

In the step S160, the second material combination is used. When the first material <NUM> is heated through ultrasonic brazing, a temperature is controlled between <NUM> and <NUM>. In this case, the ultrasonic brazing concentrates heat at the first material <NUM>, so that the first material <NUM> formed by SnSb5 is heated and melted. The second material <NUM> formed by the sintered silver and the third material <NUM> formed by SnSb5 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of the sintered silver is higher than that of SnSb5. When a temperature is controlled between <NUM> and <NUM>, the sintered silver in the power semiconductor component is not melted. The ultrasonic brazing concentrates the heat at the first material <NUM>, and a temperature of the second material <NUM> in the power semiconductor component is lower than a temperature of the first material <NUM>, so that when the temperature of the first material <NUM> is controlled between <NUM> and <NUM>, the temperature of the second material <NUM> that connects the power device <NUM> and the conductor strip <NUM> has not reached the melting point of SnSb5, and the second material <NUM> is not melted.

In the step S160, when the first material <NUM> is heated through ultrasonic brazing, a third material combination may also be used. In the third material combination, the first material <NUM> may be a multi-element alloy solder paste or SAC305, the second material <NUM> may be sintered silver, and the third material <NUM> may be SnSb5.

In the step S160, the third material combination is used. When the first material <NUM> is heated through ultrasonic brazing, a temperature is controlled between <NUM> and <NUM>. In this case, the ultrasonic brazing concentrates heat at the first material <NUM>, so that the first material <NUM> formed by the multi-element alloy solder paste or SAC305 is heated and melted. The second material <NUM> formed by the sintered silver and the third material <NUM> formed by SnSb5 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of the sintered silver is higher than that of SnSb5. When a temperature is controlled between <NUM> and <NUM>, the sintered silver in the power semiconductor component is not melted. The ultrasonic brazing concentrates the heat at the first material <NUM>, and a temperature of the second material <NUM> in the power semiconductor component is lower than a temperature of the first material <NUM>, so that when the temperature of the first material <NUM> is controlled between <NUM> and <NUM>, the temperature of the second material <NUM> that connects the power device <NUM> and the conductor strip <NUM> has not reached the melting point of SnSb5, and the second material <NUM> is not melted.

Optionally, in the step S160, the first material <NUM> is heated through vacuum reflow soldering. The vacuum reflow soldering can also concentrate heat in an area in which the first material <NUM> is located, so that a temperature gradient is formed between the power semiconductor and the heat sink, and an internal temperature of the power semiconductor is reduced when the first material <NUM> is melted. Vacuum may reduce a bubble inside the first material <NUM> after the first material <NUM> is melted, so that after the first material <NUM> is cooled, strength of a connection between the power semiconductor component and the first heat sink <NUM> that are connected through soldering is higher.

In the step S160, when the first material <NUM> is heated through vacuum reflow soldering, a fourth material combination may be used. In the fourth material combination, the first material <NUM> may be a multi-element alloy solder paste or SAC305, the second material <NUM> may be sintered silver, and the third material <NUM> may be SnSb5.

In the step S160, the fourth material combination is used. When the first material <NUM> is heated through vacuum reflow soldering, a temperature is controlled between <NUM> and <NUM>. In this case, the vacuum reflow soldering concentrates heat at the first material <NUM>, so that the first material <NUM> formed by the multi-element alloy solder paste or SAC305 is heated and melted. The second material <NUM> formed by the sintered silver and the third material <NUM> formed by SnSb5 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of the sintered silver is higher than that of SnSb5. When a temperature is controlled between <NUM> and <NUM>, the sintered silver in the power semiconductor component is not melted. A temperature of the second material <NUM> in the power semiconductor component is lower than a temperature of the first material <NUM>, so that when the temperature of the first material <NUM> is controlled between <NUM> and <NUM>, the temperature of the second material <NUM> that connects the power device <NUM> and the conductor strip <NUM> has not reached the melting point of SnSb5, and the second material <NUM> is not melted.

In the step S160, when the first material <NUM> is heated through vacuum reflow soldering, a fifth material combination may be used. In the fifth material combination, the first material <NUM> may be any one of SnSb5, a multi-element alloy solder paste, and SAC305, the second material <NUM> may be sintered silver, and the third material <NUM> may be a high-lead solder paste.

In the step S160, the fifth material combination is used. When the first material <NUM> is heated through vacuum reflow soldering, a temperature is controlled between <NUM> and <NUM>. In this case, the vacuum reflow soldering concentrates heat at the first material <NUM>, so that any one of SnSb5, the multi-element alloy solder paste, and SAC305 may be heated and melted at this temperature. The second material <NUM> formed by the sintered silver and the third material <NUM> formed by the high-lead solder paste remain in a solid state, to maintain stability of the power semiconductor component.

Optionally, in the step S160, the first material <NUM> is heated through sintering. During sintering, the first material <NUM> experiences a small external force, and is in a relatively static state. A diffusion region of the first material <NUM> after being melted is easy to control.

In the step S160, when the first material <NUM> is heated through sintering, a sixth material combination may be used. In the sixth material combination, the first material <NUM> may be nano silver, the second material <NUM> may be sintered silver, and the third material <NUM> may be a high-lead solder paste.

In the step S160, the sixth material combination is used. When the first material <NUM> is heated through sintering, a temperature is controlled between <NUM> and <NUM>, the nano silver may be softened at this temperature to form a relatively large intermolecular force. The second material <NUM> formed by the sintered silver and the third material <NUM> formed by the high-lead solder paste remain in a solid state, to maintain stability of the power semiconductor component.

It may be understood that when the first material <NUM> is heated through sintering, the first material <NUM> may also be micron silver or copper particles. When the first material <NUM> is heated and softened, the second material <NUM> and the third material <NUM> remain in a solid state.

<FIG> is an exploded view of a power semiconductor module according to another embodiment of this application. <FIG> is a sectional view of a power semiconductor module according to another embodiment of this application.

As shown in <FIG>, the power semiconductor module is a double-faced heat dissipation power semiconductor module that dissipates heat by using a first heat sink <NUM> and a second heat sink <NUM>. The power semiconductor module includes a power semiconductor component, the first heat sink <NUM>, and the second heat sink <NUM>. A face that is of the power semiconductor component and that is close to the first heat sink <NUM> forms a first heat dissipation face. The power semiconductor component and the first heat sink <NUM> are connected by using a first material <NUM>. A face that is of the power semiconductor component and that is close to the second heat sink <NUM> forms a second heat dissipation face. The power semiconductor component and the second heat sink <NUM> are connected by using a first material <NUM>. In other words, the first heat dissipation face and the second heat dissipation face are made of a same material, so that both the first heat sink <NUM> and the second heat sink <NUM> may be connected to a power semiconductor. Heat generated by the thermal power semiconductor component is transferred to the first heat sink <NUM> by using the first material <NUM> on the first heat dissipation face, and then is dissipated by using the first heat sink <NUM>. In addition, heat generated by the thermal power semiconductor component is further transferred to the second heat sink <NUM> by using the first material <NUM> on the second heat dissipation face, and then is dissipated by using the second heat sink <NUM>.

As shown in <FIG>, the power semiconductor component includes a power device <NUM>, a first substrate <NUM>, a second substrate <NUM>, and a conductive pad <NUM>. A face that is of the power device <NUM> and that faces the first heat sink <NUM> is connected to the first substrate <NUM> by using a second material <NUM>. The first substrate <NUM> enables relative positions of parts of the power device <NUM> to be fixed. The first substrate <NUM> enables the power device <NUM> to have a larger heat dissipation area, thereby improving heat dissipation efficiency of the power device <NUM>. Optionally, DBC is used as the first substrate <NUM>. The DBC has a high thermal conductivity, and can quickly take the heat generated by the power device <NUM> away from the power device <NUM>.

The power device <NUM> includes a first member <NUM> and a second member <NUM>. The first member <NUM> and the second member <NUM> are connected to a conductive pad <NUM> by using a third material <NUM>. The conductive pad <NUM> is disposed on a face that is of the power device <NUM> and that is away from the first substrate <NUM>. The first member <NUM> and the second member <NUM> are electrically connected by using the conductive pad <NUM>, so that the first member <NUM> and the second member <NUM> may be centrally powered, and a combination of the first member <NUM> and the second member <NUM> can work together to implement some functions. Optionally, the first member <NUM> may be an IGBT, and the second member <NUM> may be a diode. The diode may protect the IGBT when a voltage or a current in the power device <NUM> suddenly changes.

The second substrate <NUM> is soldered to a face that is of the conductive pad <NUM> and that is away from the power device <NUM> by using a fifth material <NUM>. The second substrate <NUM> can receive heat emitted from the conductive pad <NUM>, so that the power device <NUM> has a larger heat dissipation area, thereby improving heat dissipation efficiency of the power device <NUM>. Optionally, DBC is used as the second substrate <NUM>. The DBC has a high thermal conductivity, and can quickly take the heat generated by the power device <NUM> away from the power device <NUM>.

A first terminal <NUM> and a second terminal <NUM> are respectively connected to two ends of the power semiconductor component. Specifically, the first terminal <NUM> is connected to the first member <NUM>, and the second terminal <NUM> is connected to the second member <NUM>. The first terminal <NUM> and the second terminal <NUM> may implement on/off of the current by using the power semiconductor.

<FIG> is a flowchart of a method for producing a power semiconductor module according to another embodiment of this application. The method is used to produce the double-faced heat dissipation power semiconductor module.

S130: Place the first material <NUM> between the first heat sink <NUM> and the first heat dissipation face. The first material <NUM> is disposed between the first heat sink <NUM> and the first heat dissipation face and is configured to connect the first heat sink <NUM> and the power semiconductor component. In addition, the first material <NUM> may further have a heat transfer function, thereby improving heat transfer efficiency of the power semiconductor component and the first heat sink <NUM>. Optionally, the first material <NUM> disposed between the first heat sink <NUM> and the first heat dissipation face may be a solder pad or solder paste.

S140: Dispose the second heat sink <NUM> on the second heat dissipation face. The second heat sink <NUM> is configured to receive heat of the second heat dissipation face, and dissipate the heat away from the power semiconductor component.

S150: Place the first material <NUM> between the second heat sink <NUM> and the second heat dissipation face. The first material <NUM> is disposed between the second heat sink <NUM> and the second heat dissipation face and is configured to connect the second heat sink <NUM> and the power semiconductor component. In addition, the first material <NUM> may further have a heat transfer function, thereby improving heat transfer efficiency of the power semiconductor component and the second heat sink <NUM>. Optionally, the first material <NUM> disposed between the second heat sink <NUM> and the second heat dissipation face may be a solder pad or solder paste.

S <NUM>: Heat the first material <NUM>. The first material <NUM> is heated, so that the first material <NUM> is changed into a fluid state, so that a gap between the first heat sink <NUM> and the first heat dissipation face is filled with the first material <NUM> on the first heat dissipation face, and a gap between the second heat sink <NUM> and the second heat dissipation face is filled with the first material <NUM> on the second heat dissipation face.

S170: Cool the first materials <NUM> on the first heat dissipation face and the second heat dissipation face to connect the power semiconductor component, the first heat sink <NUM>, and the second heat sink <NUM>. After the first material <NUM> is cooled, the power semiconductor component and the first heat sink <NUM> are fastened by using the first material <NUM> on the first heat dissipation face, and the power semiconductor component and the second heat sink <NUM> are fastened by using the first material <NUM> on the second heat dissipation face.

It may be understood that the S140 may be performed before the S150. For example, the second heat sink <NUM> and the power semiconductor component are first placed close to each other, so that there is a gap between the second heat dissipation face and the second heat sink <NUM>, and then the gap is filled with the sheet-like first material <NUM>. Alternatively, a sequence of the S140 and the S150 may be exchanged. The first material <NUM> is first placed on the second heat dissipation face or on a surface of the second heat sink <NUM>, and then the second heat sink <NUM> is placed close to the second heat dissipation face, so that the second heat dissipation face and the second heat sink <NUM> clamp the first material <NUM>.

Before the S120, the heat sink and/or the power semiconductor component may further be plated, which includes the following steps.

S210: Plate the first heat sink <NUM> and the second heat sink <NUM>. Corrosion-resistant metals are plated on the surface of the first heat sink <NUM> and the surface of the second heat sink <NUM>, so that corrosion resistance performance of the first heat sink <NUM> and the second heat sink <NUM> can be improved, and service life of the first heat sink <NUM> and the second heat sink <NUM> is prolonged. A plating layer may completely cover each of the first heat sink <NUM> and the second heat sink <NUM>, or may cover only a face that is of the first heat sink <NUM> or the second heat sink <NUM> and that faces the power semiconductor component. An oxidized layer is removed after plating, so that heat dissipation efficiency of the first heat sink <NUM> and the second heat sink <NUM> can be maintained.

It may be understood that only one or both of the first heat sink <NUM>, the second heat sink <NUM>, and the power semiconductor may be plated, to improve corrosion resistance of a plated part.

In the step S150, the first material <NUM> needs to be sufficient. To make the first material <NUM> sufficient, an elevation member is disposed on a face that is of the second heat sink <NUM> and that is close to the power semiconductor component.

Optionally, when the elevation member is disposed on the second heat dissipation face, the elevation member includes a metal material that is disposed on the second heat dissipation face, and the metal material protrudes from the second heat dissipation face. Alternatively, the elevation member includes a bump that is disposed on the second heat dissipation face. Alternatively, the elevation member includes a groove that is disposed on the second heat dissipation face.

Optionally, when the elevation member is disposed on the second heat sink <NUM>, the elevation member includes a metal material that is disposed on the surface of the second heat sink <NUM>, and the metal material protrudes from the second heat dissipation face. Alternatively, the elevation member includes a bump that is disposed on the surface of the second heat sink <NUM>. Alternatively, the elevation member includes a groove that is disposed on the surface of the second heat sink <NUM>.

S <NUM>: Solder, by using a fourth material <NUM>, the conductive pad <NUM> to a face that is of the power device <NUM> and that is away from the first substrate <NUM>. The power device <NUM> includes the first member <NUM> and the second member <NUM>. The conductive pad <NUM> connects the first member <NUM> and the second member <NUM>. A melting point of the fourth material <NUM> is equal to or higher than the melting point of the first material <NUM>. When the first material <NUM> is heated in step S104, the fourth material <NUM> may remain in a solid state, to maintain stability of the power semiconductor component.

S113: Solder the second substrate <NUM> to a face that is of the conductive pad <NUM> and that is away from the power device <NUM> by using a fifth material <NUM>. A melting point of the fifth material <NUM> is equal to or higher than the melting point of the first material <NUM>. When the first material <NUM> is heated in step S104, the fifth material <NUM> may remain in a solid state, to maintain stability of the power semiconductor component.

S102: Bend the second substrate <NUM> to form a third arc-shaped segment. The third arc-shaped segment is located in a middle part of the second substrate <NUM>.

When the second substrate <NUM> and the conductive pad <NUM> are soldered, the third arc-shaped segment can reduce warpage formed by soldering the second substrate <NUM>, so that the second substrate <NUM> and the conductive pad <NUM> are relatively flat after being soldered.

It may be understood that the first arc-shaped segment and the third arc-shaped segment may not be formed in a bending manner. For example, when the first substrate <NUM> or the second substrate <NUM> is formed, heat treatment may be performed to enable the first substrate <NUM> or the second substrate <NUM> to have an internal stress for forming the arc-shaped segment.

When the step S130 and the step S140 are completed, the second arc-shaped segment may reduce a warpage stress of the first heat sink <NUM>, so that the first heat sink <NUM> and the power semiconductor component are relatively flat after being fastened.

S104: Dispose a fourth arc-shaped segment on the second heat sink <NUM>. The fourth arc-shaped segment is at a position that is of the second heat sink <NUM> and that corresponds to the power device <NUM>.

When the step S130 and the step S140 are completed, the fourth arc-shaped segment may reduce a warpage stress of the second heat sink <NUM>, so that the second heat sink <NUM> and the power semiconductor component are relatively flat after being fastened.

When the double-faced heat dissipation power semiconductor module is produced, a relatively complete method for producing a power semiconductor module includes the following steps.

S112: Solder, by using a fourth material <NUM>, the conductive pad <NUM> to a face that is of the power device <NUM> and that is away from the first substrate <NUM>. The power device <NUM> includes the first member <NUM> and the second member <NUM>. The conductive pad <NUM> connects the first member <NUM> and the second member <NUM>.

S113: Solder the second substrate <NUM> to a face that is of the conductive pad <NUM> and that is away from the power device <NUM> by using a fifth material <NUM>.

S210: Plate the first heat sink <NUM> and the second heat sink <NUM>.

S140: Dispose the second heat sink <NUM> on the second heat dissipation face.

S150: Place the first material <NUM> between the second heat sink <NUM> and the second heat dissipation face.

S170: Cool the first material <NUM> on the first heat dissipation face to connect the power semiconductor component and the first heat sink <NUM>. Cool the first material <NUM> on the second heat dissipation face to connect the power semiconductor component and the second heat sink <NUM>.

In the step S160, when the first material <NUM> is heated through ultrasonic brazing, a seventh material combination may be used. In the seventh material combination, the first material <NUM> may be a multi-element alloy solder paste or SAC305, the second material <NUM> may be SnSb5, the fourth material <NUM> may be SAC305, and the fifth material <NUM> may be SAC305.

In the step S160, the seventh material combination is used. When the seventh material is heated through ultrasonic brazing, a temperature is controlled between <NUM> and <NUM>. In this case, the ultrasonic brazing concentrates heat at the first material <NUM>, so that the first material <NUM> formed by the multi-element alloy solder paste or SAC305 is heated and melted. The second material <NUM> formed by SnSb5 and the fourth material <NUM> and the fifth material <NUM> that are formed by SAC305 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of SnSb5 is higher than those of the multi-element alloy solder paste and SAC305. When a temperature is controlled between <NUM> and <NUM>, SnSb5 in the power semiconductor component is not melted. The ultrasonic brazing concentrates the heat at the first material <NUM>, and temperatures of the fourth material <NUM> and the fifth material <NUM> of the power semiconductor component are lower than a temperature of the first material <NUM>, so that when the temperature of the first material <NUM> is controlled between <NUM> and <NUM>, a temperature of the fourth material <NUM> that connects the power device <NUM> and the conductive pad <NUM> and a temperature of the fifth material <NUM> that connects the conductive pad <NUM> and the second substrate <NUM> have not reached the melting point of SAC305, and the fourth material <NUM> and the fifth material <NUM> are not melted.

In the step S160, when the first material <NUM> is heated through ultrasonic brazing, an eighth material combination may also be used. In the eighth material combination, the first material <NUM> may be any one of SnSb5, a multi-element alloy solder paste, and SAC305, the second material <NUM> may be PbSnAg, the fourth material <NUM> may be SnSb5, and the fifth material <NUM> may be SnSb5. In PbSnAg, a weight percentage of lead is <NUM>%, a weight percentage of tin is <NUM>%, and a weight percentage of silver is <NUM>%.

In the step S160, the eighth material combination is used. When the first material <NUM> is heated through ultrasonic brazing, a temperature is controlled between <NUM> and <NUM>. In this case, the ultrasonic brazing concentrates heat at the first material <NUM>, so that the first material <NUM> formed by SnSb5, the multi-element alloy solder paste, or SAC305 is heated and melted. The second material <NUM> formed by PbSnAg and the fourth material <NUM> and the fifth material <NUM> that are formed by SnSb5 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of PbSnAg is higher than that of any one of SnSb5, the multi-element alloy solder paste, and SAC305. When the temperature is controlled between <NUM> and <NUM>, PbSnAg in the power semiconductor component is not melted. The ultrasonic brazing concentrates the heat at the first material <NUM>, and temperatures of the fourth material <NUM> and the fifth material <NUM> of the power semiconductor component are lower than a temperature of the first material <NUM>, so that when the temperature of the first material <NUM> is controlled between <NUM> and <NUM>, a temperature of the fourth material <NUM> that connects the power device <NUM> and the conductive pad <NUM> and a temperature of the fifth material <NUM> that connects the conductive pad <NUM> and the second substrate <NUM> have not reached the melting point of SnSb5, and the fourth material <NUM> and the fifth material <NUM> are not melted.

In the step S160, when the first material <NUM> is heated through vacuum reflow soldering, a ninth material combination may be used. In the ninth material combination, the first material <NUM> may be a multi-element alloy solder paste or SAC305, the second material <NUM> may be PbSnAg, the fourth material <NUM> may be SnSb5, and the fifth material <NUM> may be SnSb5.

In the step S160, the ninth material combination is used. When the first material <NUM> is heated through vacuum reflow soldering, a temperature is controlled between <NUM> and <NUM>. In this case, the vacuum reflow soldering concentrates heat at the first material <NUM>, so that the first material <NUM> formed by the multi-element alloy solder paste or SAC305 is heated and melted. The second material <NUM> formed by PbSnAg and the fourth material <NUM> and the fifth material <NUM> that are formed by SnSb5 remain in a solid state, to maintain stability of the power semiconductor component. A melting point of PbSnAg is higher than those of the multi-element alloy solder paste and SAC305. When the temperature is controlled between <NUM> and <NUM>, PbSnAg in the power semiconductor component is not melted. The vacuum reflow soldering concentrates the heat at the first material <NUM>, and temperatures of the fourth material <NUM> and the fifth material <NUM> of the power semiconductor component are lower than a temperature of the first material <NUM>, so that when the temperature of the first material <NUM> is controlled between <NUM> and <NUM>, a temperature of the fourth material <NUM> that connects the power device <NUM> and the conductive pad <NUM> and a temperature of the fifth material <NUM> that connects the conductive pad <NUM> and the second substrate <NUM> have not reached the melting point of SnSb5, and the fourth material <NUM> and the fifth material <NUM> are not melted.

In the step S160, when the first material <NUM> is heated through vacuum reflow soldering, a tenth material combination may be used. In the tenth material combination, the first material <NUM> may be any one of SnSb5, a multi-element alloy solder paste, and SAC305, the second material <NUM> may be PbSnAg, the fourth material <NUM> may be PbSnAg, and the fifth material <NUM> may be PbSnAg.

In the step S160, the tenth material combination is used. When the first material <NUM> is heated through vacuum reflow soldering, a temperature is controlled between <NUM> and <NUM>. In this case, the vacuum reflow soldering concentrates heat at the first material <NUM>, so that the first material <NUM> formed by any one of SnSb5, the multi-element alloy solder paste, and SAC305 is heated and melted. The second material <NUM>, the fourth material <NUM>, and the fifth material <NUM> that are formed by PbSnAg remain in a solid state, to maintain stability of the power semiconductor component. A melting point of PbSnAg is higher than that of any one of SnSb5, the multi-element alloy solder paste, and SAC305. When the temperature is controlled between <NUM> and <NUM>, PbSnAg in the power semiconductor component is not melted.

In the step S160, when the first material <NUM> is heated through sintering, an eleventh material combination may be used. In the eleventh material combination, the first material <NUM> may be nano silver, the second material <NUM> may be PbSnAg, the fourth material <NUM> may be PbSnAg, and the fifth material <NUM> may be PbSnAg.

In the step S160, the eleventh material combination is used. When the first material <NUM> is heated through sintering, a temperature is controlled between <NUM> and <NUM>. In this case, the temperature of the first material <NUM> is increased through sintering, and the first material <NUM> formed by the nano silver is heated and softened to form a relatively large intermolecular force. The second material <NUM>, the fourth material <NUM>, and the fifth material <NUM> that are formed by PbSnAg remain in a solid state, to maintain stability of the power semiconductor component.

It may be understood that when the first material <NUM> is heated through sintering, the first material <NUM> may also be micron silver or copper particles. When the first material <NUM> is heated and softened, the second material <NUM>, the fourth material <NUM>, and the fifth material <NUM> remain in a solid state.

Claim 1:
A method for producing a power semiconductor module, comprising:
packaging (S110) a power device (<NUM>) in plastic to form a power semiconductor component, and forming a first heat dissipation face on a surface of the power semiconductor component;
heating (S160) a first material (<NUM>) between a first heat sink (<NUM>) and the first heat dissipation face; and
cooling (S170) the first material on the first heat dissipation face to connect the power semiconductor component and the first heat sink, wherein before the step of heating the first material between the first heat sink and the first heat dissipation face, the method further comprises:
plating a metal plating layer outside the first heat sink, wherein the metal plating layer comprises any one or more of Ag, Ni, Sn, and Au;
plating a metal plating layer on the surface of the power semiconductor component, wherein the metal plating layer comprises any one or more of Ag, Ni, Sn, and Au.