A method for embedding a thermocouple in a molding power module, and a chip packaging device and system

Abstract

The application relates to the technical field of semiconductors, and discloses a method for embedding a thermocouple in a molding power module, a chip packaging device and a system. The method comprises the following steps: obtaining a preset position of a thermocouple in a lead frame; inserting a top head of a top rod into the lead frame according to the preset position of the thermocouple; performing first plastic packaging on the lead frame by using epoxy plastic packaging material; lifting the top rod in the lead frame after plastic packaging to form a reserved space for the thermocouple; and installing and packaging the thermocouple in the reserved space for the thermocouple. In the application, the top head of the top rod in the shape of the thermocouple leaves a reserved space for installing the thermocouple during the plastic packaging process, and the thermocouple is installed and packaged in the reserved space for the thermocouple. In this way, the positioning of the Molding product during the installation of the thermocouple can be ensured, invalid installation caused by chip cover opening failure can be avoided, and the efficiency of installing the thermocouple is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and for example to a method for embedding thermocouples in a molding power module, as well as a chip packaging apparatus and system. Background Technology

[0002] Chinese invention patent application number 202110070059.8 discloses a silicon carbide power module, device, and aging state identification method to solve the technical problem that existing methods for examining the aging state of silicon carbide power modules cannot reflect the aging state of the silicon carbide power module in real time. The module includes: a copper-clad ceramic substrate, a copper substrate, a solder layer, a MOS chip, and a preset number of thermocouples; the solder layer is composite with the copper-clad ceramic substrate, and a thermocouple is fixed at the center of the copper-clad ceramic substrate; the MOS chip is fixed on the copper-clad ceramic substrate, and a thermocouple is fixed at the bottom of the copper substrate corresponding to the MOS chip. The identification method includes: acquiring the temperature values ​​corresponding to the preset number of thermocouples on the silicon carbide power module in real time to determine a temperature distribution matrix; determining the thermal resistance value corresponding to the silicon carbide power module; and determining the aging state of the silicon carbide power module through the pre-stored relationship between the thermal resistance value and the aging state. The above method can reflect the aging state of the silicon carbide power module in real time.

[0003] Regarding chip junction temperature: For general potted products, the approximate junction temperature can be obtained by pre-embedding a thermocouple on the chip and then potting it with resin, and then measuring the temperature of the thermocouple; or by spraying the product with a black insulating varnish and then monitoring the chip junction temperature with a dedicated infrared thermometer. However, for molding products using epoxy molding compounds, it is difficult to use the first two methods to detect the chip junction temperature.

[0004] To detect junction temperature in molded products, a laser is typically used to open the target chip area after the product is encapsulated, removing the epoxy molding compound before embedding a thermocouple. This process is difficult to perform manually, and the laser opening process can easily damage the chip surface, causing product failure. Furthermore, the opaque epoxy molding compound makes it impossible to accurately locate the target chip, and any misalignment cannot be corrected, also easily leading to product failure.

[0005] Therefore, there is currently a lack of a method to embed thermocouples into Molding power modules to solve the problem of inefficient thermocouple installation in Molding products. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a method for embedding thermocouples in a molding power module, as well as a chip packaging device and system, to solve the problem of inefficiently installing thermocouples in molding products.

[0008] In some embodiments, a method for embedding a thermocouple in a molding power module is provided, applied to a chip packaging device having a chip package body and a push rod. The method includes: obtaining a preset position of the thermocouple in a lead frame; inserting the tip of the push rod into the lead frame according to the preset position of the thermocouple; performing a first molding of the lead frame with epoxy molding compound; raising the push rod in the molded lead frame to form a reserved space for the thermocouple; and installing and encapsulating the thermocouple in the reserved space.

[0009] Preferably, the method is applied to a chip packaging device with a second telescopic mechanism, wherein installing and encapsulating the thermocouple in the reserved space of the thermocouple includes: installing the thermocouple in the reserved space of the thermocouple; the second telescopic mechanism extends to support the thermocouple, allowing the thermocouple to fully fit with the lead frame;

[0010] A second molding process is performed using epoxy molding compound; the second telescopic mechanism lifts up, creating a gap after the second molding.

[0011] Preferably, installing and encapsulating the thermocouple in the reserved space of the thermocouple further includes: encapsulating the gap after the second molding.

[0012] Preferably, in the chip packaging device, a vision mechanism is used to identify the preset position of a thermocouple in a lead frame. In this method, the preset position of the thermocouple is identified by inserting the top of a push rod into the lead frame according to the preset position of the thermocouple using the vision mechanism.

[0013] In some embodiments, a chip packaging apparatus is disclosed, comprising: a chip packaging body and a push rod, wherein the tip of the push rod that contacts the lead frame is in the shape of a thermocouple.

[0014] Preferably, the top end of the push rod is a first telescopic mechanism.

[0015] Preferably, the top end of the push rod is provided with a second telescopic mechanism, wherein the second telescopic mechanism is used to support the thermocouple so that the thermocouple is fully fitted with the lead frame.

[0016] Preferably, the chip packaging device includes a vision mechanism for identifying the preset position of the thermocouple in the lead frame.

[0017] In some embodiments, a system for embedding thermocouples in a molding power module is disclosed, comprising: a thermocouple preset position acquisition module configured to acquire the preset position of the thermocouple in a lead frame;

[0018] The lead frame insertion module is configured to insert the tip of the push rod into the lead frame according to the preset position of the thermocouple;

[0019] The first molding module is configured to perform the first molding of the leadframe with epoxy molding compound;

[0020] The lifting rod module is configured to lift the lifting rod within the encapsulated lead frame, creating a reserved space for the thermocouple;

[0021] The thermocouple module is installed and encapsulated, and is configured to install and encapsulate the thermocouple in the reserved space for the thermocouple.

[0022] Preferably, the thermocouple module is installed, including:

[0023] Thermocouple module is configured to install thermocouples in the reserved space for thermocouples;

[0024] The thermocouple support module is configured such that the second telescopic mechanism extends to support the thermocouple, allowing the thermocouple to fully fit against the lead frame;

[0025] The second molding module is configured to perform a second molding process using epoxy molding compound;

[0026] The second telescopic lifting module is configured to lift the second telescopic mechanism, forming a gap after the second plastic sealing.

[0027] The present disclosure provides a method for embedding thermocouples in a molding power module, as well as a chip packaging device and system, which can achieve the following technical effects:

[0028] During the molding process, a space is left for installing the thermocouple by shaping the top rod into the shape of a thermocouple. The thermocouple is then installed and encapsulated in this space. This ensures accurate positioning of the thermocouple during molding and avoids ineffective installation due to chip decapsulation failure, significantly improving the efficiency of thermocouple installation.

[0029] The above general description and the description below are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0030] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0031] Figure 1 This is a schematic diagram of a chip packaging device provided in an embodiment of this disclosure;

[0032] Figure 2 This is a schematic diagram of a common top rod in the prior art for encapsulating lead frames, provided by an embodiment of this disclosure;

[0033] Figure 3 This is a schematic diagram of a push rod provided in an embodiment of this disclosure;

[0034] Figure 4 This is a schematic diagram of a method for embedding thermocouples in a molding power module according to an embodiment of the present disclosure;

[0035] Figure 5 This is a schematic diagram of the insertion of the top head of a push rod into a lead frame according to an embodiment of this disclosure;

[0036] Figure 6 This is an enlarged schematic diagram of the insertion of the top head of a push rod into a lead wire frame according to an embodiment of this disclosure;

[0037] Figure 7 This is a schematic diagram of installing and encapsulating a thermocouple in a reserved space provided by an embodiment of the present disclosure;

[0038] Figure 8 This is a schematic diagram of a system for embedding thermocouples in a Molding power module, provided in an embodiment of this disclosure. Detailed Implementation

[0039] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and push rods may be simplified in their depiction to simplify the drawings.

[0040] The following description and accompanying drawings fully illustrate specific embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of embodiments of the invention includes the entire scope of the claims and all available equivalents of the claims. In the embodiments disclosed herein, each embodiment may be referred to individually or collectively with the term "invention," which is merely for convenience and is not intended to automatically limit the scope of application to any single invention or inventive concept if more than one invention is disclosed. In the embodiments disclosed herein, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, without requiring or implying any actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or module that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or module. Without further limitations, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, or module that includes said element. The embodiments in this disclosure are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the methods, products, etc., disclosed in the embodiments, since they correspond to the method section disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section description.

[0041] To detect junction temperature in molded products, a laser is typically used to open the target chip area after the product is encapsulated, removing the epoxy molding compound before embedding a thermocouple. This process is difficult to perform manually, and the laser opening process can easily damage the chip surface, causing product failure. Furthermore, the opaque epoxy molding compound makes it impossible to accurately locate the target chip, and any misalignment cannot be corrected, also easily leading to product failure.

[0042] Therefore, there is currently a lack of a method to embed thermocouples into Molding power modules to solve the problem of inefficient thermocouple installation in Molding products.

[0043] To address the problems existing in the relevant technologies, see [link to relevant documentation]. Figure 1This disclosure provides a chip packaging apparatus, including: a chip packaging body and a push rod, wherein the top end of the push rod that contacts the lead frame is in the shape of a thermocouple.

[0044] Combination Figure 2 The image shows a common ejector pin used in existing lead frame encapsulation technologies, such as a floating ejector pin or a demolding ejector pin. See also... Figure 3 In this embodiment of the ejector pin, the ejector pin head is shaped like a thermocouple. The ejector pin head shape matches the thermocouple, thus creating a reserved space for the thermocouple shape after molding at the corresponding position. It should be noted that one type of ejector pin can be a modified version of a common ejector pin, such as a floating ejector pin or a demolding ejector pin. Designing the ejector pin head further reduces costs. Another type of ejector pin can also be any rod-shaped structure; this application does not impose any particular limitation.

[0045] Preferably, the top end of the push rod is a first telescopic mechanism. It should be understood that the top end can extend when in use and retract when not in use, becoming a conventional push rod.

[0046] See Figure 4 This disclosure provides a flowchart of a method for embedding thermocouples in a molding power module, applied to the aforementioned chip packaging device. The method includes:

[0047] S10, Obtain the preset position of the thermocouple in the lead frame.

[0048] It should be understood that the preset position of the thermocouple is the position where the thermocouple should be installed in the lead frame.

[0049] S20, according to the preset position of the thermocouple, use the tip of the push rod to insert into the lead frame.

[0050] It should be understood that the design of the push rod head is consistent with the shape of the thermocouple probe, such as cylindrical or square, with a diameter slightly larger than the thermocouple to ensure compatibility with the subsequent reserved space. In practical applications, the thermocouple's preset position can be manually positioned before inserting the push rod into the lead frame. Alternatively, a vision mechanism can be used to identify the thermocouple's preset position. The push rod can be inserted vertically using a robotic arm or cylinder to avoid damaging the lead frame; it should remain vertical during insertion to ensure the perpendicularity of the reserved space. See also Figure 5 and Figure 6 This is a schematic diagram of a push rod's tip being inserted into a lead wire frame.

[0051] S30, the lead frame is first encapsulated with epoxy molding compound.

[0052] It should be understood that the process involves placing the ejector pin and lead frame into the mold cavity, and then injecting molten epoxy molding compound. Pressure is applied to fill the entire cavity with the epoxy molding compound, encapsulating the chip, leads, and ejector pins. During the molding process, the ejector pins occupy space for the future installation of the thermocouple, preventing the epoxy molding compound from filling that area.

[0053] S40, lift the top rod in the plastic-sealed lead frame to form a reserved space for the thermocouple.

[0054] It should be understood that after the initial molding and curing, the mold is opened, and the ejector pin can be lifted vertically upwards via a robotic arm or cylinder. The lifting speed is controlled at a low level to avoid tearing the edges of the molding compound and to ensure that the inner wall of the reserved space is smooth.

[0055] S50, the thermocouple is installed and encapsulated in the reserved space for the thermocouple.

[0056] The thermocouple probe is precisely placed into the reserved space using a vacuum suction head or mechanical gripper to ensure full contact between the thermocouple probe and the bottom of the space.

[0057] In a preferred embodiment, the top end of the push rod is provided with a second telescopic mechanism, wherein the second telescopic mechanism is used to support the thermocouple so that the thermocouple is fully fitted with the lead frame.

[0058] Correspondingly, see Figure 7 S51, Installing and encapsulating the thermocouple in the reserved space for the thermocouple, including:

[0059] S51, Install the thermocouple in the reserved space for the thermocouple.

[0060] S52, the second telescopic mechanism extends to support the thermocouple, allowing the thermocouple to fully fit against the lead frame.

[0061] It should be understood that the second telescopic mechanism provides controllable support force, ensuring a full fit between the thermocouple and the lead frame, and guaranteeing a stable electrical connection and thermal conduction between the thermocouple and the lead frame. This dynamic support compensates for the poor contact problems caused by the curing shrinkage of the molding compound in traditional methods.

[0062] S53, use epoxy molding compound for a second molding process.

[0063] Secure the thermocouple in place to prevent it from loosening or shifting during use.

[0064] S54, the second telescopic mechanism lifts up, forming a gap after the second plastic sealing.

[0065] It should be understood that the gap after the second sealing can be sealed or not, depending on the situation.

[0066] Furthermore, S51, installing and encapsulating the thermocouple in the reserved space for the thermocouple, also includes:

[0067] S55 encapsulates the gaps after the second molding process.

[0068] In this way, the gap after the second molding is sealed with epoxy molding compound.

[0069] In one optimized embodiment, the chip packaging apparatus includes a vision mechanism for identifying a preset position of a thermocouple in the lead frame.

[0070] It should be understood that in chip packaging technology, the vision mechanism is a core component for achieving precise thermocouple positioning. Its role is to automatically identify preset positions on the lead frame using image processing technology, ensuring the accuracy of subsequent push rod insertion and thermocouple installation. High-precision cameras capture images of the lead frame, and algorithms are used to identify preset positioning marks, such as etched crosshairs, holes, and specific patterns, to calculate the coordinates of the preset thermocouple position.

[0071] Figure 8 This invention illustrates a system for embedding thermocouples in a molding power module, comprising:

[0072] The module for obtaining the preset position of thermocouples is configured to obtain the preset position of thermocouples in the lead frame.

[0073] The lead frame insertion module is configured to insert the tip of the push rod into the lead frame according to the preset position of the thermocouple;

[0074] The first molding module is configured to perform the first molding of the leadframe with epoxy molding compound;

[0075] The lifting rod module is configured to lift the lifting rod within the encapsulated lead frame, creating a reserved space for the thermocouple;

[0076] The thermocouple module is installed and encapsulated, and is configured to install and encapsulate the thermocouple in the reserved space for the thermocouple.

[0077] Furthermore, the thermocouple module is installed, including:

[0078] Thermocouple module is configured to install thermocouples in the reserved space for thermocouples;

[0079] The thermocouple support module is configured such that the second telescopic mechanism extends to support the thermocouple, allowing the thermocouple to fully fit against the lead frame;

[0080] The second molding module is configured to perform a second molding process using epoxy molding compound;

[0081] The second telescopic lifting module is configured to lift the second telescopic mechanism, forming a gap after the second plastic sealing.

[0082] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this invention is for describing embodiments only and is not intended to limit the claims. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms. Similarly, the term “and / or,” as used herein, means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this invention, the terms “comprise” and variations such as “comprises” and / or “comprising” refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Unless otherwise specified, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, or module that includes said element. In the embodiments of this disclosure, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, then the relevant parts can be referred to the description of the method section.

[0083] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this disclosure can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the push rod, push rod, and unit described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0084] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description; sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based push rod that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for embedding a thermocouple in a molding power module, characterized in that, It is used in chip packaging devices that have a chip packaging body and a push rod. The method includes: Obtain the preset position of the thermocouple in the lead frame; According to the preset position of the thermocouple, insert the tip of the push rod into the lead frame; The lead frame is first encapsulated with epoxy molding compound. Lift the top rod in the sealed lead frame to create a reserved space for the thermocouple; Install and encapsulate the thermocouple in the reserved space for the thermocouple.

2. The method according to claim 1, characterized in that, Applied to a chip packaging device having a second telescopic mechanism, the method of mounting and encapsulating a thermocouple in a reserved space for the thermocouple includes: Install the thermocouple in the reserved space for the thermocouple; The second telescopic mechanism extends to support the thermocouple, allowing the thermocouple to fully fit against the lead frame; A second molding process is performed using epoxy molding compound; The second telescopic mechanism lifts up, creating a gap after the second plastic sealing.

3. The method according to claim 2, characterized in that, Installing and encapsulating the thermocouple in the reserved space for the thermocouple also includes: The gaps after the second molding process are sealed.

4. The method according to claim 1, characterized in that, A chip packaging device is used to identify the preset position of a thermocouple in a lead frame using a vision mechanism. In the method, the preset position of the thermocouple is identified by inserting the tip of a push rod into the lead frame according to the preset position of the thermocouple using a vision mechanism.

5. A system for embedding thermocouples in a molding power module, characterized in that, include: The module for obtaining the preset position of thermocouples is configured to obtain the preset position of thermocouples in the lead frame. The lead frame insertion module is configured to insert the tip of the push rod into the lead frame according to the preset position of the thermocouple; The first molding module is configured to perform the first molding of the leadframe with epoxy molding compound; The lifting rod module is configured to lift the lifting rod within the encapsulated lead frame, creating a reserved space for the thermocouple; The thermocouple module is installed and encapsulated, and is configured to install and encapsulate the thermocouple in the reserved space for the thermocouple.

6. The system for embedding thermocouples in a molding power module according to claim 5, characterized in that, Installing the thermocouple module includes: Thermocouple module is configured to install thermocouples in the reserved space for thermocouples; The thermocouple support module is configured such that the second telescopic mechanism extends to support the thermocouple, allowing the thermocouple to fully fit against the lead frame; The second molding module is configured to perform a second molding process using epoxy molding compound; The second telescopic lifting module is configured to lift the second telescopic mechanism, forming a gap after the second plastic sealing.

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