Lead frame, ball bonding test method, ball bonding test device

Abstract

The application provides a lead frame, a ball welding test method for the lead frame with a chip, and a ball welding test device. The lead frame comprises at least one packaging unit, each packaging unit comprises a base island, a plurality of pins arranged side by side and spaced apart on one side of the base island, and a heat sink extending from the back of the base island in a direction away from the pins. The plurality of pins comprise a first pin connected to the base island and at least two second pins arranged spaced apart from the base island. The lead frame further comprises a connecting rib connecting the outer pin sections of the at least two second pins, and a first packaging body for packaging the periphery of the base island and the inner pin sections of the plurality of pins. That is, the first pin and the second pin are insulated from each other, which facilitates subsequent welding and testing on the lead frame with the chip, can monitor the ball welding process, and reduces the influence of the subsequent cutting rib stress on the final product.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a lead frame, a ball bonding test method for ball bonding test of the lead frame having a chip, and a ball bonding test apparatus. Background Technology

[0002] A traditional semiconductor packaging unit includes: a lead frame 10', a chip 101', and metal wires (102', 103'), such as Figure 1 As shown, in the fabrication of a semiconductor packaging unit, the lead frame comprises multiple identical and interconnected basic units. Each basic unit includes a base island 2', a pin 3', and a connecting rib 4'. During the fabrication process, the lead frame utilizes stamping or etching methods to ultimately retain the functional areas required by the product. The base island 2' and pin 3' extend from different areas of the same lead frame and are separated from each other by gaps to form different functional partitions. Silver is then plated in the areas requiring ball bonding. During the packaging process, chip scribing, die mounting, and ball bonding are performed to connect one electrode on the bottom surface of the chip to the base island. The chip surface is connected to the pin via metal wires. After encapsulation, electroplating, and shaping or cutting, an independent single semiconductor packaging unit is finally formed. Finally, testing separates good and defective products.

[0003] Traditional semiconductor packaging and testing processes mainly include the following steps:

[0004] S1. The lead frame manufacturing process completes the lead frame shape required for the product, forming several base islands and pin integration;

[0005] S2. After the packaging and testing plant processes the incoming wafers into individual chips, the individual chips are bonded to the lead frame base islands with solder to perform die assembly. One electrode of the chip (such as the drain electrode of a common MOS chip) is transferred to the base islands of the lead frame through solder to be amplified to the extended area.

[0006] S3. The polarity of the chip's upper surface (such as the G and S poles of a common MOS chip) is connected to the pins of the lead frame via ball bonding, thereby expanding the functional area of ​​the polarity to the extended area through the pins.

[0007] S4. After assembly, the lead frame, chip, solder, and metal wire are encapsulated by a molding compound to encapsulate the base island, solder, chip, and pins in each basic unit of the entire lead frame to prevent oxidation.

[0008] S5. The base island extension and pin extension outside the molding compound, as solder contact points for the terminal circuit board assembly, need to be tin-plated to obtain stable solderability.

[0009] S6. The packaging form is formed and cut into individual pieces;

[0010] S7. Each product undergoes full electrical performance testing on a testing machine, and good and defective products are separated. Good products are shipped to the circuit board assembly plant for use on the board, while defective products are analyzed by the packaging plant to determine which process caused the defect.

[0011] Traditional processes show that by the time testing begins, 80% of the product is already assembled. Numerous anomalies can arise during assembly, some explicit and others implicit. In summary, traditional semiconductor packaging testing has the following drawbacks:

[0012] 1. In the chip packaging stage, the unit functions of the product are connected together by the lead frame, and the independent functions of the product cannot be realized yet.

[0013] 2. It is impossible to perform electrical performance testing on the product during the packaging stage;

[0014] 3. Traditional packaging and testing methods cannot accurately determine the cause of defects and the process to which they belong. The accumulation of process problems makes it difficult to find the cause of defects.

[0015] In view of this, it is necessary to provide a new lead frame, a ball bonding test method for ball bonding test of the lead frame with the chip, and a ball bonding test apparatus to solve the above problems. Summary of the Invention

[0016] The purpose of this invention is to provide a lead frame, a ball bonding test method for ball bonding test of the lead frame having a chip, and a ball bonding test apparatus.

[0017] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a lead frame, comprising at least one encapsulation unit, each encapsulation unit comprising a base island, a plurality of pins arranged side-by-side and spaced apart from each other on one side of the base island, and a heat sink extending from the back of the base island in a direction away from the pins, the plurality of pins comprising a first pin connected to the base island and at least two second pins spaced apart from the base island; the lead frame further comprises connecting ribs connecting the outer pin segments of the at least two second pins, and a first encapsulation body for encapsulating the periphery of the base island and the inner pin segments of the plurality of pins, the first encapsulation body having a window for exposing the inner pin segments of the second pins to the outside.

[0018] As a further improvement of the present invention, the first package includes a first package segment located at one end of the base island near the pin, and two second package segments extending from the opposite ends of the first package segment in a direction away from the pin, the two second package segments being respectively packaged on opposite sides of the base island.

[0019] As a further improvement of the present invention, the front side of the first package is coplanar with the front side of the base island, and the back side of the first package is coplanar with the back side of the heat sink.

[0020] As a further improvement of the present invention, the inner pin segment of the second pin has a first electroplated layer, the thickness of which is between 2μm and 8μm.

[0021] To achieve the above-mentioned objectives, the present invention also provides a ball weld testing method, comprising the following steps:

[0022] Place the aforementioned lead frame with the chip on the ball bonding test device, so that one test probe contacts the outer pin segment of the connecting rib or the second pin, and the other test probe contacts the heat sink located on the side of the base island away from the pin, and simultaneously turn on the test probes.

[0023] Solder the two ends of the first wire to the G electrode bonding pad on the chip and the inner pin segment of the second pin corresponding to the G electrode, respectively.

[0024] After soldering one end of the second wire to the S-polar bonding pad on the chip, test it.

[0025] After soldering the other end of the second wire to the inner pin segment of the second pin corresponding to the S pole, test it.

[0026] After soldering the two ends of the third wire to the S-type bonding pad on the chip and the inner pin segment of the second pin corresponding to the S-type, test it.

[0027] The welding and testing process with the third conductor continues, as well as the welding and testing of other conductors on the S-pole bonding area and the inner pin segment of the second pin corresponding to the S-pole on the electrical connection chip.

[0028] After testing, an accumulated number of test anomalies will be recorded. If the number of anomalies exceeds the preset threshold, the ball welding machine will alarm and stop.

[0029] As a further improvement of the present invention, the "cumulative test anomaly" specifically means that the test anomaly is fed back to the ball welding machine and recorded on the electronic map.

[0030] As a further improvement of the present invention, the preset index is the PPM index.

[0031] To achieve the above-mentioned objectives, the present invention also provides a ball welding testing device, comprising:

[0032] Feeding device;

[0033] A ball welding track is connected to the outlet of the feeding device. The ball welding track includes a track body and a clamping device disposed on the track body.

[0034] A ball welding device is located in the ball welding area of ​​the ball welding track;

[0035] A detection device is located in the ball weld area to acquire the weld position during welding;

[0036] At least two test probes are located in the ball-welding area and are insulated from the ball-welding track;

[0037] A discharge device is connected to the discharge end of the ball welding track;

[0038] The control system includes a feeding device, a ball welding track, a ball welding device, a detection device, a test probe, and a discharging device, all of which are communicatively connected to the control system.

[0039] As a further improvement of the present invention, the ball welding track also includes a fixing plate disposed on one side of the track body and insulated from the track body, and the test probe is movably connected to the fixing plate in the up-down direction.

[0040] As a further improvement of the present invention, the ball welding track also includes a ball welding pressure plate heating block disposed on the track body.

[0041] The beneficial effects of this invention are as follows: In the lead frame of this invention, a first package body is provided to encapsulate the periphery of the base island and the inner pin segment of the plurality of pins. This can fix and insulate the second pin from the base island. At the same time, the first pin and the second pin are insulated from each other, which facilitates simultaneous soldering and testing on the lead frame with the chip. This allows for monitoring of the ball soldering process, timely detection of abnormalities in the ball soldering process, and early implementation of process control measures. Furthermore, the process of cutting the connecting ribs connecting the first pin and the second pin, as well as the connecting ribs at the end of the first pin away from the base island, is moved forward to the lead frame factory, reducing the impact of subsequent rib cutting stress on the final product. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the lead frame structure in the prior art.

[0043] Figure 2 This is a schematic diagram of the lead frame structure in this invention.

[0044] Figure 3 This is a schematic diagram of the ball welding test device in this invention.

[0045] Figures 4-13 This is a step diagram illustrating the fabrication method of the chip packaging unit in this invention. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. Please refer to the accompanying drawings for further details. Figures 1 to 13 The figures shown represent preferred embodiments of the present invention. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent modifications or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0047] Please refer to Figure 2 As shown, the present invention provides a lead frame 10, including at least one encapsulation unit. Each encapsulation unit includes a base island 1, a plurality of pins arranged side-by-side and spaced apart on one side of the base island 1, and a heat sink 2 extending from the back of the base island 1 away from the pins. The plurality of pins includes a first pin 3 connected to the base island 1 and at least two second pins 4 spaced apart from the base island 1. The lead frame 10 further includes connecting ribs 5 connecting the outer pin segments of the at least two second pins 4, and a first encapsulation body 6 for encapsulating the periphery of the base island 1 and the inner pin segments of the plurality of pins. The first encapsulation body 6 has an outward extension of the inner pin segment of the second pin 4. The exposed window, namely, the first package 6 used to encapsulate the periphery of the base island 1 and the inner pin segment of the plurality of pins, can fix and insulate the second pin 4 to the base island 1. At the same time, the first pin 3 and the second pin 4 are mutually insulated, which facilitates testing while soldering on the lead frame 10 with the chip 30. This allows for monitoring of the ball soldering process, timely detection of abnormalities in the ball soldering process, and early implementation of process control measures. In addition, the process of cutting the connecting ribs connecting the first pin 3 and the second pin 4 and the connecting ribs at the end of the first pin 3 away from the base island 1 is moved forward to the lead frame factory, reducing the impact of subsequent rib cutting stress on the final product.

[0048] It is understood that the inner pin segment refers to a portion of the structure where a pin is located inside the first package 6, and the outer pin segment refers to a portion of the structure where a pin is located outside the first package 6.

[0049] It is understood that the first package 6 can fix the second pin 4 and at the same time insulate the second pin 4 from the base island 1.

[0050] In one specific embodiment, the plurality of pins includes a first pin 3 connected to the base island 1, and two second pins 4 disposed on opposite sides of the first pin 3 and insulated from each other. Of course, this is not a limitation, and the number and relative position of the first pin 3 and the second pins 4 can be adjusted according to the specific requirements of the final chip packaging unit.

[0051] Furthermore, the first package 6 includes a first package segment located on the base island 1 near one end of the pin, and two second package segments extending from the opposite ends of the first package segment in a direction away from the pin. The two second package segments are respectively packaged on opposite sides of the base island 1, increasing the contact area between the first package 6 and the base island 1, enhancing their connection strength, and thereby enhancing the fixing strength of the second pin 4.

[0052] In one specific embodiment, the front side of the first package 6 is coplanar with the front side of the base island 1, and the back side of the first package 6 is coplanar with the back side of the heat sink 2. Increasing the thickness of the first package 6 can increase the strength of the first package 6, making it less prone to breakage, and at the same time, enhance the insulation effect.

[0053] Furthermore, the inner pin segment of the second pin 4 has a first electroplated layer 7, the thickness of which is between 2μm and 8μm, so as to facilitate the subsequent electrical connection between the second pin 4 and the chip 30 by ball bonding the end of the wire.

[0054] Further, please refer to Figure 3 As shown, the present invention also provides a ball bonding test device 20, which is used to perform tests during the ball bonding process of the lead frame 10 having the chip 30. It can monitor the ball bonding process, detect abnormalities in the ball bonding process in a timely manner, and take process control measures as early as possible. At the same time, it avoids the interference of multiple process problems superimposed when troubleshooting packaging test abnormalities after the chip packaging unit is completed.

[0055] The ball bonding test apparatus 20 includes an infeed device 201 for placing the lead frame 10 with chip 30 to be tested, a ball bonding track 202 connected to the outlet of the infeed device 201, a ball bonding device 203 disposed in the ball bonding area of ​​the ball bonding track 202, a detection device 204 disposed in the ball bonding area to obtain the bonding position during bonding, a test probe 205 located in the ball bonding area and insulated from the ball bonding track 202, an outlet device 206 connected to the outlet end of the ball bonding track 202, and a control system 207. The infeed device 201, ball bonding track 202, ball bonding device 203, detection device 204, test probe 205, and outlet device 206 are all communicatively connected to the control system 207.

[0056] The control system 207 can be a computer, but is not limited to that.

[0057] Furthermore, the ball welding track 202 includes a track body and a clamping device 208 disposed on the track body. The clamping device 208 is used to position the lead frame 10 on the track body, which can improve the accuracy of subsequent ball welding.

[0058] It is understood that the ball-bonding track 202 in the ball-bonding area is insulated from other parts of the ball-bonding track 202, so that after the lead frame 10 is located in the ball-bonding area, the lead frame 10 is insulated from other parts of the ball-bonding track 202, enabling ball-bonding processes and testing.

[0059] Specifically, the ball-welding track 202 further includes a fixing plate disposed on one side of the track body and insulated from the track body. The test probe 205 is movably connected to the fixing plate in the vertical direction. Thus, when the test probe 205 moves upward, the distance between it and the track body can be increased, allowing the lead frame 10 to enter between the test probe 205 and the track body, facilitating the adjustment of the position of the test probe 205 on the lead frame 10. When the test probe 205 moves downward, it can contact the preset position of the lead frame 10, facilitating subsequent testing.

[0060] Furthermore, there are two test probes 205. During testing, one of the two test probes 205 contacts the outer pin segment of the second pin 4 or the connecting rib 5 connecting the outer pin segment of the second pin 4, and the other contacts the heat sink 2 located on the side of the base island 1 away from the pin.

[0061] In one specific embodiment, the two test probes 205 are arranged at intervals along the traveling direction of the ball welding track 202. Of course, this is not a limitation, and the two test probes 205 can also be arranged at intervals along the vertical direction.

[0062] Furthermore, the ball welding track 202 also includes a ball welding pressure plate heating block 209 disposed on the track body to assist the ball welding process during ball welding.

[0063] Furthermore, the present invention also provides a ball weld testing method, comprising the following steps:

[0064] S1: Place the lead frame 10 with chip 30 on the ball bonding test device 20, so that one test probe 205 contacts the outer pin segment of the connecting rib 5 or the second pin 4, and the other test probe 205 contacts the heat sink 2 located on the side of the base island 1 away from the pin, and turn on the test probe 205 at the same time.

[0065] S2: Solder the two ends of the first wire to the G electrode bonding area on the chip 30 and the inner pin segment of the second pin 4 corresponding to the G electrode, respectively.

[0066] S3: Test after soldering one end of the second wire to the S-polarity bonding area on chip 30;

[0067] S4: After soldering the other end of the second wire to the inner pin segment of the second pin 4 corresponding to the S pole, test it;

[0068] S5: Solder the two ends of the third wire to the S-polar bonding pad on chip 30 and the inner pin segment of the second pin 4 corresponding to the S-polar electrode, and then test.

[0069] S6: The welding and testing process with the third wire continues, and the welding and testing of the S-polar bonding area on the electrical connection chip 30 and the other wires of the inner pin segment of the second pin 4 corresponding to the S-polar are carried out.

[0070] After testing, an accumulated number of test anomalies will be recorded. If the number of anomalies exceeds the preset threshold, the ball welding machine will alarm and stop.

[0071] It is understandable that there is only one wire between the second pin 4 corresponding to the G terminal and the chip 30, namely the first wire. Therefore, the first wire is connected first. After soldering one end of the second wire to the S terminal bonding pad on the chip 30 to form an electrical circuit, a test is performed to confirm the quality of the solder joint of the first wire and the solder joint connecting the second wire to the S terminal bonding pad on the chip 30.

[0072] In step S4, after soldering the other end of the second wire to the inner pin segment of the second pin 4 corresponding to the S pole, a test is performed. At this time, both ends of the second wire are soldered, and the quality of the solder joint between the second wire and the inner pin segment of the second pin 4 corresponding to the S pole can be confirmed.

[0073] In step S5, after both ends of the third wire are soldered, a test is performed to check the connection of the third wire. If an abnormality occurs, the electrical data can be used to preliminarily determine which solder joint is the problem. For example, if "short" appears, it means that the solder joint connecting the third wire and the chip 30 is abnormal.

[0074] In this embodiment, there are three wires that are electrically connected to the S-polar bonding area on the chip 30 and the inner pin segment of the second pin 4 corresponding to the S-polar, namely the second wire, the third wire, and the fourth wire. In step S6, after both ends of the fourth wire are soldered, a test is performed to test the connection of the fourth wire. If an abnormality occurs, it is possible to preliminarily determine which solder joint is the problem through electrical data. For example, if "short" appears, it means that the solder joint connecting the fourth wire and the chip 30 is abnormal.

[0075] Furthermore, "cumulative test anomalies" specifically refers to: reporting test anomalies to the ball welding machine and recording them on the electronic map.

[0076] Specifically, the preset index is the PPM defect index, which can also be used as one of the acceptance indicators for the ball welding test device 20.

[0077] The ball bonding test method in this invention performs the test during the ball bonding process, which can monitor the ball bonding process, detect abnormalities in the ball bonding process in a timely manner, and take process control measures as early as possible. At the same time, it avoids the interference of multiple process problems superimposed when troubleshooting packaging test abnormalities after the completion of chip packaging unit 40 in traditional methods.

[0078] Further, please refer to Figures 4-13 As shown, the present invention also provides a method for fabricating a chip packaging unit 40, comprising the following steps:

[0079] A1: As Figures 4-7 As shown, the lead frame 10 described above is provided;

[0080] A2: As Figure 8 As shown, chip 30 is soldered onto the base island 1 of the lead frame 10 described above;

[0081] A3: As Figure 9 As shown, ball welding tests were performed while welding was being carried out;

[0082] A4: As Figure 10 As shown, after the ball bonding test is completed and the test abnormality does not exceed the preset index, plasma cleaning is performed and the base island 1 and the inner pin section of the pin are encapsulated to obtain a semi-finished product.

[0083] A5: As Figures 11-12 As shown, the exposed areas of the semi-finished product are electroplated with tin;

[0084] A6: As Figure 13 As shown, the chip is packaged and cut into individual pieces to obtain chip packaging unit 40;

[0085] A7: Perform electrical performance testing on chip packaging unit 40.

[0086] The structure of the lead frame 10 is as described above, and will not be repeated here.

[0087] Specifically, please refer to Figures 4-7 As shown, step A1 includes the following steps:

[0088] A11: As Figure 4As shown, a base frame with a lead frame shape is formed, and multiple sub-units are formed on the base frame. Each sub-unit has a heat sink 2, a base island 1, a first pin 3 connected to the base island 1, a connecting rib 5, and at least two second pins 4 spaced apart from the base island 1.

[0089] A12: As Figure 5 As shown, the periphery of the base island 1, the inner pin segment of the first pin 3, and the inner pin segment of the second pin 4 are pre-encapsulated together, and the inner pin segment of the second pin 4 is exposed.

[0090] A13: As Figure 6 As shown, the connecting ribs between the first pin 3 and the second pin 4, as well as the end of the first pin 3 away from the base island 1, are removed by stamping.

[0091] A14: Cleaning;

[0092] A15: As Figure 7 As shown, the inner pin section of the second pin 4 is electroplated after cleaning.

[0093] In step A12, the first package 6 is defined as the pre-encapsulated assembly of the periphery of the base island 1, the inner pin segment of the first pin 3, and the inner pin segment of the second pin 4. The first package 6 has the functions of fixing and insulating, and can fix and insulate the second pin 4 from the base island 1. At the same time, the first pin 3 and the second pin 4 are mutually insulated, which facilitates testing while soldering on the lead frame 10 with the chip 30.

[0094] Specifically, the front side of the first package 6 is coplanar with the front side of the base island 1, and the back side of the first package 6 is coplanar with the back side of the heat sink 2. Increasing the thickness of the first package 6 can increase the strength of the first package 6, making it less prone to breakage, and at the same time, enhance the insulation effect.

[0095] It is understood that the first package 6 can fix the second pin 4, thereby preventing the second pin 4 from detaching from the base island 1 after the connecting rib between the first pin 3 and the second pin 4 is removed by stamping in step A13.

[0096] In step A13, the connecting ribs between the first pin 3 and the second pin 4, as well as the end of the first pin 3 away from the base island 1, are removed by stamping, that is, the first pin 3 and the second pin 4 are insulated from each other, which facilitates subsequent solder ball testing.

[0097] Furthermore, in step A15, the thickness of the first electroplated layer formed after electroplating is between 2μm and 8μm.

[0098] Further, step A3 specifically involves placing the lead frame 10 with the chip 30 onto the ball bonding test apparatus 20 and performing the test according to the ball bonding test method described above.

[0099] After step A15, the formed lead frame 10 has multiple packaging units. Each packaging unit includes a base island 1, multiple pins arranged side by side and spaced apart from each other on one side of the base island 1, and a heat sink 2 extending from the back of the base island 1 away from the pins. The multiple pins include a first pin 3 connected to the base island 1 and at least two second pins 4 spaced apart from the base island 1.

[0100] The ball welding test device 20 and the ball welding test method are as described above, and will not be repeated here.

[0101] Specifically, in step A4, CEL-9220 material cakes are used for encapsulation.

[0102] Furthermore, step A5 specifically includes the following steps:

[0103] The exposed areas of the first pin 3 and the heat sink 2 are simultaneously electroplated with tin;

[0104] The exposed areas of the second pin 4 and the connecting rib 5 are simultaneously electroplated with tin.

[0105] It is understood that the first pin 3 is electrically connected to the base island 1, and the heat sink 2 is electrically connected to the base island 1. Thus, the first pin 3 is electrically connected to the heat sink 2. The second pin 4 and the connecting rib 5 are mutually insulated from the base island 1 and the first pin 3. Therefore, it is necessary to perform tin plating in steps.

[0106] Meanwhile, in the tin plating step, the exposed areas of the first pin 3 and the heat sink 2 can be tin-plated simultaneously first, and then the exposed areas of the second pin 4 and the connecting rib 5 can be tin-plated simultaneously; or the exposed areas of the second pin 4 and the connecting rib 5 can be tin-plated simultaneously first, and then the exposed areas of the first pin 3 and the heat sink 2 can be tin-plated simultaneously.

[0107] Specifically, the thickness of the second electroplated layer in the exposed areas of the second pin 4 and the connecting rib 5 is between 8μm and 20μm.

[0108] Furthermore, the electrical performance tests in step A7 include, but are not limited to, heat dissipation, resistance, withstand voltage, thermal resistance, open circuit, and short circuit. Appropriate electrical performance tests can be selected based on the specific requirements of chip 30.

[0109] Compared with the prior art, the lead frame 10 of the present invention is provided with a first package 6 for encapsulating the periphery of the base island 1 and the inner pin segment of the plurality of pins. This can fix and insulate the second pin 4 from the base island 1. At the same time, the first pin 3 and the second pin 4 are insulated from each other, which facilitates testing while soldering on the lead frame 10 with the chip 30. This allows for monitoring of the ball soldering process, timely detection of abnormalities in the ball soldering process, and early implementation of process control measures. In addition, the process of cutting the connecting rib 5 connecting the first pin 3 and the second pin 4 and the connecting rib at the end of the first pin 3 away from the base island 1 is moved forward to the lead frame factory, reducing the impact of subsequent rib cutting stress on the final product.

[0110] Meanwhile, the ball bonding test device 20 in this invention is used to perform tests during the ball bonding process of the lead frame 10 having the chip 30, which can monitor the ball bonding process, detect abnormalities in the ball bonding process in a timely manner, and take process control measures as early as possible. At the same time, it avoids the interference of multiple process problems superimposed when troubleshooting packaging test abnormalities after the chip packaging unit 40 is completed.

[0111] The ball bonding test method in this invention performs the test during the ball bonding process, which can monitor the ball bonding process, detect abnormalities in the ball bonding process in a timely manner, and take process control measures as early as possible. At the same time, it avoids the interference of multiple process problems superimposed when troubleshooting packaging test abnormalities after the completion of chip packaging unit 40 in traditional methods.

[0112] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0113] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lead frame, comprising at least one packaging unit, each packaging unit comprising a base island, a plurality of pins arranged side-by-side and spaced apart from each other on one side of the base island, and a heat sink extending from the back of the base island in a direction away from the pins, the plurality of pins including a first pin connected to the base island and at least two second pins spaced apart from the base island; characterized in that: The first pin and the second pin are insulated from each other; the lead frame further includes a connecting rib connecting the outer pin segments of the at least two second pins, and a first encapsulation body for encapsulating the periphery of the base island and the inner pin segments of the plurality of pins, the first encapsulation body having a window for exposing the inner pin segments of the second pins to the outside.

2. The lead frame as described in claim 1, characterized in that: The first package includes a first package segment located at one end of the base island near the pin, and two second package segments extending from opposite ends of the first package segment in a direction away from the pin, the two second package segments being respectively packaged on opposite sides of the base island.

3. The lead frame as described in claim 1, characterized in that: The front side of the first package is coplanar with the front side of the base island, and the back side of the first package is coplanar with the back side of the heat sink.

4. The lead frame as described in claim 1, characterized in that: The inner pin segment of the second pin has a first electroplated layer, the thickness of which is between 2μm and 8μm.

5. A ball weld testing method, characterized in that: The ball welding test method includes the following steps: The lead frame with the chip as described in any one of claims 1-4 is placed on the ball bonding test device, so that one test probe contacts the outer pin segment of the connecting rib or the second pin, and another test probe contacts the heat sink located on the side of the base island away from the pin, and the test probes are turned on at the same time. Solder the two ends of the first wire to the G electrode bonding pad on the chip and the inner pin segment of the second pin corresponding to the G electrode, respectively. After soldering one end of the second wire to the S-polar bonding pad on the chip, test it. After soldering the other end of the second wire to the inner pin segment of the second pin corresponding to the S pole, test it. After soldering the two ends of the third wire to the S-type bonding pad on the chip and the inner pin segment of the second pin corresponding to the S-type, test it. The welding and testing process with the third conductor continues, as well as the welding and testing of other conductors on the S-pole bonding area and the inner pin segment of the second pin corresponding to the S-pole on the electrical connection chip. After testing, an accumulated number of test anomalies will be recorded. If the number of anomalies exceeds the preset threshold, the ball welding machine will alarm and stop.

6. The ball weld testing method as described in claim 5, characterized in that: "Cumulative test anomalies" specifically refers to: reporting test anomalies to the ball welding machine and recording them on the electronic map.

7. The ball weld testing method as described in claim 5, characterized in that: The preset indicator is the PPM indicator.

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