A power semiconductor bonding contact detection device and detection method thereof

Abstract

The present invention discloses a power semiconductor bonding contact detection device and a detection method thereof, which relates to the field of semiconductor processing technology, and includes a welding detection part and a finished product detection part; the welding detection part is arranged in a welding assembly of a processing device, and includes a displacement sensor, a down force generator, an ultrasonic transducer, a splitter, an aluminum wire feeding tube, a cutter and an aluminum wire; the displacement sensor and the down force generator are hard-connected to the welding assembly as a whole; the finished product detection part is arranged on one side of the product moving direction in the processing device, and includes a truncation component and a detection component; the truncation component and the detection component are respectively fixed to the two sides of the sample to be detected. The present invention can perform multiple detections on the product by setting the welding detection part and the finished product detection part, thereby improving the quality of the product; when the welding detection part is used for detection, poor contact or surface damage caused by inconsistent welding surface height can be avoided during each welding.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing, and in particular to a power semiconductor bonding contact detection device and a detection method thereof. Background Art

[0002] The production process of power semiconductor products is divided into three processes: design, manufacturing, and packaging and testing. In the packaging and testing production link, the main processing techniques are divided into Die Bond (chip welding) and Wire Bond (wire bonding); the main purpose of wire bonding is to use an ultrasonic mechanism to weld thick aluminum wire (100um-500um) to the welding point between the chip and the lead frame under the action of external force; when the welding head contacts the welding surface, it needs to be pressed down to a certain depth. Accurately controlling the pressing length is the basis for product bonding reliability and consistency.

[0003] In traditional ultrasonic aluminum wire bonding equipment, the downward stroke control is that the welding head driving arm is pressed down a certain distance. It is generally required to continue moving 100um after contacting the welding surface. However, due to the lead frame or the previous process, there will be a slight height difference between the welded surfaces. Therefore, the method of pressing down a certain distance to determine that the lead frame is pressed is unreliable. Especially when high-speed batch bonding products, product consistency often fails. This is closely related to the reason. Therefore, it is important to know how to press down accurately and quickly. Summary of the invention

[0004] The object of the present invention is to provide a power semiconductor bonding contact detection device and a detection method thereof.

[0005] The technical problem solved by the present invention is: how to quickly detect semiconductor bonding parts while processing them.

[0006] The present invention can be implemented by the following technical solutions: A power semiconductor bonding contact detection device includes a welding detection part and a finished product detection part;

[0007] The welding inspection part and the finished product inspection part are both arranged inside the processing device;

[0008] The processing device comprises a processing table, on which at least one set of path platforms is installed, a driving assembly is arranged on one side of the path platform and inside the finished product detection part, and at least one set of welding assemblies is arranged on the upper side of the path platform;

[0009] The driving assembly on one side of the path platform sequentially passes the substrate of the product to be processed from the lower side of the welding assembly;

[0010] The finished product detection part is arranged on one side of the moving direction of the path platform and includes a cutting component, a detection component and a monitoring component;

[0011] The truncation component and the detection component are sequentially arranged on one side of the moving direction of the path platform, the monitoring component is arranged on the upper side of the truncation component and the detection component, the truncation component and the detection component respectively fix the two sides of the sample to be detected, and the fixing parts of the sample are located on both sides of the bonding part, and the sample is selected from the processed product periodically or actively by the staff;

[0012] After the truncation component is activated, the sample is truncation, and the truncation part is located at the lower side of the bonding part;

[0013] After the detection component is started, the bonding part is stretched along the direction of the bonding wire to evaluate the strength of the bonding wire when subjected to tensile load;

[0014] The welding assembly includes a lifting module, and the welding detection part is arranged inside the lifting module, including a displacement sensor, a down force generator, an ultrasonic transducer, a splitter, an aluminum wire feeding tube, a cutter and aluminum wire;

[0015] The displacement sensor and the downforce generator are hard-connected to the welding assembly as a whole;

[0016] The ultrasonic transducer, the splitter, the aluminum wire feeding tube, the cutter and the aluminum wire are softly connected to the welding assembly as a whole, and the ultrasonic transducer, the splitter, the aluminum wire feeding tube, the cutter and the aluminum wire as a whole can move up and down with a small amplitude relative to the displacement sensor and the downward pressure generator;

[0017] The displacement sensor is used to detect the relative positions of the ultrasonic transducer, the splitter, the aluminum wire feeding tube, the cutter and the aluminum wire relative to the displacement sensor and the down force generator;

[0018] The chopping knife is fixedly connected to the ultrasonic transducer;

[0019] The cutter is installed close to the riving knife and does not touch it;

[0020] The aluminum wire feeding tube is installed close to the splitter and does not touch it;

[0021] The aluminum wire passes through the aluminum wire feeding tube and is placed on one side of the bottom end of the riving cutter.

[0022] A further technical improvement of the present invention is that: the truncation assembly includes a connection block, and power modules are installed on both sides of the connection block along the moving direction of the path platform, which are used to apply power to the product when it passes by;

[0023] Connecting frames are installed at both ends of the upper surface of the connecting block, and first fixing modules are installed at the top ends of the two sets of connecting frames;

[0024] After the sample enters the cut-off assembly, the first fixing module fixes the sample.

[0025] A further technical improvement of the present invention is that: a storage groove is provided inside the connection block between the two groups of power modules;

[0026] A cutting mechanism is installed inside the storage tank via a first lifting mechanism.

[0027] A further technical improvement of the present invention is that: the detection assembly includes a base, the base is connected to the processing device, a connecting platform is provided on the upper side of the base, and a horizontal driving mechanism is installed on the upper surface of the base, and the horizontal driving mechanism is connected to the connecting platform through a pressure detection module;

[0028] After the horizontal driving mechanism is started, the connecting platform is driven to slide along the base through the pressure detection module;

[0029] The height of the upper surface of the connecting platform is the same as that of the upper surface of the path platform;

[0030] A fixing frame is installed on the upper side of the connecting platform, and at least one set of second fixing modules is installed on the top of the fixing frame;

[0031] After the sample moves to the upper side of the connecting platform, the second fixing module fixes the corresponding part of the sample, and then the horizontal driving mechanism is started to stretch the corresponding part of the sample through the connecting platform and detect it through the pressure detection module.

[0032] A further technical improvement of the present invention is that a plurality of reinforcement blocks are installed on the lower side of the connecting platform, and the bottom end of each reinforcement block abuts against the upper side of the base. When the connecting platform moves along the base, the stability can be increased by the reinforcement blocks.

[0033] A further technical improvement of the present invention is that: the displacement sensor comprises a coil hollow shaft and a movable part, the movable part slides along the coil hollow shaft and has a built-in ferrite;

[0034] The more ferrite enters the hollow shaft of the coil, the greater the magnetic flux induction of the coil inside the hollow shaft of the coil, and its resonant frequency decreases. The actual output frequency is obtained through the frequency detection circuit and converted into displacement.

[0035] A further technical improvement of the present invention is that the data update rate of the displacement sensor is 0.3-0.7 ms.

[0036] A further technical improvement of the present invention is that the displacement accuracy of the displacement sensor is 0.1-0.4 μm.

[0037] The present invention also discloses a detection method for a power semiconductor bonding contact detection device, the detection method comprising the following steps:

[0038] Step 1: The product passes through the welding components in the processing device in sequence;

[0039] Step 2: The welding assembly moves downward as a whole, contacts with the upper surface of the lead frame and shrinks, and welding inspection is performed;

[0040] Step 3: Calculate the displacement of the welding assembly, stop moving after reaching the target displacement, and weld the product;

[0041] Step 4: Select the sample, move it to the cutting assembly after welding, and fix the two sides of the bonding part of the sample with the cutting assembly and the detection assembly;

[0042] Step 5: Start the testing component and perform a tensile test on the bonding parts of the sample.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention can perform multiple inspections on products by setting a welding inspection part and a finished product inspection part, thereby improving the quality of the products;

[0045] When testing through the welding detection part, poor contact or surface damage caused by inconsistent welding surface height can be avoided during each welding, ensuring welding reliability and consistency, thereby greatly improving the stability and reliability of product pressing;

[0046] When testing through the finished product inspection part, the bonding parts of the finished product can be inspected periodically, thereby achieving the purpose of re-inspection and further ensuring the packaging quality and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0048] Figure 1 It is a front view of the present invention;

[0049] Figure 2 is a cross-sectional view of a truncation component in the detection device of the present invention;

[0050] Figure 3 is a cross-sectional view of a detection component in the detection device of the present invention;

[0051] Figure 4 is a side sectional view of a detection component in the detection device of the present invention;

[0052] Figure 5 It is a structural schematic diagram of the welding detection part in the detection device of the present invention;

[0053] Figure 6 It is a schematic diagram of the structure of the displacement sensor in the structure of the present invention;

[0054] In the figure: 1. welding assembly; 2. cutting assembly; 3. detection assembly; 4. monitoring assembly; 5. processing table; 6. path platform; 7. driving assembly; 21. storage slot; 22. connecting block; 23. power module; 24. connecting frame; 25. first fixing module; 26. first lifting mechanism; 27. cutting mechanism; 31. base; 32. horizontal driving mechanism; 33. pressure detection module; 34. connecting platform; 35. fixing frame; 36. second fixing module; 37. reinforcement block; 11. displacement sensor; 12. down pressure generator; 13. ultrasonic transducer; 14. splitting knife; 15. aluminum wire feeding tube; 16. cutting knife; 17. aluminum wire; 111. hollow shaft of coil; 112. movable part; 113. ferrite; 110. lifting module. DETAILED DESCRIPTION

[0055] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0056] See also Figure 1-6 As shown, a power semiconductor bonding contact detection device includes a welding detection part and a finished product detection part;

[0057] The welding inspection part and the finished product inspection part are both arranged inside the processing device;

[0058] The processing device includes a processing table 5, on which a plurality of path platforms 6 are mounted, a driving assembly 7 is disposed on one side of the path platform 6 and inside the finished product detection part, and a plurality of welding assemblies 1 are disposed on the upper side of the path platform 6;

[0059] In this embodiment, each group of products to be processed is composed of a plurality of substrates, and every certain number of groups of products, the substrates in a group of products to be processed are replaced by the detection plate;

[0060] In this embodiment, the driving assembly 7 includes a driving part, and a contact part is installed at the output end of the driving part. When the driving part is started, the contact part is driven to contact the product, and the product is driven to move a unit distance along the path platform 6. The unit distance is set based on the size of the substrate in the product. When moving, the substrate is moved to the lower side of the corresponding welding assembly 1 by moving an integral multiple of the unit distance.

[0061] The driving assembly 7 on one side of the path platform 6 sequentially passes the substrate of the product to be processed from the lower side of the welding assembly 1;

[0062] The detection board is provided with a bonding welding part corresponding to the moving direction of the path platform 6, the bonding welding part is used to weld the bonding wire, and the body of the detection board is provided with a cutting part for facilitating subsequent cutting;

[0063] The finished product detection part is arranged on one side of the moving direction of the path platform 6, and comprises a cutting component 2, a detection component 3 and a monitoring component 4;

[0064] The cutting component 2 and the detection component 3 are sequentially arranged along one side of the moving direction of the path platform 6, and the monitoring component 4 is arranged on the upper side of the cutting component 2 and the detection component 3. The cutting component 2 and the detection component 3 respectively fix the two sides of the sample to be detected, and the fixing parts of the sample are located on both sides of the bonding part. In this embodiment, the detection plate is selected as the sample;

[0065] After the cutting component 2 is started, the sample is cut along the cutting part, and the cutting part is located at the lower side of the bonding part;

[0066] After the detection component 3 is started, the bonding part is stretched along the direction of the bonding wire to evaluate the strength of the bonding wire when subjected to a tensile load;

[0067] The welding assembly 1 includes a lifting module 110, and a welding detection part is arranged inside the lifting module 110, including a displacement sensor 11, a down force generator 12, an ultrasonic transducer 13, a splitter 14, an aluminum wire feeding tube 15, a cutter 16 and an aluminum wire 17;

[0068] The displacement sensor 11 and the downforce generator 12 are rigidly connected to the welding assembly 1 as a whole;

[0069] The data update rate of the displacement sensor 11 is 0.5 ms, and the displacement accuracy is 0.3 μm.

[0070] The ultrasonic transducer 13, the splitter 14, the aluminum wire feeding tube 15, the cutter 16 and the aluminum wire 17 are softly connected to the welding assembly 1 as a whole, and the ultrasonic transducer 13, the splitter 14, the aluminum wire feeding tube 15, the cutter 16 and the aluminum wire 17 as a whole can move up and down with a small amplitude relative to the displacement sensor 11 and the lower pressure generator 12;

[0071] The displacement sensor 11 is used to detect the relative positions of the ultrasonic transducer 13, the splitter 14, the aluminum wire feeding tube 15, the cutter 16 and the aluminum wire 17 relative to the displacement sensor 11 and the down force generator 12;

[0072] The chopping knife 14 is fixedly connected to the ultrasonic transducer 13;

[0073] The cutter 16 is mounted close to the riving knife 14 and does not contact it;

[0074] The aluminum wire feeding tube 15 is installed close to the splitter 14 and does not contact it;

[0075] The aluminum wire 17 passes through the aluminum wire feeding tube 15 and is placed on one side of the bottom end of the riving knife 14.

[0076] See also Figure 2 As shown, the cutting assembly 2 includes a connecting block 22, and power modules 23 are installed on both sides of the connecting block 22 along the moving direction of the path platform 6, which are used to apply power to the product when it passes by;

[0077] Connecting frames 24 are installed at both ends of the upper surface of the connecting block 22, and first fixing modules 25 are installed at the top ends of the two sets of connecting frames 24;

[0078] After the sample enters the cutting component 2 , the first fixing module 25 fixes the sample.

[0079] A receiving slot 21 is provided inside the connection block 22 between the two sets of power modules 23;

[0080] A cutting mechanism 27 is installed inside the storage groove 21 through the first lifting mechanism 26. The cutting mechanism 27 adopts mechanical cutting in this embodiment. Because the detection plate is provided with a cutting part, when mechanical cutting is adopted, the cutting quality and efficiency can be improved, and no damage is caused to the bonding part.

[0081] See also Figure 3-4 As shown, the detection assembly 3 includes a base 31, the base 31 is connected to the processing device, a connecting platform 34 is provided on the upper side of the base 31, and a horizontal driving mechanism 32 is installed on the upper surface of the base 31, and the horizontal driving mechanism 32 and the connecting platform 34 are connected through a pressure detection module 33;

[0082] After the horizontal driving mechanism 32 is started, the connecting platform 34 is driven to slide along the base 31 through the pressure detection module 33;

[0083] The height of the upper surface of the connecting platform 34 is the same as the height of the upper surface of the path platform 6, and the driving component 7 in the detection component 3 is arranged on one side of the connecting platform 34;

[0084] A fixing frame 35 is installed on the upper side of the connecting platform 34, and a plurality of second fixing modules 36 are installed on the top of the fixing frame 35;

[0085] After the sample moves to the upper side of the connecting platform 34 , the second fixing module 36 fixes the corresponding part of the sample, and then the horizontal driving mechanism 32 is started to stretch the corresponding part of the sample through the connecting platform 34 and detect it through the pressure detection module 33 .

[0086] A plurality of reinforcement blocks 37 are installed on the lower side of the connection platform 34 , and the bottom end of each reinforcement block 37 abuts against the upper side of the base 31 . When the connection platform 34 moves along the base 31 , the reinforcement blocks 37 can increase stability.

[0087] See also Figure 6 As shown, the displacement sensor 11 includes a coil hollow shaft 111 and a movable member 112. The movable member 112 slides along the coil hollow shaft 111 and has a built-in ferrite 113.

[0088] The more the ferrite 113 enters the coil hollow shaft 111, the greater the magnetic flux induction of the coil inside the coil hollow shaft 111, and the lower its resonant frequency. The actual output frequency is obtained through the frequency detection circuit and converted into displacement.

[0089] When the present invention is used:

[0090] The product passes through the welding assembly 1 in sequence along the path platform 6, and the welding assembly 1 is processed and welded while being inspected;

[0091] The welding component 1 moves downward as a whole, and shrinks after contacting the upper surface of the lead frame;

[0092] When descending, the welding assembly 1 is driven downward by the driving arm as a whole, and moves at high speed. After running to 3 mm above the contact surface, it changes to low-speed downward movement;

[0093] After the welding assembly 1 contacts the upper surface of the lead frame, it drives the movable part 112 in the displacement sensor 11 to contract into the hollow coil shaft 111;

[0094] The more the ferrite 113 in the movable part 112 enters the hollow shaft 111 of the coil, the greater the magnetic flux induction of the coil in the hollow shaft 111 of the coil, and the lower the resonant frequency. The actual output frequency is obtained through the frequency detection circuit and converted into displacement.

[0095] After the system reaches the target displacement through the displacement sensor 11, it stops moving, reaches the target position, and welds the product;

[0096] A sample is selected, and when the welding assembly 1 welds it, the bonding direction after welding is the same as the moving direction of the path platform 6. After welding, it is moved to the cutting assembly 2, and the end of the sample facing away from the cutting assembly 2 is moved to the inside of the detection assembly 3. The first fixing module 25 in the cutting assembly 2 and the second fixing module 36 in the detection assembly 3 are started to fix both sides of the bonding part of the sample;

[0097] Then the first lifting mechanism 26 is started to cut off the sample along the cutting position, and finally the horizontal driving mechanism 32 in the detection component 3 is started to perform a tensile test on the bonding position of the sample, and the monitoring component 4 monitors the bonding position to record the force value when the bonding wire in the bonding position is broken or detached from the pad.

[0098] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A power semiconductor bonding contact detection device, characterized in that: Including welding inspection part and finished product inspection part; The welding detection part is arranged in the welding assembly of the processing device, and includes a displacement sensor, a down force generator, an ultrasonic transducer, a splitter, an aluminum wire feeding tube, a cutter and an aluminum wire; The displacement sensor and the downforce generator are hard-connected to the welding assembly as a whole; The ultrasonic transducer, the splitter, the aluminum wire feeding tube, the cutter and the aluminum wire are softly connected to the welding assembly as a whole, and the ultrasonic transducer, the splitter, the aluminum wire feeding tube, the cutter and the aluminum wire as a whole move up and down relative to the displacement sensor and the down pressure generator; The finished product detection part is arranged on one side of the product moving direction in the processing device, and comprises a cutting component, a detection component and a monitoring component, wherein the monitoring component is arranged on the upper side of the cutting component and the detection component; The truncation component and the detection component are respectively fixed on two sides of the sample to be detected; After the truncation component is activated, the sample is truncation; After the detection component is activated, the bonding part of the sample is stretched along the direction of the bonding line; The truncation assembly comprises a connection block, and power modules are installed on both sides of the connection block along the product moving direction; Connecting frames are installed at both ends of the upper surface of the connecting block, and first fixing modules are installed at the top ends of the two sets of connecting frames; A storage slot is provided inside the connection block between the two groups of power modules; A cutting mechanism is installed inside the storage tank through a first lifting mechanism; The detection assembly includes a base station; A connecting platform is provided on the upper side of the base, and a horizontal driving mechanism is installed on the upper surface of the base, and the horizontal driving mechanism and the connecting platform are connected via a pressure detection module; A fixing frame is installed on the upper side of the connecting platform, and at least one set of second fixing modules is installed on the top of the fixing frame.

2. A power semiconductor bonding contact detection device according to claim 1, characterized in that: The chopping knife is fixedly connected to the ultrasonic transducer; The cutter is installed close to the riving knife and does not touch it; The aluminum wire feeding tube is installed close to the splitter and does not touch it; The aluminum wire passes through the aluminum wire feeding tube and is placed on one side of the bottom end of the riving cutter.

3. A power semiconductor bonding contact detection device according to claim 1, characterized in that: The displacement sensor comprises a coil hollow shaft and a movable part, wherein the movable part slides along the coil hollow shaft and has ferrite built therein.

4. A power semiconductor bonding contact detection device according to claim 1, characterized in that: The data update rate of the displacement sensor is 0.3-0.7 ms.

5. A power semiconductor bonding contact detection device according to claim 1, characterized in that: The displacement accuracy of the displacement sensor is 0.1-0.4 μm.

6. A detection method for a power semiconductor bonding contact detection device according to any one of claims 1 to 5, characterized in that: The detection method comprises the following steps: Step 1: The product passes through the welding assembly along the path platform in sequence, and the welding assembly is processed and welded while being inspected; Step 2: The welding assembly moves downward as a whole and shrinks after contacting the upper surface of the lead frame; Step 3: Calculate the displacement of the welding assembly, stop moving after reaching the target displacement, and weld the product; Step 4: Select the sample, move it to the cutting assembly after welding, and fix the two sides of the bonding part of the sample with the cutting assembly and the detection assembly; Step 5: Start the testing component and perform a tensile test on the bonding parts of the sample.

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