TW445500B - Method and device for testing wafer in a bare die state - Google Patents

Abstract

The present invention relates to a method and device for testing bare die. The wafer module to be tested is positioned on a positioning platform. A plurality of probes on a testing platform are used to correspondingly press and touch the ball pads pre-arranged on the bottom of the wafer module. A testing current is inputted from the testing platform via the probes and ball pads for thereby forming a circuit loop in the die. The testing platform also detects and compares the voltage signals of the bare die circuit outputted from the ball pads. Accordingly, based on the bare die state of the wafer before being molded, it is able to detect and determine the correct position of the bad contact point of the circuit, and further save the manufacturing cost.

Description

445500

V. Description of the invention (1) The present invention relates to a test method and device design for a wafer in a bare die state, and particularly refers to a method for detecting and determining a bare crystal state before the wafer is sealed. The correct position of the bad contact of the internal circuit can further achieve the test method for saving wafer cost and other functions in the bare die state and its installer. According to the continuous progress of 1C manufacturing technology, from several micron process technology to the current sub-micron technology, and even the deep sub-micron technology one to two years later, the continuous increase of IC functions' has driven the excellence of packaging technology in the downstream packaging industry. Due to the current design trends of electronic products, they are generally moving towards high speed, multifunctionalization, small plasticization and light weight, and 丨 c design is also generally toward high integration, rapidization, multifunctionality, low energy consumption and high energy consumption. The trend of frequency development has developed, so the development trend of packaging has gradually moved towards multi-pin counting, miniaturization of wires, miniaturization, and high heat dissipation. At present, IC wafer packaging types can be roughly divided into two categories, one is a lead-insertion type and the other is a surface-adhesive type. Among them, the surface-adhesive type is used as an example. /, The main package type is a ball grid array (B a Ug 丨 id Aray (BGA) ball-grid array (BGA) packaging technology is currently the latest high-pin integrated circuit packaging technology 'applicable to ultra-large-scale accumulation manufactured today with sub-micron resolution ( Ultra-Large Scale Integration). The packaging steps of the crystal 0 line are the upper substrate—molding—the upper solder ball—segmentation, sample + α r —, ° 5 ', and its packaging method is mainly to fix the separated single wafer to the array package. After the wire bonding operation is performed on the substrate of the printed circuit board, glue is used to encapsulate the wafer protruding above the surface of the substrate. The aforementioned “ball grid array sealing” " point

5. Explanation of the invention (2+), and in order to make the die-cutting operation of the subsequent die-cutting operation short-circuited as a solder ball, the above-mentioned crystal-knowledge wafer package should not be detected, so that it is not only the people but the others. Operation method? Is it not < Since the detection of this case is due to the negligence of the detection speed, the manufacturing process has been successfully plated, and if the ball will fall off, the package will be used for each wafer step. , Can not pin the wave on the material; or have been measured after the line step into a line collapse, not the rate difference, and the situation. In view of the fact that Xi Dan found that the lack of access to the South and so on was concentrated after the mold is closed. The entire finished product must be scrapped because it has been engaged in phases for many years. When the electrical quality of the tin is required to be rounded and packaged, the original virtual work is caused by the slow motion and the artificial detection is slowed down. The inventor's business is misjudged ... Cost inspection, adding solder balls, and forming the solder joint Completed the application of electrical rounds to the sealing system and the wafer to the bad fee, and the use of a human bow before sealing the mold can not avoid the failure of the packaging point. After conceiving that each solder joint is not successfully defective, it is a sexual detection mold. The former said that the naked-eye short-circuit current generator of the bare die before the sealing of the mold had to be plated with gold before finalizing the crystal operation. Make a one-by-one inspection of the status of any worker before entering the bare crystal. This test is performed by forging a layer of metal plating on the eyes and then sequentially entering the circle. Due to the practice, during the remedial operation and manual inspection, the test line is measured. This kind of operator is not only tired or away from people: the heart of the moon "is to provide a kind of bare wafer"; the other method is that it can really determine whether the wafer is bare. , The correct position of the bad contact of the internal circuit, etc.% Another object of the present invention is to provide a kind of wafers

445500 V. Description of the invention (3) The test device can really save the manufacturing cost and other effects. '' According to the above purpose, the present invention is characterized by positioning the wafer module of the piano to be tested on a positioning abutment. The ball pad on the bottom of the group is input by the test bench through the probe and the ball pad to form a loop inside the wafer module wafer. At the same time, the test bench detects and compares the wafer output from the ball pad. The voltage signal of the internal circuit can be used to determine the correct position of the bad contact in the internal circuit before the die is die-sealed before the wafer is sealed, thereby achieving effects such as saving manufacturing costs. b Sequential package; the base plate of the base station has been terminated-the ball wave should pass through the circuit; the circuit of the circuit is mounted on the bare chip. 3 is used on the platform, the hair contains positioning, the positioning, the The crystal is preset to use multiple pads, and then a pad is used; then the probe and the ball are then used to detect the pressure signal. When the state is set, the crystal is wrapped in a positioning base to suppress the crystal method. Certainly, it is on the side; and in the step of contacting the front-facing wafer and the alignment step, the round module wire is provided with a test bench for signal input and comparison with the signal pad, and it contains a lower round group in the inside. The die and signal are the wafers to be waited for, and there are multiple output steps on the pre-supply tin, and the step is to set the value into the circuit rack, the rack positioning output, and test the bottom ball positioning of the bare substrate. The number of probes is the same as that in the bare crystal system. The receiving line is relatively short-circuited or the measurement position is placed again and the corresponding ball pad is aligned when the wafer mold status is detected. The test state is obtained from the ball pad. Open circuit in the rack test bench, The test results of a circle's internal output are determined by the platform; the above-mentioned set-up and set-up phase and phase comparison test with a wire f constitutes-wafer transport chip n is located in this position and i is positioned at Test drive

V. Description of the invention (4) The lifting device and other components under the platform that can be moved up and down in conjunction with the test platform; and the top surface of the test platform is arranged with a plurality of probes in accordance with the circuit design of the wafer in the bare crystal state, and the test A testing machine capable of providing a test current and receiving a detection voltage is connected in parallel, so that the correct position of the bad contact of the internal circuit can be detected and judged before the die state of the wafer before the mold is sealed. Those who save the cost of manufacturing. In order to have a more detailed and clear understanding of the purpose, effect, and characteristics of the present invention, the preferred embodiment of the present invention will be described in conjunction with the drawings as follows: First, please refer to the first figure, which is a preferred embodiment of the present invention. Process flow-block diagram, as shown in the figure. As can be seen from the previous knowledge, the general packaging operation process can be roughly divided into operating steps such as substrates on wafers, wire bonding, mold sealing, solder balls and punching. The test method 1 of the wafer in the die state of the present invention is implemented after the aforementioned conventional wire bonding operation and before the mold sealing operation; the die test method 1 mainly includes positioning 1 1 and alignment 1 2 in order. , Signal output 1 3, detection and comparison 1 4 and other steps; the detailed description of the process of each step is as follows. Please refer to the second and third figures at the same time, which are schematic diagrams of the implementation status of the positioning and alignment steps of a preferred embodiment of the present invention, and a schematic diagram of a bare crystal test device of a preferred embodiment of the present invention, as shown in the figure. The positioning step 1 1 i can use a robotic arm or a conveyor belt to transfer the wafer module 2 to the positioning base 31, wherein the wafer module 2 has a substrate 2 1 and a substrate 2 is positioned on the substrate Η. The wafer (d 1 e) 2 2 in a bare state, and the side of the wafer 2 2 is connected to the substrate 21 with a plurality of wires 23, and the bottom of the substrate 2 1 corresponds to the junction of one end of the wires 2 3 Ball pads for pre-supplied solder ball positioning

445 5 Ο Ο 5. Description of the invention (5) "--H 'And in the alignment step 12, most of the probes on a test bench 32 are used, and the alignment top touches the corresponding ball pad 24. . Wee_ Next in the signal output step 23, the test bench 32 inputs a test electric = two by the probe 321 and the ball pad 24 'to make the wafer 22 internal structure-go back to the detection and comparison step 24' Receive The voltage signal of the crystal circuit output from the ball pad 24 is compared with the preset value, so as to determine the short circuit or open circuit condition of the internal circuit of the wafer 2 (that is, the failure of the ^ k circuit in the wafer). The correct position of the contact point), so that the semi-finished product can be compensated immediately before the mold is sealed to improve the habit of testing before the mold is sealed. Once the contact is found to be bad, the entire finished product needs to be scrapped, resulting in a lack of increased manufacturing costs. 'Still referring to the second and third figures, the bare-crystal test device 3 for achieving the foregoing test method according to the present invention mainly includes a frame 33, a positioning base 31 provided on the bar 33, a A test stand 3 2 ′ provided on the machine wood below the positioning base 31, a positioning device 34 provided on the positioning base 31 to suppress the wafer 2 2 to the position, and a positioning device 34 provided below the test stand 32 and A lifting device 35 and other components capable of interlocking with the test bench 32 can be linked; in the middle, the top surface of the test bench 32 is arranged with a plurality of probes 32 1 ′ in accordance with the circuit design of the wafer 22 and the test bench 32 is provided in parallel. —Testing machine 322 capable of providing test current and receiving detection voltage; the positioning device 34 has a plurality of guide rods 341 standing on the positioning base 31, and a pressing seat capable of following the guide rods 341 for lifting and displacement 3 4 2 and other components' The pressing seat 3 4 2 is provided with a groove 343 in the place corresponding to the wafer 2 2 'to enable the pressing seat 342 to lower the substrate 21 of the wafer group 2' wafer 22 is just Can be relatively extended into the groove 343; another

V. Description of the invention ¢ 6) In addition, the lifting device 3 5 series can be a hydraulic cylinder, and the hydraulic cylinder has a telescopic rod 3 5 1 which can be telescopically moved, and the other end of the telescopic rod 3 5 1 is fixed on the test bench. 3 2 bottom. Therefore, when detecting the open and short circuit conditions of the internal circuit of the wafer 22, it is only necessary to position the wafer module 2 to be tested on the positioning base 31, and use most of the probes 3 on a test platform 32. 2 1 Alignment top contacts the substrate 2 preset on the wafer module 2 1 The ball pad 2 on the bottom surface 2 and a test machine 3 2 2 is used to pass a test current through the probe 3 2 1 and the ball on the test table 3 2 Pad 2 4 input, so that the wafer 2 2 internally constitutes a loop. At the same time, the tester 3 2 2 detects and compares the voltage signal of the wafer 2 2 circuit output from the pad 2 4 through the test bench 32. Before the wafer 2 2 is sealed, the correct position of the bad contact in the internal circuit of the wafer 2 2 can be determined to immediately remedy the semi-finished product with the defective circuit. If two are detected during the inspection process: If the same group has bad contacts, it can be reasonably suspected. The preset parameters of the bare chip test device are wrong, and they can be adjusted immediately to avoid loss; the loss is enlarged. '' Therefore, the method and device for testing a wafer in a bare state according to the present invention is to position the wafer module to be tested on a positioning base and use most of the probes on a test stand to align and touch. The ball pad which is preset on the bottom surface of the wafer module, a test current is input by the test bench through the probe and the ball pad, so that the wafer inside the crystal state constitutes a loop, and the test bench detects The voltage signal of the die circuit output from the ball pad is compared, so as to provide a die test method and device that can be implemented before the mold sealing and the detection method is simple, so that the wafer is in the state of the die before the mold is filled and sealed. You can test and determine the correct position of the bad contact in the internal circuit first, and you can also detect the failure of wiring.

_4455 0 Q_ V. Description of the invention (7) The rate (such as whether there is a short-circuit phenomenon caused by wire collapse caused by insufficient arc height of the wire), in order to immediately remedy the semi-finished product with poor circuit, if more than two are measured during the testing process With the same bad contacts, it is also possible to reasonably suspect that the preset parameters of the bare chip test device are wrong and adjust them immediately to avoid loss expansion. At the same time, the present invention does not need to perform manual inspection after the wire bonding step, which can avoid the conventional The human body's human body causes false judgments when it is detected by human eyes, which can save human resources, so it can really achieve the effects of saving manufacturing costs and other effects. To sum up * the bare die test method and device of the present invention are based on the bare die state of the wafer before the mold is sealed, that is, the correct position of the bad contact in the internal circuit is detected to immediately repair the semi-finished product with bad wiring. Further, it can achieve the effects of saving manufacturing costs, etc. Therefore, the present invention is a progressive design *, and no similar or similar method has been disclosed in the city, and the patent application has been filed according to law. However, the above are only the preferred embodiments of the present invention. Therefore, any equivalent structural changes made by applying the description of the present invention and the scope of patent application should be included in the patent scope of the present invention.

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Claims (1)

145 5 0 0 VI. Application for Patent Scope 1-A test method for wafers in bare die state. The main methods are as follows: The positioning step is to position the wafer module to be tested on a positioning base. Wherein, the wafer module has a substrate. A wafer is positioned on the substrate, and a plurality of wires are connected to the side of the wafer and the substrate. In addition, a joint on one end of the bottom of the substrate corresponding to the wires is provided with a pre-assembly. Ball pad for solder ball positioning; x Alignment step 'uses most of the closed test to touch the corresponding ball pad; + Alignment top signal output step, a test current passes a test current through the probe And ball pad input to form a loop inside the wafer; and a detection and comparison step is to receive the voltage signal of the wafer loop output from the ball pad and compare it with a preset value to detect the inside of the wafer. Short circuit or open circuit conditions. 2 · According to the test method of the wafer in the bare die state described in item 1 of the scope of the patent application, in the positioning step, the robot module can be used to grip and transfer the wafer module to the positioning base · on the stage ° 3 According to the test method of the wafer in the bare state described in item (2) of the scope of the patent application, in the positioning step, the wafer module can be transported to the positioning base by using a conveyor belt transmission method. The test device of the wafer in the bare die state mainly includes-a rack,-a positioning base set on the rack =, and a test stand on a rack below the positioning base is set on the positioning base. A positioning device for pressing wafer modules to achieve positioning, and a lifting device such as a patent application and a lifting device that can be linked to the testing table, which are located below the testing table; among them, the top surface of the testing table is matched with bare The wafer line in the crystalline state is provided with a plurality of probes, and the test bench is also connected with a tester that can provide a test current and receive a detection voltage. a _ The test device for a wafer in a bare state according to item 4 of the scope of the patent application, wherein the positioning device has a plurality of guide rods standing on a positioning abutment, and a guide rod capable of following the guide rods A component such as a pressing seat for lifting and displacing is provided with a groove on the pressing seat corresponding to the placement of the wafer, so that when the pressing seat lowers the substrate of the pressing wafer module, the wafer can be relatively extended into the depression. Those in the slot. & The testing device for the wafer in bare state according to item 4 of the scope of the patent application, wherein the lifting device can be a hydraulic cylinder, and the hydraulic cylinder has a telescopic rod that can be telescopically moved, and the telescopic rod The other end is fixed at the bottom of the test bench. Page 13