A tool set and method for detecting chip craters in a wafer flip-chip process

Abstract

The present invention discloses a tool set and method for detecting chip craters in a wafer flip-chip process. The tool set includes a paper cup, a first beaker, a second beaker, a third beaker, a stirring rod, a heating table, an ultrasonic cleaner, a special bracket, tweezers, a glass plate, double-sided tape, and a high-power microscope; the special bracket includes a connecting rod, a handle, and a bracket body that can extend into the second beaker; the surface of the bracket body is recessed with a product groove for placing and supporting the FCB product, and the bottom surface of the product groove is provided with a separation port that penetrates the bottom surface of the bracket body and is adapted to the chip. By adopting the tool set and method of the present invention, the quality of the current chip natural separation technology for the FCB product crater experiment can be improved, more accurate crater experiment results can be obtained, the unstable factors of the current method can be solved, the quality and efficiency of the FCB crater experiment can be improved, the report passing rate can be increased, and the time and material costs for rework can be reduced.

Description

Technical Field

[0001] The present invention relates to the technology in the field of wafer production, and particularly to a tool set and method for detecting chip craters in a wafer flip-chip process. Background Art

[0002] In the chip flip-chip process, the connection between the gold bumps of the chip and the substrate is the most basic guarantee for packaging and an important link. In order to monitor the connection points between the chip and the substrate, it is necessary to conduct a crater experiment in the quality inspection items. The crater experiment is carried out after Wire Boding or Flip chip bonding. The product is immersed in a strong acid or strong alkali solution to separate the chip and the substrate. After the chip naturally separates from the substrate without external force interference, the pads of the chip are observed. By checking whether the pads are damaged and the crater phenomenon, it is confirmed whether the current process parameters need to be adjusted.

[0003] Currently, the tools used for detecting chip craters in the wafer flip-chip process are relatively simple. The common method is to soak the product after chip flip-chip with a certain proportion of potassium hydroxide solution. After a certain soaking time, the chip automatically separates from the substrate. This crater experiment method has always had problems such as chip pad damage, and the experimental results are very unstable. Therefore, it is necessary to study a solution to solve the above problems. Summary of the Invention

[0004] In view of this, in view of the deficiencies of the existing technology, the main purpose of the present invention is to provide a tool set and method for detecting chip craters in a wafer flip-chip process, which can effectively improve the quality of the crater experiment.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A tool set for detecting chip craters in a wafer flip-chip process includes a paper cup, a first beaker, a second beaker, a third beaker, a stirring rod, a heating table, an ultrasonic cleaner, a special bracket, tweezers, a glass plate, double-sided tape, and a high-power microscope; the second beaker is removably disposed on the heating table or the ultrasonic cleaner; the special bracket includes a connecting rod, a handle, and a bracket body that can extend into the second beaker; a product groove for placing and supporting the FCB product is recessed on the surface of the bracket body, and a separation port that penetrates the bottom surface of the bracket body and is adapted to the chip is opened on the bottom surface of the product groove; one end of the connecting rod is fixedly connected to the bracket body; the handle is fixedly connected to the other end of the connecting rod; the double-sided tape is disposed on the glass plate, and the glass plate is removably disposed on the high-power microscope.

[0007] Preferably, there are two connecting rods arranged left and right, one ends of the two connecting rods are respectively fixedly connected to the left and right sides of the bracket body, there are two handles arranged left and right, and the two handles are respectively fixedly connected to the other ends of the corresponding connecting rods.

[0008] Preferably, the connecting rod extends vertically and the handle extends horizontally.

[0009] Preferably, the connecting rod and the bracket body are fixedly connected by welding.

[0010] A method for detecting chip craters in a wafer flip-chip process, using the aforementioned tool set for detecting chip craters in a wafer flip-chip process, includes the following steps:

[0011] (1) Weigh 11.5 g of potassium iodide and 6.5 g of iodine separately using a paper cup in proportion.

[0012] (2) Prepare 15 ml of pure water in the first beaker.

[0013] (3) Put the weighed 11.5 g of potassium iodide into the second beaker.

[0014] (4) Then pour the pure water in the first beaker into the second beaker, stir with a stirring rod, and then place the second beaker on a heating platform and heat it to 40 °C, stirring while heating.

[0015] (5) Put the second beaker containing the potassium iodide solution into an ultrasonic cleaner and vibrate it for 1 minute.

[0016] (6) After vibrating for 1 minute, add 6.5 g of iodine, continue to stir with a stirring rod, and place the second beaker on a heating platform and heat it to 40 °C.

[0017] (7) Then put the second beaker into the ultrasonic cleaner and vibrate it for 1 minute again.

[0018] (8) Place the prepared FCB product in the product slot of a special bracket, and place the chip of the FCB product downward in the product slot.

[0019] (9) Then move the special bracket carrying the FCB product and immerse it in the solution prepared in the second beaker for 5 minutes.

[0020] (10) When the solution reacts with the gold bumps and the chip pads, the chip pads and the gold bumps are separated, and the chip separates from the substrate downward under its own weight.

[0021] (11) Record the separation time when the chip falls off, take out the special bracket, and use tweezers to pick up the chip from the second beaker and put it into the third beaker.

[0022] (12) Then add pure water to wash the chip, pick up the chip from the third beaker with tweezers, fix the back of the chip on a glass plate with double-sided tape, and finally observe the result of crater detection with a high-power microscope.

[0023] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0024] By adopting the tool kit and method of the present invention, the quality of the natural separation technology of the current FCB product crater test chip can be improved, more accurate crater test results can be obtained, and the unstable factors of the current method can be solved. The quality and efficiency of the FCB crater test can be improved, the report passing rate can be increased, and the time and material cost of re-doing can be reduced.

[0025] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three-dimensional schematic diagram of a preferred embodiment of the present invention;

[0027] Figure 2 is an enlarged three-dimensional schematic diagram of a special bracket in a preferred embodiment of the present invention;

[0028] Figure 3 is a side view of an FCB product in a preferred embodiment of the present invention;

[0029] Figure 4 is a top view of an FCB product in a preferred embodiment of the present invention;

[0030] Figure 5 It is a reverse side view of the FCB product in a preferred embodiment of the present invention.

[0031] Description of the accompanying drawings:

[0032] 11. Paper cup 12. First beaker

[0033] 13. Second beaker 14. Third beaker

[0034] 15. Stirring rod 16. Heating table

[0035] 17. Ultrasonic cleaning machine 20. Special bracket

[0036] 21. Connecting rod 22. Handle

[0037] 23. bracket body 201, product slot

[0038] 202, separation port 31, tweezers

[0039] 32. Glass plate 33. Double-sided tape

[0040] 34. High-power microscope 40. FCB products

[0041] 41. Chip 42. Substrate

[0042] 401, Gold bump; 402, Chip pad Detailed implementation mode

[0043] Please refer to Figure 1 and Figure 2 As shown in

[0044] and

[0045] which shows the specific structure of a tool set for detecting chip craters in a wafer flip-chip process according to a preferred embodiment of the present invention, including a paper cup 11, a first beaker 12, a second beaker 13, a third beaker 14, a stirring rod 15, a heating table 16, an ultrasonic cleaner 17, a special bracket 20, tweezers 31, a glass plate 32, double-sided tape 33 and a high-power microscope 34.

[0046] The second beaker 13 is removably disposed on the heating table 16 or the ultrasonic cleaner 17; the special bracket 20 includes a connecting rod 21, a handle 22 and a bracket body 23 that can extend into the second beaker 13; a product groove 201 for placing and supporting the FCB product 40 is recessed on the surface of the bracket body 23, and a separation opening 202 that penetrates the bottom surface of the bracket body 23 and is adapted to the chip 41 is provided at the bottom of the product groove 201; one end of the connecting rod 21 is fixedly connected to the bracket body 23; the handle 22 is fixedly connected to the other end of the connecting rod 21; the double-sided tape 33 is disposed on the glass plate 32, and the glass plate 32 is removably disposed on the high-power microscope 34.

[0047] In this embodiment, there are two connecting rods 21 arranged left and right, one ends of the two connecting rods 21 are respectively fixedly connected to the left and right sides of the bracket body 23, there are two handles 22 arranged left and right, the two handles 22 are respectively fixedly connected to the other ends of the corresponding connecting rods 21, the connecting rods 21 extend vertically, the handles 22 extend horizontally, and the connecting rods 21 and the bracket body 23 are fixedly connected by welding.

[0048]

[0049]

[0050]

[0051] (1) Weigh 11.5 g of potassium iodide and 6.5 g of iodine respectively using the paper cup 11 according to the ratio.(2) Prepare 15 ml of pure water in the first beaker 12.(3) Put the weighed 11.5 g of potassium iodide into the second beaker 13. (4) Then pour the pure water in the first beaker 12 into the second beaker 13, stir with the stirring rod 15, and then place the second beaker 13 on the heating table 16 and heat it to 40 °C, stirring while heating.(5) Place the second beaker 13 containing potassium iodide solution into the ultrasonic cleaner 17 and vibrate for 1 minute.

[0052] (6) After vibrating for 1 minute, add 6.5 g of iodine, continue to stir with the stirring rod 15, and place the second beaker 13 on the heating platform 16 and heat to 40 °C.

[0053] (7) Then place the second beaker 13 into the ultrasonic cleaner 17 again and vibrate for 1 minute.

[0054] (8) Place the prepared FCB product 40 into the product slot 201 of the special bracket 20, and place the chip 41 of the FCB product 40 downward (as shown) in the product slot 201. Figure 5 shown) in the product slot 201.

[0055] (9) Then move the special bracket 20 carrying the FCB product 40 and immerse it in the prepared solution in the second beaker 13 for 5 minutes.

[0056] (10) When the solution reacts with the gold bumps 401 and the chip pads 402, the chip pads 402 and the gold bumps 401 are separated, and the chip 41 separates from the substrate 42 downward under its own weight.

[0057] (11) Observe and record the separation time when the chip 41 falls off, take out the special bracket 20, use the tweezers 31 to pick up the chip 41 from the second beaker 13 and put it into the third beaker 14.

[0058] (12) Then add pure water to clean the chip 41, take out the chip 41 from the third beaker 14 with the tweezers 31, then fix the back of the chip 41 on the glass plate 32 with double-sided tape 33, and finally observe the result of the crater detection with a high-power microscope 34.

[0059] Thus, the process of the chip crater experiment is completed. The results of 4 repeated crater experiments are as follows:

[0060] Example The 1st time The 2nd time The 3rd time The 4th time Separation time 5.2 min 4.9 min 5.6 min 5.3 min Crater result Pass Pass Pass Pass

[0061] The design focus of the present invention is: by adopting the tool set and method of the present invention, the quality of the chip natural separation technology in the current FCB product crater experiment can be improved, more accurate crater experiment results can be obtained, the unstable factors of the current method can be solved, the quality and efficiency of the FCB crater experiment can be improved, the report passing rate can be increased, and the time and material costs of rework can be reduced.

[0062] The technical principle of the present invention has been described in conjunction with specific embodiments above. These descriptions are only for explaining the principle of the present invention and cannot be construed as limiting the protection scope of the present invention in any way. Based on the explanations herein, those skilled in the art can readily conceive of other specific embodiments of the present invention without creative efforts, and these embodiments will fall within the protection scope of the present invention.

Claims

1. A tool set for detecting chip craters in a wafer flip-chip process, characterized in that: It includes a paper cup, a first beaker, a second beaker, a third beaker, a stirring rod, a heating table, an ultrasonic cleaner, a special bracket, tweezers, a glass plate, double-sided tape, and a high-power microscope; the second beaker is removably disposed on the heating table or the ultrasonic cleaner; the special bracket includes a connecting rod, a handle, and a bracket body that can extend into the second beaker; a product groove for placing and supporting the FCB product is recessed on the surface of the bracket body, and a separation opening that penetrates the bottom surface of the bracket body and is adapted to the chip is opened on the bottom surface of the product groove; one end of the connecting rod is fixedly connected to the bracket body; the handle is fixedly connected to the other end of the connecting rod; the double-sided tape is disposed on the glass plate, and the glass plate is removably disposed on the high-power microscope.

2. A tool set for detecting chip craters in a wafer flip-chip process according to claim 1, characterized in that: There are two connecting rods arranged left and right, one ends of the two connecting rods are respectively fixedly connected to the left and right sides of the bracket body, there are two handles arranged left and right, and the two handles are respectively fixedly connected to the other ends of the corresponding connecting rods.

3. A tool set for detecting chip craters in a wafer flip-chip process as described in claim 1, characterized in that: The connecting rod extends vertically, and the handle extends horizontally.

4. A tool set for detecting chip craters in a wafer flip-chip process according to claim 1, characterized in that: The connecting rod and the bracket body are fixedly connected by welding.

5. A method for detecting chip craters in a wafer flip-chip process, characterized in that: Adopt a tool set for detecting chip craters in a wafer flip-chip process as described in any one of claims 1-4, including the following steps: (1) Weigh 11.5 g of potassium iodide and 6.5 g of iodine respectively in a paper cup according to the ratio. (2) Prepare 15 ml of pure water in the first beaker. (3) Put the weighed 11.5 g of potassium iodide into the second beaker. (4) Then pour the pure water in the first beaker into the second beaker, stir with a stirring rod, and then place the second beaker on the heating table and heat it to 40 °C, stirring while heating. (5) Put the second beaker containing the potassium iodide solution into the ultrasonic cleaner and vibrate for 1 minute. (6) After vibrating for 1 minute, add 6.5 g of iodine, continue to stir with a stirring rod, and place the second beaker on the heating table and heat it to 40 °C. (7) Then put the second beaker into the ultrasonic cleaner again and vibrate for 1 minute. (8) Place the prepared FCB product in the product groove of the special bracket, and place the chip of the FCB product downward in the product groove. (9) Then move the special bracket carrying the FCB product and immerse it in the prepared solution in the second beaker for 5 minutes. (10) When the solution reacts with the gold bumps and the chip pads, the chip pads and the gold bumps are separated, and the chip separates from the substrate downward under its own weight. (11) Observe and record the separation time when the chip falls off, take out the special bracket, and use tweezers to pick out the chip from the second beaker and put it into the third beaker. (12) Then add pure water to clean the chip, take out the chip from the third beaker with tweezers, fix the back of the chip on the glass plate with double-sided tape, and finally observe the result of crater detection with a high-power microscope.

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