Semiconductor wafer film laminating device and film laminating method

Abstract

The present invention relates to a semiconductor wafer film lamination device and method, belonging to the field of semiconductor production. The device includes a body, a vacuum wafer holding table and a film lamination mechanism disposed within the body, and a chamber vacuum duct disposed at the bottom of the body. The vacuum wafer holding table includes a table top and legs with interconnected internal spaces, the interconnected internal space between the table top and the legs forming a chamber B, the legs being connected to the wafer holding table vacuum duct for evacuating chamber B, one or more wafer holding areas disposed on the table top, each of which is provided with evenly distributed circular holes. The film lamination mechanism is disposed on a lifting device. Initially, the film lamination mechanism is higher than the vacuum wafer holding table, and the lifting device is lowered to cover the blue film on the table top of the vacuum wafer holding table. During film lamination, there is an air pressure difference between chambers A and B, with the pressure value of chamber B being lower than that of chamber A. The present invention can effectively remove bubbles between the blue film and the wafer, reduce adhesion between the blue film and the device, and facilitate wafer removal.

Description

Technical Field

[0001] The present invention relates to a semiconductor wafer film laminating device and a film laminating method, which are suitable for many occasions such as laminating before wafer grinding, laminating before cutting, and laminating before testing. It has the characteristics of no bubbles and convenient wafer removal, and belongs to the field of semiconductor production technology. Background Art

[0002] During the semiconductor production process, wafer grinding, cutting, testing and other steps, due to the thin thickness of the wafer (70-200μm), it is not convenient to fix the wafer, and a blue film is needed as a carrier to hold the wafer. This process involves laminating the wafer to the blue film. During the ordinary laminating process, bubbles will remain between the blue film and the wafer. The bubbles vary in size, usually with a diameter of 0.5mm-5mm and a height of 0.2mm-0.5mm. The presence of bubbles affects the height of the wafer, which will cause problems such as chip cracking, inaccurate testing, and chip falling during subsequent grinding, testing, and cutting.

[0003] To address air bubbles during the lamination process, the blue film is often pressed repeatedly to dislodge them. This method can partially resolve the problem, but it is less effective for large wafer sizes, such as 4-12 inches. Repeated pressing can cause excessive adhesion between the blue film and the lamination machine, making it difficult to remove the wafer after lamination. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a semiconductor wafer film laminating device and a film laminating method, which can effectively remove bubbles between the blue film and the wafer, reduce the adhesion between the blue film and the device, and facilitate wafer removal.

[0005] Explanation of terms:

[0006] Frame: commonly known as "iron ring" or "frame", it is actually a metal frame used to support the blue film. Since the blue film is flexible, it needs to be supported by a frame. This is a professional term in this field and is an existing structure.

[0007] The present invention adopts the following technical solutions:

[0008] A semiconductor wafer film attaching device comprises a body, a vacuum wafer stage and a film attaching mechanism are provided in the body, a chamber cover is provided on the top of the body, and a chamber vacuum pipe is provided at the bottom of the body for evacuating a chamber A inside the body;

[0009] The vacuum wafer holding table includes a table top and legs with interconnected internal spaces, wherein the internal space between the table top and the legs forms a chamber B, and the legs are connected to a wafer holding table vacuum pipe for evacuating the chamber B. The table top is provided with one or more wafer holding areas, each of which is provided with evenly distributed circular holes, through which the wafer can be vacuum-adsorbed on the wafer holding area;

[0010] The film attaching mechanism is arranged on the lifting device. Initially, the height of the film attaching mechanism is higher than the vacuum wafer table. The blue film is covered on the table surface of the vacuum wafer table by descending the lifting device.

[0011] When the film is applied, there is a pressure difference between the chamber A and the chamber B, and the pressure value of the chamber B is lower than the pressure value of the chamber A.

[0012] The chamber A (the area inside the machine body except the vacuum wafer table) and chamber B of the present invention are two independent vacuum environments, which can be evacuated through the chamber vacuum pipe and the wafer table vacuum pipe respectively. There is an air pressure difference between the two vacuum environments, which can not only ensure the vacuum of chamber A, but also enable the chip to be vacuumed to the desired position.

[0013] Preferably, workpiece grooves are provided on both sides of the table for easy removal of the film. The workpiece grooves are formed by recessing a certain depth (3-5mm) on both sides of the upper surface of the film receiving area, making it convenient for fingers of both hands to remove the frame from the recessed area.

[0014] Preferably, the lifting device is two cylinders, which are respectively located at the two ends of the wafer platform, and the top ends of the piston rods of the two cylinders are provided with a bearing area;

[0015] The film attaching mechanism comprises a film winding roller and a traction roller, and the film winding roller and the traction roller are respectively placed on the bearing areas of the two cylinders.

[0016] The film attaching mechanism used in the present invention is a common mechanism in this field. A blue film reel is set on the film winding roller, and the traction roller pulls the other end of the blue film, which can be stretched manually to tighten and fix the blue film and make the blue film located above the sheet-carrying area. The blue film is covered on the table surface by the up and down movement of two cylinders.

[0017] Before chamber A is energized with vacuum, the chamber cover can be opened, the blue film can be manually tightened and both ends of the blue film can be fixed on the load-bearing area. The chamber cover is closed, and chamber A is energized with vacuum again. The tightened blue film follows the piston rods of the two cylinders and descends to cover the table.

[0018] Preferably, silicone oil paper is placed on the wafer holding area. The silicone oil paper has holes, which can transmit vacuum and prevent the blue film from adhering to the wafer holding table and affecting the wafer taking frame.

[0019] Preferably, the diameter of the circular holes on the carrier area is less than 1.5 mm, and the distance between the centers of two adjacent circular holes is 5 mm;

[0020] The diameter of the holes in the silicone oil paper is 5-7 mm, the holes are evenly distributed, and the distance between the centers of two adjacent holes is 1-1.5 cm.

[0021] The circular holes on the wafer receiving area and the holes in the silicone oil paper do not need to be set correspondingly, and can be staggered to achieve wafer fixation.

[0022] Preferably, during film application, the pressure in chamber A is maintained at 5-10 Torr, and the pressure in chamber B is maintained at <5 Torr.

[0023] Preferably, one side of the chamber cover is hinged to one side of the machine body.

[0024] In the present invention, to prevent air leakage, O-rings can be installed at the joints between the machine body and various structures for sealing, such as the joint between the machine body top and the chamber cover, the joint between the machine body and the chamber vacuum line, the joint between the machine body and the wafer stage vacuum line, and the joint between the machine body and the cylinder. Because chamber A does not operate at a high vacuum, this sealing method is a mature technology in the art and will not be described in detail here.

[0025] Preferably, a heating device is provided under the tabletop of the vacuum wafer holding table, and an existing heating rod or other heating plate can be used. There is no limitation here and it does not affect the implementation of the present invention.

[0026] The above-mentioned film attaching method of the semiconductor wafer film attaching equipment comprises the following steps:

[0027] (1) Open the chamber cover and place a blue film or other film material on the bearing area of ​​one of the cylinders;

[0028] (2) Heat the tabletop of the vacuum wafer carrier to a set temperature of 45-70°C;

[0029] (3) Place silicone oil paper on the wafer holding area, and place the wafer and frame on the surface of the silicone oil paper; the surface of the silicone oil paper has holes to facilitate vacuum suction of the vacuum wafer holding table;

[0030] (4) Open the vacuum channel of the wafer stage, the vacuum degree can be less than 5 torr, and use vacuum adsorption to fix the wafer;

[0031] (5) stretching the blue film from the film winding roller to the traction roller, and fixing the tail end of the blue film to the traction roller;

[0032] (6) Open the chamber vacuum pipe and the vacuum degree reaches 5-10 torr. After the vacuum is stable for 0.5-1 minute, the two cylinders are simultaneously lowered to the table position of the vacuum wafer table or slightly below the table position, and the blue film is covered on the table surface of the vacuum wafer table;

[0033] When applying the film, the inside of the machine body is in a vacuum state, and no bubbles will be generated between the blue film and the wafer in the vacuum state;

[0034] (7) Break the vacuum in chamber A and chamber B to atmospheric pressure;

[0035] The chamber vacuum pipe and the wafer stage vacuum pipe of the present invention are both provided with electromagnetic valves. When the vacuum needs to be broken, the electromagnetic valves are opened to break the vacuum and eventually reach atmospheric pressure.

[0036] (8) Open the chamber cover, use the existing tool to cut the blue film, take down the frame from the film removal location (i.e. the workpiece slot), and the two cylinders rise and return to their positions to complete the wafer film attachment.

[0037] In the present invention, one wafer can be placed on the wafer receiving area, or the design of the wafer receiving area can be changed to achieve the placement of 2-3 wafers.

[0038] Where the present invention is not exhaustive, existing technologies may be used.

[0039] The beneficial effects of the present invention are:

[0040] 1. The present invention adopts two independent vacuum channels, that is, chamber A and chamber B are independent of each other, and there is a pressure difference between chamber A and chamber B. It can not only use vacuum adsorption to fix the wafer, but also make chamber A a vacuum environment, so that no bubbles are left between the blue film and the wafer.

[0041] 2. The wafer table of the present invention is attached with silicone oil paper, and there will be no adhesion between the silicone oil paper and the blue film. After the film is pasted, the blue film only adheres to the wafer and does not adhere to the wafer table, which is convenient for taking out the wafer and effectively avoids the situation where the blue film adheres to the wafer table area and affects the wafer taking out.

[0042] 3. The wafer position of the present invention is always fixed and is always located in a vacuum environment. The film lamination process is achieved by moving the blue film up and down, which ensures the fixity of the wafer position and the stability of the vacuum environment, and the film lamination effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of a semiconductor wafer film attaching device of the present invention;

[0044] Figure 2 A top view of a semiconductor wafer film attaching device according to the present invention;

[0045] Figure 3 This is a schematic structural diagram of the silicone oil paper of the present invention;

[0046] Among them, 1-body, 2-vacuum wafer carrier, 3-chamber cover, 4-chamber vacuum pipe, 5-chamber A, 6-table, 7-leg, 8-chamber B, 9-wafer carrier vacuum pipe, 10-round hole, 11-silicone oil paper, 12-hole, 13-cylinder A, 14-cylinder B, 15-carrying area A, 16-carrying area B, 17-Frame, 18-film removal area. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, they will be described in detail below with reference to the accompanying drawings and specific embodiments, but are not limited thereto. Matters not fully described in the present invention shall be based on conventional techniques in the art.

[0048] Example 1:

[0049] A semiconductor wafer laminating device, such as Figure 1-3 As shown, it includes a body 1, a vacuum wafer stage 2 and a film attaching mechanism are provided in the body 1, a chamber cover 3 is provided on the top of the body 1, and a chamber vacuum pipe 4 is provided at the bottom of the body 1 for evacuating the chamber A 5 inside the body 1;

[0050] The vacuum wafer holding table 2 includes a table top 6 and legs 7, the internal spaces of which communicate with each other. The internal space between the table top 6 and the legs 7 forms a chamber B 8. The legs 7 are connected to a wafer holding table vacuum pipe 9 for evacuating the chamber B 8. The table top 6 is provided with one or more wafer holding areas, each of which is provided with evenly distributed circular holes 10. The circular holes 10 allow the wafer to be vacuum-adsorbed onto the wafer holding area.

[0051] The film attaching mechanism is set on the lifting device. Initially, the height of the film attaching mechanism is higher than the vacuum wafer table 2. The blue film is covered on the table surface 6 of the vacuum wafer table by the lowering of the lifting device.

[0052] When laminating, there is a pressure difference between chamber A5 and chamber B8, and the pressure value of chamber B8 is lower than the pressure value of chamber A5.

[0053] The chamber A5 (the area inside the machine body except the vacuum wafer table) and the chamber B8 of the present invention are two independent vacuum environments, which can be evacuated respectively through the chamber vacuum pipe 4 and the wafer table vacuum pipe 9. There is an air pressure difference between the two vacuum environments, which can not only ensure the vacuum of chamber A, but also enable the wafer to be vacuumed to the desired position.

[0054] Example 2:

[0055] A semiconductor wafer film bonding device has a structure as described in Example 1, except that workpiece grooves are provided on both sides of the table 6 for facilitating wafer removal. The workpiece grooves are formed by recessing a certain depth (3-5mm) on both sides of the upper surface of the wafer receiving area, making it convenient for fingers of both hands to remove Frame 17 from the recess.

[0056] Example 3:

[0057] A semiconductor wafer laminating device having the same structure as that described in Example 1, except that the lifting device comprises two cylinders, one at each end of the wafer stage, namely cylinder A 13 and cylinder B 14. The top end of the piston rod of cylinder A 13 is provided with a bearing area A 15, and the top end of the piston rod of cylinder B is provided with a bearing area B 16.

[0058] The film attaching mechanism includes a film winding roller and a pulling roller, which are placed on the carrying area A 15 and the carrying area B 16 respectively.

[0059] The film attaching mechanism used in the present invention is a common mechanism in this field. A blue film reel is set on the film winding roller, and the traction roller pulls the other end of the blue film. It can be stretched manually to tighten and fix the blue film and make the blue film located above the sheet-carrying area. The blue film is covered on the table surface by moving up and down simultaneously through two cylinders.

[0060] Example 4:

[0061] A semiconductor wafer laminating device, having the same structure as that described in Example 3, except that a silicone oil paper 11 is placed on the wafer receiving area, and the silicone oil paper 11 has holes 12. The silicone oil paper can also be replaced by commonly used steamer paper.

[0062] The diameter of the circular holes 10 on the receiving area is less than 1.5 mm, and the distance between the centers of two adjacent circular holes is 5 mm;

[0063] The diameter of the holes 12 of the silicone oil paper 11 is 5-7 mm, the holes are evenly distributed, and the distance between the centers of two adjacent holes is 1-1.5 cm.

[0064] The circular holes on the wafer receiving area and the holes in the silicone oil paper do not need to be set correspondingly, and can be staggered to achieve wafer fixation.

[0065] Example 5:

[0066] A semiconductor wafer film lamination device has a structure as described in Example 4, except that during film lamination, the pressure value of chamber A5 is 5-10 torr, and the pressure value of chamber B8 is <5 torr.

[0067] Example 6:

[0068] A semiconductor wafer film bonding device has a structure as described in Example 1, except that one side of the chamber cover 3 is hinged to one side of the body, and an O-ring is provided at the connection between the top of the body 1 and the chamber cover 3.

[0069] Example 7:

[0070] A method for laminating a semiconductor wafer using a laminating device, comprising the following steps:

[0071] (1) Open the chamber cover 3 and place a blue film on the bearing area of ​​one of the cylinders;

[0072] (2) Heating the table 6 of the vacuum wafer holding table to a set temperature of 45-70°C;

[0073] (3) Place silicone oil paper 11 in the wafer holding area, and place the wafer and Frame 17 on the surface of the silicone oil paper 11; the surface of the silicone oil paper has holes 12 to facilitate vacuum suction of the vacuum wafer holding table;

[0074] (4) Open the wafer stage vacuum channel 9, the vacuum degree is less than 5 torr, and the wafer is fixed by vacuum adsorption;

[0075] (5) stretching the blue film from the film winding roller to the traction roller, and fixing the tail end of the blue film to the traction roller;

[0076] (6) Open the chamber vacuum pipe 4, and the vacuum degree reaches 5-10 torr. After the vacuum is stable for 0.5-1 minute, the two cylinders are simultaneously lowered to a position slightly lower than the table surface, and the blue film is covered on the table surface 6 of the vacuum holding table;

[0077] When applying the film, the inside of the machine body is in a vacuum state, and no bubbles will be generated between the blue film and the wafer in the vacuum state;

[0078] (7) Break the vacuum in chamber A and chamber B to atmospheric pressure;

[0079] The chamber vacuum pipe and the wafer stage vacuum pipe of the present invention are both provided with electromagnetic valves. When the vacuum needs to be broken, the electromagnetic valves are opened to break the vacuum and eventually reach atmospheric pressure.

[0080] (8) Open the chamber cover 9, use the existing tool to cut the blue film, take down the frame 17 from the film taking place 18 (i.e. the workpiece slot), and the two cylinders rise and return to their positions to complete the wafer film bonding.

[0081] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for laminating a semiconductor wafer using a laminating device, characterized in that: The semiconductor wafer film attaching equipment includes a body, a vacuum wafer stage and a film attaching mechanism are provided in the body, a chamber cover is provided on the top of the body, and a chamber vacuum pipe is provided at the bottom of the body for evacuating the chamber A inside the body; The vacuum wafer table includes a table top and legs with interconnected internal spaces, wherein the internal space between the table top and the legs forms a chamber B, and the legs are connected to a wafer table vacuum pipe for evacuating the chamber B. The table top is provided with one or more wafer holding areas, each of which is provided with evenly distributed circular holes. The film attaching mechanism is arranged on the lifting device. Initially, the height of the film attaching mechanism is higher than the vacuum wafer table. The blue film is covered on the table surface of the vacuum wafer table by descending the lifting device. When applying the film, there is a pressure difference between the chamber A and the chamber B, and the pressure value of the chamber B is lower than the pressure value of the chamber A; Both sides of the table are provided with workpiece slots for facilitating the taking of the sheets; A silicone oil paper with holes is placed on the substrate area; During film application, the pressure in chamber A is 5-10 torr, and the pressure in chamber B is less than 5 torr. A method for laminating a semiconductor wafer using a laminating device comprises the following steps: (1) Open the chamber cover and place a blue film on the bearing area of ​​one of the cylinders; (2) Raise the temperature of the vacuum table to the set temperature of 45-70°C; (3) Place silicone oil paper on the wafer receiving area, and place the wafer and frame on the surface of the silicone oil paper; (4) Open the vacuum channel of the wafer stage, the vacuum degree is <5 torr, and the wafer is fixed by vacuum adsorption; (5) stretching the blue film from the film winding roller to the traction roller, and fixing the tail end of the blue film to the traction roller; (6) Open the chamber vacuum pipe and the vacuum degree reaches 5-10 torr. After the vacuum is stable for 0.5-1 minute, the two cylinders are simultaneously lowered to the table position of the vacuum wafer table or a position below the table position, and the blue film is covered on the table surface of the vacuum wafer table; (7) Break the vacuum in chamber A and chamber B to atmospheric pressure; (8) Open the chamber cover, use the existing tool to cut the blue film, remove the frame from the film removal position, that is, the workpiece slot, and the two cylinders rise and return to their positions to complete the wafer film attachment; The lifting device is composed of two cylinders, which are respectively located at the two ends of the wafer holding platform, and the top ends of the piston rods of the two cylinders are provided with a bearing area; The film attaching mechanism includes a film winding roller and a traction roller, which are respectively placed on the bearing areas of the two cylinders; The diameter of the circular holes on the receiving area is less than 1.5 mm, and the distance between the centers of two adjacent circular holes is 5 mm; The diameter of the holes in the silicone oil paper is 5-7 mm, the holes are evenly distributed, and the distance between the centers of two adjacent holes is 1-1.5 cm.

2. The film attaching method of semiconductor wafer film attaching equipment according to claim 1, characterized in that: One side of the chamber cover is hinged to one side of the machine body.

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