A wire drawing and cutting method for package without residual adhesive

Abstract

The invention discloses a method for drawing and cutting a package body without residual glue, comprising the following steps: a first coating step: covering a surface of a packaged whole board after packaging with a fixed film A; a cutting path irradiation step: using a digital imaging exposure device to align the surface of the packaged whole board covered with the fixed film A and irradiate and irradiate the fixed film A corresponding to the cutting path area of ​​the packaged whole board, so that the irradiated part of the fixed film A is solidified and the unirradiated part of the fixed film A remains sticky; a second coating step: continuing to cover the fixed film B on the side of the fixed film A away from the packaged whole board; using a cutting knife to vertically cut the packaged whole board at the cutting path position from the opposite surface of the packaged whole board covered with the fixed film A. The invention loses stickiness by covering a thicker fixed film A for the first time and irradiating and curing in the cutting path area, so that no stickiness drawing occurs during cutting, and a thinner fixed film B is covered on the fixed film A for the second time, so that the fixed film A is bonded as a whole to avoid cutting flying materials.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor finished product cutting, and in particular relates to a wiredrawing cutting method for a package body without residual glue. Background Art

[0002] The packaging process generally arranges at least one bare chip neatly, and then uses a series of technologies to achieve the layout, connection, and encapsulation of each bare chip. After the encapsulation is cured, the encapsulation as a whole needs to be cut into product units, that is, the encapsulation material is cut vertically on the cutting path in the safe area through the cutting process until the final product is formed. After the cutting is completed, the surface of the product is prone to adherence to cutting waste and dust, and needs to be cleaned with cleaning equipment to ensure that the product's appearance is qualified.

[0003] In the current panel-level fan-out packaging process, the final molding and cutting of the product is mainly divided into two methods: Jig saw and Tape saw. Among them, Jig saw is mainly limited by the capacity of the equipment, that is, the package size range is basically large, and small-sized packages are difficult to cut using Jip saw, so Tape saw is more widely used, while Tape In the saw process, in order to ensure the requirements of product molding and to prevent product flying during cutting, a fixed film is an indispensable condition. The package is adhered to the fixed film as a whole for cutting, and the lower part is cut to the upper part of the fixed film without cutting off to ensure that the product unit is completely cut. However, since blade cutting is mainly a structural destructive process, the blade cutting the fixed film causes residual glue, and the residual glue is mixed with the product and is not easy to separate. In addition, the cutting knife will bring out glue threads after cutting, which will adhere to the side and bottom of a single product. Although UV glue threads can be dissolved by special potions, the larger the glue thread particles, the longer the dissolution time required. The longer the dissolution time, the more abnormal quality conditions such as whitening of the surface of the product plastic packaging material will be caused. If the dissolution time is insufficient, glue threads will remain. The remaining glue threads will affect the efficiency of the next process product quality test and cause the product appearance to be unqualified. In addition, the glue threads will roll up in the cutting path during cutting, making it impossible to see the cutting path during cutting, resulting in cutting errors. Summary of the invention

[0004] In order to solve the above problems in the prior art, the present invention provides a wire drawing and cutting method for a package without residual adhesive.

[0005] To achieve the above object, the present invention provides a method for wiredrawing and cutting a package without residual adhesive, comprising the following steps: The first film coating step: Covering one surface of the packaged whole board with a fixed film A; Cutting line irradiation step: using a digital imaging exposure device to align the surface of the packaged whole board covering the fixed film A and expose and irradiate the fixed film A corresponding to the cutting line area of ​​the packaged whole board, so that the irradiated part of the fixed film A is solidified, and the unirradiated part of the fixed film A remains sticky; Second laminating step: continue to cover the fixed film B on the side of the fixed film A away from the packaged whole board; Finished product cutting steps: Use a cutting knife to vertically cut the entire package board at the cutting path position from the opposite surface of the package entire board covered with the fixed film A. The cutting knife completely cuts off the entire package board and cuts the fixed film A. The cutting depth of the fixed film A is less than the thickness of the fixed film A. The fixed film A corresponding to the cutting path position is cured and loses adhesion. There is no residual glue when cutting and separating. Fixed film separation step: remove fixed film A and fixed film B to obtain a finished product unit.

[0006] Furthermore, in the first coating step and the second coating step, the fixed film A and the fixed film B are coated in the same manner, and the thickness of the fixed film A is greater than or equal to the thickness of the fixed film B.

[0007] Furthermore, in the first coating step, the fixed film A is a photosensitive material.

[0008] Furthermore, in the cutting line irradiation step, the digital imaging exposure equipment sets the irradiation time and wavelength according to the thickness of the fixed film A, sets the image information according to the size and position of the cutting line of the packaged whole board, emits ultraviolet light, and irradiates and cures the fixed film A corresponding to the cutting line area to remove the adhesion.

[0009] Furthermore, in the cutting line irradiation step, the width of the irradiated area is symmetrical about the central axis plane of the cutting line of the entire packaging board, and is 1.75 to 2.5 times the width of the cutting line of the entire packaging board.

[0010] Furthermore, in the fixed film separation step, the adhesiveness of the fixed film A and the fixed film B is reduced by a disintegrator, and ultrasonic wave is used to assist in stripping, so that the cut finished unit is peeled off from the fixed film A under vibration.

[0011] Furthermore, the method also includes a finished product inspection step, which includes inspecting the flatness of the cutting edge of the fixed film A after stripping, and inspecting the residual glue and cutting error on the side of the finished product unit.

[0012] The present invention: 1. Through two laminations, the first time, a thicker fixed film A is covered and cured by irradiation in the cutting area to lose its stickiness, so there is no sticky wire drawing during cutting, and there is no residual glue on the side of the finished unit. The second time, a thinner fixed film B is covered on the fixed film A to bond the fixed film A as a whole to avoid cutting flying materials; 2. The fixed film A is irradiated by using a digital imaging exposure device to set the image information according to the size and position of the cutting path of the package whole board, set the irradiation time and irradiation wavelength according to the thickness of the fixed film A, emit ultraviolet light for irradiation, and use laser scanning to directly image the set image information on the fixed film A. The image is more detailed, the resolution is high, the error is small, the cutting is more precise, the exposure width area can be flexibly adjusted, and the irradiation curing degree of the fixed film A is controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A cross-sectional view of a whole package board in a package body wiredrawing and cutting method without residual adhesive of the present invention; Figure 2 A top view of a packaged whole board of a packaged body wire drawing and cutting method without residual adhesive of the present invention; Figure 3 A top view of a cutting path of a whole package board in a wire drawing cutting method for a package without residual adhesive of the present invention; Figure 4 It is a cross-sectional view of the first laminating step of a package body wire drawing and cutting method without residual adhesive of the present invention; Figure 5 A cross-sectional view of a cutting line irradiation step of a package body wire drawing cutting method without residual adhesive of the present invention; Figure 6 It is a cross-sectional view of the second laminating step of a package body wire drawing and cutting method without residual adhesive of the present invention; Figure 7 It is a cross-sectional view of the finished product cutting step of a package body wiredrawing cutting method without residual glue of the present invention.

[0014] In the figure: 1. Encapsulating the whole board; 2. Fixing film A; 3. Cutting road; 4. Fixing film B. DETAILED DESCRIPTION

[0015] The content of the present invention will be explained below in conjunction with specific embodiments, examples of which are shown in the accompanying drawings, wherein the same or similar numbers throughout represent the same or similar components or components with the same or similar functions.

[0016] The directional terms mentioned in the present invention, such as: up, down, left, right, front, back, inside, outside, front, back, side, etc., are only reference directions of the drawings. The embodiments described below with reference to the drawings and the directional terms used are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention. In addition, the various specific process and material examples provided in the present invention are all those skilled in the art who can recognize the application of other processes and / or the use of other materials.

[0017] In order to better understand the purpose, structure and function of the present invention, the following Figure 1 -Attached Figure 6 , a method for wire drawing and cutting a package without residual glue proposed by the present invention is further described in detail.

[0018] Before the various steps of the wire drawing and cutting method for a package body without residual adhesive of the present invention are carried out, it is necessary to first form a package whole board 1 to be cut as a basis for the implementation of subsequent processes.

[0019] Specifically, multiple bare chips are evenly arranged and packaged through layer-by-layer packaging technology to form a packaged whole board 1 as a whole, as shown in the attached Figure 1 and attached Figure 2 As shown, the bare chip can be an optoelectronic device (Optoelectronic Devices), a micro-electromechanical system (MEMS), a power amplifier chip, a power management chip, a biometric identification device, a microfluidic system (Microfluidic Systems), a light-emitting diode (Light-Emitting Diodes, LEDs), a resistor, a capacitor, etc., but is not limited thereto. The selection is made according to the specific product, and the electrical connection structure is also designed according to the specific product. In the final encapsulation, the bare chip and the electrical structure are all encapsulated in the encapsulation material, but the electrical connection port is exposed outside the encapsulation material. After the encapsulation is completed, the electrical properties of the bare chip are led out of the encapsulation material.

[0020] The packaging material used in the present invention can be epoxy resin, cyanate, polyimide, etc., which has low cost and good curing performance. The packaging process plays an important role in the field of semiconductor manufacturing, mainly in protection, connection, support, reliability and promotion of technological progress. The protection function means that the chip packaging can protect the chip from mechanical damage, moisture, dust and other external environmental factors, ensuring the normal operation of the chip in extreme environments; the connection function means that the packaging provides a way to connect the chip with other electronic components, so that the chip can be installed and used on the circuit board; the support function means that the packaging can fix the chip while supporting the chip to prevent it from being damaged; reliability means that the reliability requirements for packaging materials and processes are getting higher and higher, so as to ensure that the chip can operate normally in various extreme environments.

[0021] Then the package board is cut to separate each bare chip and its electrical structure to form a finished product unit. The cutting is carried out in the safe area reserved in the product design. The safe area refers to the area where the bare chip and its electrical structure (such as wiring layer and pins, etc.) are not damaged during cutting. There is only packaging material in the safe area. Cutting the packaging material makes the product unitized. A cutting lane 3 is designed in the safe area, which is the actual cutting part. The packaging material is cut at the cutting lane 3 position. The width of the safe area is greater than the width of the cutting lane 3. The cutting design is the common cutting lane 3 and safety area design in this packaging field, as shown in the attached figure. Figure 3 shown.

[0022] After the whole package board 1 is packaged, it is necessary to cover the bottom surface of the whole package board 1 with an adhesive film before cutting. The adhesive film is made of a commonly used material in this field, such as polyimide (PI), polyethylene terephthalate (PET), silicone or blue glue. The cutting knife vertically feeds from the top surface of the whole package board 1 to cut the packaging material at the cutting path 3 until the adhesive film at the bottom is cut. The cut part of the adhesive film is not cut off, thereby ensuring that the whole package board 1 is completely cut and separated into finished product units, and the overall bonded finished product units will not fly due to cutting stress, affecting the subsequent process. The cut part of the adhesive film is prone to wiredrawing residual glue adhering to the cut surface of the finished product unit when the cutting knife is closed, causing the residual glue to exceed the standard.

[0023] Therefore, a wire drawing and cutting method for a package without residual adhesive is provided to solve the above problem. The method comprises the following steps: The first film coating step: covering the surface of the packaged whole board 1 with a fixing film A2; Cutting line 3 irradiation step: using a digital imaging exposure device to align the surface of the packaged whole board 1 covering the fixed film A2 and expose and irradiate the fixed film A2 corresponding to the cutting line 3 area of ​​the packaged whole board 1, so that the irradiated fixed film A2 is cured and the unirradiated fixed film A2 remains sticky; Second film coating step: continue to coat the fixed film B4 on the side of the fixed film A2 away from the packaged whole board 1; Finished product cutting steps: Use a cutting knife to vertically cut the entire package board 1 at the cutting line 3 position from the opposite surface of the entire package board 1 covered with the fixing film A2, the cutting knife completely cuts off the entire package board 1, cuts the fixing film A2, the cutting depth of the fixing film A2 is less than the thickness of the fixing film A2, the part of the fixing film A2 corresponding to the cutting line 3 position is cured and loses adhesion, and there is no residual glue when cutting and separating; Fixed film separation step: remove the fixed film A2 and the fixed film B4 to obtain a finished product unit.

[0024] Among them, as attached Figure 4As shown, the first laminating step is to cover the fixed film A2 on the opposite surface of the cutting feed surface of the package whole board 1 by a laminating method commonly used in the art. The fixed film A2 can be a material commonly used in the art, such as polyimide (PI), polyethylene terephthalate (PET), silicone or blue glue, etc. In this application, UV film is used, which is also called ultraviolet light curing film or UV curing glue, etc. It is a single-component, high-strength, low-toxic acrylic adhesive, which is cured and formed by ultraviolet radiation. The UV film mainly has three components: polymer, auxiliary agent and adhesive. Among them, the polymer mainly plays the role of UV light curing. After absorbing ultraviolet light under the irradiation of ultraviolet light, it produces active free radicals or cations, which then triggers chemical reactions such as monomer polymerization and cross-linking, so that the adhesive is converted from liquid to solid in a short time; the auxiliary agent is used to adjust the rheological properties of the coating, reduce viscosity, increase light intensity, promote reaction, etc.; and the adhesive is the key to bonding the UV film to the covered object; therefore, the UV film is a photosensitive material.

[0025] Among them, as attached Figure 5 As shown, in the step of irradiating the cutting path 3, the whole package board 1 coated with the fixed film A2 is exposed to the digital imaging equipment, and the automatic recognition and alignment system is used to accurately align the cutting path area of ​​the whole package board 1, turn on the light, emit the ultraviolet wavelength, and transmit the set image information to the surface of the fixed film A2 of the photosensitive material. The digital imaging exposure equipment sets the irradiation time and wavelength according to the thickness of the fixed film A2, and sets the image information according to the size and position of the cutting path 3 of the whole package board 1. The irradiated part of the fixed film A2 is cured and loses its viscosity; the digital imaging exposure equipment (LDI) uses a laser scanning method to directly image the set image information on the fixed film A2, and the image is more detailed, the resolution is high, the alignment is more accurate, the error is small, and the cutting is more accurate; for product designs with smaller cutting path 3 sizes, the cutting path 3 area can also be accurately exposed to cure the film, and the number of packages on a single carrier is greatly increased.

[0026] The width of the area irradiated by ultraviolet light is symmetrical about the central axis plane of the cutting path 3 of the packaging whole board 1, and is 1.75 to 2.5 times the width of the cutting path 3 of the packaging whole board 1. The width of the irradiated area is greater than the width of the cutting path 3, which can ensure that the fixing film A2 at the position of the cutting path 3 is completely irradiated and cured and loses its stickiness.

[0027] Taking the DFN package with a cutting line 3 width of 40μm and a substrate product size of 334*330mm for the panel-level packaging process as an example, after covering with the UV6360-25 model fixed film A2, the automatic recognition and alignment system is used for precise alignment, and the wavelength of the emitted ultraviolet light is 405~410nm. The size of the exposed cutting line 3 is expanded by 30~60μm, that is, the width of the exposed area is symmetrical about the central axis plane of the cutting line 3 of the entire package board 1, and the width range is 70~100μm. The exposure width area can be flexibly adjusted. According to the thickness of the fixed film A2, the exposure time is set to 50s, and the irradiation curing degree of the fixed film A2 can be controlled.

[0028] Among them, as attached Figure 6 As shown, in the second coating step, the fixed film B4 continues to cover the surface of the fixed film A2 away from the packaged whole board 1, the covering method of the fixed film A2 and the fixed film B4 is the same, the materials of the fixed film A2 and the fixed film B4 are the same or different, without limitation, the thickness of the fixed film A2 ≥ the thickness of the fixed film B4, the fixed film B4 adheres to the fixed film A2, and the thickness of the fixed film B4 is thinner, which is convenient for subsequent peeling and removal.

[0029] Among them, as attached Figure 7 As shown, the finished product cutting step is to use a cutting knife to vertically cut the package whole board 1 at the cutting path 3 position from the opposite surface of the package whole board 1 covered with the fixing film A2. The cutting knife completely cuts off the package whole board 1, and continues to advance the knife to cut the fixing film A2 corresponding to the cutting path 3 position. Since the fixing film A2 corresponding to the cutting path 3 position is irradiated and cured, it loses its viscosity and changes color after irradiation and curing. Therefore, there is no sticky wire drawing during cutting, and thus there is no residual glue on the side of the finished product unit. In order to ensure that there is no wire drawing and residual glue during cutting, the cutting depth of the fixing film A2 is less than the thickness of the fixing film A2. However, since the cut part of the fixing film A2 is irradiated and cured, even if the cutting knife is not completely When the fixed film A2 is cut off, the cutting stress will cause the cracks at the fracture to continue to extend, thereby causing the entire fixed film A2 covered by the package whole board 1 to be disconnected. Continuing cutting will easily cause cutting flying, resulting in incomplete cutting or other product problems, affecting the subsequent normal process. In the second lamination step, a fixed film B4 is adhered to the surface of the fixed film A2 to bond the fixed film A2 as a whole, which effectively avoids the above problems; by adhering a thinner fixed film B4, all fixed films can be removed under normal process conditions and work efficiency to obtain a finished product unit without adding extra process burden; and there is no need for residual glue cleaning process, which simplifies the process and saves cleaning costs.

[0030] Among them, the fixed film separation step removes the fixed film A2 and the fixed film B4 through a UV dissolving machine. The UV dissolving machine is a fully automatic dissolving equipment that reduces the viscosity of the UV film and removes it. It is often used in the semiconductor chip production process. UV light is used to directly irradiate all fixed films in the entire range to make the fixed film solidify and harden and lose its viscosity. In order to ensure that the fixed film A2 covered by the fixed film B4 is also normally irradiated by ultraviolet light, the thickness of the fixed film B4 is designed to be smaller than the thickness of the fixed film A2, and ultrasonic equipment is used to assist in stripping, thereby accelerating the peeling of the finished unit from the fixed film A2, thereby removing the fixed film A2 and the fixed film B4.

[0031] Among them, the finished product inspection step checks the flatness of the cutting edge of the fixed film A2 after stripping, and checks the residual glue and cutting error on the side of the finished product unit. It can be found that this method significantly improves the residual glue situation and has higher cutting quality than the traditional cutting process.

[0032] The present invention uses two laminations. The first time, a thicker fixed film A2 is covered and irradiated and cured in the cutting path 3 area to lose its stickiness. Therefore, there is no sticky wire drawing during cutting, and then there is no residual glue on the side of the finished product unit. The second time, a thinner fixed film B4 is covered on the fixed film A2 to bond the fixed film A2 as a whole to avoid cutting flying materials. The fixed film A2 is irradiated by using a digital imaging exposure device (LDI) to set image information according to the size and position of the cutting path 3 of the packaged whole board 1, and to set the irradiation time and irradiation wavelength according to the thickness of the fixed film A2, and ultraviolet light is emitted for irradiation. The set image information is directly imaged on the fixed film A2 by a laser scanning method. The image is more refined, the resolution is high, the alignment is more precise, the error is small, the cutting is more precise, the exposure width area can be flexibly adjusted, and the irradiation curing degree of the fixed film A2 is controllable.

[0033] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present invention are within the scope of protection of the present invention.

Claims

1. A method for wire drawing and cutting a package without residual adhesive, characterized in that: The following steps are involved: The first film coating step: Covering one surface of the packaged whole board with a fixed film A; Cutting line irradiation step: using a digital imaging exposure device to align the surface of the packaged whole board covering the fixed film A and expose and irradiate the fixed film A corresponding to the cutting line area of ​​the packaged whole board, so that the irradiated fixed film A is solidified, and the unirradiated fixed film A remains sticky; Second laminating step: continue to cover the fixed film B on the side of the fixed film A away from the packaged whole board; Finished product cutting steps: Use a cutting knife to vertically cut the entire package board at the cutting path position from the opposite surface of the package entire board covered with the fixed film A. The cutting knife completely cuts off the entire package board and cuts the fixed film A. The cutting depth of the fixed film A is less than the thickness of the fixed film A. The fixed film A corresponding to the cutting path position is cured and loses adhesion. There is no residual glue when cutting and separating. Fixed film separation step: remove fixed film A and fixed film B to obtain a finished product unit.

2. The method for drawing and cutting a package without residual adhesive according to claim 1, characterized in that: In the first coating step and the second coating step, the fixed film A and the fixed film B are coated in the same manner, and the thickness of the fixed film A is greater than or equal to the thickness of the fixed film B.

3. The method for wire drawing and cutting a package without residual adhesive according to claim 1, characterized in that: In the first coating step, the fixed film A is a photosensitive material.

4. The method for drawing and cutting a package without residual adhesive according to claim 3, characterized in that: In the cutting line irradiation step, the digital imaging exposure equipment sets the irradiation time and wavelength according to the thickness of the fixed film A, sets the image information according to the size and position of the cutting line of the entire package board, emits ultraviolet light, and irradiates and cures the fixed film A corresponding to the cutting line area to debond.

5. The method for wire drawing and cutting a package without residual adhesive according to claim 4, characterized in that: In the cutting line irradiation step, the width of the irradiated area is symmetrical about the central axis plane of the cutting line of the entire packaging board, and is 1.75 to 2.5 times the width of the cutting line of the entire packaging board.

6. The method for wire drawing and cutting a package without residual adhesive according to claim 1, characterized in that: In the fixed film separation step, the adhesiveness of the fixed film A and the fixed film B is reduced by a disintegrator, and ultrasonic wave is used to assist the stripping, so that the cut finished unit is peeled off from the fixed film A under vibration.

7. The method for drawing and cutting a package without residual adhesive according to claim 1, characterized in that: The method also includes a finished product inspection step, which includes inspecting the flatness of the cutting edge of the fixed film A after stripping, and inspecting the residual glue and cutting error on the side of the finished product unit.

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