A method for chip coating

Abstract

The present invention discloses a method for chip glue coating, belonging to the field of semiconductor device packaging. The method includes: placing a substrate to be glue-coated directly below a glue coating device, wherein the glue coating device adopts a sheet-type porous glue coating method; during glue coating, the glue coating holes of the glue coating device do not contact the substrate, and the number and size of the glue coating holes (31) are adjusted according to the size of the chip. The glue coating device of the present invention does not use a needle design, does not contact the substrate, is not easily deformed, blocked or leaked with glue, and can complete glue coating at one time, improving the glue coating efficiency.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor device packaging, and in particular to a chip gluing method. Background Art

[0002] In the semiconductor device packaging industry, products packaged in lead frames (L / F) require bonding the bare chip to the L / F during the die mounting process (hereinafter referred to as "bonding"). The bonding material is typically resin or solder paste. Because some L / F pins and the substrate supporting the chip have a stepped, integrated structure, applying the adhesive between the chip and substrate cannot be accomplished using stencil printing of resin or solder paste. Instead, the industry generally uses dispensing and painting processes to apply the adhesive.

[0003] When mounting chips, the resin filling must be full and the resin quantity must be precisely controlled. Too much resin can easily overflow onto the chip surface; too little can result in incomplete filling of the connection between the chip and the substrate; and uneven resin distribution can easily cause the cured chip to tilt or partially lack resin filling (resin generally has lower fluidity than solder paste, so precise placement is crucial when dispensing or applying the adhesive). This can affect the chip's electrical properties and the quality of subsequent processes (such as bonding), potentially leading to quality issues.

[0004] The dispensing process requires a custom, multi-hole dispensing head. The level consistency between the dispensing holes and the dispensing surface is extremely high. Even a slight tilt can result in uneven dispensing or even missing dispensing. Furthermore, traditional dispensing and painting processes rely on the dispensing head's pinhole contact or critical contact L / F substrate. This unevenness can cause severe wear and tear on the dispensing head, easily leading to deformation and clogging of the dispensing holes during production, resulting in product quality defects. Furthermore, the high precision required for dispensing shortens the life of the dispensing head and increases the cost of replacing it.

[0005] The glue dispensing process requires equipment that supports this function, and the UPH (unit productivity per hour) value of the glue dispensing process is very low, which affects mass production efficiency. Therefore, in the implementation of large-scale production, it is very important to develop a glue dispensing device that can support all equipment. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problems existing in traditional glue dispensing and glue painting, and provide a chip glue coating method.

[0007] The object of the present invention is achieved through the following technical solutions:

[0008] In one embodiment, a chip gluing method is provided, comprising:

[0009] Place the substrate to be coated directly below the coating device, where the coating device uses a sheet-type porous coating method;

[0010] During coating, the coating holes of the coating device do not contact the substrate, and the number and size of the coating holes (31) are adjusted according to the size of the chip.

[0011] As a preferred option, the coating device includes:

[0012] A coating block, which is internally formed with a first channel for storing the bonding material, and a coating hole sheet connected to the bottom of the first channel and a bottom cavity for connecting the substrate, where the bottom cavity is directly below the coating hole sheet, and the coating hole sheet includes a plurality of coating holes;

[0013] And a coating power unit for driving the bonding material to flow out of the coating hole sheet, and the coating power unit is communicated with the first channel.

[0014] As a preferred option, the adjusting the number and size of the coating holes according to the size of the chip includes:

[0015] The thicker the chip, the denser and larger the coating holes; the thinner the chip, the sparser and smaller the coating holes.

[0016] As a preferred option, the length of the bottom cavity is less than the length of the coating block, and the height of the bottom cavity is half of the chip thickness or equal to the chip thickness.

[0017] As a preferred option, the adjusting the number and size of the coating holes according to the size of the chip includes:

[0018] There is a socket on the side of the coating block for inserting the coating hole sheet, and different coating hole sheets are replaced through the socket according to different chip sizes.

[0019] As a preferred option, the coating hole sheet is rectangular, and the coating holes are evenly arranged within the chip size to match the position where the chip needs to be dispensed and the amount of glue.

[0020] As a preferred option, the coating power unit includes a second channel provided at the top of the coating block, the second channel communicates with the first channel, and the second channel is a vacuum / compressed air channel.

[0021] As a preferred option, compressed air is introduced into the second channel to extrude the glue, and when the amount of glue discharged meets the requirements, vacuum is introduced into the second channel to stop the glue discharge.

[0022] As a preferred option, a glue - applying block balancing mechanism is vertically provided at the top of the glue - applying block. The glue - applying block balancing mechanism is square, and a spherical rod and a movable sleeve ball are arranged inside it. The lower end of the spherical rod is connected to the glue - applying block, and the upper end of the spherical rod is embedded in the movable sleeve ball.

[0023] As a preferred option, the glue - applying block balancing mechanism is parallel to the glue - applying power part.

[0024] It should be further noted that the technical features corresponding to the above options can be combined or replaced with each other without conflict to form a new technical solution.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) The glue - applying device of the present invention adopts the method of sheet - type porous glue - applying. When applying glue, the glue - applying holes of the glue - applying device do not contact the substrate, which is different from the method of the glue - applying needle contacting the substrate for glue - applying in the usual dot - glue and painting - glue functions. The glue - applying device of the present invention does not use a needle design and does not contact the substrate, so it is not easy to deform, block, or leak glue. At the same time, the glue - applying can be completed at one time, improving the glue - applying efficiency.

[0027] (2) The position and amount of the glue output in the present invention are controlled by the glue - applying hole sheet. The glue - applying holes of the glue - applying hole sheet match the positions and glue amounts required for the chip to be dot - glued. The positions are evenly distributed within the chip size. Since there will be a downward pressure when the chip is mounted, the downward pressure will cause the resin dots of the dot - glue to spread around. In this way, the opening size determines the resin amount. If the chip is thicker, the openings can be appropriately dense and larger, so that the resin amount will be more. If the chip is thinner, the openings can be slightly sparser and smaller, so that the resin amount will be reduced, thus avoiding the bad mode caused by the extrusion of the resin until it overflows onto the chip surface when the chip is mounted.

[0028] (3) In the present invention, the bottom cavity is mainly designed to control the height of the resin amount. Its length is less than the length of the glue - applying block, and there is a certain distance from the outer dimension to ensure that it does not deform when contacting the L / F substrate.

[0029] (4) The present invention is provided with a socket for inserting the glue - applying hole sheet on the side of the glue - applying block. According to different chip sizes, different glue - applying hole sheets can be replaced through the socket, which can be applied to glue - applying for chips of various sizes.

[0030] (5) The present invention is vertically provided with a glue - applying block balancing mechanism at the top of the glue - applying block, ensuring that the glue - applying block is horizontal with the L / F substrate when applying glue, reducing the horizontal adjustment step of the glue - applying head before height measurement. During continuous operation, it also avoids the bad mode caused by the non - horizontal glue - applying contact surface. Description of the Drawings

[0031] Figure 1Schematic structural diagram of a chip gluing device shown for the present invention;

[0032] Figure 2 Cross-sectional view of the gluing device shown for the present invention;

[0033] Figure 3 Schematic structural diagram of the glue application orifice plate shown for the present invention;

[0034] Figure 4 Schematic structural diagram of the gluing device with a glue block balancing mechanism shown for the present invention;

[0035] Figure 5 Schematic diagram of the glue block balancing mechanism shown for the present invention. Detailed implementation manners

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] Embodiment 1

[0041] In an exemplary embodiment, a chip gluing method is provided, and the method includes:

[0042] Place the substrate to be coated directly below the coating device, where the coating device uses a sheet-type porous coating method;

[0043] During coating, the coating holes 31 of the coating device do not contact the substrate, and the number and size of the coating holes 31 are adjusted according to the size of the chip.

[0044] Specifically, a sheet-type structure is used to replace the needle. Different from the way of the dispensing needle contacting the substrate for dispensing in the usual dispensing and scribing functions, the coating device of the present invention does not use a needle design and does not contact the substrate, and is not easy to deform, clog, and leak dispensing. Due to porous coating, and the number and size of the coating holes 31 are adjusted according to the size of the chip, and at the same time, the coating can be completed at one time, improving the coating efficiency.

[0045] Embodiment 2

[0046] Based on a chip coating method in Embodiment 1, a coating device is provided, as Figures 1 - 3 shown, the coating device includes:

[0047] A coating block 1, which is internally formed with a first channel 2 for storing the bonding material, and a coating hole sheet 3 connected to the bottom of the first channel 2 and a bottom cavity 4 for connecting the substrate, where the bottom cavity 4 is located directly below the coating hole sheet 3, and the coating hole sheet 3 includes a plurality of coating holes 31;

[0048] And a coating power part 5 for driving the bonding material to flow out of the coating hole sheet 3, and the coating power part 5 is communicated with the first channel 2.

[0049] When the device is in use, place the coating hole sheet 3 below the first channel 2, place the substrate to be coated into the bottom cavity 4, and horizontally place it directly below the coating hole sheet 3, while ensuring that there is a certain gap between the coating hole sheet 3 and the substrate.

[0050] After the coating power part 5 is installed and connected to the first channel 2, coating can be carried out. Specifically, turn on the coating power part 5, squeeze the bonding material in the first channel 2 onto the coating hole sheet 3 by gas pressure or other extrusion methods, and the bonding material is coated onto the substrate by the coating holes 31. Among them, the bonding material is generally a paste-like substance such as resin or solder paste.

[0051] Furthermore, the position and amount of glue extrusion are controlled by the glue application orifice plate 3. The number and size of the glue application orifices 31 are adjusted according to the size of the chip. The glue application block 1 is rectangular, the glue application orifice plate 3 is rectangular, and the glue application orifices 31 are cylindrical or square holes, and different shapes can be designed according to the specific chip structure. The glue application orifices 31 of the glue application orifice plate 3 match the positions and the amount of glue required for the chip to be dispensed. The positions are evenly distributed within the size of the chip. When the chip is mounted, there will be a downward pressure, which will cause the dispensed resin dots to spread around. Thus, the size of the orifice determines the amount of resin. If the chip is thicker, the glue application orifices 31 can be appropriately denser and the orifice size can be larger, so that the amount of resin will be more. If the chip is thinner, the glue application orifices 31 can be slightly sparser and the orifice size can be smaller, so that the amount of resin will be reduced, thus avoiding the bad mode caused by the extrusion of the resin until it overflows onto the chip surface during chip mounting.

[0052] Furthermore, the length of the bottom cavity 4 is less than the length of the glue application block 1, and the height of the bottom cavity 4 is half of the chip thickness or equal to the chip thickness. Specifically, the hollow structure at the bottom of the glue application block 1, i.e., the bottom cavity 4, is the main design for controlling the height of the resin amount. Its length is less than the length of the glue application block, and there is a certain distance from the outer dimension to ensure that it does not deform when contacting the L / F substrate. Generally, the remaining part after hollowing out is 2 - 3 mm thick (wall), and this remaining part of the wall is also the part that contacts the L / F substrate during height measurement. There is also a hollow part in the upper part of the glue application block 1, which is used to store the resin to be used.

[0053] Furthermore, adjusting the number and size of the glue application orifices 31 according to the size of the chip includes:

[0054] There is an insertion slot 32 for inserting the glue application orifice plate 3 on the side of the glue application block 1. According to different chip sizes, different glue application orifice plates 3 are replaced through the insertion slot 32. Specifically, the opening shape, distribution number, and opening size of the glue application orifice plate 3 are determined according to the size and thickness of the chip. When measuring the height, the height of the hollow part at the bottom of the upper glue application block 1 needs to be considered. The glue application orifice plate 3 is the only mechanism that needs to be changed and replaced to adapt to the glue application of chips of various sizes, and it is also the structure for controlling the amount during the entire glue application method process. According to different chip sizes, different glue application orifice plates are replaced through the insertion slot, which can be applicable to the glue application of chips of various sizes.

[0055] Further, the glue application power unit 5 includes a second channel 51 provided at the top of the glue application block 1. The second channel 51 communicates with the first channel 2, and the second channel 51 is a vacuum / compressed air channel. Compressed air is introduced into the second channel 51 to extrude the glue. When the amount of glue discharged meets the requirement, vacuum is introduced into the second channel 51 to stop the glue discharge. Specifically, the vacuum / compressed air channel is the power for the entire dispensing operation to discharge and cut off the glue. Compressed air is responsible for providing pressure to the resin, so that the resin is extruded onto the L / F substrate through the glue application orifice plate 3 under the action of pressure. At this time, the pressure and duration of the compressed air are controlled by the equipment (this function can be achieved by almost all equipment). After the resin amount is satisfied, at this time, the compressed air is disconnected, and vacuum is introduced to interrupt the resin extrusion function, and the resin is cut off at the glue application orifice plate 3. At this time, the resin remaining on the L / F substrate is the required resin amount. During the process, the vacuum pressure and the vacuum action time are determined by the amount (this time and pressure control function can be achieved by almost all equipment).

[0056] Embodiment 3

[0057] Based on the above embodiments, an improvement is made to a chip glue application device. As Figures 4 - 5 shown, a glue application block balance mechanism 6 is vertically provided at the top of the glue application block 1. The glue application block balance mechanism 6 is square, and a spherical rod 61 and a movable sleeve ball 62 are arranged inside it. The lower end of the spherical rod 61 is connected to the glue application block 1, and the upper end of the spherical rod 61 is embedded in the movable sleeve ball 62.

[0058] The movable sleeve ball 62 includes an upper sleeve ball 621 and a lower sleeve ball 622. Among them, the upper sleeve ball 621 passes through the rod portion of the spherical rod 61, and the lower sleeve ball 622 is sleeved on the spherical portion of the spherical rod 61. Specifically, when the movable sleeve ball 62 is connected to the spherical rod 61, the spherical rod 61 can be rotated arbitrarily by nearly 270 degrees. There is an appropriate air gap between the movable sleeve ball 62 and the spherical portion of the spherical rod 61. In this way, when the glue application block 1 contacts the L / F substrate, the glue application block 1 can freely rotate by an angle under the action of the glue application block balance mechanism 6 to achieve horizontal landing. The movable sleeve ball 62 is divided into upper and lower parts, which are connected and fixed by four screws at the four corners. The upper sleeve ball 621 has a cylindrical hole slightly larger than the diameter of the rod portion of the spherical rod 61. The installation of the entire glue application balance mechanism 6 is as follows: the spherical portion of the spherical rod 61 is placed in the lower sleeve ball 622, the upper sleeve ball 622 passes through the ball rod of the spherical rod 61, the upper and lower parts of the movable sleeve ball 62 coincide, and the four corners are locked and fixed with four screws to form a whole. At this time, the whole is fixed to the glue application block 1 with four more screws to complete the installation of the glue application balance connection mechanism 6.

[0059] Further, the glue application block balance mechanism 6 is parallel to the glue application power unit 5. The installation positions of the glue application block balance mechanism 6 and the glue application power unit 5 need to meet the requirement that when the two are installed simultaneously, the entire glue application block 1 is substantially horizontal, so as to reduce the rubbing and obstruction of the hardware part when the components move.

[0060] Height measurement refers to measuring the distance from the origin of the dispensing arm to the substrate. The equipment automatically records and memorizes the distance between the dispensing head and the substrate each time, so as to keep the distance between the dispensing head and the substrate consistent, so as to achieve the purpose of constant dispensing. The dispensing unit starts to measure the height after the entire dispensing mechanism is installed. The height measurement is achieved according to the device's own height measurement principle. The contact point for height measurement is the horizontal position of the edge of the glue block 1, rather than the contact position with the L / F substrate (because the glue hole piece 3 is not needle-shaped, it cannot contact the substrate). If the height measurement principle is that the glue hole piece 3 contacts the L / F for conductivity as a test point, the dispensing mechanism material is selected from conductive materials (such as metals). If the device height measurement principle is that the dispensing arm's reverse force contacts or disconnects as a test point, the dispensing mechanism material can be selected according to the applicable material. Among them, the dispensing arm is a built-in mechanism of the equipment, which is used to realize automatic gluing. Generally, dispensing equipment has a dispensing arm, which is a component of the equipment. The dispensing mechanism of the present invention is only a structure developed at the end of the dispensing part of the equipment.

[0061] Furthermore, a spring is installed in the second channel 51 of the glue-applying power unit 5 and at the appropriate location where the glue-applying block balancing mechanism 6 connects to the equipment fixture. This serves as a buffer to relieve force during height measurement and also prevents the height difference between the bottom of the glue-applying block 1 and the substrate being glued, which may be caused by slight precision errors after long-term operation of the equipment. The length and tension of the spring are determined according to actual needs.

[0062] The above specific implementation methods are detailed descriptions of the present invention. It cannot be considered that the specific implementation methods of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions and substitutions without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for chip gluing, characterized in that, The method includes: Placing the substrate to be coated directly below the coating device, wherein the coating device uses a sheet-type porous coating method; During coating, the coating holes (31) of the coating device do not contact the substrate, and the number and size of the coating holes (31) are adjusted according to the size of the chip; The coating device includes: A coating block (1) internally formed with a first channel (2) for storing the bonding material, and a coating hole sheet (3) connected to the bottom of the first channel (2) and a bottom cavity (4) for connecting to the substrate. Among them, the bottom cavity (4) is located directly below the coating hole sheet (3), and the coating hole sheet (3) includes a plurality of coating holes (31); And a coating power unit (5) for driving the bonding material to flow out of the coating hole sheet (3), and the coating power unit (5) is communicated with the first channel (2); The adjusting the number and size of the coating holes (31) according to the size of the chip includes: There is an insertion port (32) for inserting the coating hole sheet (3) on the side of the coating block (1), and different coating hole sheets (3) are replaced through the insertion port (32) according to different chip sizes.

2. The chip gluing method according to claim 1, wherein, The adjusting the number and size of the coating holes (31) according to the size of the chip includes: The thicker the chip, the denser and larger the coating holes (31); the thinner the chip, the sparser and smaller the coating holes (31).

3. A chip gluing method according to claim 1, characterized in that, The length of the bottom cavity (4) is less than the length of the coating block (1), and the height of the bottom cavity (4) is half of the chip thickness or equal to the chip thickness.

4. A chip gluing method according to claim 1, characterized in that, The coating block (1) is rectangular, the coating hole sheet (3) is rectangular, and the coating holes (31) are evenly arranged within the chip size to match the position where the chip needs to be dispensed and the amount of glue.

5. A method for chip gluing according to claim 1, characterized in that, The coating power unit (5) includes a second channel (51) provided at the top of the coating block (1), and the second channel (51) communicates with the first channel (2), and the second channel (51) is a vacuum / compressed air channel.

6. A chip gluing method according to claim 5, characterized in that, Compressed air is introduced into the second channel (51) to extrude the glue, and when the amount of glue discharged meets the requirements, vacuum is introduced into the second channel (51) to stop the glue discharge.

7. A chip gluing method according to claim 1, characterized in that, A coating block balancing mechanism (6) is vertically provided at the top of the coating block (1). The coating block balancing mechanism (6) is square, and a spherical rod (61) and a movable sleeve ball (62) are arranged inside it. The lower end of the spherical rod (61) is connected to the coating block (1), and the upper end of the spherical rod (61) is embedded in the movable sleeve ball (62).

8. A method for applying glue to a chip according to claim 7, characterized in that, Align the coating block balancing mechanism (6) parallel to the coating power unit (5).

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