WO2016065618A1

WO2016065618A1 - Encapsulation device having arc edge fingerprint identification chip and encapsulating and cutting method

Info

Publication number: WO2016065618A1
Application number: PCT/CN2014/090055
Authority: WO
Inventors: 方丽文
Original assignee: 方丽文
Priority date: 2014-10-31
Filing date: 2014-10-31
Publication date: 2016-05-06

Abstract

Provided is an encapsulation device having an arc edge fingerprint identification chip, comprising: a set of molds. The molds have an upper mold (20) and a lower mold (10), and a slot for accommodating a PCB board (30) is provided in the lower mold (10), the PCB board (30) is entirely welded with a plurality of sets of fingerprint identification devices, the upper mold (20) is provided with a circular or oval or flat-oval cavity (21) having an arc edge for accommodating the identification devices and having the same shape as the fingerprint chip, the cavity (21) is arranged corresponding to the fingerprint identification devices on the PCB board (30), the space between the cavities (21) connects to an injection port of the encapsulation material via a hot runner, the hot runner is divided into a primary runner (41) and a branch runner (42), the primary runner (41) is in communication with the injection port (50), the branch runner (42) is in communication with the sides of the cavity (21), the distance from the inner surface of the upper mold (20) to the bottom surface of the slot is equal to the thickness of the PCB board (30), and the depth of the cavity (21) is greater than the height from the surface of the PCB board (30) to the upper surface of the identification devices.

Description

Packaging device with arc edge fingerprint identification chip and packaging and cutting method

Technical field

The invention belongs to the technical field of electronic device packaging, and in particular relates to a packaging device and a production method of a fingerprint chip.

Background technique

Fingerprint identification technology has been widely used, and it is involved in attendance machines, security access control, and customs clearance. Nowadays, fingerprint recognition technology is gradually used on mobile phones to unlock and unlock devices. The technology uses a capacitive fingerprint identification chip, which does not require light source acquisition. It has the advantages of ultra-thin and ultra-small size. It is usually installed on the button of the mobile phone and covered with a layer of plastic for wear protection and line protection. Describe the construction of a capacitive fingerprinting chip, which is mainly soldered by the identification device. a PCB board, and then the identified signal is introduced from the two ends of the upper surface of the identification device to the connection end of the PCB by a thin bonding wire, where the connection is not from the back of the identification device and the PCB The board is connected, but from the upper surface and the PCB The upper surface of the board is connected. The result of the connection is that the soldering wire is exposed obliquely downward. When the plastic material is covered, if the pressure is not well controlled, it is easy to impact the bonding wire, resulting in an increase in the defective rate of the broken wire of the bonding wire. There are some specific production problems in the technology of adding such identification chips to oval or flat oval mobile phone buttons.

First, the thickness of the surface coating is uneven, and the sensitivity cannot be guaranteed. In the prior art, the identification device is usually arranged and soldered to the whole PCB. On the board, then the whole plastic is injected (integrally poured like a prefabricated component), and then cut into finished chips for installation. This way of injecting plastic is actually using a micro SD card, TF. The packaging technology of memory cards such as cards, because the memory chips such as SD cards do not have sensing problems, the thickness of the surface of the plastic does not have much influence, but the surface coating of the fingerprint identification chip must be controlled at 0.035mm - Between 0.05mm, due to the deformation of the PCB itself, in the process of high temperature packaging, PCB After the deformation of the plate, the phenomenon of warping is easy to occur. Therefore, in the case of integrally injecting plastic, it is difficult to ensure that the overall coating is within this thickness value, and the phenomenon that the thickness of one region exceeds the standard and the thickness of one region is not up to standard often occurs.

Secondly, the huge impact generated during injection molding tends to break the wire. Since there is no fine wire bonding when the memory card is packaged in the conventional process, it is not necessary to consider the pressure shock during the injection molding process, but the wire of the fingerprint identification chip is This contraindication exists, so there is a problem in the prior art that the yield of the product has not been improved.

Third, the cutting process is complicated and the edge of the chip is not fine. In the conventional process, because of the overall injection molding, it is necessary to separately remove each chip by laser cutting, and the laser cutting method has a problem that it is easy to burn the packaging material. Coke carbonization, usually epoxy resin when the material is packaged, the cut surface after laser cutting is not smooth or even cracked, and the acceptance cannot pass.

technical problem

The invention provides a packaging device, which aims to solve the problem of uneven thickness of the surface coating of the prior art chip and low yield.

Technical solution

In order to solve the above problems, the present invention provides a packaging device having an edge-edge fingerprint recognition chip. The utility model comprises a pair of molds, wherein the mold is divided into an upper mold and a lower mold, wherein the lower mold is provided with a slot for accommodating the PCB, and the PCB is a whole PCB with multiple sets of fingerprint identification devices soldered a plate having a circular or elliptical or flat elliptical arcuate cavity accommodating the identification device and conforming to the shape of the fingerprint chip, the cavity and the PCB The fingerprint identifiers on the board are correspondingly disposed, and the cavities are connected to the packaging material injection port through a hot runner, the hot runners are divided into a main flow channel and a branch flow channel, and the main flow is connected to the injection port. a branch channel communicating with a side of the cavity, a distance from an inner surface of the upper mold to a bottom surface of the slot and the The thickness of the PCB is equal, and the depth of the cavity is greater than the height of the surface of the PCB to the upper surface of the identification device.

Preferably, the depth of the cavity is greater than the height of the surface of the PCB to the upper surface of the identification device 0.035-.0.05 mm .

Preferably, the side sections of the cavity are all isosceles trapezoids, and the sides of the cavity form an angle of 3 to 5 degrees with the vertical line.

Preferably, the encapsulating material is epoxy.

Preferably, the PCB The plate has a positioning hole, and the slot is provided with a positioning post that can pass through the positioning hole, and the upper and lower mold edges are connected and positioned by a plurality of positioning pins.

According to the above technical solution, the packaging device provided by the present invention is changed by the conventional casting type packaging scheme, and the mold is injected into the packaging material, and the upper mold presses the surface of the PCB board completely, thereby completely avoiding PCB board warp angles do not maintain the overall technical problem on a horizontal plane, while the top surface of each of the cavities is away from the PCB The upper surface distance of the identification device on the board is fixed and can be accurate to each device. This also ensures that the surface coverage of each device is in the same arc. In addition, the shape of the cavity can also be used to package the chip. Keeping the desired smooth arc edge does not require cutting the edge of the arc, ensuring that the side smoothness of the chip particles also prevents the edge of the package material from being burnt after the laser cutting edge is not smooth. The main channel and the branch channel disposed between the cavities can gradually reduce the injected high-temperature and high-pressure liquid encapsulating material to impact the bonding wires at both ends of the identification device, and then break, and the inlet injected into the cavity is also disposed in the The side of the cavity further avoids the impact on the welding wire and improves the product yield.

The invention also provides a packaging and cutting method with an edge-edge fingerprint identification chip, and the above packaging device is applied, and the specific steps are as follows:

Step 1 : placing the PCB board into a slot of the lower mold, and positioning the positioning post through the positioning hole to position the PCB board

Step 2, the upper mold is fastened to the lower mold through the positioning pin;

Step 3 And vacuuming the mold, injecting a packaging material from the injection port, the encapsulating material enters the main channel and the branch channel in a high-temperature liquid state after entering the injection port, and gradually reduces the injection pressure. The side of the identification device injects a gap between the cavity and the identification device;

Step 4: maintaining a clamping time of 40 seconds to 120 seconds to cure and mold the packaging material, and the PCB The identification device on the board is wrapped by the encapsulating material to form a cover layer having a surface thickness of 0.035-0.05 mm;

Step 5, from the PCB The back side of the board is marked with a contour line for each identification chip, and the contour line is consistent with the contour of the identification chip;

Step 6: cutting along the contour line from the back surface of the PCB by a cutter or a laser or a combination of the two;

Preferably, the heating mold working step is added at any step before the step 3, so that the temperature of the mold cavity reaches a temperature of 160 degrees. Any number of degrees between -200 degrees, and maintain the temperature until the end of step 3;

Preferably, the cutting method includes prior to the PCB The plate is positioned, and then the edge of the identification chip having a curvature is cut by laser, and then the cutting chip is used to cut the identification chip to have a straight edge.

Preferably, the laser is cut to a depth of the PCB.

Beneficial effect

According to the above technical solution, the method provided by the invention has two key beneficial effects. First, each identification chip is separately packaged by a mold design, thereby ensuring the size of each identification chip and the thickness of the surface coating. In addition, the design of the mold defines the flow path of the packaging material, which avoids the impact of the high pressure liquid packaging material on the welding line affecting the product yield. Secondly, the cutting method further ensures the smoothness of the edge of the identification chip. Since the position with the arc edge has been formed by the mold, during the cutting process, the straight edge portion is still cut by the conventional cutting tool, and the packaging material of the branch channel can be ensured. The junction with the side of the identification chip is neatly and smoothly cut, and the arc portion of the identification chip is cut by laser cutting, and only The PCB board can be partially cut. Since the packaged part has been formed, laser cutting is not required, so the high heat generated by the laser does not damage the packaging material, and the arc edge of the identification chip is smooth and tidy.

DRAWINGS

1 is a schematic diagram of an unpackaged PCB with an identification device provided by the present invention;

2 is a partial side elevational view of an unpackaged PCB with an identification device provided by the present invention;

3 is a schematic rear view of a PCB board provided by the present invention;

4 is a schematic diagram of a packaged PCB board provided by the present invention;

Figure 5 is a side cross-sectional view of the identification chip provided by the present invention.

Figure 6 is a side view of the cavity provided by the present invention;

Figure 7 is a schematic view of a lower mold provided by the present invention;

Figure 8 is a schematic view of the upper mold provided by the present invention;

Figure 9 is an enlarged schematic view of the portion of Figure 8A;

Embodiments of the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Embodiment 1 of the present invention provides a packaging device with an edge-edge fingerprint identification chip, as shown in FIG. 1-9. A pair of molds are included, the mold being divided into an upper mold 20 and a lower mold 10, and the lower mold 10 is provided with a slot 11 for accommodating a PCB, the PCB 30 The upper mold 20 is provided to accommodate the identification device 31 for the entire PCB of the plurality of fingerprint recognition devices 31 that have been soldered. a circular or elliptical or flat elliptical cavity having a curved edge conforming to the shape of the fingerprint chip, the cavity 21 and the fingerprint recognition device 31 on the PCB 30 Correspondingly, the cavities 21 are connected to the encapsulating material injection port 50 through the hot runner 40, and the hot runner 40 is divided into a main flow channel 41 and a branch flow channel 42. The main flow channel 41 The liquid-passing channel 42 is in communication with the side of the cavity 21, and the encapsulating material is made of epoxy resin. When the liquid encapsulating material is injected, the liquid encapsulating material passes through the main flow path 41. The gradual decompression to the branch passage 42 and then entering the cavity from the side 21 package protects the end portion of the bonding wire 32 from impact fracture, the distance from the inner surface of the upper mold 20 to the bottom surface of the slot 11 and the The PCB board 30 has the same thickness and can function to press the PCB board 30 to prevent the PCB board 30 from being deformed. The depth of the cavity 21 is greater than the PCB board 30. The surface is at a height to the upper surface of the identification device 31, thereby forming a cover layer on the surface of the identification device 31 when the package material is injected. The thickness interval of the cover layer is selected to be 0.035-.0.05 mm With the development of technology, the thickness of the cover layer may increase further, but the thickness required at present must be controlled within this range. If the thickness is too thick, the sensitivity will be affected. If it is too thin, it is easy to expose the identification device after wear. Reduce their lifespan. In addition, the cavity 21 The side sections are all isosceles trapezoids, and the sides of the cavity 21 form an angle of 3 to 5 degrees with the vertical line, that is, the bottom surface area of the cavity 21 is smaller than the opening area, and the cavity 21 thus designed. After the encapsulation material is injected, the upper part of the whole identification chip is formed into a trapezoidal package portion, which brings two advantages, the first is convenient to demould, and the second is cut in the cutting process, especially in the laser cutting process, from the vertical direction. When the package part is not damaged, the burnt side is not easily generated, and the smooth side of the upper half of the chip is further ensured. According to the above technical solution, the packaging device provided by the present invention is modified by the conventional casting type packaging scheme, and the mold is injected into the packaging material by the upper mold. 20 pressing down the upper surface of the PCB board 30 completely avoids the technical problem that the PCB board 30 cannot maintain the entire level on one horizontal surface, and each of the cavities 21 The bottom surface (since the opening of the cavity 21 is referred to as the top surface) is away from the identification device 31 on the PCB board 30. The upper surface distance is fixed and can be accurate to each device, which also ensures that the surface coating thickness of each device is uniform, and in addition, the cavity 21 The shape can also maintain the desired smooth arc edge of the packaged chip, without cutting the edge of the arc, ensuring the smoothness of the side of the chip particle and preventing the encapsulation material from being burnt after laser cutting the edge. The edge is not smooth. The cavity The main channel 41 and the branch channel 42 disposed between 21 can gradually reduce the bonding wire of the injected high temperature and high pressure liquid packaging material to the identification device 31. The impact is generated and then fracture occurs, and the inlet into the cavity 21 is also disposed on the side of the cavity 21, further avoiding the impact on the bonding wire 32, and improving the product yield.

In order to be accurately positioned, it is prepared for the steps of packaging, demoulding, cutting, etc. in the subsequent work, and the PCB board 30 has a positioning hole. 33. The slot 11 is provided with a positioning post 13 that can pass through the positioning hole 33. The edges of the upper and lower molds 20 and 10 are connected and positioned by a plurality of positioning pins 22, and during operation, the The PCB board 30 is placed in the slot 11 and the pre-drilled positioning holes 33 on the PCB board 30 are placed on the positioning post 13 to prevent the PCB board 30. The phenomenon of offset sloshing at the edge wear causes the package position to be inaccurate, laying the foundation for the entire package work. .

Embodiment 2, refer to Figure 1-9 As shown in the figure, the present invention further provides a package and a cutting method for the edge-edge fingerprint identification chip. The package device according to the first embodiment is applied. The specific steps are as follows:

Step 1 , placing the PCB board 30 into the slot 11 of the lower mold 10, and positioning the positioning post 13 Positioning the PCB board 30 after passing through the positioning hole 33;

Step 2 , the upper mold 20 is fastened to the lower mold 10 through the positioning pin 22 ;

Step 3: vacuuming the mold, heating the mold and maintaining it to a certain temperature, and then from the injection port 50 The encapsulating material is injected into the inlet port 50 after entering the injection port 50 in a high temperature liquid state, and sequentially enters the main channel 41 and the branch channel 42 to gradually reduce the injection pressure from the identification device 31. The side of the cavity is injected into the gap between the cavity 21 and the identification device 31;

Step 4: maintaining the mold clamping time of 40 seconds to 120 seconds to cure and mold the packaging material, and the PCB board 30 The upper identification device 31 is wrapped by the encapsulating material to form a cover layer having a surface thickness of 0.035-0.05 mm;

Step 5, from the PCB board 30 The back side is contoured for each identification chip, the contour line being consistent with the identification chip profile;

Step 6: cutting along the contour line from the back surface of the PCB board 30 by a cutter or a laser or a combination of both;

Preferably, the cutting method includes prior to the PCB board 30 Positioning is performed, and then the edge of the identification chip having a curvature is cut by laser, and then the cutting is performed using the cutter to have a straight edge, since the laser cutting is applied to the PCB 30 The encapsulation material is not caused to be scorched by the laser at a high temperature.

Preferably, the laser is cut to a depth of the PCB 30.

According to the above technical solution, the method provided by the invention has two key beneficial effects. First, each identification chip is separately packaged by a mold design, thereby ensuring the size of each identification chip and the thickness of the surface coating. In addition, the flow path of the packaging material is specified by the design of the mold, and the high-pressure liquid packaging material is prevented from the bonding wire. 32 The impact of the impact on product yield. Secondly, the cutting method further ensures the smoothness of the edge of the identification chip. Since the position with the arc edge has been formed by the mold, the straight edge portion is still cut by the conventional cutting tool during the cutting process, and the branch channel can be ensured. The package material of 42 and the side edge of the identification chip are neatly and smoothly cut, and the arc edge portion of the identification chip is cut by laser cutting, and only the PCB board 30 is needed. Partial cutting is sufficient. Since the packaged portion has been formed, laser cutting is not required, so the high heat generated by the laser does not damage the packaging material, and the arc edge of the identification chip is ensured to be smooth and tidy.

The embodiment 3 further provides a method for encapsulating and cutting a circular fingerprint identification chip. The package device according to the first embodiment is different from the above embodiment in that the identification chip that needs to be produced is Round, so it is necessary to provide a plurality of said branch runners 42 At the junction with the side of the cavity, it is necessary to keep the flow path at the junction relatively thin, which is convenient to leave a small burnt surface when laser cutting is used in the cutting process.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

A packaging device having an edge-edge fingerprint identification chip, comprising: a pair of molds, the mold being divided into an upper mold and a lower mold, wherein the lower mold is provided with a housing The slot of the PCB board, which is a whole PCB with multiple sets of fingerprint identification devices soldered a plate having a circular or elliptical or flat elliptical arcuate cavity accommodating the identification device and conforming to the shape of the fingerprint chip, the cavity and the PCB The fingerprint identifiers on the board are correspondingly disposed, and the cavities are connected to the packaging material injection port through a hot runner, the hot runners are divided into a main flow channel and a branch flow channel, and the main flow is connected to the injection port. a branch channel communicating with a side of the cavity, a distance from an inner surface of the upper mold to a bottom surface of the slot and the The thickness of the PCB is equal, and the depth of the cavity is greater than the height of the surface of the PCB to the upper surface of the identification device.
The package device with an arc edge fingerprint identification chip according to claim 1, wherein the cavity has a depth greater than the PCB The height of the surface of the plate to the upper surface of the identification device is 0.035-.0.05 mm.
The package device with an edge-edge fingerprint identification chip according to claim 2, wherein the cavity side sections are all isosceles trapezoids, and the cavity sides are formed with vertical lines. Degree to 5 degrees.
The packaging device with an edge-edge fingerprinting chip according to claim 1, wherein the encapsulating material is made of epoxy resin.
A packaging device with an edge fingerprinting chip according to claim 1, wherein said PCB The plate has a positioning hole, and the slot is provided with a positioning post that can pass through the positioning hole, and the upper and lower mold edges are connected and positioned by a plurality of positioning pins.
Packaging and cutting method with arc edge fingerprinting chip, applying the above claims 1 to 4 The packaging device is characterized in that

Step 1 : placing the PCB into a slot of the lower mold, and positioning the positioning post through the positioning hole to position the PCB Board

Step 2, the upper mold is fastened to the lower mold through the positioning pin;

Step 3 And vacuuming the mold, injecting a packaging material from the injection port, the encapsulating material enters the main channel and the branch channel in a high-temperature liquid state after entering the injection port, and gradually reduces the injection pressure. The side of the identification device injects a gap between the cavity and the identification device;

Step 4: maintaining a clamping time of 40 seconds to 120 seconds to cure and mold the packaging material, and the PCB The identification device on the board is wrapped by the encapsulating material to form a cover layer having a surface thickness of 0.035-0.05 mm;

Step 5: Mark a contour line from the back of the PCB for each identification chip, and the contour line is consistent with the contour of the identification chip;

Step 6: cutting along the contour line from the back surface of the PCB by a cutter or a laser or a combination of the two;
A method of encapsulating and cutting a curved edge fingerprint identification chip according to claim 6, wherein in said step 3 Add any heating step in the previous step to make the temperature of the mold cavity reach any degree between 160 ° and 200 ° C and keep the temperature until the step 3 End;
The method of encapsulating and cutting a curved edge fingerprint identification chip according to claim 7, wherein the cutting method comprises preceding the PCB The plate is positioned, and then the edge of the identification chip having a curvature is cut by laser, and then the cutting chip is used to cut the identification chip to have a straight edge.
The method of encapsulating and cutting a curved edge fingerprint identification chip according to claim 8, wherein the laser is cut to a depth of PCB The thickness of the board.