A mold structure of a fingerprint product and a chip packaging method thereof

Abstract

The present invention relates to a mold structure of a fingerprint product and a chip packaging method thereof, belonging to the field of semiconductor chip packaging technology. The front of the lower mold (81) includes a plurality of curved groove strips (82) and positioning holes (83) arranged in parallel, and the positioning holes (83) are arranged on the sides of the lower mold. The upper mold (85) includes vacuum holes (89), fixed claws (87), and positioning pins (88). The positioning pins (88) are arranged on the sides of the upper mold and match the positioning holes (83). The vacuum holes (89) are evenly distributed in the center of the mold, and the fixed claws (87) are fixed on both sides of the long sides of the upper mold (85). The present invention provides a curved surface plastic sealing mode.

Description

Technical Field

[0001] The invention relates to a mold structure of a fingerprint product and a chip packaging method thereof, belonging to the technical field of semiconductor chip packaging. Background Art

[0002] Traditional fingerprint products are flat fingerprint products, suitable for the front and back of mobile phones. With the development of technology, flat plastic-sealed fingerprint products can no longer meet the needs of diversified development of fingerprint products. In order to pursue a better mobile phone screen occupancy ratio, it is necessary to develop under-screen fingerprints and side fingerprints. Compared with the front and back, the side fingerprint of the mobile phone requires a narrower size of fingerprint products. Since the sides of most mobile phones are not completely flat and present a certain curvature, in order to meet the consistency of the side, the optimized side fingerprint also presents a curved surface. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a mold structure of a fingerprint product and a chip packaging method thereof, so as to provide a curved surface plastic packaging mode.

[0004] The present invention is achieved in that:

[0005] The present invention provides a mold structure for a fingerprint product, wherein the mold is in an elongated strip shape and comprises a lower mold and an upper mold, wherein the front surface of the lower mold comprises a plurality of curved groove strips and positioning holes arranged in parallel, wherein the positioning holes are arranged on the sides of the lower mold, and the arc radius R1 of the groove bottom surface of the curved groove strip is in the range of 4 to 8 mm; wherein the upper mold comprises a vacuum hole, a fixing claw and a positioning pin, wherein the positioning pin is arranged on the sides of the upper mold and matches the positioning hole, wherein the vacuum holes are evenly distributed on the four sides of the upper mold, and the fixing claw is fixed on the long side of the upper mold.

[0006] Furthermore, the surface roughness of the lower mold is 0.5+ / -0.2um.

[0007] Furthermore, the radius R1 of the groove bottom surface of the curved groove strip is 5.5 mm.

[0008] Furthermore, the chamfer radius R2 of the curved groove strip is 0.2 mm.

[0009] Furthermore, the vacuum hole is in a cross shape.

[0010] The present invention also provides a packaging structure of a fingerprint product, which includes a substrate, a chip and a plastic packaging material. A chip bonding area is provided on the upper surface of the substrate. The chip is mounted on the chip bonding area of ​​the substrate. The gold wire of the chip is punched onto the substrate. The plastic packaging material plasticizes the chip and the gold wire above the substrate to form a raised arc-shaped plastic packaging layer. A solder pad is provided on the lower surface of the substrate.

[0011] Furthermore, the arc-shaped surface smoothness Ra of the plastic sealing layer is less than 0.6 um, and the arc radius R3 is 4-8 mm.

[0012] Furthermore, the arc radius R3 of the arc-shaped plastic sealing layer is 5.5 mm, and the arc radius R4 of the chamfer thereof is 0.2 mm.

[0013] The present invention also provides a packaging method for a packaging structure of a fingerprint product, and the process steps are as follows:

[0014] Step 1, provide a substrate, the upper surface of the substrate 1 is provided with a chip pasting area, a cutting path and a positioning hole, a positioning small gold dot, a cross positioning point and a positioning point on the short side, place the substrate on the front of the upper mold, the positioning hole of the substrate corresponds to the positioning pin of the upper mold, the cross positioning point is accurately positioned, and then the substrate is fixed with a fixed claw, the vacuum valve of the upper mold is opened, and the substrate is sucked through the vacuum hole;

[0015] Step 2: Use surface mounting technology on the upper surface of the substrate to mount the back of the chip to the chip bonding area of ​​the substrate in turn, and fix the chip to the substrate through the chip mounting film. Then, use the wire bonding process to connect the gold wire to the substrate with reference to the positioning small gold dots on the long side of the substrate and the positioning points on the short side;

[0016] Step 3: Spread a separation film with good ductility on the powder sprinkling platform, then place the powder sprinkling tray cover on the separation film on the powder sprinkling platform, and transport the separation film with the plastic sealing material to the top of the lower mold by vacuum adsorption of the separation film. The lower mold vacuum adsorbs the separation film with the plastic sealing material powder and evenly adsorbs it in the curved groove strip of the lower mold.

[0017] Step 4: Invert the upper mold, and connect the positioning pins of the upper mold with the positioning holes of the lower mold, and close the upper and lower molds to complete the mold closing process;

[0018] Step 5: Vacuum the mold cavity and heat it to complete the injection molding;

[0019] Step 6: Open the mold cavity, remove the separation film, complete the demolding of the separation film, and complete the curved surface plastic sealing; on the back of the substrate, each unit is set with a gold finger, each corresponding to a different circuit, for testing the circuit conduction;

[0020] Step 7: Cut along the cutting path of the substrate to form a plurality of fingerprint product packaging units.

[0021] Beneficial Effects

[0022] The packaging structure and packaging method of the fingerprint product proposed in the present invention break the traditional flat plastic packaging mode of fingerprint products and provide a curved plastic packaging mode to meet the diversified development of fingerprint products and optimize customer tactile experience; at the same time, since the curved fingerprint becomes narrower and the overall size becomes smaller, the number of particles that can be arranged on the entire substrate becomes more, which not only saves costs but also increases production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the bottom structure of a mold of a fingerprint product of the present invention;

[0024] Figure 2 for Figure 1 A partial enlarged view of the AA section;

[0025] Figure 3 This is a structural schematic diagram of an upper mold of a mold for a fingerprint product of the present invention;

[0026] Figure 4 A schematic top view of a packaging structure of a fingerprint product of the present invention;

[0027] Figure 5 for Figure 4 BB cross-sectional diagram;

[0028] Figure 6 It is a front structural schematic diagram and a partial enlarged schematic diagram of a packaging body of a packaging method for a packaging structure of a fingerprint product of the present invention;

[0029] Figure 7 for Figure 6 A schematic diagram of the back structure of the package and a partial enlarged schematic diagram;

[0030] Figure 8 for Figure 6 A schematic diagram of the longitudinal section of the packaging structure monomer of the Zhongzhiji product;

[0031] In the figure:

[0032] Substrate 1

[0033] Chip 2

[0034] Plastic layer 3

[0035] Lower mold 81

[0036] Curved groove strip 82

[0037] Positioning hole 83

[0038] Upper mold 85

[0039] Fixed claw 87

[0040] Positioning needle 88

[0041] Vacuum hole 89

[0042] Anchor point 62

[0043] Cross mark 63

[0044] Positioning small gold dot 64

[0045] Cutting Road 65

[0046] Cutting road 66. DETAILED DESCRIPTION

[0047] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. For ease of description, spatial relative terms (such as "below", "beneath", "lower", "above", "upper", etc.) may be used to describe the relationship of one element or component to another element or component shown in the figures. In addition to the orientation shown in the figures, spatial relative terms also include different orientations of the device in use or operation. The device can be oriented in other ways, rotated 90 degrees or in other orientations, and the spatial relative descriptions used herein may be interpreted similarly accordingly.

[0048] like Figures 1 to 3 As shown, a mold structure of a fingerprint product according to an embodiment of the present invention comprises a lower mold 81 and an upper mold 85 . The lower mold 81 is in a long strip shape, and the upper mold 85 is in a long strip shape matching the lower mold 81 . Figure 1 This is a schematic structural diagram of a lower mold of a fingerprint product mold of the present invention. Figure 2 for Figure 1 A partial enlarged view of the AA section.

[0049] like Figure 2 As shown, the front side of the lower mold 81 includes a plurality of curved groove strips 82 and positioning holes 83 arranged in parallel. The positioning holes 83 are arranged on the sides of the lower mold. The curvature radius R1 of the groove bottom of the curved groove strip 82 ranges from 4 to 8 mm, and the surface roughness Ra is 0.5+ / -0.2 um. Generally, the curvature radius R1 of the groove bottom of the curved groove strip 82 is preferably 5.5 mm, and the chamfer curvature radius R2 is 0.2 mm.

[0050] like Figure 3 As shown, Figure 3 The upper mold 85 of the mold of a fingerprint product of the present invention is a schematic diagram of the structure. The upper mold 85 includes vacuum holes 89, fixed claws 87 and positioning pins 88. The positioning pins 88 are arranged on the sides of the upper mold and match the positioning holes 83 of the lower mold 81. The vacuum holes 89 are evenly distributed around the upper mold in a cross shape. The fixed claws 87 are fixed on both sides of the long sides of the upper mold 85.

[0051] A packaging structure of a fingerprint product according to an embodiment of the present invention is provided. Figure 4 This is a top view schematic diagram of a packaging structure of a fingerprint product of the present invention. Figure 5 for Figure 4 The BB cross-sectional schematic diagram includes a substrate 1, a chip 2 and a plastic encapsulation material. The upper surface of the substrate 1 is provided with a chip pasting area, the chip 2 is mounted on the chip pasting area of ​​the substrate 1, the gold wire 21 of the chip 2 is hit on the substrate 1, and the plastic encapsulation material plastic encapsulates the chip 2 and the gold wire 21 above the substrate 1 to form a raised arc-shaped plastic encapsulation layer 3. The arc-shaped surface smoothness Ra of the plastic encapsulation layer 3 is less than 0.6um, and the arc radius R3 is 4~8mm. Generally, the arc radius R3 of the arc-shaped plastic encapsulation layer 3 is 5.5mm, and the chamfer arc radius R4 is 0.2mm.

[0052] like Figure 6 and Figure 8 FIG. 1 is a packaging method for a packaging structure of a fingerprint product according to an embodiment of the present invention, and the process steps are as follows:

[0053] Step 1, provide a substrate 1, the upper surface of the substrate 1 is provided with a chip pasting area, a cutting path 65, a cutting path 66, a positioning hole 61, a positioning small gold dot 64, a cross positioning point 63 and a positioning point 62 on the short side, place the substrate 1 on the front of the upper mold 85, the positioning hole 61 of the substrate 1 corresponds to the positioning pin 88 of the upper mold 85, and the cross positioning point 63 is accurately positioned, and then the substrate 1 is fixed with a fixing claw 87, and the vacuum valve of the upper mold 85 is opened, and the substrate 1 is sucked through the vacuum hole 89, as shown in FIG. Figure 6 As shown, Figure 6 It is a front structural schematic diagram and a partial enlarged schematic diagram of a packaging body of a packaging method for a packaging structure of a fingerprint product of the present invention;

[0054] Step 2: On the upper surface of the substrate 1, the back of the chip 2 is sequentially mounted to the chip bonding area of ​​the substrate 1 through the surface mounting technology, and the chip 2 is fixed to the substrate 1 through the chip mounting film. Then, through the wire bonding process, the gold wire 21 is connected to the substrate 1 with reference to the positioning small gold dots 64 on the long side of the substrate 1 and the positioning points 62 on the short side. Figure 6 As shown;

[0055] Step 3: Spread a separation film with good ductility on the powder sprinkling platform, then place the powder sprinkling tray cover on the separation film of the powder sprinkling platform, and transport the separation film with the plastic sealing material to the top of the lower mold 81 by vacuum adsorption of the separation film. The lower mold vacuum adsorbs the separation film with the plastic sealing material powder and evenly adsorbs it in the curved groove strip 82 of the lower mold 81;

[0056] Step 4: Invert the upper mold 85, and connect the positioning pins 88 of the upper mold 85 with the positioning holes 83 of the lower mold 81 to complete the mold closing process;

[0057] Step 5: The mold cavity is evacuated and heated and pressurized to complete the injection molding;

[0058] Step 6: Open the mold cavity, remove the separation film, complete the demolding of the separation film, and complete the curved surface plastic sealing; Figure 7 for Figure 6 On the back side of the substrate 1, each unit is provided with a gold finger 11, each corresponding to a different circuit, for testing the circuit conduction.

[0059] Step 7: Cut along the cutting lines 65 and 66 of the substrate 1 to form a plurality of packaged monomers of fingerprint products, such as Figure 8 shown.

[0060] The specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A mold structure of a fingerprint product, characterized in that: The mold structure of the fingerprint product is in the shape of a long strip, and comprises a lower mold (81) and an upper mold (85). The front surface of the lower mold (81) comprises a plurality of curved groove strips (82) and positioning holes arranged in parallel. The positioning holes are arranged on the sides of the lower mold. The arc radius R1 of the groove bottom surface of the curved groove strip (82) ranges from 4 to 8 mm. The surface roughness of the lower mold (81) is 0.5+ / -0.2 um. The upper mold (85) comprises vacuum holes (89), fixed claws (87) and positioning pins (88). The positioning pins (88) are arranged on the sides of the upper mold and match the positioning holes. The vacuum holes (89) are evenly distributed on the sides of the upper mold. The vacuum holes (89) are in a cross shape. The fixed claws (87) are fixed on the long sides of the upper mold (85).

2. The mold structure of the fingerprint product according to claim 1, characterized in that: The arc radius R1 of the groove bottom surface of the curved groove strip (82) is 5.5 mm.

3. The mold structure of the fingerprint product according to claim 1, characterized in that: The chamfer radius R2 of the curved groove strip (82) is 0.2 mm.

4. A packaging method for a packaging structure of a fingerprint product, the process steps of which are as follows: Step 1, providing a substrate (1), wherein the upper surface of the substrate (1) is provided with a chip pasting area, a cutting path (65) and a positioning hole, a positioning gold dot (64), a cross positioning point (63) and a positioning point (62) on the short side, placing the substrate (1) on the front side of the upper mold (85), the positioning hole of the substrate (1) corresponds to the positioning pin (88) of the upper mold (85), and the cross positioning point (63) is accurately positioned, and then the substrate (1) is fixed with a fixing claw (87), and the vacuum valve of the upper mold (85) is opened, and the substrate (1) is sucked through the vacuum hole (89); Step 2: Using surface mounting technology, the back side of the chip (2) is sequentially mounted on the chip bonding area of ​​the substrate (1) on the upper surface of the substrate (1), and the chip (2) is fixedly connected to the substrate (1) via a chip mounting film. Then, a wire bonding process is performed with reference to the positioning small gold dots (64) on the long side of the substrate (1) and the positioning points (62) on the short side to complete the connection between the gold wire (21) and the substrate (1); Step 3: Spread a separation film with good ductility on the powder sprinkling platform, then place the powder sprinkling tray cover on the separation film on the powder sprinkling platform, and transport the separation film with the plastic sealing material to the top of the lower mold (81) by vacuum adsorbing the separation film. The lower mold vacuum adsorbs the separation film with the plastic sealing material powder and evenly adsorbs it in the curved groove strip (82) of the lower mold (81); Step 4: the upper mold (85) is inverted, and the positioning pins (88) of the upper mold (85) are matched and connected with the positioning holes of the lower mold (81), and the upper mold and the lower mold are tightly closed to complete the mold closing process; Step 5: Vacuum the mold cavity and heat it to complete the injection molding; Step 6: Open the mold cavity, remove the separation film, complete the demolding of the separation film, and complete the curved surface plastic sealing; on the back of the substrate (1), each unit is provided with a gold finger (11), each corresponding to a different circuit, for testing the circuit conduction; Step 7: Cut along the cutting path (65) of the substrate (1) to form a plurality of packaged fingerprint products.

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