Packaging method of SIM (Subscriber Identity Module) card packaging structure

Abstract

The invention provides a packaging method of an SIM card packaging structure, the SIM card packaging structure comprises a strip, a plurality of SIM cards and a conductive film connecting the strip and the SIM cards, the SIM cards are DFN packaging chips, and the packaging method comprises the following steps: step 1, SMT is performed on the DFN packaging chips to the strip bonded with the conductive film; and 2, carrying out FT test to obtain the SIM card packaging structure. According to the technical scheme, the novel SIM card is formed by packaging the SIM card through the DFN packaging technology, the novel SIM card is the DFN packaging chip, the DFN packaging chip is attached to the strip through the SMT technology, and finally FT testing is carried out, the technological process is optimized, the number of procedures is reduced from existing four procedures to two procedures, material and equipment investment is reduced, production efficiency is improved by 150%, cost is reduced, and development is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging, and in particular to a packaging method for a SIM card packaging structure. Background Art

[0002] SIM card is the abbreviation of Subscriber Identity Module, also known as smart card or user identification card. Before SIM card is produced as a finished product, SIM card chip suppliers generally provide SIM card manufacturers and developers with chips packaged in strips. Strip packaging chips are an important part of SIM card production.

[0003] The conventional SIM card packaging process generally includes DB (Die Bond) patch - WB (Wire Bond) wire welding - UV packaging - FT (Final Test) testing, a total of 4 production links, which requires a lot of materials and equipment, low production efficiency and increased costs, which is not conducive to development. Summary of the invention

[0004] The object of the present invention is to provide a packaging method for a SIM card packaging structure.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical solution: a packaging method of a SIM card packaging structure, wherein the SIM card packaging structure comprises a strip, a plurality of SIM cards and a conductive film for welding and connecting the strip and the SIM cards, wherein the SIM card is a DFN packaged chip, and the packaging method comprises the following steps:

[0006] Step 1: SMT the DFN packaged chip onto the strip bonded with the conductive film;

[0007] Step 2: Perform FT test to obtain the SIM card packaging structure.

[0008] As a further improved technical solution of the present invention, the DFN packaged chip is a pin-free structure with double-row pads, with a length range of 1mm-5mm, a width range of 1mm-5mm, and a thickness range of 0.3mm-0.5mm.

[0009] As a further improved technical solution of the present invention, the strip is a soft strip and a vacuum treatment is performed on the strip.

[0010] As a further improved technical solution of the present invention, the SMT patch process includes:

[0011] Prepare a soft strip for double-sided circuits, and adhere a conductive film to the pads for single-sided circuits;

[0012] Place the DFN packaged chip on the fitting position of the strip;

[0013] The pins of the DFN packaged chip are welded to the pads of the strip through a conductive film using a thermal ultrasonic welding process.

[0014] As a further improved technical solution of the present invention, a thermo-ultrasonic structure is added to the nozzle of the SMT equipment to melt the conductive film by thermo-ultrasonic welding while realizing the patch, and to weld the pins of the DFN packaged chip to the pads of the strip through the conductive film.

[0015] As a further improved technical solution of the present invention, the conductive film is adhered to the strip by a laminating machine.

[0016] As a further improved technical solution of the present invention, the conductive film includes a conductive PE layer composited with a PE substrate and a carbon film and hot melt adhesive layers located on both sides of the conductive PE layer. The thickness of the conductive film ranges from 15 to 25 μm and the bonding force ranges from 10 to 35 g / cm.

[0017] As a further improved technical solution of the present invention, the conductive film is a unidirectional conductive film with a forward resistivity range of 1-5 uΩ.cm and a reverse insulation resistivity greater than 10 7 ohm.

[0018] As a further improved technical solution of the present invention, the conductive film is welded to the pins of the DFN package chip and the pads of the strip by thermal ultrasonic melting at room temperature, and the welding strength of the conductive film after melting is in the range of 5-15N.

[0019] As a further improved technical solution of the present invention, the temperature range of thermal ultrasonic melting is 60-80°C, the heating time is 1-2sec, the ultrasonic amplitude range is 15-25KHz, the welding time is 0.2-1.0sec, and the pressure range is 1-3N.

[0020] The beneficial effects of the present invention are as follows: a SIM card is packaged by adopting DFN packaging technology to form a new type of SIM card, the new type of SIM card is a DFN packaged chip, the DFN packaged chip is attached to the strip by SMT patch technology, and finally an FT test is performed, the process flow is optimized, and the existing 4 processes are reduced to 2, the material and equipment investment is reduced, the production efficiency is improved by 150%, the cost is reduced, and it is conducive to development. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the steps of a packaging method of a SIM card packaging structure of the present invention;

[0022] Figure 2It is a schematic diagram of a SIM card packaging structure of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings. Please refer to the drawings for preferred embodiments of the present invention. However, it should be noted that these embodiments are not limitations of the present invention, and equivalent changes or substitutions in functions, methods, or structures made by ordinary technicians in the field according to these embodiments are all within the protection scope of the present invention.

[0024] Please refer to Figure 1 and Figure 2 The present invention discloses a packaging method of a SIM card packaging structure. The SIM card packaging structure includes a strip 1, a plurality of SIM cards, and a conductive film 3 for welding and connecting the strip 1 and the SIM card. The SIM card is a DFN package (Dual Flat No-lead Package) chip 2. The packaging method includes the following steps:

[0025] Step 1: SMT (Surface Mounted Technology) the DFN packaged chip 2 onto the strip 1 bonded with the conductive film 3;

[0026] Step 2: Perform FT test to obtain the SIM card packaging structure.

[0027] The SIM card is packaged using DFN packaging technology to form a new type of SIM card. The new type of SIM card is a DFN packaged chip 2. The DFN packaged chip 2 is attached to the strip 1 through the SMT patch technology, and finally the FT test is performed. The process flow has been optimized, reducing the existing 4 processes to 2, reducing the material and equipment investment, and increasing the production efficiency by 150%, reducing costs and facilitating development. At the same time, the use of DFN and SMT technology has a much greater bonding force than conventional chip patches, and the thrust value can be increased by 3 times or more. And because of the increase in bonding force, the ability of the SIM card's three-round compression test has been significantly improved, from the existing 12N to 18N, far exceeding the industry standard 12N, which increases the reliability of the product and increases its service life.

[0028] Furthermore, the DFN packaged chip 2 is a pinless structure with double-row pads, with a length ranging from 1 mm to 5 mm, a width ranging from 1 mm to 5 mm, and a thickness ranging from 0.3 mm to 0.5 mm. The DFN packaged chip 2 has good pressure resistance and waterproof capabilities.

[0029] Furthermore, the strip 1 is a soft strip, and a vacuum treatment is performed on the strip 1 to ensure its flatness and improve the packaging quality.

[0030] Furthermore, the SMT patch process includes:

[0031] Prepare a soft strip 1 for double-sided circuits, and adhere a conductive film 3 to the pad 11 for single-sided circuits;

[0032] Place the DFN packaged chip 2 on the matching position of the strip 1;

[0033] The pins 21 of the DFN packaged chip are welded to the pads 11 of the strip 1 through the conductive film 3 by using a thermal ultrasonic welding process.

[0034] The SIM card uses DFN packaging technology to obtain a new type of SIM card with a pinless double-row pad, and then uses a conductive film for SMT patching, which can replace and cancel the existing WB wire bonding process, thereby saving gold or copper wire used in WB wire bonding, and further canceling the UV packaging process to save UV materials, thereby reducing material investment. In addition, the use of DFN and SMT technology increases the bonding force, thereby increasing the thrust value, and the ability of the SIM card to withstand three rounds of compression tests is also significantly improved, which increases the reliability of the product and increases its service life.

[0035] Furthermore, a thermosonic structure is added to the nozzle of the SMT equipment to realize the patch while melting the conductive film by thermosonic welding, and welding the pin 21 of the DFN package chip 2 and the pad 11 of the strip 1 by the conductive film 3. The conductive film 3 is laminated to the strip 1 by a laminating machine.

[0036] The conductive film 3 includes a conductive PE layer composed of a PE substrate and a carbon film and hot melt adhesive layers on both sides of the conductive PE layer. The thickness of the conductive film 3 is in the range of 15-25 μm, and the adhesive force is in the range of 10-35 g / cm. The conductive film 3 is a unidirectional conductive film with a forward resistivity in the range of 1-5 uΩ.cm, reverse insulation and a resistivity greater than 10 7 The conductive film 3 is welded to the pin 21 of the DFN package chip 2 and the pad 11 of the strip 1 by thermal ultrasonic melting at room temperature. The conductive area 31 of the conductive film 3 is in metal contact with the pad 11 and the pin 21 and is conductive, while other areas of the non-metal surface still maintain reverse insulation performance. The welding strength of the conductive film 3 after melting is in the range of 5-15N, which can meet the impact resistance requirements of SIM card products.

[0037] The temperature range of thermal ultrasonic melting is 60-80℃, the heating time is 1-2sec, the ultrasonic amplitude range is 15-25KHz, the welding time is 0.2-1.0sec, and the pressure range is 1-3N. It can form a firm bond and has strong conductivity.

[0038] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0039] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A packaging method for a SIM card packaging structure, characterized in that: The SIM card packaging structure comprises a strip, a plurality of SIM cards and a conductive film connecting the strip and the SIM cards, the SIM card is a DFN packaged chip, and the packaging method comprises the following steps: Step 1: SMT the DFN packaged chip onto the strip bonded with the conductive film; Step 2: Perform FT test to obtain the SIM card packaging structure.

2. The packaging method of a SIM card packaging structure according to claim 1, characterized in that: The DFN packaged chip is a pin-free structure with double-row pads, with a length ranging from 1 mm to 5 mm, a width ranging from 1 mm to 5 mm, and a thickness ranging from 0.3 mm to 0.5 mm.

3. The packaging method of a SIM card packaging structure according to claim 1, characterized in that: The strip is a soft strip and is subjected to a vacuum treatment.

4. The packaging method of a SIM card packaging structure according to claim 1, characterized in that: The SMT patch process includes: Prepare a soft strip for double-sided circuits, and adhere a conductive film to the pads for single-sided circuits; Place the DFN packaged chip on the fitting position of the strip; The pins of the DFN packaged chip are welded to the pads of the strip through a conductive film using a thermal ultrasonic welding process.

5. The packaging method of a SIM card packaging structure according to claim 4, characterized in that: A thermo-ultrasonic structure is added to the nozzle of the SMT equipment to melt the conductive film through thermo-ultrasonic welding while achieving chip mounting, and to weld the pins of the DFN packaged chip to the pads of the strip through the conductive film.

6. The packaging method of a SIM card packaging structure according to claim 4, characterized in that: The conductive film is adhered to the strip by a laminating machine.

7. The packaging method of a SIM card packaging structure according to claim 4, characterized in that: The conductive film comprises a conductive PE layer formed by a composite of a PE substrate and a carbon film and hot melt adhesive layers located on both sides of the conductive PE layer. The thickness of the conductive film is in the range of 15-25 μm and the bonding force is in the range of 10-35 g / cm.

8. The packaging method of a SIM card packaging structure according to claim 7, characterized in that: The conductive film is a unidirectional conductive film with a forward resistivity range of 1-5 uΩ.cm and a reverse insulation resistivity greater than 10 7 ohm.

9. The packaging method of a SIM card packaging structure according to claim 7, characterized in that: The conductive film is welded to the pins of the DFN package chip and the pads of the strip by thermal ultrasonic melting at room temperature, and the welding strength of the conductive film after melting is in the range of 5-15N.

10. The packaging method of a SIM card packaging structure according to claim 9, characterized in that: The temperature range of thermal ultrasonic melting is 60-80°C, the heating time is 1-2sec, the ultrasonic amplitude range is 15-25KHz, the welding time is 0.2-1.0sec, and the pressure range is 1-3N.

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