A metal packaging enclosure and a sealing method thereof

Abstract

The present application belongs to the technical field of assembly process, and particularly relates to a metal packaging shell and a sealing method thereof; the metal packaging shell comprises a shell, a first cover plate, a second cover plate and a solder ring; screw mounting holes are arranged on the shell and the cover plates; an annular solder groove is arranged around the mounting hole, and the solder ring is placed in the annular solder groove; the first cover plate and the second cover plate are respectively welded on the upper and lower surfaces of the shell, and the screw mounting holes arranged on the two cover plates correspond to the positions on the shell; the cover plate and the shell are connected in a parallel sealing and welding mode; the screw mounting hole is sealed by the solder ring; the soldering iron head has a special structure, and can realize targeted heating and welding; the present application realizes the installation of double-sided mounted PCB and the airtight packaging, and meets the screw mounting requirements of the manufactured assembly; the manufactured product has a compact structure, high packaging structure strength, good environmental adaptability, and is beneficial to mass production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of assembly process, and particularly relates to a metal packaging shell and a sealing method thereof. BACKGROUND

[0002] With the development of electronic technology, the requirements for various components and assemblies are not only limited in electrical performance, but also increasingly strict in volume, and the sealing performance of components and assemblies is increasingly becoming a concern of people.

[0003] The airtight packaging is to separate electronic devices from the surrounding environment by using a cavity made of air-tight and waterproof materials to prevent the invasion of surrounding moisture during use. The airtight packaging has good environmental adaptability and is the basis of high reliability packaging.

[0004] The metal shell is a commonly used material for airtight packaging, but the commonly used packaging processes, such as parallel welding and energy storage welding, have relatively strict requirements on product shell structure design and plating materials. In addition, in order to meet the purpose of miniaturization and installation, the screw mounting holes of some products are dispersedly arranged on the surface of the product shell, which further poses a severe challenge to the sealing of metal packaging products. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a metal packaging shell and a sealing method thereof. The metal packaging shell comprises a shell, a first cover plate, a second cover plate and a solder ring. The shell is provided with a screw mounting hole, and an annular solder groove is arranged at a position corresponding to the screw mounting hole. The solder ring is placed in the annular solder groove. The first cover plate and the second cover plate are respectively welded on the upper and lower surfaces of the shell, and each of the two cover plates is provided with a screw mounting hole corresponding to the position of the screw mounting hole on the shell.

[0006] Preferably, the depth H1 of the annular solder groove is 0.2mm-0.6mm; the width L2 of the solder ring is 1-2mm, and the thickness H2 of the solder ring is equal to the depth H1 of the annular solder groove.

[0007] Preferably, the diameter of the screw mounting hole on the cover plate is equal to the sum of the inner diameter and the outer diameter of the solder ring divided by 2.

[0008] Preferably, the shell is internally provided with a PCB mounting step.

[0009] Further, the width of the PCB mounting step is 1-3mm.

[0010] Preferably, a plurality of input and output ports are arranged around the shell, and the input and output ports are internally connected to the PCB by welding.

[0011] Preferably, the thickness of the cover plate in the shell contact area is 0.1 to 0.3 mm.

[0012] Preferably, the thickness of the non-shell contact area of ​​the cover plate is greater than that of the shell contact area of ​​the cover plate.

[0013] A sealing method for a metal package housing, comprising:

[0014] S1: After the double-sided PCB board passes inspection, use conductive glue or screws to install the PCB board on the PCB mounting steps, and connect the input and output ports by soldering. Test and ensure that the electrical performance indicators of the formed component are qualified.

[0015] S2: Place a solder ring in each annular solder groove on the housing;

[0016] S3: Place the top cover plate on the housing and use a parallel sealing welding process to encapsulate and connect it around its perimeter;

[0017] S4: A specially designed ring-shaped concave soldering iron tip is used to heat and melt the solder ring;

[0018] S5: Repeat steps S2 to S4 to seal the lower cover plate;

[0019] S6: Product Inspection: Inspect the solder ring under a 20x magnifying glass to see if it is well melted. If it is well melted, a complete metal package shell is obtained; if it is poorly melted, add solder as needed and perform secondary melting and soldering with a special soldering iron tip.

[0020] Furthermore, the process of heating and melting the solder ring using a specially designed annular concave soldering iron tip includes: applying pressure to the specially designed annular concave soldering iron tip against the cover plate, and heating and melting the annular solder ring at a temperature of 350-380℃; wherein, the shape of the end of the specially designed annular concave soldering iron tip is the same as that of the annular solder ring, its inner diameter is 0.2mm smaller than that of the annular solder ring, and its outer diameter is 0.2mm larger than that of the annular solder ring.

[0021] The beneficial effects of this invention are as follows: By designing a miniaturized metal housing and its sealing method, this invention achieves the installation of double-sided PCB boards and hermetic encapsulation, while also meeting the screw mounting requirements of the manufactured components. The resulting product has a compact structure, high packaging strength, good environmental adaptability, and is conducive to mass production. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall metal encapsulation shell in this invention;

[0023] Figure 2 This is a partial dimensional diagram of the metal encapsulation shell in this invention;

[0024] Figure 3This is a dimensioned diagram of the annular solder ring of the metal packaging shell in this invention;

[0025] Figure 4 This is a dimensional diagram of the cover plate of the metal encapsulation shell in this invention;

[0026] Figure 5 This is a schematic diagram of the cover plate of the metal encapsulation shell in this invention;

[0027] Figure 6 This is a diagram showing the solder ring insertion of the metal packaging shell in this invention;

[0028] Figure 7 This is a schematic diagram of the welding process of the annular solder ring in this invention;

[0029] Figure 8 This is a schematic diagram of the specially designed annular concave soldering iron tip in this invention;

[0030] Figure 9 This is a schematic diagram showing the dimensions of the specially designed annular concave soldering iron tip used in this invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention proposes a metal encapsulation shell and its sealing method, such as... Figure 1 As shown, the metal encapsulation shell includes: a housing, a first cover plate, a second cover plate, and a solder ring; the housing has screw mounting holes, and an annular solder groove is provided around the screw mounting holes; the solder ring is placed in the annular solder groove; the first cover plate and the second cover plate are respectively welded to the upper and lower surfaces of the housing, and both cover plates have screw mounting holes corresponding to the positions of the screw mounting holes on the housing. The housing is a through-type structure, and its material can be selected from Kovar, stainless steel, aluminum, etc., with nickel or gold plating on the surface being recommended, providing good resistance to water vapor, salt spray, and other environmental conditions.

[0033] Screw mounting holes are used to insert screws, facilitating the installation of the metal enclosure. These mounting holes are threadless through holes, and their number is determined by product installation and usage requirements, and is not limited to four. Ideally, the mounting holes should be distributed around the perimeter of the enclosure. Commonly used mounting screw sizes are M1.6, M2, M3, and M4 series. The diameter of the screw mounting hole (D1) is determined by the screw size, and it is recommended to make it slightly larger than the nominal diameter (M) of the screw by 0.2mm to 0.5mm.

[0034] likeFigure 2 , Figure 3 As shown, the inner diameter of the annular solder groove is D2 = D1 + 2 * L1, and the outer diameter is D3 = D1 + 2 * L2. D1 is the diameter of the screw mounting hole, L1 is the reserved distance, and L2 is the width of the solder ring. The setting of the L1 dimension is a key part of the housing sealing structure. Its dimension is set according to the housing machining process to ensure that the minimum value of the housing without deformation during the machining process is appropriate. When the welding is completed, the molten solder should fully wet the cover plate and the L1 part of the housing to form a sealed weld.

[0035] Preferably, the depth H1 of the annular solder groove is 0.2mm to 0.6mm, and the thickness H2 of the solder ring is equal to the depth H1 of the annular solder groove. The composition of the solder ring is not limited, but it should maintain good weldability with the cover plate and the housing, and can be composed of tin-silver, tin-lead, tin-silver-copper, etc.

[0036] like Figure 4 As shown, the diameter of the screw mounting hole on the cover plate is the sum of the inner and outer diameters of the solder ring width divided by 2, i.e., D4 = (D2 + D3) / 2. The screw mounting hole achieves hermetic sealing through the molten solder ring and the annular solder groove of the shell.

[0037] Preferably, the housing has internal PCB mounting steps, the width of which is 1–3 mm. The PCB can be mounted and fixed to the housing using reflow soldering or screws. Because the PCB uses a stepped mounting design, it can employ double-sided wiring and component assembly, i.e., a double-sided surface mount structure, thereby increasing the product's functional density.

[0038] Preferably, the housing has multiple input / output ports around its perimeter for connecting to the electrical signals of the PCB board and transmitting and exchanging signals with external signals; preferably, the input / output ports are connected to the PCB board internally by soldering, and the output ports are made using a sealed integrated high-temperature sintering process, which gives them their own sealing performance.

[0039] Preferably, to ensure the quality of the sealing weld, the thickness of the cover plate in the contact area with the shell is 0.1 to 0.3 mm; the cover plate is connected to the shell by parallel welding around its perimeter, and after welding, the cover plate should be on the same plane as the L1 area of ​​the shell.

[0040] The cover material and plating should be the same as the housing. Typically, both the housing and cover are made of materials such as aluminum, stainless steel, and Kovar alloy, and their surfaces are nickel-plated or gold-plated. A parallel sealing weld process is used to achieve a sealed connection between the cover and the housing.

[0041] Preferred, such as Figure 5 As shown, if the overall size of the outer shell is too large, the non-shell contact area of ​​the cover plate can be thickened, that is, the thickness of the non-shell contact area of ​​the cover plate is greater than that of the shell contact area of ​​the cover plate. When the encapsulation is completed, it faces the inside of the product, thereby improving the overall strength of the encapsulated outer shell.

[0042] The present invention also provides a sealing method for a metal package housing, the sealing method being based on the aforementioned metal package housing, comprising:

[0043] S1: After the double-sided PCB board passes inspection, use conductive glue or screws to install the PCB board on the PCB mounting steps, and connect the input and output ports by soldering. Test and ensure that the electrical performance indicators of the formed component are qualified.

[0044] S2: Place a solder ring in each annular solder groove on the housing;

[0045] S3: As Figure 6 As shown, the top cover is placed on the housing, and its perimeter is sealed using a parallel sealing welding process. This parallel sealing welding process ensures a tight seal between the cover and the housing.

[0046] S4: A specially designed ring-shaped concave soldering iron tip is used to heat and melt the solder ring;

[0047] The dimensions of the solder ring should ensure that it fully fills the solder groove after melting, forming a good weld between the shell and the cover plate. The inner diameter of the annular solder groove is D2 = D1 + 2 * L1, and the outer diameter is D3 = D1 + 2 * L2. For example... Figure 7 As shown, a specially designed ring-shaped soldering iron tip is used for localized heating to melt the solder, avoiding damage to components on the internal PCB. During soldering, the soldering iron tip should cover the solder ring mounting area to achieve one-time heating and melting of the solder ring, thus achieving soldering. Compared to ordinary soldering iron tips, this type of tip is more targeted, has higher heating efficiency, and higher production efficiency. Preferably, the soldering temperature is 350–380℃. Figure 8 , Figure 9 As shown, the soldering iron tip is specially made with a concave ring shape, and its outer dimensions are slightly larger than the solder trough. The inner diameter is 0.2mm smaller than the inner diameter of the ring solder ring, i.e., D5 = D2 - 0.2mm, and the outer diameter is 0.2mm larger than the outer diameter of the ring solder ring, i.e., D6 = D3 + 0.2mm.

[0048] S5: Repeat steps S2 to S4 to seal the lower cover plate;

[0049] S6: Product inspection. Under a 20x magnifying glass, inspect whether the solder ring is well melted. When the melt is well melted, a continuous weld is formed between the cover plate and the L1 dimension of the shell. If the melt is well melted, a complete metal package shell is obtained. If the melt is poor (such as poor solder melting or discontinuous weld), add appropriate solder and use a special soldering iron tip for secondary melting and soldering.

[0050] In summary, this invention achieves double-sided mounting and hermetic encapsulation of PCB boards through a miniaturized metal housing design and sealing method, while also meeting the screw mounting requirements of the manufactured components. The resulting product has a compact structure, high packaging strength, good environmental adaptability, and is suitable for mass production.

[0051] The above-described embodiments further illustrate the purpose, technical solution, and advantages of the present invention. It should be understood that the above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A metal encapsulation housing, characterized in that, include: The enclosure comprises a housing, a first cover plate, a second cover plate, and a solder ring. The first and second cover plates are mounted on the upper and lower surfaces of the housing via parallel sealing. Screw mounting holes are provided at corresponding positions on the housing, the first cover plate, and the second cover plate to meet the screw mounting requirements of the packaged component. An annular solder groove is provided at the corresponding positions of the screw mounting holes on the housing. The solder ring is placed in the annular solder groove. The first and second cover plates are sealed to the housing by heating and melting the annular solder ring with a specially designed annular concave soldering iron tip. The housing has PCB board mounting steps inside for mounting double-sided surface mount printed circuit boards. Multiple input / output ports are integrally formed by high-temperature sintering around the housing, and the input / output ports are connected to the PCB board internally by welding. The packaged component can achieve hermetic sealing.

2. The metal encapsulation housing according to claim 1, characterized in that, The depth H1 of the annular solder groove is 0.2mm~0.6mm; the width L2 of the solder ring is 1~2mm; and the thickness H2 of the solder ring is equal to the depth H1 of the annular solder groove.

3. A metal encapsulation housing according to claim 1, characterized in that, The diameter of the screw mounting holes on the first and second cover plates is the sum of the inner and outer diameters of the solder ring width divided by 2.

4. A metal encapsulation housing according to claim 1, characterized in that, The width of the PCB board mounting step is 1~3mm.

5. A metal encapsulation housing according to claim 1, characterized in that, The thickness of the shell contact area of ​​the first cover plate and the second cover plate is 0.1~0.3mm.

6. A metal encapsulation housing according to claim 1, characterized in that, The thickness of the non-shell contact area of ​​the first cover plate and the second cover plate is greater than that of the shell contact area of ​​the first cover plate and the second cover plate.

7. A sealing method for a metal encapsulation housing, the sealing method being based on the metal encapsulation housing according to any one of claims 1-6, characterized in that, include: S1: After the double-sided PCB board passes inspection, use conductive glue or screws to install the PCB board on the PCB mounting steps, and connect the input and output ports by soldering. Test and ensure that the electrical performance indicators of the formed component are qualified. S2: Place a solder ring in each annular solder groove on the housing; S3: Place the first cover plate on the housing and use a parallel sealing welding process to encapsulate and connect the first cover plate to the housing around the perimeter; S4: A specially designed ring-shaped concave soldering iron tip is used to heat and melt the solder ring; S5: Repeat steps S2~S4 to perform the second cover plate sealing; S6: Product Inspection: Inspect the solder ring under a 20x magnifying glass to see if it is well melted. If it is well melted, a complete metal package shell is obtained. If the melting is incomplete, add appropriate solder and use a special soldering iron tip for secondary melting and soldering.

8. The sealing method for a metal encapsulation housing according to claim 7, characterized in that, The process of heating and melting the solder ring using a specially designed annular concave soldering iron tip includes: applying pressure to the first cover plate and the second cover plate with the specially designed annular concave soldering iron tip, and heating and melting the annular solder ring at a temperature of 350~380℃; wherein, the shape of the end of the specially designed annular concave soldering iron tip is the same as that of the annular solder ring, its inner diameter is 0.2mm smaller than that of the annular solder ring, and its outer diameter is 0.2mm larger than that of the annular solder ring.

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