DPC ceramic tube shell solder resist device and solder resist method

Abstract

The application provides a solder resist method suitable for DPC ceramic tube shells, which comprises a DPC ceramic tube shell, a ring frame arranged on the surface of the DPC ceramic tube shell and used for limiting an external space, and a convex frame arranged on the surface of the DPC ceramic tube shell and used for limiting an internal space. The ring frame and the convex frame are matched to leak out the part of the surface of the DPC ceramic tube shell which needs to be scanned by laser, the gold layer in the nickel-palladium-gold layer of the surface of the DPC ceramic tube shell is scanned off, and part of the nickel layer is reserved. In the gold-tin soldering process, the overflow of the gold-tin soldering material is accumulated on the scanned gold part, and cannot overflow to the core area or the device bonding area. The scanning range of the laser is limited through the physical convex structure of the ring frame and the convex frame, a barrier is creatively constructed on the surface of the DPC ceramic tube shell, and the technical problem that the gold-tin soldering material is disorderedly overflowed to the core area in the soldering process is fundamentally solved. The method has high precision, good reliability and strong compatibility with the existing process.

Description

Technical Field

[0001] This invention relates to the field of ceramic tube shells, and more particularly to a DPC ceramic tube shell welding resistance device and welding resistance method. Background Technology

[0002] In the current field of DPC ceramic housings, the mainstream process typically uses a 0.5mm single-layer ceramic as the substrate, and completes the manufacturing process through laser drilling, sputtering of metal layers, electroplating of copper layers, etching and grinding, and solder resist gold plating. Then, the airtightness is ensured by gold-tin welding of the frame and parallel seam welding of the cover plate. This is the current trend of miniaturization and integration of electronic devices, and has the advantages of good process compatibility, good electrical performance, low cost and high reliability. It is often used in aerospace and precision packaging.

[0003] In the existing field of ceramic tube shells, green solder resist can already ensure that solder does not overflow in various areas, but there are still some problems with green solder resist that cannot be solved. 1. Green solder mask itself needs to have a certain width, generally the narrowest part is not less than 0.2mm. Secondly, there is a positioning tolerance of 0.1mm. Usually, a tolerance distance of 0.1mm is left on the left and right sides. Therefore, in a ceramic package with very high integration, this 0.4mm takes up a lot of space for the chip and the traces, which increases the design difficulty of the package and even makes the package larger. 2. The existing green solder mask can only withstand a temperature of 320℃ for 5 minutes. During this period, slight discoloration may occur. Gold soldering may cause poor adhesion of the green solder mask in narrow areas, which may lead to detachment during subsequent encapsulation, resulting in foreign matter in the entire casing and affecting test use. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the existing technology. The present invention proposes a DPC ceramic tube shell resist welding device and resist welding method.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a solder resist method applicable to DPC ceramic tube shells, comprising: a DPC ceramic tube shell, a ring frame disposed on the surface of the DPC ceramic tube shell to limit the external space, and a raised frame disposed on the surface of the DPC ceramic tube shell to limit the internal space. The ring frame and the raised frame cooperate to expose the part of the DPC ceramic tube shell surface that needs to be laser-gold-sweeped, and sweep away the gold layer in the nickel-palladium-gold layer on the surface of the DPC ceramic tube shell, leaving a part of the nickel layer, so that during the gold-tin soldering process, the overflow of gold-tin solder will accumulate on this gold-sweeped part and cannot overflow into the core area or the device bonding area.

[0006] Preferably, the DPC ceramic tube shell is fixed by a mold, and after the equipment automatically identifies the product positioning, it is laser scanned.

[0007] Preferably, by precisely controlling the power parameters of the laser, it is ensured that only the gold layer is removed, while partially retaining the nickel layer underneath.

[0008] Preferably, the ring frame and the raised frame cooperate to form an outer channel, and the surface of the raised frame is provided with an inner channel.

[0009] Preferably, the design width of the inner channel and the outer channel is 0.03mm-0.1mm.

[0010] Preferably, the design width of the inner channel and the outer channel is 0.05mm, and the positioning tolerance reserved on both sides of the inner channel and the outer channel is 0.05mm each.

[0011] Preferably, the retained portion of the nickel layer can withstand high temperatures above 400°C.

[0012] A method for resisting welding of DPC ceramic tube shells, comprising: On the surface of the DPC ceramic tube shell, a structure is formed by the cooperation of a ring frame and a raised frame to expose the area to be treated. The area to be treated includes an outer channel formed between the ring frame and the raised frame and an inner channel provided on the surface of the raised frame. The exposed area to be processed is laser-scanned, and by precisely controlling the power parameters of the laser, the gold layer in the nickel-palladium-gold layer on the surface of the DPC ceramic tube shell is removed, while retaining part of the nickel layer underneath. In the subsequent gold-tin soldering process, the gold-tin solder accumulates in the area where the gold layer has been removed, thus being blocked from overflowing to the core area or the device bonding area.

[0013] Compared with the prior art, the beneficial effects of the present invention include: by defining the area through the physical protrusion structure of the raised frame and the ring frame, the scanning range of the laser is limited, and a barrier is creatively constructed on the surface of the DPC ceramic tube shell, which fundamentally solves the technical problem of disordered overflow of gold-tin solder into the core area during the welding process. It has high precision, good reliability and strong compatibility with existing processes. Attached Figure Description

[0014] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts. Wherein: Figure 1 The schematic diagram shows a structural schematic of a weld resist device for a DPC ceramic tube shell according to an embodiment of the present invention.

[0015] Figure 2 The schematic diagram shows a planar structural schematic of a weld resist device for a DPC ceramic tube shell according to an embodiment of the present invention.

[0016] The diagram labels are: 1. Ring frame; 2. Raised frame; 3. DPC ceramic tube shell; 4. Inner channel; 5. Outer channel; Detailed Implementation

[0017] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0019] Example 1 like Figures 1-2 As shown, this embodiment provides a DPC ceramic tube shell welding resistance device, the core of which lies in the combination of physical structure and laser technology to achieve precise welding resistance function.

[0020] The device is primarily designed for DPC ceramic housings 3 with a surface metallization layer, typically a nickel-palladium-gold layer. The device includes physical structures pre-designed and fabricated on the surface of the DPC ceramic housing 3: a ring frame 1 set on the periphery of the housing to restrict the external space, and a raised frame 2 set inside the housing, closer to the core area or device bonding area, to restrict the internal space.

[0021] The ring frame 1 and the raised frame 2 work together, leaving the area between them and specific surface areas of the raised frame 2 uncovered, thus precisely exposing the parts of the DPC ceramic tube shell 3 that require special treatment. Specifically, the area between the ring frame 1 and the raised frame 2 forms a continuous outer channel 5, while the top surface of the raised frame 2 itself is designed with an inner channel 4. These channel areas are the "areas to be treated" for subsequent laser processing.

[0022] Furthermore, to ensure the solder resist effect while taking into account the processing accuracy, the design width of the inner channel 4 and the outer channel 5 is 0.03mm to 0.1mm. In a preferred embodiment, the design width of the channel is set to 0.05mm. At the same time, considering the tolerance of laser positioning and processing, a positioning tolerance zone of 0.05mm is reserved on each side of the channel, namely the side wall of the ring frame 1 and the raised frame 2. This means that the actual path width of the laser scanning will be slightly larger than the design width of the channel to ensure complete coverage of the area to be processed.

[0023] In practical applications, the DPC ceramic tube shell 3 is first fixed using a special mold. Then, an automated device with a vision recognition system automatically identifies the positioning marks on the product, thereby achieving precise alignment of the device. After positioning, the device performs laser scanning on the areas to be processed exposed by the inner channel 4 and the outer channel 5 according to a preset program. The key to the laser process lies in the precise control of parameters. Through repeated experiments and optimization, specific parameters such as laser power, frequency, scanning speed, and defocusing amount are selected to ensure that the laser energy can only remove the surface gold layer while partially retaining the underlying nickel layer. This requires the laser energy threshold to be exactly between the ablation threshold of the gold layer and the damage threshold of the nickel layer. The retained nickel layer, due to its material properties, must be able to withstand the high temperature of over 400°C during the subsequent gold-tin soldering process without oxidation or peeling, in order to maintain its solder resist function.

[0024] After laser processing, the gold layer is selectively removed in the channel area that was originally a nickel-palladium-gold layer, exposing the underlying nickel layer. During the subsequent eutectic soldering process, the molten solder wets and spreads on the metal surface. Since the exposed nickel layer has much lower wettability to the gold-tin solder than the gold layer, the flow of solder in this area is greatly suppressed. Therefore, the solder overflow is confined to the channel area and accumulates there, forming an effective "solder dam". This prevents the solder from overflowing into the core area protected by the raised frame 2 or the internal device bonding area, thus avoiding problems such as short circuits, contamination, or thermal performance degradation caused by solder overflow.

[0025] Example 2: A method for resisting welding of DPC ceramic tube shells This embodiment provides a solder resist method applied to the above-mentioned device, and the specific steps are as follows: S100: Structural preparation and positioning.

[0026] Provide a DPC ceramic tube shell 3 with the ring frame 1 and raised frame 2 already made on the surface. Install the tube shell into a special fixture or mold and fix it. Start the automated laser processing equipment. Its vision system captures the features on the tube shell and completes high-precision positioning to ensure that the laser scanning path is completely aligned with the designed inner channel 4 and outer channel 5 areas.

[0027] S200: Laser selective removal of gold layers.

[0028] According to a preset program, the equipment controls the laser beam to scan along a predetermined channel path. By precisely controlling the core parameters such as laser power, pulse width, repetition frequency, and scanning speed (for example, using a nanosecond or picosecond laser of a specific wavelength to reduce the heat-affected zone while ensuring processing efficiency), the laser energy is just enough to vaporize or peel off the surface gold, but not enough to damage the underlying nickel layer. Ultimately, in the inner channel 4 and outer channel 5 area, the effect of removing only the gold layer while retaining the complete nickel layer is achieved.

[0029] S300: Achievement of welding and resist welding effects.

[0030] The laser-treated DPC ceramic housing 3 is used in subsequent packaging processes. When gold-tin eutectic bonding is performed, the molten solder normally wets and spreads in the metallized area (complete gold layer area) on the surface of the housing. When the solder flows to the laser-treated channel area (i.e. exposed nickel layer area), the flow front of the solder is blocked at this point due to the sudden change in wettability. The surface tension causes the solder to accumulate and thicken in the channel, without crossing the raised frame 2 and intruding into the internal functional area. The raised frame 2 itself acts as a physical barrier, further enhancing the barrier effect.

[0031] This invention creatively constructs a barrier on the surface of DPC ceramic tube shell by combining "physical protrusion structure to define the area" with "laser selective gold stripping" process, fundamentally solving the technical problem of disordered overflow of gold-tin solder into the core area during the welding process. This method has the advantages of high precision, good reliability and strong compatibility with existing processes.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0033] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A DPC ceramic tube shell weld resistance device, characterized in that, include: The DPC ceramic housing (3), the ring frame (1) set on the surface of the DPC ceramic housing (3) to restrict the external space, and the protruding frame (2) set on the surface of the DPC ceramic housing (3) to restrict the internal space, the ring frame (1) and the protruding frame (2) work together to expose the part of the DPC ceramic housing (3) surface that needs to be laser-gold-sweeped, sweep away the gold layer in the nickel-palladium-gold layer on the surface of the DPC ceramic housing (3), and retain part of the nickel layer, so that during the gold-tin soldering process, the overflow of gold-tin solder will accumulate on this sweeping part and cannot overflow to the core area or the device bonding area.

2. The DPC ceramic tube shell weld resistance device according to claim 1, characterized in that, The DPC ceramic tube shell is fixed by a mold, and after the equipment automatically identifies the product positioning, it is laser scanned.

3. The DPC ceramic tube shell weld resistance device according to claim 1, characterized in that, By precisely controlling the laser power parameters, it is ensured that only the gold layer is removed, while partially retaining the nickel layer underneath.

4. The DPC ceramic tube shell weld resistance device according to claim 1, characterized in that, The ring frame (1) and the raised frame (2) cooperate to form an outer channel (5), and the surface of the raised frame (2) is provided with an inner channel (4).

5. The DPC ceramic tube shell weld resistance device according to claim 4, characterized in that, The design width of the inner channel (4) and the outer channel (5) is 0.03mm-0.1mm.

6. The DPC ceramic tube shell weld resistance device according to claim 5, characterized in that, The design width of the inner channel (4) and the outer channel (5) is 0.05mm, and the positioning tolerance reserved on both sides of the inner channel (4) and the outer channel (5) is 0.05mm.

7. The DPC ceramic tube shell weld resistance device according to claim 1, characterized in that, The retained portion of the nickel layer can withstand temperatures above 400°C.

8. A method for resisting welding of DPC ceramic tube shells, characterized in that, The DPC ceramic tube shell weld resistance device applied to any one of 1-7 includes: On the surface of the DPC ceramic tube shell (3), a structure is formed by the cooperation of a ring frame (1) and a raised frame (2) to expose the area to be treated. The area to be treated includes an outer channel (5) formed between the ring frame (1) and the raised frame (2) and an inner channel (4) provided on the surface of the raised frame (2). The exposed area to be processed is laser scanned. By precisely controlling the power parameters of the laser, the gold layer in the nickel-palladium-gold layer on the surface of the DPC ceramic tube shell (3) is removed, while retaining part of the nickel layer below it. In the subsequent gold-tin soldering process, the gold-tin solder accumulates in the area where the gold layer has been removed, thus being blocked from overflowing to the core area or the device bonding area.

Images