A packaging housing for optoelectronic devices and a manufacturing method thereof

Abstract

The present invention discloses a packaging housing for optoelectronic devices and a manufacturing method thereof. The manufacturing method obtains a bottom plate assembly through fusion sealing, performs an oxide film purification treatment before brazing, brazes the purified bottom plate assembly with the remaining spare parts to obtain a semi-finished packaging housing; finally, a nickel layer and a gold layer are plated on the surface of the semi-finished packaging housing to manufacture the packaging housing. The manufacturing method has a simple process, and the manufactured packaging housing meets the standard of the visual inspection requirements for metal housings in Appendix A of GJB2440A-2006 "General Specification for Hybrid Integrated Circuit Housings", and has a high yield.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic device packaging, and particularly relates to a manufacturing method for a packaging shell for optoelectronic devices, and also relates to a packaging shell for optoelectronic devices obtained by the manufacturing method. Background Art

[0002] With the development of large-scale integrated circuits and high-power electronic devices, iron-nickel-cobalt alloys have been widely used in glass-to-metal sealing, ceramic-to-metal sealing, and soldering processes due to their suitable thermal expansion coefficients. In the realization process of traditional packaging shells for optoelectronic devices, first, the machined parts are subjected to wet hydrogen decarburization-pre-oxidation-sealing, then the sealed components are chemically treated to remove the surface oxide layer, and then the relevant parts are soldered into a packaging shell for optoelectronics in a mixed atmosphere of inert gas and hydrogen using solder, and finally, it is applied to the field of optoelectronic device packaging to meet the mechanical support of the internal circuit and the optical circuit signal interconnection inside and outside the device.

[0003] With the increasing requirements for the environmental reliability of optoelectronic devices, in recent years, the sealing level of optoelectronic devices equipped with optical fibers and other chip circuits has been increasing year by year, and the requirements for the soldering quality of the shell have also become higher and higher. In actual production and use, there are phenomena such as the airtightness and functional failure of the shell due to the insufficient soldering bonding force between the parts.

[0004] The main reasons for the airtightness and functional failure of the optoelectronic device shell are as follows: on the one hand, it is related to the soldering quality in the manufacturing process of the packaging shell. A complex surface film is formed on the surface of the shell after wet hydrogen decarburization-pre-oxidation-high-temperature sealing. This complex surface film cannot be effectively removed by simple chemical treatment, and the solder cannot wet and spread well on the remaining surface film, resulting in unqualified phenomena such as weld seams after soldering, and thus the risk of solder weld seams and even airtightness failure of the packaging shell; on the other hand, it is related to the raw materials of the packaging shell. For example, commonly used materials such as 4J29 or 4J42, in which impurity elements such as silicon and aluminum are prone to form complex oxides, hindering the wetting and spreading of the solder. And during the manufacturing process of optoelectronic devices, the impurity elements such as silicon and aluminum in 4J29 or 4J42 materials diffuse and accumulate on the material surface during high-temperature treatment to form a complex surface film that cannot be removed by hydrochloric acid, thereby leading to the risk of weld seams and even airtightness failure during the soldering of the packaging shell for optoelectronics, and ultimately greatly reducing the production qualification rate of the packaging shell for optoelectronics. Summary of the Invention

[0005] In view of this, it is necessary for the present invention to provide a manufacturing method for a packaging housing for optoelectronic devices. By improving the process in the traditional packaging housing, the oxide film of the bottom plate assembly is purified before brazing, the complex surface film on the material surface is removed, and the wettability of the solder on the material surface is improved, so as to ensure that the optoelectronic packaging housing after brazing meets the standard of the visual inspection requirements for metal housings in Appendix A of GJB2440A-2006 "General Specification for Hybrid Integrated Circuit Housings", and the manufacturing method has low process cost and high yield.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a manufacturing method for a packaging housing for optoelectronic devices, including the following steps:

[0008] Provide and clean the spare parts, where the spare parts include a bottom plate, insulating leads, a ring frame, a conduit, and shorting leads;

[0009] After subjecting the bottom plate and the insulating leads to wet hydrogen decarburization and pre-oxidation in sequence, they are hermetically sealed to obtain a bottom plate assembly;

[0010] Purify the oxide film of the bottom plate assembly;

[0011] Brazing the purified bottom plate assembly with the remaining spare parts to obtain a semi-finished packaging housing;

[0012] Plating a nickel layer and a gold layer on the surface of the semi-finished packaging housing to obtain the packaging housing.

[0013] In a further aspect, the spare parts are obtained by machining the raw materials, and the machining accuracy is controlled within ±0.02 mm.

[0014] In a further aspect, the raw materials are selected from kovar alloy or iron-nickel alloy.

[0015] In a further aspect, the cleaning process of the spare parts is specifically as follows: after soaking in a cleaning agent for more than 1 h, it is spray-cleaned with pure water, then soaked in anhydrous ethanol for dehydration, and finally dried at 80-100 °C, where the cleaning agent is selected from an alkali solution or a synthetic detergent.

[0016] In a further aspect, the specific steps of the oxide film purification are as follows: soaking in a first acid solution for 30-180 s, and then soaking in a second acid solution for 10-180 s;

[0017] Among them, the first acid solution is hydrochloric acid or sulfuric acid with a volume fraction of more than 20%, and the second acid solution is hydrofluoric acid with a volume fraction of more than 10%.

[0018] Further, the first acid solution is hydrochloric acid or sulfuric acid with a volume fraction of 20%-50%, and the second acid solution is hydrofluoric acid with a volume fraction of 10%-50%.

[0019] Further, the length and width dimensions of the bottom plate are 0.1-1.0 mm smaller than those of the ring frame.

[0020] Further, the inner wall of the ring frame is roughened.

[0021] Further, the roughening treatment method is: sandblasting the inner wall of the ring frame.

[0022] The present invention further provides a packaging housing for optoelectronic devices, which is obtained by using the manufacturing method described in any one of the foregoing.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The manufacturing method described in the present invention removes metal oxides and non-metal oxides on the material surface through oxide film purification treatment before brazing, improves the wettability of the solder on the material surface, and thus ensures that the packaging housing for optoelectronic devices after brazing meets the standard of sealing reliability R1≤1×10 -3 Pa·cm 3 / s(He).

[0025] Moreover, the process cost of this manufacturing method is low, which can greatly improve the qualified rate of products and the yield is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic process flow diagram of manufacturing a packaging housing in a preferred embodiment of the present invention;

[0027] Figure 2 It is a schematic three-dimensional structure diagram of the packaging housing obtained in a preferred embodiment of the present invention;

[0028] Figure 3 is Figure 2 the bottom structure diagram of the packaging housing in

[0029] In the figure: 10-bottom plate, 20-ring frame, 30-insulating lead, 40-glass sealing area, 50-short circuit lead, 60-conduit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] For ease of understanding of the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of this invention herein are for the purpose of describing specific embodiments only and are not intended to limit the invention.

[0032] The first aspect of the present invention discloses a manufacturing method for a packaging shell of an optoelectronic device, and its technological process is as Figure 1 shown below, mainly including the following steps:

[0033] Provide and clean spare parts, and the spare parts include a bottom plate, insulating leads, a ring frame, a conduit, and short-circuit leads;

[0034] After subjecting the bottom plate and the insulating leads to wet hydrogen decarburization and pre-oxidation in sequence, perform fusion sealing to obtain a bottom plate assembly;

[0035] Purify the oxide film of the bottom plate assembly;

[0036] Brazing the purified bottom plate assembly with the remaining spare parts to obtain a semi-finished packaging shell;

[0037] Plating a nickel layer and a gold layer on the surface of the semi-finished packaging shell to obtain the packaging shell.

[0038] By performing oxide film purification treatment before brazing, the present invention removes metal oxides and non-metal oxides on the material surface, thereby improving the wettability of the solder on the material surface, and the appearance of the brazed welding joint of the obtained packaging shell meets the standard of the visual inspection requirements for metal shells in Appendix A of GJB2440A-2006 "General Specification for Hybrid Integrated Circuit Packages". In addition, the manufacturing method of the present invention has low process cost and high yield in actual production.

[0039] Among them, the spare parts described in the present invention are all conventional components of the packaging shell for optoelectronic devices. In addition to the main parts mentioned herein, other spare parts commonly used in the field for the packaging shell of optoelectronic devices may also be included. Further, the spare parts are obtained by mechanical processing of raw materials. Among them, the raw materials can be selected from the materials commonly used in the field, such as kovar alloy or iron-nickel alloy. Specific examples that can be mentioned are 4J29 or 4J42 materials; there is no particular limitation on the mechanical processing method used, and any conventional machining methods in the field can be used. Specific examples that can be mentioned include, but are not limited to, milling, punching, wire cutting, MIMU processing, etc. It can be understood that the processing can be carried out according to the designed dimensions, and the processing accuracy is controlled within ±0.02 mm.

[0040] A further solution is that after the spare parts are mechanically processed and formed, they need to be cleaned in order to remove grease and dirt on the surface of the material. The cleaning process can adopt conventional methods in the field and can be appropriately adjusted as needed. In one or more embodiments of the present invention, the cleaning process of the spare parts is specifically as follows: after soaking in a cleaning agent for more than 1 hour, spraying with pure water, then soaking and dehydrating with anhydrous ethanol, and finally drying at 80-100°C. The cleaning agent can be a conventional agent in the field that can remove grease and dirt. Specific examples that can be mentioned include alkaline solutions or synthetic detergents.

[0041] It can be understood that the assembly of the base plate assembly in this article is a conventional process in the field. Specifically, the base plate and the insulated lead are subjected to wet hydrogen decarburization and pre-oxidation in sequence, and then sealed to obtain the base plate assembly. The wet hydrogen decarburization described in this article is a conventional process in the field, and its purpose is to remove impurities and gases in the material, especially compounds such as oxygen and carbon. The specific process parameters are not particularly limited, and those skilled in the art can adjust them as needed. In one or more embodiments of the present invention, the process parameters of the wet hydrogen decarburization are: decarburization temperature 900-1100°C, dew point 15-25°C, and insulation time 15-50min.

[0042] The pre-oxidation described herein is a conventional process in the art, and its purpose is to form a transition layer mainly composed of low-valent oxides on the metal surface, which serves as a bridge for the bonding between glass and metal in the subsequent sealing process. The specific parameters can be adjusted as needed. In one or more embodiments of the present invention, the process parameters of the pre-oxidation are: the oxidizing atmosphere is an inert gas, the temperature is 800-1000°C, the dew point is 15-25°C, and the insulation time is 5-20min, wherein the inert gas is a gas element corresponding to the Group 0 element in the periodic table of chemical elements (such as helium, argon, etc.) or nitrogen.

[0043] It is also understandable that the sealing described in the present invention is to seal the spare parts and glass beads, and the process is a conventional process in the art, and can be selected according to the different properties of the glass beads, so there is no special limitation. In one or more embodiments of the present invention, the process parameters of the sealing are: sealing temperature 900-980°C, sealing atmosphere is inert gas protection, and time is 5-30min, wherein the meaning of inert gas is the same as the pre-oxidation process, which will not be elaborated here.

[0044] Further solution: The specific steps for purifying the oxide film are as follows: First, soak in the first acid solution for 30 - 180 s, and then soak in the second acid solution for 10 - 180 s. Among them, the first acid solution is selected from hydrochloric acid or sulfuric acid with a concentration of more than 20% (V / V). Preferably, the first acid solution is 20% - 50% (V / V) hydrochloric acid or sulfuric acid, and the second acid solution is selected from hydrofluoric acid with a concentration of more than 10% (V / V). Preferably, the second acid solution is 10% - 50% (V / V) hydrofluoric acid. Preferably, both hydrochloric acid and hydrofluoric acid are of EL grade. Through this treatment step, metal oxides and non-metal oxides on the material surface can be removed, especially iron oxide and impurities such as silicon and aluminum on the material surface, improving the wettability of the solder on the material surface, making the welding part smooth and flat, without phenomena such as weld seams and porous solder, so as to avoid unqualified phenomena such as rust and discoloration of the packaging shell during subsequent storage and use due to the residual plating solution at the weld seams and porous solder positions during the subsequent nickel plating and gold plating processes.

[0045] Further solution: The brazing process in the present invention is not particularly limited, and conventional processes in the art can be used, which can be adjusted or selected according to different solders and raw materials of spare parts. In one or more embodiments of the present invention, the solder is selected from silver-copper solder or silver-copper-nickel solder, and the brazing is carried out under the protection of a mixed atmosphere of hydrogen and inert gas with a volume ratio of 2% - 15%, and the brazing temperature is 800 - 850 °C.

[0046] Further solution: In some other embodiments of the present invention, the length-width ratio of the bottom plate of the packaging shell in this article is 0.1 - 1.0 mm smaller than that of the ring frame, and the single-side size of the bottom plate is 0.05 - 0.5 mm smaller than the size of the ring frame. By designing the difference between the bottom plate size and the ring frame size, a brazing fortress is formed in the space of 0.05 - 0.5 mm after brazing, making the weld bead full and dense, and further improving the requirements for product airtightness and reliability.

[0047] Further solution: In some other embodiments of the present invention, the roughness of the inner wall of the ring frame is increased through roughening treatment, and its roughness S a is controlled between 0.1 - 0.16 μm; the roughening treatment can be a conventional means in the art. Preferably, in one or more embodiments of the present invention, the inner wall of the ring frame is sandblasted, so that by increasing the roughness of the inner cavity of the ring frame, the capillary action is reduced, the flowing height of the solder along the ring frame is reduced, thereby avoiding the solder flowing on the sealing surface, reducing the grinding process, and at the same time, avoiding the potential difference caused by solder residue and the corrosion phenomenon of the sealing surface during plating.

[0048] In addition, plating the nickel layer and the gold layer on the encapsulation housing is a conventional technique in the art, and their thicknesses are controlled according to the standard requirements in the art to be 2.54 - 5.8 μm for the nickel layer and 1.3 - 5.7 μm for the gold layer, so no specific elaboration will be made here.

[0049] The second aspect of the present invention provides an encapsulation housing for optoelectronic devices, prepared by using the manufacturing method according to any one of the first aspects of the present invention. The welding joints of this encapsulation housing are smooth and flat, without phenomena such as weld seams and porous solders, meeting the standard of sealing reliability R1 ≤ 1×10 -3 Pa·cm 3 / s(He), and it has a high yield.

[0050] The technical solutions in the present invention will be further elaborated below in conjunction with specific embodiments.

[0051] Example 1

[0052] Figure 2 shows the structure of the encapsulation housing for optoelectronic devices prepared in this embodiment, which includes a bottom plate 10. A plurality of through holes are provided on the bottom plate 10, and in the through holes, insulating leads 30 and the bottom plate 10 are hermetically sealed by glass beads to form Figure 2 the glass sealing area 40 shown in the figure; the bottom plate 10 is brazed to the ring frame 20, and a short - circuit lead 50 is brazed in one of the through holes of the bottom plate 10. A conduit 60 is provided on one of the side walls of the ring frame 20. The structure of the encapsulation housing is relatively conventional, so no further description will be given here. It can be understood that the structure of the encapsulation housing shown in this embodiment is only a specific example, and the rest of the conventional encapsulation housings in the art are also applicable.

[0053] In this embodiment, the encapsulation housing is 14 mm × 13 mm × 5 mm, the wall thickness of the housing is 1.0 mm, the bottom plate 10 leads out 8 leads (including 7 insulating leads 30 and one short - circuit lead 50), and a conduit 60 (for transmitting internal and external electrical signals of the optical fiber) is provided on the side wall of the ring frame 20. The manufacturing method is as follows:

[0054] Select raw materials of grade 4J29 for machining to obtain spare parts. Among them, as Figure 3 shown in the figure, the designed length × width of the bottom plate 10 is 13.4 mm × 12.6 mm, the outer dimensions of the ring frame 20 are 13.5 mm × 12.7 mm in length × width, and the inner wall of the ring frame 20 is treated by sandblasting;

[0055] After cleaning and refining the surfaces of the machined spare parts, the bottom plate 10 and the insulating leads 30 are subjected to wet hydrogen decarburization - pre - oxidation treatment, and then the pre - oxidized bottom plate 10, the insulating leads 30, and the glass beads are assembled and hermetically sealed to obtain the bottom plate assembly.

[0056] The sealed bottom plate assembly is successively soaked in 50% (V / V) hydrochloric acid for 30 s and 10% (V / V) hydrofluoric acid for 90 s for oxide film purification treatment;

[0057] The bottom plate assembly after oxide film purification treatment is assembled with the ring frame 20, the conduit 60, the short - circuit lead 50, and the silver - copper eutectic solder, and then brazed to obtain a semi - finished metal package shell for optoelectronics;

[0058] Finally, the surface of the semi - finished metal package shell for optoelectronics after brazing is nickel - plated and gold - plated to obtain the package shell.

[0059] Example 2

[0060] This embodiment adopts the same implementation manner as in Embodiment 1, the difference being that: for the oxide film purification treatment, it is successively soaked in 20% (V / V) hydrochloric acid for 180 s and 30% (V / V) hydrofluoric acid for 180 s for oxide film purification treatment.

[0061] Example 3

[0062] This embodiment adopts the same implementation manner as in Embodiment 1, the difference being that: for the oxide film purification treatment, it is successively soaked in 30% (V / V) hydrochloric acid for 50 s and 50% (V / V) hydrofluoric acid for 10 s for oxide film purification treatment.

[0063] Examples 4 - 6

[0064] This embodiment adopts the same implementation manner as in Embodiment 1, the difference being that: in the oxide film purification treatment, the first acid solution respectively adopts sulfuric acid with concentrations of 20%, 40%, and 50%.

[0065] Examples 7 - 8

[0066] This embodiment adopts the same implementation manner as in Embodiment 1, the difference being that: the outer dimensions of the ring frame 20 in length × width are respectively 0.4 and 1.0 mm larger than the length × width dimensions of the bottom plate 10, and the single - side dimensions are 0.2 and 0.5 mm larger.

[0067] Comparative Example 1

[0068] This comparative example adopts the same implementation manner as in Embodiment 1, the difference being that: the oxide film is purified by soaking in hydrochloric acid for 2 min.

[0069] Comparative Example 2

[0070] This comparative example adopts the same implementation manner as in Embodiment 1, the difference being that: the length and width dimensions of the bottom plate 10 are the same as those of the ring frame 20, that is, no brazing fortress is formed.

[0071] Comparative Example 3

[0072] This comparative example adopts the same implementation method as in Example 1, except that: the inner wall of the ring frame 20 is not subjected to sandblasting treatment.

[0073] Test Example

[0074] (1) According to the visual inspection requirements of metal housings in Appendix A of GJB2440A-2006 "General Specification for Hybrid Integrated Circuit Housings", the depressions on the inner and outer sides of the ring frame brazing shall not exceed 0.13 mm; if the brazing solder is discontinuous and the bottom of the hole or pit is recessed by more than 0.13 mm, it shall be rejected; for the pits with spongy brazing solder, if the bottom of the hole cannot be seen under a 10-fold magnifying glass or the diameter of the pit is greater than 0.13 mm, it shall be rejected; if the brazing solder overflows excessively and there is solder trace in the sealing area, it shall be rejected.

[0075] Using the above standards, visual inspection of the package housings in Example 1 and Comparative Examples 1-3 was carried out. Among them, the weld bead of the package housing in Example 1 was full without solder holes or pits, and the solder did not flow to the sealing area of the sealing surface. However, in Comparative Example 1, 15% of the brazing solder was discontinuous and the depression of the pit exceeded 0.13 mm; in Comparative Example 2, the solder amount in the outer weld bead area after brazing was not full, and 5% of the depressions on the outer side of the ring frame were greater than 0.13 mm; in Comparative Example 3, 50% of the products had solder flowing to the key sealing surface after brazing, and the sealing solder needed to be polished. The yield of Example 1 was the highest, reaching over 99%, while the yields of Comparative Examples 1-3 were 85%, 95%, and 50% respectively.

[0076] (2) The sealing reliability test was carried out according to Method 1014, Condition A4 R1≤1×10 -3 Pa·cm 3 / s(He). After testing, the package housing in Example 1 met the standard of sealing reliability reaching 1×10 -3 Pa·cm 3 / s(He). However, in Comparative Example 1, 15% of the brazing solder pit products could not meet the standard of 1×10 -3 Pa·cm 3 / s(He), and the maximum leakage rate reached 1×10 -1 Pa·cm 3 / s(He); in Comparative Example 2, 5% of the depressions on the outer side of the ring frame exceeded 0.13 mm, and among them, 2.5% of the products had a sealing reliability lower than the standard of 1×10 -3 Pa·cm 3 / s(He), and the maximum leakage rate reached 1×10 -2 Pa·cm 3 / s(He); The sealing reliability in Comparative Example 3 can both reach 1×10 -3 Pa·cm 3 / s(He).

[0077] The encapsulation shells in Examples 2 - 8 were detected by the above method. After testing, the weld beads of the encapsulation shells obtained in Examples 2 - 6 were full without solder voids or pits, and the solder did not flow to the sealing area of the sealing surface. The yield rate could reach over 99%, and the sealing reliability reached the standard of 1×10 -3 Pa·cm 3 / s(He), and the manufacturing process was simple.

[0078] The technical features of the above - described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above - described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0079] The above - described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A manufacturing method for a packaging housing of an optoelectronic device, characterized in that, It includes the following steps: Provide and clean the spare parts, which include a bottom plate, an insulating lead, a ring frame, a conduit, and a short-circuit lead. Among them, the length and width dimensions of the bottom plate are 0.1 - 1.0 mm smaller than those of the ring frame; After subjecting the bottom plate and the insulating lead to wet hydrogen decarburization and pre-oxidation in sequence, seal them by melting to obtain a bottom plate assembly; Purify the oxide film of the bottom plate assembly. The specific steps of the oxide film purification are: soak it in the first acid solution for 30 - 180 s, and then soak it in the second acid solution for 10 - 180 s; among them, the first acid solution is hydrochloric acid or sulfuric acid with a volume fraction of more than 20%, and the second acid solution is hydrofluoric acid with a volume fraction of more than 10%; Brazing the purified bottom plate assembly with the remaining spare parts to obtain a semi-finished package shell; Plating a nickel layer and a gold layer on the surface of the semi-finished package shell to obtain a package shell.

2. The manufacturing method according to claim 1, characterized in that, The spare parts are obtained by machining the raw materials, and the machining accuracy is controlled within ±0.02 mm.

3. The manufacturing method according to claim 2, wherein The raw materials are selected from kovar alloy or iron-nickel alloy.

4. The manufacturing method according to claim 1, wherein The cleaning process of the spare parts is specifically: soak them in a cleaning agent for more than 1 h, then spray and wash them clean with pure water, then soak them in anhydrous ethanol for dehydration, and finally dry them at 80 - 100 °C. Among them, the cleaning agent is selected from an alkaline solution or a synthetic detergent.

5. The manufacturing method according to claim 1, wherein, The first acid solution is hydrochloric acid or sulfuric acid with a volume fraction of 20% - 50%, and the second acid solution is hydrofluoric acid with a volume fraction of 10% - 50%.

6. The manufacturing method according to claim 1, characterized in that The inner wall of the ring frame is roughened.

7. The manufacturing method according to claim 6, wherein The method of roughening is: perform sandblasting on the inner wall of the ring frame.

8. A packaging housing for optoelectronic devices, characterized in that, It is prepared by using the manufacturing method according to any one of claims 1 - 7.

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