A silicon carbide module structure and method of fabrication thereof

Abstract

The application relates to the field of module structure production equipment, in particular to a silicon carbide module structure and a manufacturing method thereof; the silicon carbide module structure comprises a plastic encapsulation body, a substrate is arranged in the plastic encapsulation body, a silicon carbide chip is arranged on the substrate, and the substrate is connected with a pin; after tin paste printing of the substrate, the silicon carbide chip is pasted, then the copper substrate with the silicon carbide chip is subjected to reflow and cleaning, then the individual substrates in the whole copper substrate are subjected to wire bonding operation, then the substrates are divided into single substrate structures through subsequent plate dividing, then the substrates are assembled with a pin frame through the subsequent auxiliary tooling, the whole product circuit is sealed and insulated through a plastic encapsulation process, finally, the product is packaged through electroplating and rib cutting forming; the silicon carbide module disclosed by the application can meet the application requirements of special environments such as high frequency, high power, high temperature resistance and radiation resistance; meanwhile, the manufacturing method of the silicon carbide module disclosed by the application can conveniently realize production of the silicon carbide module.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of module structure production equipment, in particular to an auxiliary positioning device for packaging silicon carbide modules. BACKGROUND

[0002] With the market demand for silicon carbide modules, the corresponding packaging process, materials and auxiliary tooling for silicon carbide modules need to be developed.

[0003] At present, the tooling for silicon carbide products is relatively unstable due to the process, so the production process of silicon carbide modules needs to be optimized.

[0004] In addition, because the tooling for silicon carbide products is relatively unstable due to the process, there is no relatively solid tooling type, how to effectively and reasonably cooperate with the packaging process to develop the corresponding auxiliary tooling is a relatively urgent problem to be solved. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a new silicon carbide module structure.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A silicon carbide module structure, comprising a plastic package, the plastic package is provided with a substrate; the substrate is provided with a silicon carbide chip, and the substrate is connected with a pin; the pin extends through the plastic package to the outside of the plastic package.

[0008] A manufacturing method of a silicon carbide module, characterized in that the manufacturing method comprises the following steps:

[0009] Step 1: copper substrate printing; the copper substrate is printed with tin paste by using a large plate process;

[0010] Step 2: add silicon carbide chip; add a silicon carbide chip on the copper substrate coated with tin paste;

[0011] Step 3: perform wire bonding operation; after the silicon carbide chip patching in step 2 is completed, perform copper substrate reflow and cleaning operation, and then perform wire bonding operation on the silicon carbide chip and the copper substrate;

[0012] Step 4: after step 2 is completed, perform plate separation operation on the entire copper substrate, so that it is separated into multiple single substrates;

[0013] Step 5: pin frame assembly reflow; after step 4 is completed, assemble the substrate with the pin frame; the pin frame is assembled with each substrate after separation;

[0014] Step 6: After step 5 is completed, the assembled substrate and pin frame are subjected to a plastic sealing operation;

[0015] Step 7: After step 6 is completed, the product processed in step 6 is subjected to electroplating;

[0016] Step 8: After step 7 is completed, the product after electroplating is subjected to a pin frame rib cutting and forming operation;

[0017] Step 9: After step 8 is completed, the product after rib cutting and forming is subjected to inspection and testing.

[0018] The substrate is a ceramic copper-clad substrate; the ceramic copper-clad substrate has an aluminum nitride component.

[0019] In step 5, the substrate is connected to the pin frame by an auxiliary tool.

[0020] The auxiliary tool comprises a base plate, and a plurality of accommodation grooves are arranged on the base plate; each accommodation groove comprises a placing groove arranged on the base plate; the accommodation groove further comprises a placing sink groove; and the placing sink groove is in communication with the placing groove.

[0021] The plurality of accommodation grooves are arranged in parallel at intervals; the depth of the placing sink groove in each accommodation groove is greater than the depth of the placing groove; and a positioning mechanism is arranged in the placing sink groove, and the positioning mechanism comprises a limiting plate arranged in the placing sink groove,

[0022] The limiting plate is provided with a positioning inclined surface away from the base plate.

[0023] The limiting plate is provided with a positioning pin.

[0024] The positioning mechanism further comprises a pressing plate arranged above the limiting plate.

[0025] An adsorption mechanism is arranged between the pressing plate and the base plate, and the adsorption mechanism comprises a lower magnet arranged on the base plate and an upper magnet arranged on the pressing plate; and the upper magnet and the lower magnet are arranged opposite to each other.

[0026] The present application has the following advantages:

[0027] The present application discloses a silicon carbide module and a manufacturing method thereof; the disclosed silicon carbide module can meet the application requirements in special environments such as high frequency, high power, high temperature resistance and radiation resistance; meanwhile, the manufacturing method of the silicon carbide module can facilitate the production of the silicon carbide module; in addition, the disclosed manufacturing method uses an auxiliary tool to realize the assembly between the pin frame and the substrate, which facilitates the assembly and connection between the substrate and the pin frame. BRIEF DESCRIPTION OF DRAWINGS

[0028] Brief Description of the Drawings

[0029] Figure 1 is a top view of the chassis in the present application.

[0030] Figure 2 is a side view of the chassis in the present application.

[0031] Figure 3 is a top view of the limiting plate in the present application.

[0032] Figure 4 is a side view of the limiting plate in the present application.

[0033] Figure 5 is a top view of the pressing plate in the present application.

[0034] Figure 6 is a structural schematic view of the substrate to be produced and the pin frame in the present application.

[0035] Figure 7 is a top view of the pressing and fixing of the substrate and the pin frame in the present application.

[0036] Figure 8 is a top view of the positioning mechanism arranged on the chassis in the present application.

[0037] Figure 9 is a schematic view of the abutting and pressing of the limiting plate and the pressing plate in the present application.

[0038] Figure 10 is a process flow chart of the production of the silicon carbide module in the present application.

[0039] Figure 11 is a structural schematic view of the silicon carbide module in the present application.

[0040] Figure 12 is a structural schematic view of the copper substrate as a whole structure in the present application.

[0041] Figure 13 is a structural schematic view of the pin frame in the present application.

[0042] The marks in the above-mentioned drawings are as follows:

[0043] 1, chassis, 2, limiting plate, 3, pressing plate; 4, substrate, 41, pin frame, 5, plastic package, 6, silicon carbide chip, 7, lead. DETAILED DESCRIPTION

[0044] The specific embodiments of the present application will be further described in detail with reference to the accompanying drawings.

[0045] A silicon carbide module structure, comprising a plastic package 5, a substrate is arranged in the plastic package 5; a silicon carbide chip 6 is arranged on the substrate; the substrate is connected with a pin 411; the pin 411 extends through the plastic package 5 to the outside of the plastic package 5; the silicon carbide module disclosed in the application mainly comprises a substrate and a silicon carbide chip 6, the substrate and the silicon carbide chip 6 are connected through a lead wire 7, the lead wire 7 is connected with adjacent components through welding, and meanwhile, in order to ensure the use effect of the silicon carbide module disclosed in the application and reduce the influence of the external environment on the use of the silicon carbide module, it is required in the application that the substrate and the silicon carbide chip 6 are coated with the plastic package 5; through the structure disclosed above, the silicon carbide module disclosed in the application can meet the application requirements in special environments such as high frequency, high power, high temperature resistance and radiation resistance.

[0046] A manufacturing method of a silicon carbide module, characterized in that the manufacturing method comprises the following steps:

[0047] Step 1: copper substrate 4-1 printing; the copper substrate 4-1 is subjected to tin paste printing through a large plate process;

[0048] Step 2: adding a silicon carbide chip 6; a silicon carbide chip 6 is added on the copper substrate 4-1 coated with tin paste;

[0049] Step 3: lead wire 7 bonding operation; after the silicon carbide chip 6 patching in step 2 is completed, the copper substrate 4-1 is subjected to reflow and cleaning operation, and then the silicon carbide chip 6 and the copper substrate 4-1 are subjected to wire bonding operation;

[0050] Step 4: after step 2 is completed, the entire copper substrate 4-1 is subjected to plate separation operation, so that it is separated into a plurality of single substrates;

[0051] Step 5: pin frame assembly reflow; after step 4 is completed, the substrate is assembled with a pin frame 41; the pin frame 41 is assembled with each substrate separated;

[0052] Step 6: after step 5 is completed, the assembled substrate and pin frame 41 are subjected to plastic packaging operation;

[0053] Step 7: after step 6 is completed, the product processed in step 6 is subjected to electroplating;

[0054] Step 8: after step 7 is completed, the product after electroplating is subjected to pin frame 41 rib cutting and forming;

[0055] Step 9: after step 8 is completed, the product after rib cutting and forming is subjected to inspection and testing.

[0056] Specifically, the method for manufacturing the silicon carbide module mainly comprises tin paste printing on a copper substrate 4-1, wherein the copper substrate 4-1 adopts a large plate process (the large plate refers to a plate structure with a larger size including multiple single substrates), and the large plate process is used as a whole copper substrate for production. After the tin paste printing on the copper substrate 4-1, silicon carbide chips 6 are pasted, then the copper substrate 4-1 with the silicon carbide chips 6 is reflowed and cleaned, then the single substrates in the whole copper substrate 4-1 are bonded with leads 7, and then the substrates are separated into single substrate structures. Then, the substrates are assembled with a pin frame 41 by means of an auxiliary tool. Since the bonding part of the substrate and the pin 411 has been printed with tin paste in the previous process, the auxiliary flux is only added to the pin 411, and then the secondary reflow soldering is performed. The reflowed product is sealed and insulated by a plastic sealing process, and finally, the product is electroplated and cut to form a complete product package.

[0057] Further, in the present application, the substrate is a ceramic copper-clad substrate 4-1; the ceramic copper-clad substrate 4-1 has an aluminum nitride composition; the ceramic copper-clad substrate 4-1 used in the present product has an aluminum nitride composition, which has an internal insulation function. Therefore, the customer does not need to separately install an insulating sheet at the application end, and the thermal conductivity of the ceramic is much higher than that of the plastic sealing material, so the heat dissipation of the product itself is also better.

[0058] In addition, in the present application, the pin frame 41 adopts a design of ten pins 411 in one row, which can be used with a conventional product mold during plastic sealing.

[0059] In addition, in the present application, the ceramic copper-clad substrate 4-1 adopts a large plate for operation, so that the defects in the previous process can be directly removed after the plate is separated, without the need for special marking and screening until the cutting of the ribs. In this way, the defective products are completely prevented from flowing into the next process, thereby avoiding resource waste.

[0060] Through the above disclosed manufacturing method, it can be known that the present application adopts a needle-free design in the plastic sealing process when producing the silicon carbide module, thereby simplifying the production process.

[0061] In addition, in the present application, an inclination angle of 3-6° is formed when the substrate and the pin frame 41 are assembled. In order to achieve the above density, the present application adopts an auxiliary tool, which can achieve the above technical effect through the use of the auxiliary tool. In addition, the ceramic copper-clad substrate 4-1 can tightly adhere to the cavity surface of the plastic sealing mold during the mold closing operation, ensuring that the exposed surface is 100% free of glue overflow, and ensuring that the overall heat dissipation function of the product is not affected.

[0062] Further, in the present application, the substrate is connected with the pin frame 41 by means of an auxiliary tool in step 5.

[0063] Before being more specific, for the convenience of understanding, the following is explained, in the drawings of the present application Figure 8 In the drawings, the paper is taken as the reference; the first placing groove (left one) on the chassis is placed in the placing groove; the second placing groove (left two) is placed in the placing groove; the third and fourth placing grooves (left three and left four) are placed in the placing groove. Figure 8 In the drawings, the paper is taken as the reference; the first placing groove (left one) on the chassis is placed in the placing groove; the second placing groove (left two) is placed in the placing groove; the third and fourth placing grooves (left three and left four) are placed in the placing groove. Figure 8 In the drawings, the paper is taken as the reference; the first placing groove (left one) on the chassis is placed in the placing groove; the second placing groove (left two) is placed in the placing groove; the third and fourth placing grooves (left three and left four) are placed in the placing groove.

[0064] Specifically, the auxiliary tool disclosed by the present application comprises a chassis 1, and a plurality of placing grooves 1-1 are arranged on the chassis 1; the auxiliary tool disclosed by the present application is mainly convenient for tin paste coating of a substrate 4 and assembly connection between the substrate 4 and a pin frame 41.

[0065] The chassis disclosed by the present application can be used alone, and when used, the substrate is placed in the placing groove on the chassis, thereby facilitating subsequent tin paste coating operation of the substrate.

[0066] Specifically, the auxiliary tool disclosed by the present application mainly comprises a chassis 1, and the chassis 1 facilitates placement of a substrate 4 and a pin frame 41 to be produced; mainly plays a bearing role, in addition, the placing grooves 1-1 are arranged on the chassis 1 in the present application, the arrangement of the placing grooves 1-1 plays a role of placing and positioning the substrate 4 and the pin frame 41, thereby facilitating positioning and placement of the substrate 4 before tin paste coating, in addition, it also facilitates subsequent installation and positioning between the substrate 4 and the pin frame 41; in other words, through the arrangement of the placing grooves 1-1, the present application facilitates positioning and placement of the substrate 4, thereby facilitating subsequent tin paste coating, and finally facilitates connection and assembly between the pin frame 41 and the substrate 4.

[0067] Further, in the present application, the plurality of placing grooves 1-1 are distributed in parallel at intervals; such arrangement can enable the pin frame 41 and the substrate 4 to be assembled as a whole, and after assembly, the components are cut, and finally a plurality of silicon carbide module main structures are formed; in addition, each placing groove 1-1 in the present application comprises a placing groove 13 arranged on the chassis 1; and in the present application, the plurality of placing grooves 11 are distributed in parallel at intervals; such arrangement facilitates the auxiliary positioning device to simultaneously produce a plurality of silicon carbide modules, which is beneficial to increase the application range of the present application and improve the production efficiency of the silicon carbide modules.

[0068] In addition, the placing groove in the application is provided with a partition 13-1, which comprises a partition block 13-11 arranged in the placing groove. The application separates the placing groove into multiple single-groove structures through the arrangement of the partition block 13-11, and each single groove accommodates a single substrate, which facilitates the single positioning of the substrate and the subsequent butt joint with the pin frame. In actual use, each partition 13-1 comprises two partition blocks 13-11 arranged opposite to each other on both sides of the placing groove, as shown in the drawings. The adjacent partitions 13-1 are arranged at intervals, and the single-groove structure is formed between the adjacent partitions 13-1. The partition blocks 13-11 in each partition 13-1 are symmetrically distributed at intervals, which can ensure the accuracy of the substrate positioning. In addition, the partition block 13-11 can be designed as a hollow structure, and the partition block 13-11 can be made of a flexible material. Such an arrangement can make the partition block 13-11 deformable, facilitating the clamping and fixing of the side surface of the substrate without damaging the substrate.

[0069] Further, the placing groove 1-1 in the application further comprises a placing sink 11; the placing sink 11 is in communication with the placing groove 13; in actual use, the placing sink 11 cooperates with the positioning mechanism to support the pin frame 41; the placing groove 13 is used to place and support the substrate 4, and the cooperation of the placing sink 11 and the placing groove 13 can facilitate the placement of the substrate 4 and the pin frame 41, and facilitate the subsequent installation and connection of the substrate 4 and the pin frame 41.

[0070] In addition, the application requires that each placing groove comprises a placing groove arranged on the bottom plate; the placing groove further comprises a placing sink; the placing sink is in communication with the placing groove; that is, the depth of the placing sink 11 is greater than the depth of the placing groove 13 in the application; such an arrangement makes the placing sink 11 and the placing groove 13 have a height difference, forming a stepped platform structure, which facilitates the cooperation of the limiting plate to support the pin frame 41 and facilitates the subsequent connection and assembly of the substrate 4 and the pin frame 41.

[0071] Further, the placing sink 11 in the application is provided with a positioning mechanism, which comprises a limiting plate 2; the limiting plate is arranged in the placing sink 11, and the limiting plate 2 serves as a basic support, facilitating the subsequent cooperation of the pressing plate 3 to press and position the pin frame 41.

[0072] In addition, it should be noted that when the substrate 4 is coated with tin paste, the substrate 4 is directly placed inside the placement groove 13, which does not require placing a limiting plate in the placement sink 11. After the substrate 4 is coated with tin paste, the pin frame 41 needs to be assembled, and then the limiting plate is placed in the placement sink 11. After the limiting plate is placed, the pin frame 41 to be assembled is placed on the limiting plate. That is, when the pin frame 41 is assembled with the substrate 4, the limiting plate is below the pin frame 41. The upper end of the pin frame 41 is then fixed by the pressing plate.

[0073] In actual use, the limiting plate 2 is placed in the placement sink 11, and the substrate 4 is placed in the placement groove 13. The pin frame 41 is placed on the limiting plate 2. The cooperation between the limiting plate 2 and the placement sink 11 can facilitate the support and limiting of the pin frame 41. The placement of the placement groove 13 facilitates the placement and positioning of the substrate 4.

[0074] Further, in the present application, the limiting plate 2 is provided with a positioning inclined surface 21 away from the bottom disc 1. The inclination angle of the positioning inclined surface 21 can be 5° with the horizontal plane. Such inclination allows the inclination angle of the pin frame 41 when placed to be consistent with the angle of the pin frame 41 for the silicon carbide module, ensuring that after assembly, the head of the substrate 4 is raised by about 5°, ensuring that the assembled semi-finished product is fully bonded with the mold cavity during the plastic sealing operation, without overflow phenomenon, and the heat dissipation surface is fully exposed.

[0075] Further, in the present application, the limiting plate 2 is provided with a positioning pin 22. The positioning pin 22 plays a good positioning role, facilitates the connection with the through hole on the pin frame 41, facilitates the placement and positioning of the pin frame 41 on the bottom disc 1, and also facilitates the positioning of the pin frame 41 on the limiting plate 2, and further facilitates the subsequent connection of the pin frame 41 and the substrate 4.

[0076] Further, in the present application, the limiting plate 2 is provided with an avoiding sink 23. The avoiding sink 23 is arranged at the end of the limiting plate 2. The avoiding sink 23 facilitates the clamping of the limiting plate 2 in the placement sink 11 and facilitates the protruding limiting of the limiting plate 2. In addition, in the present application, the avoiding sink 23 is provided with a positioning protrusion 24. The thickness of the positioning protrusion 24 is greater than the maximum thickness of the limiting plate 2. Such arrangement allows the limiting plate 2 to have a protrusion, thereby facilitating the positioning operation between the limiting plate 2 and the subsequent pressing plate 3.

[0077] Further, in the present application, the positioning mechanism further comprises a pressing plate 3 arranged above the limiting plate 2. The pressing plate 3 plays a good pressing and fixing role, and can well ensure the stability of the placement of the pin frame 41 on the bottom disc 1.

[0078] Further, the adsorption mechanism is arranged between the pressing plate 3 and the bottom plate 1, the adsorption mechanism comprises a lower magnet 12 arranged on the bottom plate 1 and an upper magnet 31 arranged on the pressing plate 3, and the upper magnet 31 and the lower magnet 12 are arranged oppositely; through the arrangement of the adsorption mechanism, the stability of the pressing plate 3 is well ensured; the integrity of the auxiliary positioning device is improved; and meanwhile, the stability of the pressing plate to the pin frame 41 is ensured.

[0079] Further, the placing groove on the bottom plate 1 is provided with a placing sink 121, and the lower magnet 12 is arranged in the placing sink 121; the arrangement of the placing sink 121 facilitates the arrangement of the lower magnet 12, and avoids the influence of the external leakage of the lower magnet 12 on the arrangement of the limiting plate 2.

[0080] Further, the horizontal projection of the pressing plate 3 is in the shape of a Chinese character You; through such an arrangement, the pressing plate 3 is provided with a notch at the edge, the notch facilitates the cooperation with the positioning block 24 on the limiting plate 2, and thus the accuracy of the relative position of the pressing plate 3 and the limiting plate 2 is ensured.

[0081] In order to avoid the installation interference between the pressing plate and the positioning pin 22 on the limiting plate, the pressing plate is required to be provided with a avoiding through hole in the application; the positioning pin can pass through the pressing plate, and thus the existence of the positioning pin does not affect the placement of the pressing plate.

[0082] In addition,

[0083] The auxiliary tool disclosed in the application can be used in the printing and assembling links, and does not need to be converted back and forth, the bottom plate 1 is made of graphite material, the heat conduction of the product in the reflow process is improved, the reflow effect of the product is ensured, the limiting plate 2 and the pressing plate 3 are made of synthetic stone, the overall tool has low thermal expansion, and the operation precision of the product can be fully ensured.

[0084] In addition, when the auxiliary tool disclosed in the application is used alone, the substrate 4 is first placed in the placing groove 13, and the substrate 4 is coated with tin paste.

[0085] When the substrate and the pin frame are assembled:

[0086] The substrate is placed in each single-groove structure of the placing groove; then the limiting plate is placed in the placing sink 11, and then the pin frame 41 to be assembled is placed on the limiting plate; after the placement is completed, the pressing plate is used to cover the pin frame 41 of the limiting plate, the upper magnet on the pressing plate and the lower magnet on the bottom plate 1 are adsorbed oppositely, the stability of the pin frame 41 is ensured, and then the subsequent installation and assembly of the pin frame 41 and the substrate 4 are facilitated.

[0087] Obviously, the specific implementation of the present application is not limited by the above manner, as long as various non-essential improvements are made by adopting the method concept and technical solutions of the present application, which are within the protection scope of the present application.

Claims

1. A method for manufacturing a silicon carbide module, characterized in that, The silicon carbide module structure includes a molding compound, a substrate is disposed within the molding compound; a silicon carbide chip is disposed on the substrate, and pins are connected to the substrate; the pins extend through the molding compound to the outside of the molding compound. The manufacturing method includes the following steps: Step 1: Copper substrate printing; Solder paste is printed on the copper substrate using a large-board process. Step 2: Add silicon carbide chip; Add silicon carbide chip to copper substrate coated with solder paste; Step 3: Perform wire bonding operation; After the silicon carbide chip is mounted in step 2, perform copper substrate reflow and cleaning operation, and then perform wire bonding operation between silicon carbide chip and copper substrate. Step 4: After step 2 is completed, the entire copper substrate is split into multiple individual substrates. Step 5: Lead frame assembly reflow; After step 4 is completed, assemble the substrate and lead frame; Assemble the lead frame with the separated substrates; The substrate is connected to the pin frame via an auxiliary tooling; The auxiliary tooling includes a chassis, on which a plurality of mounting slots are provided; each mounting slot includes a placement groove provided on the chassis; The placement slot also includes a placement sink; the placement sink is connected to the placement groove. The plurality of placement slots are distributed in parallel at intervals; the depth of the placement trough in each placement slot is greater than the depth of the placement recess. The placement trough is equipped with a positioning mechanism, which includes a limiting plate arranged within the placement trough; The limiting plate has a positioning slope on the side away from the chassis. Step 6: After completing Step 5, perform a molding process on the assembled substrate and pin frame; Step 7: After completing Step 6, electroplat the product processed in Step 6; Step 8: After step 7 is completed, the lead frame of the electroplated product is cut and shaped. Step 9: After completing Step 8, inspect and test the product after the ribs are cut and shaped.

2. The method for manufacturing a silicon carbide module according to claim 1, characterized in that, The substrate is a ceramic copper-clad substrate; the ceramic copper-clad substrate contains aluminum nitride.

3. The method for manufacturing a silicon carbide module according to claim 1, characterized in that, The limiting plate is equipped with a positioning pin.

4. The method for manufacturing a silicon carbide module according to claim 1, characterized in that, The positioning mechanism also includes a pressure plate, which is disposed above the limiting plate.

5. The method for manufacturing a silicon carbide module according to claim 4, characterized in that, An adsorption mechanism is provided between the pressure plate and the chassis. The adsorption mechanism includes a lower magnet disposed on the chassis and an upper magnet disposed on the pressure plate. The upper magnet and the lower magnet are arranged relative to each other.

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