Method for assembling flexible Rogers plate in multi-channel assembly

Abstract

The invention discloses a method for assembling a flexible Rogers board in a multi-channel assembly in the technical field of integrated circuit group packaging. The method comprises the following steps: flattening the flexible Rogers board; the flattened flexible Rogers plate is bonded in the channel area, where the conductive adhesive is evenly dispensed, in the multi-channel assembly, and overflowing redundant conductive adhesive is cleaned; after an isolation layer is placed on the surface of the flexible Rogers plate, the flexible Rogers plate is pressed and fixed through a balancing weight and placed in a drying oven to be cured; and after curing is completed, the balancing weight and the isolation layer are sequentially removed, and assembling of the flexible Rogers plate is completed. According to the method, the bonding voidage of the Rogers plate can be effectively reduced, the bonding strength and the stability of the electrical property are improved, and finally the reliability of a device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic packaging, and specifically to an assembly method for a flexible Rogers board in a multi-channel component. Background Art

[0002] Millimeter-wave radars are composed of multiple millimeter-wave transmitting components. With the development of military equipment towards miniaturization and integration, flexible Rogers boards are often used in multi-channel components for high-frequency signal transmission. As a key material widely used in the communication field, Rogers boards have excellent performance and significant advantages. It adopts advanced material preparation processes and has characteristics such as a low dielectric constant, low dielectric loss, and high stability, enabling effective reduction of signal attenuation and distortion during high-frequency signal transmission and ensuring stable signal transmission.

[0003] To ensure stable and high-quality reliable transmission of electrical signals, the void ratio of the Rogers board should be lower than 10%. Currently, the assembly process of the Rogers board and the component base mainly uses solder welding. The void ratio of solder welding is affected by many factors. For example, base contamination, solderability of the plating, and whether the flux can be smoothly discharged, etc. These factors make it difficult to control the welding void ratio of the Rogers board during the processing. Summary of the Invention

[0004] The purpose of the present invention is to provide an assembly method for a flexible Rogers board in a multi-channel component to meet the requirements of the multi-channel component for the low void ratio of the flexible Rogers board.

[0005] To achieve the above purpose, the present invention is implemented by adopting the following technical solutions:

[0006] An assembly method for a flexible Rogers board in a multi-channel component includes the following steps:

[0007] Flatten the flexible Rogers board;

[0008] Bond the flattened flexible Rogers board in the channel area where conductive adhesive is evenly dot-coated in the multi-channel component, and clean the excess conductive adhesive that overflows;

[0009] Place an isolation layer on the surface of the flexible Rogers board, then press and fix it with a weight block, and place it in an oven for curing;

[0010] After curing is completed, remove the weight block and the isolation layer in sequence to complete the assembly of the flexible Rogers board.

[0011] Further, the flattening process of the flexible Rogers board includes:

[0012] Place the flexible Rogers board between two hard wooden boards, place a pressure block on the hard wooden boards and let it stand until the flexible Rogers board is flattened.

[0013] Further, the multi-channel component includes a housing, and the channel area is arranged inside the housing;

[0014] Before bonding the flattened flexible Rogers board in the channel area where conductive adhesive is evenly dot-coated in the multi-channel component, it further includes:

[0015] Nickel plating is applied to the surface of the channel area and then gold plating is carried out, and conductive oxidation treatment is carried out on the non-channel area to obtain the treated housing;

[0016] The treated housing is ultrasonically cleaned.

[0017] Further, the conductive adhesive is H20E type A and B two-component conductive epoxy resin, where the mass ratio of component A to component B is 1:1, and the weighing tool is an analytical balance.

[0018] Preferably, before use, the conductive adhesive is stirred with a metal spatula for not less than 5 min.

[0019] Preferably, the conductive adhesive is dot-coated in a "return" shaped dispensing trajectory. The dispensing needle head model for dot-coating the conductive adhesive is screw mouth 27G transparent, with an outer diameter of 0.4 mm, a dispensing pressure of 80 psi to 120 psi, and a dispensing time of 1 to 2 s.

[0020] Further, after bonding the flattened flexible Rogers board in the channel area where conductive adhesive is evenly dot-coated in the multi-channel component, the surface of the flexible Rogers board is pressed to discharge the excess air between the flexible Rogers board and the channel area.

[0021] Preferably, the isolation layer is made of filter paper with a thickness of 0.25 to 0.34 mm, and the shape and size of the filter paper are consistent with those of the flexible Rogers board.

[0022] Preferably, the counterweight includes a metal block with a shape similar to that of the flexible Rogers board and weights made of C45 steel chrome-plated; the mass of each weight is 10 g, and the number of weights required for pressing and fixing is not less than 9;

[0023] When pressing and fixing, the metal block is placed on the filter paper, and the weights are placed on the metal block.

[0024] Preferably, the curing parameters are: temperature is 100 °C, and time is 60 minutes.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The flexible Rogers board is pasted in the channel area of the multi-channel component by means of conductive adhesive bonding. Compared with the assembly method of solder welding, the technical solution provided by the present invention can meet the requirement that the void ratio is lower than 10%, ensure the electrical performance and the reliability of the quality, and the product has good consistency. There is no contamination or oxidation on the surface of the Rogers board after bonding.

[0027] The process of the present invention is simple, highly operable, and can be reworked and repaired multiple times. The conductive adhesive bonding process of the Rogers board can be completed without using complex tooling, equipment, etc.

[0028] The present invention has strong versatility, and this process can also be applied to the assembly of Rogers boards on other integrated circuits. The present invention is also applicable to the bonding of Rogers boards of other sizes and shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flowchart of a method for assembling a flexible Rogers board in a multi-channel component provided by an embodiment of the present invention;

[0030] Figure 2 is a schematic structural diagram of the flexible Rogers board with a filter paper placed on its surface and pressed and fixed;

[0031] Figure 3 is a schematic diagram of the conductive adhesive dispensing trajectory;

[0032] Figure 4 is a schematic structural diagram of the pressing block;

[0033] Figure 5 is a schematic structural diagram of a weight placed on a metal block;

[0034] Figure 6 is a schematic structural diagram of the filter paper.

[0035] REFERENCE SIGNS:

[0036] 1 - weight, 2 - metal block, 3 - filter paper, 4 - flexible Rogers board, 5 - conductive adhesive, 6 - housing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The technical solution of the present invention will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0038] As Figure 1 shown, the present invention provides a method for assembling a flexible Rogers board 4 in a multi-channel component, which mainly includes the following steps:

[0039] Step 1: Flatten the flexible Rogers board 4;

[0040] The flexible Rogers board 4 is usually thinner than a rigid board and the material may be softer, so it may be more likely to bend or deform under physical pressure. The flattening process can ensure that the surface of the flexible Rogers board 4 is flat, which is more conducive to reducing the void ratio after assembly.

[0041] Step 2: Bond the flattened flexible Rogers board 4 in the channel area where the conductive adhesive 5 is evenly dot-coated in the multi-channel component, and clean the excess conductive adhesive 5 that overflows;

[0042] The conductive adhesive 5 can be automatically dot-coated by a dispensing device. Before dot-coating, a suitable dispensing trajectory can be set according to the shape and size of the bonding area;

[0043] After bonding, the surface of the flexible Rogers board 4 can be gently pressed to expel the excess air between the flexible Rogers board 4 and the channel area, so that the flexible Rogers board 4 fits well with the channel area.

[0044] Step 3: Place an isolation layer on the surface of the flexible Rogers board 4, press and fix it with a counterweight, and place it in an oven for curing;

[0045] When pressing and fixing with a counterweight, some of the conductive adhesive 5 may overflow, and the isolation layer can be used to prevent the overflowing adhesive from causing the flexible Rogers board 4 to adhere to the counterweight.

[0046] Step 4: After curing is completed, remove the counterweight and the isolation layer in sequence to complete the assembly of the flexible Rogers board 4.

[0047] In summary, for the assembly method of the flexible Rogers board 4 in the multi-channel component provided by the embodiment of the present invention, the flexible Rogers board 4 is pasted in the channel area of the multi-channel component by means of bonding with the conductive adhesive 5. Compared with the assembly method of solder welding, the technical solution provided by the embodiment of the present invention can meet the requirement that the void ratio is lower than 10%, can ensure the electrical performance and the reliability of the quality of the multi-channel component, and the product has good consistency. There is no contamination or oxidation on the surface of the bonded Rogers board.

[0048] In some embodiments of the present invention, for the flattening process described in Step 1, two hard wooden boards with dimensions not smaller than those of the flexible Rogers board 4 can be used. Place the flexible Rogers board 4 between the two hard wooden boards, and place pressing blocks on the hard wooden boards and let it stand still until the flexible Rogers board 4 is flattened. Optionally, when the flexible Rogers board 4 is a Rogers 5880 board with a thickness of 0.5 - 0.8 mm, the weight of the pressing blocks placed on the hard wooden boards can be selected as 500 g, and the corresponding standing time can be 12 hours. Without limitation, depending on the type selection of the flexible Rogers board 4, pressing blocks with relatively lighter or heavier weights can also be chosen. However, it should be understood that according to the different weights of the pressing blocks selected, correspondingly, the standing time can also be adjusted as long as it ensures that the flexible Rogers board 4 can be flattened.

[0049] As Figure 2 shown, the multi-channel component includes a housing 6, and the channel area is arranged inside the housing 6. Among them, the housing 6 can be made of silicon aluminum alloy. After nickel plating is applied to the channel area as a primer and then gold plating is applied on the surface, the nickel plating thickness can be 5 μm, and the gold plating thickness can be 0.5 μm. The nickel plating and gold plating treatments can ensure that the channel area has good oxidation resistance and electrical conductivity. For the non-channel area, conductive oxidation treatment can be carried out. To avoid contamination of the housing 6 by dirt, plating, flux, etc., which may affect the void ratio, before assembly, the treated housing 6 should be ultrasonically cleaned. During specific operation, the housing 6 can be placed in a glass beaker filled with alcohol for ultrasonic cleaning.

[0050] In some embodiments, the conductive adhesive 5 described in Step 2 can be an H20E type A and B two-component conductive epoxy resin, where the mass ratio of the A and B components is 1:1, and the weighing tool is an analytical balance. Before use, the conductive adhesive 5 can be stirred with a metal spatula for no less than 5 min.

[0051] As Figure 3 shown, the conductive adhesive 5 can be dot-coated in a "return" - shaped dispensing trajectory. The dispensing needle head model of the dispensing equipment used for dot-coating the conductive adhesive 5 can be selected as a screw-thread 27G transparent one, with an outer diameter of 0.4 mm, a dispensing pressure of 80 psi - 120 psi, and a dispensing time of 1 - 2 s.

[0052] For the isolation layer described in Step 3, filter paper 3 with a thickness of 0.25 - 0.34 mm can be selected. As Figure 4 shown, the shape of the filter paper 3 is basically the same as that of the flexible Rogers board 4, and its size can also be the same as or slightly larger than that of the flexible Rogers board 4 to play a better role in isolating the conductive adhesive 5.

[0053] As Figure 5As shown in the figure, for the counterweight described in Step 4, a metal block 2 with a shape similar to that of the flexible Rogers board 4 and a weight 1 made of C45 steel chrome-plated can be used. When pressing and fixing, the metal block 2 is placed on the filter paper 3, and the weight 1 is placed on the metal block 2.

[0054] As Figure 6 shown in the figure, in order to make the metal block 2 adapt to the flexible Rogers board 4, so that the flexible Rogers board 4 is more evenly stressed when pressed and fixed, the shape and size of the contact surface between the metal block 2 and the flexible Rogers board 4 can be set to be consistent with those of the flexible Rogers board 4. In some embodiments, the mass of each weight 1 is 10 g, and the number of weights 1 required for pressing and fixing is not less than 9. During curing, the assembled circuit component can be placed in a metal tray, and the curing parameters in the oven can be set as follows: the temperature is 100 °C and the time is 60 minutes.

[0055] For the cured flexible Rogers board 4, X-ray photography can be used to calculate the void ratio. The assembly process provided by the embodiments of the present invention greatly reduces the void ratio after solder welding, has strong operability, and can be reworked multiple times, which has great guiding significance for the bonding of flexible Rogers boards 4 of other sizes.

[0056] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for assembling a flexible Rogers plate in a multi-channel assembly, characterized in that: The following steps are involved: Flattening the flexible Rogers sheet; Adhere the flattened flexible Rogers board to the channel area where the conductive glue is evenly dotted in the multi-channel component, and clean up the excess conductive glue that overflows; After placing an isolation layer on the surface of the flexible Rogers board, it is pressed and fixed with a counterweight block and placed in an oven for curing; After curing is completed, the counterweight block and the isolation layer are removed in sequence to complete the assembly of the flexible Rogers board.

2. The method for assembling a flexible Rogers board in a multi-channel assembly according to claim 1, characterized in that: The flattening process of the flexible Rogers plate comprises: The flexible Rogers board is placed between two hard wood boards, and a pressing block is placed on the hard wood boards to press and let stand until the flexible Rogers board is flattened.

3. The method for assembling a flexible Rogers board in a multi-channel assembly according to claim 1, characterized in that: The multi-channel assembly includes a housing, and the channel region is disposed within the housing; Before bonding the flattened flexible Rogers board to the channel region in the multi-channel component where the conductive glue is evenly dotted, the method further includes: The channel region is subjected to nickel-plating as a base and then gold-plating on the surface, and the non-channel region is subjected to conductive oxidation treatment to obtain a treated shell; The treated shell is ultrasonically cleaned.

4. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: The conductive adhesive is H20E type A and B two-component conductive epoxy resin, wherein the mass ratio of components A and B is 1:1, and the weighing tool is an analytical balance.

5. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: The conductive adhesive is stirred with a metal spatula for no less than 5 minutes before use.

6. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: The conductive glue is applied in a "U"-shaped glue dispensing track. The glue dispensing needle used for applying the conductive glue is a screw-mouth 27G transparent glue needle with an outer diameter of 0.4 mm, a glue dispensing pressure of 80psi to 120psi, and a glue dispensing time of 1 to 2s.

7. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: After the flattened flexible Rogers board is bonded to the channel region where the conductive glue is evenly dotted in the multi-channel component, the surface of the flexible Rogers board is pressed to discharge excess air between the flexible Rogers board and the channel region.

8. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: The isolation layer is made of filter paper with a thickness of 0.25 to 0.34 mm, and the shape and size of the filter paper are consistent with those of the flexible Rogers board.

9. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: The counterweight block includes a metal block similar in shape to the flexible Rogers plate and a weight made of chrome-plated C45 steel; the mass of each weight is 10g, and the number of weights required for compaction and fixation is not less than 9; When pressed and fixed, the metal block is placed on the filter paper, and the weight is placed on the metal block.

10. The method for assembling a flexible Rogers plate in a multi-channel assembly according to claim 1, characterized in that: The curing parameters are: temperature of 100° C. and time of 60 minutes.

Images