DDR bus interconnection design method based on fuzz button connector

Abstract

The invention discloses a DDR (Double Data Rate) bus interconnection design method based on a fuzz button connector, which is characterized in that a processor with higher design complexity and a DDR interconnection circuit are split into a DDR memory card which is interconnected with the processor through the fuzz button connector, the decoupling of a complex circuit and a simple circuit is realized, the circuit of the DDR part after decoupling is complex but does not need to be repeatedly designed, and the design complexity is greatly reduced. The processor circuit needs to be redesigned for each item but the complexity is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of DDR circuits in avionics equipment circuits, and to a DDR bus interconnection design method based on a fur button connector, wherein the fur button connector is used to realize the interconnection between a DDR memory card and a processor, thereby decoupling a part of the complex DDR circuit from the entire circuit. Background Art

[0002] Avionics equipment has the engineering characteristics of high reliability requirements, high density and high solution iteration cost. DDR, as the core circuit in the smallest system of the processor, uses a high-speed parallel bus with high design difficulty. With the continuous improvement of performance requirements, the selection of DDR is constantly upgraded, the signal rate is getting higher and higher, the layout and wiring are becoming more and more difficult, and the requirements for signal integrity design and timing control are becoming more and more stringent. The design of DDR has become a difficult point in the entire circuit board design. Any design error in any detail may cause DDR access failure or rate reduction. At present, the mainstream DDR used in the aviation field has gradually upgraded from DDR3 to DDR4, and the signal rate has been upgraded from more than 1Gbps to more than 2Gbps. In order to meet the requirements of product performance indicators, the number of DDR4 particles in each channel is usually 4, 5, or 9. The address line using flyby topology is prone to signal integrity problems after mounting multiple DDR4 particle loads. The layout and wiring of DDR4 has the characteristics of strong independence and is only related to the processor. In traditional circuit board modules, the DDR circuit is directly laid out next to the processor. The DDR layout is constrained by the size and shape of the circuit board and has to be repeatedly adjusted and redesigned. The soldering yield rate of high-density circuits is lower than that of ordinary circuit boards. The stress after assembly is more complicated than that of ordinary circuit boards. The component desoldering rate caused by printed circuit board deformation is higher. When the components are reworked after desoldering, the peripheral components are more likely to desolder due to the small component spacing. DDR4 has a higher probability of soldering problems due to the large number of components and the large floor space it occupies. When soldering problems occur, it is difficult to locate the chip with the soldering problem.

[0003] Based on the above design difficulties, the present invention proposes a DDR bus interconnection design method based on a wool button connector. This method separates the DDR memory card to form an easy-to-disassemble DDR memory card, and realizes the interconnection between the DDR memory card and the processor through a low-loss, high-reliability, and solder-free wool button connector. It can not only occupy a smaller area of ​​the circuit board, but also can separately decouple the complex circuit of the DDR part from the entire circuit, bringing benefits in reliability, efficiency, cost and other aspects, and has considerable value and application prospects. Summary of the invention

[0004] The invention aims to provide a DDR bus interconnection design method based on a button connector, which realizes the interconnection between a DDR memory card and a processor through a button connector, thereby splitting the DDR circuit with a high design complexity to form an independent DDR memory card, decoupling it from the processor, and reducing the difficulty of processor wiring. It solves the problems of high design complexity of the DDR circuit, low welding yield, difficulty in failure location, and difficulty in rework in aviation product applications, effectively improves the efficiency of design and troubleshooting, reduces the number of product iterations, and achieves cost reduction and efficiency improvement.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A DDR bus interconnection design method based on a button connector is provided, wherein a DDR memory card is interconnected with a functional module including a processor through a button connector, and includes the following designs:

[0007] The pin impedance of the button connector is controlled to 45±5Ω for single-ended signal and 75±8Ω for differential signal;

[0008] The impedance of the wiring directly interconnected with the button connector in the functional module containing the processor is consistent with the impedance control of the button connector;

[0009] The button connector is filled with sufficient copper wire to ensure uniform pins;

[0010] The needle length of the button connector is set to 5mm, the compression amount is 1mm, the housing height of the button connector is 4±0.03mm, and the DDR memory card is installed on the back of the processor;

[0011] The pin spacing on the fur button connector is set to 1mm;

[0012] The button connector is set to float on both sides, eliminating the need for soldering.

[0013] Furthermore, positioning pins are provided on the button connector, and positioning holes are provided at corresponding positions on the functional module containing the processor and the DDR memory card.

[0014] Furthermore, one mounting hole is added on both sides and in the middle of the button connector housing, and mounting holes are also added at the corresponding positions of the DDR memory card and the functional module containing the processor, and the DDR memory card, the button connector, and the functional module containing the processor are fixed by screws.

[0015] Furthermore, the diameter of the mounting hole on the fur button connector housing is 2.3±0.2 mm.

[0016] Furthermore, two mounting holes are provided on the DDR memory card and the functional module containing the processor on the opposite side of the button connector, and studs with a height of 4 mm are used to assemble between the DDR memory card and the functional module containing the processor.

[0017] Furthermore, a pressure strip is provided on the outer side of the DDR memory card and the functional module including the processor according to whether there is deformation.

[0018] Furthermore, the pressure strip is made of metal, and an insulating pad is provided between the pressure strip and the functional module containing the processor and between the pressure strip and the DDR memory card.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a DDR bus interconnection design method based on a button connector, which splits the processor and DDR interconnection circuit with a relatively high design complexity into a DDR memory card, which is interconnected with the processor through a button connector, thereby realizing the decoupling of complex circuits and simple circuits. After decoupling, the DDR part circuit is complex but does not need to be repeatedly designed, and the processor circuit needs to be redesigned for each project but the complexity is greatly reduced. This method has significant benefits in improving the design success rate, reliability, welding success rate, rework success rate, and fault location efficiency of the product, and can shorten the project development cycle and save project costs. It has considerable value and application prospects for further improving the reliability and development cycle of my country's aviation electronic products.

[0021] The advantages of the button connector without soldering can bring the following benefits: reduce the soldering density of the circuit board, indirectly improve the soldering yield; when reworked, the DDR part of the circuit can be removed independently to reduce the impact of local heating of the soldering when the device is reworked; when the DDR capacity or model is changed, the DDR memory card can be directly changed to reduce the cost and cycle of redevelopment; the button connector design can not only meet the signal integrity requirements of the DDR high-speed parallel bus, but also reduce the occupied area on the circuit board, which is more conducive to adapting to various size requirements, and greatly reduces the difficulty of circuit board design and saves a lot of circuit board wiring resources. It has significant benefits in improving the design success rate, reliability, soldering success rate, rework success rate, and fault location efficiency of the product, and can shorten the project development cycle and save project costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the assembly interconnected by the fur button connector in the present invention;

[0023] Figure 2 It is a schematic diagram of the effect of the DDR bus interconnection design method based on the fur button connector of the present invention.

[0024] Description of labels:

[0025] 1—button connector, 2—processor function module, 3—DDR memory card, 4—pressing bar, 5—insulating pad, 6—pressing bar, 7—screw, 8—screw, 9—stud, 10—nut DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0027] See also Figure 1 The present embodiment shows a DDR bus interconnection design method based on a button connector, which involves one connection component (a button connector 1), two functional components (a functional module 2 including a processor and a DDR memory card 3), 11 reinforcement components (a pressure strip 4 including a threaded hole, a pressure strip 6 including a through hole, three screws 7, two screws 8, two studs, and two nuts) and two insulating components (insulating pads 5), and splits the processor and DDR interconnection circuit with a relatively high design complexity into a DDR memory card interconnected with the functional module including the processor through a button connector.

[0028] When designing, consider the following:

[0029] The pin impedance of the button connector 1 is controlled to be 45±5Ω for single-ended signals and 75±8Ω for differential signals.

[0030] The impedance of the wiring directly interconnected with the fur button connector 1 in the functional module 2 containing the processor should be consistent with the impedance control of the fur button connector 1.

[0031] The button connector 1 is filled with sufficient copper wire to ensure uniform pins and reduce the insertion loss introduced by the pins. The single-ended insertion loss of the connector at 3GHz is controlled within 0.1dB, and the return loss is controlled to more than 20dB, and the impact on the signal is negligible.

[0032] The needle length of the button connector 1 is set to 5mm, the compression amount is 1mm, the shell height of the button connector is 4±0.03mm, and the DDR memory card 3 can be installed on the back of the processor to meet the welding height requirements of the decoupling capacitor on the back of the processor and the DDR memory card device.

[0033] The pin spacing on the button connector 1 is set to 1 mm. This spacing is easy to control the impedance of the button connector 1 while meeting the requirements of the button connector itself for the crimping plate size and the wiring spacing.

[0034] A positioning pin is set on the button connector 1, and a positioning hole should be set at the corresponding position on the functional module containing the processor and the DDR memory card. The positioning pin and the positioning hole design can realize precise positioning to achieve the purpose of signal interconnection.

[0035] The button connector 1 is configured to be bilaterally floating, thereby eliminating the need for a welding process and improving contact quality.

[0036] A mounting hole is added on both sides and the middle of the housing of the button connector 1 to fix the button connector and reduce the deformation of the printed circuit board after being subjected to the compression force of the button connector. A small aperture of 2.3±0.2mm is used to reduce the area occupied.

[0037] Two mounting holes are set on the DDR memory card 3 and the functional module 2 on the opposite sides of the button connector 1, and a 4mm high stud is assembled between the functional module 2 and the DDR memory card 3 to support the functional module 2 and the DDR memory card 3 together with the button connector 1.

[0038] Depending on whether there is deformation, pressure strips 4 and 6 are arranged on the outside of the functional module 2 and the DDR memory card 3 to provide strength support. In order to better reduce deformation, pressure strips 4 and 6 are made of metal. In order to solve the short circuit risk caused by the metal pressure strips, an insulating pad 5 is arranged between the pressure strip 6 and the functional module 2 and between the pressure strip 4 and the DDR memory card.

[0039] During interconnection, after the functional module 2 containing the processor is interconnected with the button connector 1, it is determined whether the pressure strip 6 containing through holes is needed to offset the deformation according to the deformation amount of the functional module 2 containing the processor, and an insulating pad 5 is arranged between the functional module 2 containing the processor and the pressure strip 6 containing through holes to avoid short circuit. When the thickness of the functional module 2 is not less than 2.5 mm, there is a possibility that its own rigidity is sufficient to offset the deformation, and the pressure strip 6 containing through holes may not be used.

[0040] The DDR memory card 3 has a simple circuit and the printed circuit board itself is not rigid enough, so a pressure strip 4 with threaded holes is needed to offset deformation and an insulating pad 5 is provided between the DDR memory card 3 and the pressure strip 4 with threaded holes to avoid short circuit.

[0041] After the screw 7 penetrates the through-hole-containing pressure strip 6, the insulating pad 5, the functional module 2, the button connector 1, the DDR memory card 3, and the insulating pad 5, it is finally connected with the thread on the pressure strip 4 containing the threaded hole. The number of screws 7 is set to 3 to ensure reliable connection. According to the actual operation convenience requirements, the screw 7 and the pressure strip 6 containing the through hole and the pressure strip 4 containing the threaded hole can also be swapped to achieve the purpose of reliable connection.

[0042] The screw 8 penetrates the functional module 2, the stud 9, and the DDR memory card 3 and is connected to the thread on the nut 10. The number of interconnections is not less than 2, which supports the interconnection between the functional module 2 and the DDR memory card 3. According to the actual operation convenience, the screw 8 and the nut 10 can also be swapped to achieve the purpose of reliable connection.

[0043] Flat washers and spring washers may also be added to the contact surfaces of the screws 7, 8 and nuts 10 with other components to further improve the reliability of reinforcement.

[0044] See also Figure 2 The effect diagram after assembly is shown in the figure. The left side of the figure is the front view, where the processor is located. This side can be normally equipped with structural parts to dissipate the heat of the processor. Due to the complex functions of the processor, this side has more layers of printed circuit boards, thicker printed circuit boards, and higher rigidity. This side does not have a reinforcement strip; the right side of the figure is the back view, where the DDR memory card is located. The two sides are interconnected using a button connector, and the DDR particles occupy the space at the bottom of the processor.

[0045] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A DDR bus interconnection design method based on a button connector, wherein a DDR memory card is interconnected with a functional module containing a processor through a button connector, characterized in that Contains the following designs: The pin impedance of the button connector is controlled to 45±5Ω for single-ended signal and 75±8Ω for differential signal; The impedance of the wiring directly interconnected with the button connector in the functional module containing the processor is consistent with the impedance control of the button connector; The button connector is filled with sufficient copper wire to ensure uniform pins; The needle length of the button connector is set to 5mm, the compression amount is 1mm, the housing height of the button connector is 4±0.03mm, and the DDR memory card is installed on the back of the processor; The pin spacing on the fur button connector is set to 1mm; The button connector is set to float on both sides, eliminating the need for soldering.

2. A DDR bus interconnection design method based on a fur button connector according to claim 1, characterized in that Positioning pins are set on the button connector, and positioning holes should be set at corresponding positions on the functional module containing the processor and the DDR memory card.

3. A DDR bus interconnection design method based on a fur button connector according to claim 1, characterized in that A mounting hole is added on both sides and in the middle of the button connector housing, and mounting holes are also added at the corresponding positions of the DDR memory card and the functional module containing the processor. The DDR memory card, the button connector, and the functional module containing the processor are fixed by screws.

4. A DDR bus interconnection design method based on a fur button connector according to claim 3, characterized in that The diameter of the mounting hole on the fur button connector housing is 2.3±0.2mm.

5. A DDR bus interconnection design method based on a fur button connector according to claim 3, characterized in that Two mounting holes are set on the DDR memory card and the functional module containing the processor on the opposite side of the button connector, and a stud with a height of 4 mm is used to assemble between the DDR memory card and the functional module containing the processor.

6. A DDR bus interconnection design method based on a fur button connector according to claim 3, characterized in that A pressure strip is set on the outer side of the DDR memory card and the functional module including the processor according to whether there is deformation.

7. A DDR bus interconnection design method based on a fur button connector according to claim 6, characterized in that The pressure strip is made of metal, and an insulating pad is arranged between the pressure strip and the functional module containing the processor and between the pressure strip and the DDR memory card.

Images