Pad assembly, circuit board, memory card, card holder and start determination device

Abstract

The invention relates to the technical field of solid state disks, in particular to a bonding pad assembly, a circuit board, a memory card, a card seat and a starting judgment device. The bonding pad assembly is distributed on a substrate of the memory card; the bonding pad assembly comprises a plurality of rows of bonding pads; the plurality of rows of bonding pads comprise a first row of bonding pads; the first row of bonding pads comprise a first grounding bonding pad; the width of the first grounding bonding pad is greater than that of any bonding pad in the first row of bonding pads; the length of the first grounding bonding pad is greater than or equal to the length of any bonding pad of the first row of bonding pads; the distance from the central point of the first grounding bonding pad to a preset reference line on the substrate is smaller than the distance from the central point of any bonding pad in the first row of bonding pads to the reference line; wherein the linear direction parallel to the reference line is the width direction of each component of the bonding pad component. The bonding pad assembly is small in size and can support hot plug.

Description

Technical Field

[0001] The present application relates to the technical field of solid-state hard disks, and in particular to a pad assembly, a circuit board, a memory card, a card holder, and a startup determination device. Background Art

[0002] BGA packaging is a technology that directly solders integrated circuit chips on PCB boards, connecting the chip and PCB board through a series of solder balls. BGA SSD refers to a solid-state drive that uses BGA (Ball Grid Array) packaging technology. For example, the main control and nand bare chip are packaged into a package using BGA packaging technology, and then soldered on the PCB board as a chip particle to obtain a BGA SSD. Among them, BGA SSD needs to be fixedly soldered on the system PCB, and BGA SSD particles cannot be easily replaced, which causes certain difficulties in maintenance or system upgrades. In addition, BGA SSD has difficulties in further thinning particles because the solder balls themselves have a non-negligible height of hundreds of microns. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a pad assembly, a circuit board, a memory card, a card holder, and a startup determination device, wherein the pad assembly is small in size and can support hot plugging.

[0004] In a first aspect, an embodiment of the present application provides a pad assembly, wherein the pad assembly is distributed on a substrate of a storage card; The pad assembly includes multiple rows of pads; The multiple rows of pads include a first row of pads; the first row of pads includes a first ground pad; the width of the first ground pad is greater than the width of any pad in the first row of pads; the length of the first ground pad is greater than or equal to the length of any pad in the first row of pads; The distance from the center point of the first ground pad to a preset reference line on the substrate is smaller than the distance from the center point of any pad in the first row of pads to the reference line; The straight line direction parallel to the reference line is the width direction of each component of the pad assembly.

[0005] In some embodiments, the first row of pads is a row of pads having the smallest vertical distance to the reference line among the multiple rows of pads; the first row of pads further includes a plurality of long strip-shaped power pads and a plurality of long strip-shaped second ground pads; The lengths of each of the second grounding pads are equal to the lengths of the first grounding pad, and the center points of the first grounding pad and each of the second grounding pads are on a first straight line parallel to the reference line; The lengths of the power pads are consistent, and the center points of the power pads are located on a second straight line parallel to the reference line; The distance between the first straight line and the reference line is less than the distance between the second straight line and the reference line. In some embodiments, the width of the first grounding pad is N times the width of the second grounding pad; N is an integer greater than or equal to 2; and the length of the first grounding pad is equal to the length of each of the power pads.

[0006] In some embodiments, the plurality of power pads are divided into a corresponding number of power pad units according to the number of planned power networks, and each group of power pad units includes at least two power pads; the plurality of second ground pads are divided into a plurality of groups of second ground pad units, and each group of second ground pad units includes at least one second ground pad; The power pad unit, the second ground pad unit and the first ground pad are arranged in sequence from both ends of the first pad row to the middle.

[0007] In some embodiments, the first row of pads includes two groups of power pad units, one group of power pad units includes two power pads belonging to a first power network, and the other group of power pad units includes three power pads belonging to a second power network; The first row of pads includes two groups of second ground pad units, one group of the second ground pad units includes one second ground pad, and the other group of the second ground pad units includes two second ground pads.

[0008] In some embodiments, a second row of pads is further included; the vertical distance between the second row of pads and the reference line is greater than the vertical distance between the first row of pads and the reference line; The second row of pads includes at least two groups of mixed pad units; Each group of the mixed pad units includes at least one second ground pad and at least one first signal pad; the second ground pad is arranged close to the first signal pad in the mixed pad unit to which it belongs; the length of the first signal pad is less than the length of the second ground pad; Center points of all the second ground pads and all the first signal pads are on a third straight line parallel to the reference line.

[0009] In some embodiments, a third row of pads is further included; the vertical distance from the third row of pads to the reference line is greater than the vertical distance from the first row of pads to the reference line; The center points of the pads in the third row of pads are arranged at intervals on a fourth straight line parallel to the reference line; The third row of pads includes at least one group of differential signal pads, and a third ground pad is disposed on each side of the differential signal pads; the length of the third ground pad is greater than the length of the differential signal pads.

[0010] In some embodiments, the invention further comprises a rectangular solder resist component having the same number as the third ground pad; the differential signal pad comprises a positive phase signal pad and a negative phase signal pad; The solder resist component is provided with a plurality of via holes; The wide side of the third ground pad is parallel to a corresponding long side of the solder resist component and the distance between them is less than a preset spacing threshold, and the first wide side of the solder resist component is located on the center line of the positive phase signal pad adjacent to one side of the third ground pad, and the second wide side of the solder resist component is located on the center line of the negative phase signal pad adjacent to the other side of the third ground pad and overlaps with it.

[0011] In some embodiments, the substrate includes a first short side and a first long side; an anti-missing corner is set between the first short side and the first long side; the reference line is the first short side, the second short side corresponding to the first short side, or a middle line in the substrate parallel to the first short side.

[0012] In some embodiments, each pad in the pad assembly is a gold finger pad.

[0013] In a second aspect, an embodiment of the present application provides a printed circuit board, including a substrate; a pad assembly as provided in the first aspect of the present application is welded on a passive surface of the substrate; The substrate is provided with a plurality of circuit layers; a plurality of device pads are welded on the active surface of the substrate; the device pads are used for welding bare cores, and each of the device pads is connected to a corresponding pad in the pad assembly through the circuits in the plurality of circuit layers and the opened vias.

[0014] In some embodiments, the method further includes: providing a plurality of hollowed-out areas in other circuit layers except the determined middle circuit layer; The middle circuit layer is a complete circuit layer.

[0015] In some embodiments, the intermediate circuit layer is determined by the following method: According to the fact that the area of ​​each device pad and each pad in the pad assembly is positively correlated with the plane capacitance and inversely correlated with the distance from the reference plane, a signal quality simulation is performed with the minimum plane capacitance as the goal to obtain the intermediate circuit layer; wherein the reference plane is the projection of the pad on the circuit layer.

[0016] In a third aspect, an embodiment of the present application provides a memory card, the memory card comprising a master control die, at least one flash memory die, a plurality of electronic components and a printed circuit board as provided in the second aspect of the present application; The master bare core, the flash memory bare core and the plurality of electronic components are soldered to the printed circuit board via corresponding device pads on the printed circuit board.

[0017] In some embodiments, the memory card further comprises a plastic package; the master control die, the at least one flash memory die and the plurality of electronic components are all wrapped by the plastic package.

[0018] In a fourth aspect, an embodiment of the present application provides a card holder, comprising: a sampling signal terminal, a comparison signal terminal and a plurality of spring electrode terminals; At the first moment when a memory card provided by the third aspect of the present application is inserted into the card holder, the comparison signal terminal begins to contact the first ground pad to output a comparison signal; At a second moment when the memory card is inserted into the card holder, the plurality of spring electrode terminals begin to contact one by one with each pad on the edgeless surface of the printed circuit board in the memory card except the first ground pad; At a third moment when the memory card is inserted into the card holder, the sampling signal terminal starts to contact the first ground pad to output a start signal of the memory card; The first time is earlier than the second time, and the second time is earlier than the third time.

[0019] In some embodiments, the length of the comparison signal terminal is greater than the length of the sampling signal terminal.

[0020] In a fifth aspect, an embodiment of the present application provides a startup determination device for an electronic device, comprising a processor; the processor is connected to a sampling signal terminal and a comparison signal terminal on a card holder provided in the fourth aspect of the present application; When a memory card provided in the third aspect of the present application is inserted into the card holder, a comparison signal is acquired through the comparison signal terminal; At a third moment when the memory card is completely inserted into the card holder, a start signal is acquired through the sampling signal terminal; Turning on power is determined according to the comparison signal and the start signal to start the memory card.

[0021] The embodiments of the present application have the following beneficial effects: The pad assembly of the present application includes multiple rows of pads; the multiple rows of pads include a first row of pads; the first row of pads includes a first ground pad; the width of the first ground pad is greater than the width of any pad in the first row of pads; the length of the first ground pad is greater than or equal to the length of any pad in the first row of pads; the distance from the center point of the first ground pad to a preset reference line on the substrate is less than the distance from the center point of any pad in the first row of pads to the reference line; wherein the straight line direction parallel to the reference line is the width direction of each component of the pad assembly. The pad assembly of the present application is obtained by using LGA (Land Grid Array) packaging technology, and the pad assembly is small in size and can support hot plugging; secondly, the distance between the first ground pad and the reference line is the shortest, which is conducive to discharging static electricity and improving safety; finally, the width of the first ground pad is relatively large, and can accommodate two spring electrode terminals for startup detection of the memory card. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A physical diagram of a memory card according to an embodiment of the present application is shown; Figure 2 A physical diagram of a card holder according to an embodiment of the present application is shown; Figure 3 A schematic structural diagram of a pad assembly according to an embodiment of the present application is shown; Figure 4-1 A schematic diagram of a first pad layout of a pad assembly according to an embodiment of the present application is shown; Figure 4-2 A schematic diagram of a second pad layout of the pad assembly of an embodiment of the present application is shown; Figure 4-3 A third pad layout schematic diagram of the pad assembly of an embodiment of the present application is shown; Figure 5 A schematic structural diagram of a substrate with anti-missing corners according to an embodiment of the present application is shown; Figure 6 A schematic structural diagram of a pad assembly according to an embodiment of the present application is shown; Figure 7 A front view of a memory card according to an embodiment of the present application is shown; Figure 8 A side view of a memory card according to an embodiment of the present application is shown; Fig. 9A cross-sectional view of a printed circuit board according to an embodiment of the present application is shown.

[0024] Description of main component symbols: 100-memory card; 110-printed circuit board; 120-master bare core; 130-flash memory bare core; 140-electronic components; 150-epoxy resin plastic packaging material; 111-pad assembly; 1111-rectangular solder resist component; 1112-high-speed differential signal line and layer-changing via; 1113-LGA pad; 112-substrate; 1121-anti-missing corner; 1122-first short side; 1123-first long side, 1124-second short side; 1125-circuit layer; 1126-device pad; 1127-hollow area; 200-card holder; 201-comparison signal terminal; 202-sampling signal terminal. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0026] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0027] Hereinafter, the terms "including", "having" and their cognates that can be used in various embodiments of the present application are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions and cannot be understood as indicating or implying relative importance.

[0028] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0029] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0030] In the prior art, BGA SSDs use BGA packaging technology, which requires two reflow soldering processes: particle ball planting and particle PCB mounting. That is, before being divided into unit particles, they will undergo a high-temperature reflow soldering ball planting process, and after being divided and mounted on the PCB, they will undergo high-temperature reflow soldering again. These two processes will increase the production cycle and cost, and multiple high-temperature reflow soldering will reduce the reliability of the product. Therefore, the present application provides a pad assembly, a circuit board, a memory card, a card holder, and a startup determination device. The pad assembly is small in size, supports hot plugging of memory cards, and improves the reliability of memory cards.

[0031] like Figure 1 As shown, an embodiment of the present application provides a memory card 100. Exemplarily, the memory card 100 includes a printed circuit board 110 and a bare die disposed on an active surface.

[0032] The present application also provides a printed circuit board 110 in the above-mentioned memory card 100. Exemplarily, the printed circuit board 110 includes a substrate 112; a pad assembly 111 provided in the present application is welded on the passive surface of the substrate 112. The present application has designed the layout of the pad assembly 111, and the pad assembly 111 is distributed on the substrate 112. The pad assembly 111 is used to plug and unplug the memory card 100 and a card holder 200 provided in the present application.

[0033] The present application embodiment also provides a card holder 200. For example, Figure 2 As shown, the card holder 200 includes: a comparison signal terminal 201, a sampling signal terminal 202 and a plurality of spring electrode terminals (e.g., spring-pressed electronic terminals). The card holder 200 in the embodiment of the present application is fixedly arranged on the system PCB board. Exemplarily, the length of the comparison signal terminal 201 is greater than the length of the sampling signal terminal 202.

[0034] The memory card 100 (also known as LGA SSD) of the present application is packaged using LGA (Land Grid Array) packaging technology, and does not require secondary high-temperature reflow production process installation, which improves the stability of the memory card. In the present application, the card holder 200 is first mounted on the PCB board, and the LGA SSD is decoupled from the PCB mounting. The LGA SSD only needs to be manually inserted into the card holder 200, and the LGA SSD can transmit signals with the PCB through the card holder 200. The LGA SSD supports hot plugging, and the LGA SSD can be unplugged from the card holder 200 at any time, making installation easier.

[0035] The pad assembly 111 is described below in conjunction with some specific embodiments.

[0036] The embodiment of the present application provides a pad assembly 111. It can be understood that the pad assembly is distributed on the substrate of the storage card.

[0037] For example, Figure 3 As shown, the pad assembly includes multiple rows of pads. The multiple rows of pads include a first row of pads; the first row of pads includes a first ground pad; the width of the first ground pad is greater than the width of any pad in the first row of pads; the length of the first ground pad is greater than or equal to the length of any pad in the first row of pads. That is, the first ground pad is inconsistent with the other pads in size, and the first ground pad requires a larger size width to accommodate two spring-loaded electrode terminals (spring-loaded electrode terminals), and the other pads only need to accommodate one spring-loaded electrode terminal to ensure support for memory card startup detection.

[0038] The distance from the center point of the first ground pad to a preset reference line on the substrate is smaller than the distance from the center point of any pad in the first row of pads to the reference line.

[0039] The straight line direction parallel to the reference line is the width direction of each component of the pad assembly. Figure 3 The pad numbered "5" is the first ground pad. Exemplarily, each pad in the pad assembly 111 is a long strip of gold finger pads, such as a rectangular gold finger pad, wherein the short side of the rectangular pad is parallel to the reference line of the substrate 112, and if it is an elliptical gold finger pad, wherein the long axis of the ellipse is perpendicular to the reference line of the substrate 112.

[0040] In this application, the original round solder ball pad is designed into a rectangular pad through LGA packaging technology, the original solder ball is removed, the surface process is designed to be hard gold, and the pads in the pad assembly 111 are collectively referred to as LGA pads 1113 to facilitate plug-in contact and plug-in reliability. Hardware gold fingers replace solder balls with a certain height, and the thickness of LGA SSD can be further reduced, with higher integration.

[0041] In one embodiment, the substrate includes a first short side 1122 and a first long side 1123. An anti-missing corner 1121 is set between the first short side 1122 and the first long side 1123; the reference line is the first short side 1122, the second short side 1124 corresponding to the first short side 1122, or a middle line in the substrate parallel to the first short side 1122. Exemplarily, the pad assembly includes 3 rows of pads. If the reference line is the first short side 1122, the first row of pads is the row of pads closest to the first short side 1122, such as Figure 4-1 If the reference line is the second short side 1124, Figure 4-2 As shown, the first row of pads is the row of pads closest to the second short side 1124; if the reference line is the middle line, such as Figure 4-3 As shown, the first row of pads is the row of pads closest to the middle line, where the middle line is a line between the first short side 1122 and the second short side 1124 .

[0042] In one embodiment, the first row of pads is a row of pads having the smallest vertical distance to the reference line among the multiple rows of pads. The first row of pads also includes a plurality of long strip-shaped power pads and a plurality of long strip-shaped second ground pads.

[0043] The lengths of each of the second grounding pads and the first grounding pad are equal, and the center points of the first grounding pad and each of the second grounding pads are on a first straight line parallel to the reference line. Further, the width of the first grounding pad is N times the width of the second grounding pad; N is an integer greater than or equal to 2. For example, the width of the first grounding pad is twice the width of the second grounding pad. Thus, it can be ensured that the first grounding pad can accommodate two pressure spring electronic terminals.

[0044] The length of the first ground pad is equal to the length of each of the power pads.

[0045] The lengths of the power pads are consistent, and the center points of the power pads are located on a second straight line parallel to the reference line. The lengths of the second ground pad and the first ground pad are greater than or equal to the length of the power pad. The vertical distance between the first straight line and the second straight line is less than the length of the power pad.

[0046] The distance from the first straight line to the reference line is smaller than the distance from the second straight line to the reference line, that is, the vertical distance from the center point of the plurality of second grounding pads and the first grounding pad to the reference line is smaller than the vertical distance from the center point of any pad among the plurality of power pads to the reference line.

[0047] Exemplarily, the second ground pad, the first ground pad and the power pad are all rectangular pads, and the vertical distance from the target wide side of the plurality of second ground pads and the first ground pad to the reference line is less than the vertical distance from the target wide side of any pad of the plurality of power pads to the reference line; wherein the target wide side is the wide side of the plurality of second ground pads and the first ground pad with the smallest vertical distance from the reference line. The ground pad is closest to the reference line to ensure that the electrode terminal of the pressure spring sheet contacts the ground pad first to release static electricity.

[0048] A first ground pad that can accommodate two spring electrode terminals is placed in the first row of pads. The two spring electrode terminals on the card holder 200 are connected to the first ground pad. The two spring electrode terminals are of different lengths, one in front and one behind. The long spring electrode terminal is consistent with the length of the spring electrode terminal connected to the other pads. The short spring electrode terminal is a detection pin. When the card body is inserted and the card body is not inserted in place, except for the detection pin, the other spring electrode terminals have contacted with each pad in the pad assembly 111. At this time, no function instruction is output, and no function output is temporarily available. When the memory card 100 is inserted in place, the detection pin and the detection pin in the card holder 200 are short-circuited, the memory card 100 is powered on, the system recognizes that the memory card 100 is inserted, and the memory card 100 starts running.

[0049] In one embodiment, a plurality of power pads are divided into a corresponding number of power pad units according to the number of planned power networks, and each group of power pad units includes at least two power pads. Wherein, each power pad is divided into different power pad units according to the power network to which it belongs. A power network refers to different voltage rails used for power supply on a circuit board. Each power network usually represents a specific power supply voltage, such as +5V, +3.3V, +1.8V, etc.

[0050] The plurality of second grounding pads are divided into a plurality of second grounding pad units, and each second grounding pad unit group includes at least one second grounding pad.

[0051] The power pad unit, the second ground pad unit and the first ground pad are arranged in sequence from both ends of the first pad row to the middle.

[0052] For example, Figure 5 As shown, the first row of pads includes two groups of power pad units, and one group of power pad units includes two power pads (PWR1) belonging to the first power network. Figure 5 The other group of power pad units includes three power pads (PWR2) belonging to the second power network. Figure 5The numbers "1", "2" and "3" are in the bid.

[0053] The first row of pads includes two groups of second ground pad units, one group of second ground pad units includes one second ground pad (GND). Figure 5 The second ground pad unit of another group includes two second ground pads (GND), such as Figure 5 The winning numbers are "6" and "7".

[0054] In one embodiment, a second row of pads is further included; the vertical distance between the second row of pads and the reference line is greater than the vertical distance between the first row of pads and the reference line. The second row of pads includes at least two groups of mixed pad units.

[0055] Each group of the mixed pad units includes at least one second ground pad and at least one first signal pad; the second ground pad is arranged close to the first signal pad in the mixed pad unit to which it belongs; the length of the first signal pad is less than the length of the second ground pad. The first signal pad is small and short in order to reduce the pad area, further reduce the capacitive reactance value, and improve impedance continuity. The ground pad next to the first signal pad is longer, which can increase the contact area of ​​the electronic terminal of the pressure spring to reduce the contact resistance, and the section on the ground pad can also better shield the signal to form an enclosure.

[0056] The center points of all the second ground pads and all the first signal pads are on a third straight line parallel to the reference line. For example, two mixed pad units are included, each of which includes two first signal pads (SIGNAL) and one second ground pad (GND). Figure 5 The two first signal pads included in one of the mixed pad units are numbered "11" and "12", and the second ground pad is numbered "10". The two first signal pads included in another mixed pad unit are numbered "14" and "15", and the second ground pad is numbered "13". The distance between the third straight line and the second straight line is greater than the length of the second ground pad.

[0057] In one embodiment, a third row of pads is further included; the vertical distance between the third row of pads and the reference line is greater than the vertical distance between the first row of pads and the reference line. The center points of the pads in the third row are arranged at intervals on a fourth straight line parallel to the reference line. The third row of pads includes at least one group of differential signal pads, and a third ground pad is provided on each side of the differential signal pad; the length of the third ground pad is greater than the length of the differential signal pad. For example, the difference between the length of the third ground pad and the length of the differential signal pad is 0.3 mm.

[0058] For example, Figure 4-1 As shown, if the reference line is the first short side 1122, the first row of pads is the row of pads closest to the first short side 1122, and the distance between the third straight line and the second straight line is greater than (L1+L2) / 2 and less than L3 / 2. Wherein, L1 is the length of the power pad, L2 is the length of the first information pad, and L3 is the length of the substrate. The vertical distance between the fourth straight line and the second short side 1124 is the smallest. The distance from the fourth straight line to the second short side 1124 is greater than half the length of the third ground pad and less than half the length of the substrate.

[0059] For example, Figure 5 As shown, there are 4 groups of differential signal pads, each group includes a positive phase signal pad (SIGNAL) and a negative phase signal pad (DIFF), which are numbered "17, 18", "20, 21", "23, 24" and "26, 27" respectively. There is a ground pad GND between each group of differential signal pads, and there is a ground pad GND outside the differential signal pads at both ends, where the labels are "16", "19", "22", "25" and "28" respectively.

[0060] Furthermore, it also includes a rectangular solder resist component 1111 having the same number as the third ground pads; the differential signal pads include a positive phase signal pad and a negative phase signal pad. Figure 6 As shown, the solder resist component is provided with a plurality of vias. A high-speed differential signal line and a layer-changing via 1112 are provided on the substrate 112 above one end of the positive phase signal pad and the negative phase signal pad close to the reference line.

[0061] The wide side of the third ground pad is parallel to a corresponding long side of the solder resist component and the distance is less than the preset spacing threshold, and the first short wide side of the solder resist component is located on the center line of the positive phase signal pad adjacent to one side of the third ground pad, and the second short wide side of the solder resist component is located on the center line of the negative phase signal pad adjacent to the other side of the third ground pad and overlaps. For example, the preset spacing threshold is zero, and the wide side of the third ground pad is spliced ​​with the corresponding long side of the solder resist component. That is, the present application also combines SIPI technology to perform impedance continuity and crosstalk reduction design of key signals, and uses the impedance continuity dynamic processing method to further reduce the capacitive reactance value of the large pad.

[0062] The third row of pads is a high-speed signal pad, and two short pads form a pair of differential signal pads, and there are multiple pairs of high-speed differential signal pads. A long ground pad is set adjacent to the high-speed differential signal pad to form a semi-enclosed shape for the high-speed signal pad, which plays a good role in ground shielding. The high-speed differential signal is connected to the circuit layer through the high-speed differential signal line through the layer-changing via. The high-speed differential signal line and the layer-changing via are arranged between two rectangular solder mask components 1111. The adjacent ground pads and the corresponding solder mask components form a semi-enclosed return shielding component, which can further enclose and shield the differential signal, and the adjacent ground vias can shorten the signal return path and improve the signal quality. The solder mask insulation can prevent the spring electrode terminal on the card holder 200 from contacting the rectangular pad area beyond the solder mask, so as to cause a signal short circuit.

[0063] According to the characteristics of high-speed interface signals, this application redesigns the pad position layout and reduces the number of pads to dozens less than that of BGA SSD. The reduced space can be used for line design optimization, improving signal design quality and achieving higher particle integration.

[0064] The present application also provides a memory card 100. For example, Figure 7 , Figure 8 The memory card 100 includes a printed circuit board 110 , a master bare core 120 , a plurality of stacked flash bare cores 130 , and a plurality of electronic components 140 .

[0065] The master bare core 120 , the flash bare core 130 and the plurality of electronic components 140 are soldered to the printed circuit board 110 via corresponding device solder pads 1126 on the printed circuit board 110 .

[0066] Furthermore, the memory card 100 further includes a plastic package; the master bare core 120, the plurality of flash bare cores 130 and the plurality of electronic components 140 are all wrapped by the plastic package, which includes but is not limited to epoxy resin molding compound 150.

[0067] The present application also provides a printed circuit board 110 in the memory card 100, which exemplarily includes a substrate 112; a pad assembly 111 provided by the present application is soldered on the passive surface of the substrate 112. Various types of pads in the pad assembly 111 are collectively referred to as LGA pads 1113.

[0068] like Figure 8As shown, a multi-layer circuit layer 1125 is provided on the substrate 112; a plurality of device pads 1126 are welded on the active surface of the substrate 112; the device pads 1126 are used for welding bare cores, and each of the device pads 1126 is connected to the corresponding LGA pad 1113 in the pad assembly 111 through the circuits in the multi-layer circuit layer 1125 and the opened vias.

[0069] Exemplarily, the substrate 112 has more than two layers of circuit line layers 1125 for transmitting electrical signals. The surface of the substrate 112 in contact with the main control bare core 120, multiple flash bare cores 130 and multiple electronic components 140 is the front side, and has a device pad 1126. The chip signal is soldered from the chip pad to the device pad 1126 on the top surface of the substrate through wireBond bonding or solder ball welding. The other side of the substrate 112 is the back side, and the LGA pads 1113 are distributed on the back side of the substrate as external contact electrode terminals. The LGASSD contacts the spring electrode terminals on the card holder 200 on the PCB motherboard through the LGA pads, thereby transmitting the signal to the PCB motherboard.

[0070] Furthermore, if Fig. 9 As shown, it also includes: multiple hollowed-out areas 1127 set in other circuit layers except the determined middle circuit layer; the middle circuit layer is a complete circuit layer 1125; the hollowed-out area 1127 is an empty area obtained by hollowing out the copper foil of the projection area of ​​each device pad 1126 or each pad in the pad assembly 111 on the corresponding circuit layer 1125.

[0071] Furthermore, the intermediate circuit layer is determined by the following method: According to the fact that the area of ​​each device pad 1126 and each pad in the pad assembly 111 is positively correlated with the plane capacitance and inversely correlated with the distance from the reference plane, a signal quality simulation is performed with the minimum plane capacitance as the goal to obtain the intermediate circuit layer; wherein the reference plane is the projection of the pad on the circuit layer 1125. A device pad 1126 is provided on the front side of the substrate 112. The substrate 112 has several circuit layers 1125. The device pad 1126 on the front side of the substrate and the LGA pad 1113 on the back side of the substrate will form a planar capacitor with the adjacent circuit layer 1125. The planar capacitor generates a large capacitive reactance on the link and damages the impedance continuity. According to the formula C=ε*S / d, (ε is the dielectric constant, S is the projection of the pad on the plane of the circuit layer 1125, and d is the plane distance), the area size of the device pad 1126 and the LGA pad 1113 is positively correlated with the planar capacitance, and the plane distance between the pad and the adjacent circuit layer 1125 is inversely correlated. A circuit layer 1125 is retained between the device pad 1126 and the LGA pad on the Z axis, and the conductors of other layers are removed. The retained intermediate circuit layer can be determined by confirming the signal quality through signal quality simulation with different pad areas. This method of dynamically selecting the middle circuit layer can minimize the space that needs to be hollowed out for copper processing, isolate it from other signals, and facilitate the anti-interference routing of high-speed signals in high-density circuit areas.

[0072] The signal quality is related to the parasitic capacitance of the pad. If the parasitic capacitance is large, the signal quality will deteriorate. The size of the parasitic capacitance is related to the area of ​​the reference layer (also known as the middle line layer) relative to the pad and the distance between the two. Since the substrate thickness is fixed, the signal quality can only be adjusted by adjusting the area and distance of the reference layer corresponding to the pad.

[0073] The ideal state of the front and back pads is to have their own decoupled reference layers and adjust the distance and area at will. However, due to distance limitations, retaining the middle layer of circuit layer 1125 is already the best approach. Therefore, the middle reference layer will be either close or far away from the pads on both sides, and the parasitic capacitance of the pads at both ends will be either small or large. Simulation is needed to confirm the proportion of the capacitance values ​​at both ends to find an optimal reference layer.

[0074] Exemplarily, in the embodiment of the present application, the pad assembly 111 is divided into three rows, the memory card 100 is rectangular, and the substrate 112 is provided with an anti-mistaken missing corner 1121. The wide side connected to the anti-mistaken missing corner 1121 is a reference line, and the socket card holder 200 is pushed in from the end of the anti-mistaken missing corner 1121, and the first row of pads, the second row of pads, and the third row of pads are arranged in order according to the time of contacting the card holder 200. The first row of pads includes power pads, the second row includes ordinary signal pads, and the third row includes high-speed signal pads (differential signals). A certain number of ground pads are arranged at adjacent positions of the power pads and the signal pads. Moreover, in the first row of pads, the ground pad is closer to the wide side (first short side 1122) connected to the missing edge of the anti-mistaken missing corner 1121 than the power pad. When the LGA SSD is pushed into the card holder 200, the ground pad first contacts the spring electrode terminal on the card holder 200, which discharges the static electricity of the LGA SSD and reduces the risk of product static electricity reliability.

[0075] In summary, the substrate 112 has more than two circuit layers (circuit layers) for transmitting electrical signals. The contact surface of the substrate 112 with the chip is the active surface (also called the front surface), and has an electric pad (device pad 1126). The chip signal is bonded from the chip pad to the electric pad on the active surface of the substrate 112 through wireBond bonding or solder ball welding. The other side of the substrate 112 is the passive surface (also called the back surface), and the pad assembly 111 is distributed on the back surface of the substrate. The LGA SSD contacts the spring electrode terminal on the card holder 200 on the PCB motherboard through the pad assembly 111, thereby transmitting the signal to the PCB template.

[0076] The card holder 200 provided in the embodiment of the present application exemplarily includes: a sampling signal terminal 202, a comparison signal terminal 201 and a plurality of spring electrode terminals; the sampling signal terminal 202 and the comparison signal terminal 201 are connected to the same voltage. Exemplarily, the length of the comparison signal terminal 201 is greater than the length of the sampling signal terminal 202.

[0077] When the memory card 100 of the embodiment of the present application is inserted into the card holder 200 for the first time, the comparison signal terminal 201 starts to contact the first ground pad to output a comparison signal. During the insertion of the memory card 100, the first ground pad is used to start contacting the comparison signal terminal 201 on the card holder 200 at the first moment.

[0078] At the second moment when the memory card 100 is inserted into the card holder 200, the plurality of spring electrode terminals begin to contact one by one with each pad on the edgeless surface of the printed circuit board 110 in the memory card 100 except the first ground pad.

[0079] When the memory card 100 is inserted into the card holder 200 at the third moment, the sampling signal terminal 202 starts to contact the first ground pad to output a start signal of the memory card 100. The first ground pad is also used to start to contact the sampling signal terminal 202 on the card holder 200 at the third moment.

[0080] The first moment is earlier than the second moment, and the second moment is earlier than the third moment. The order of contact between each pad and the terminal on the card holder 200 is from first to last: comparison signal terminal 201 (long terminal), each spring electrode terminal and sampling signal terminal 202 (short terminal). Among them, the length of the spring electrode terminal is the same as that of the sampling signal terminal 202.

[0081] Exemplarily, the card holder 200 in the embodiment of the present application is fixedly disposed on the system PCB board.

[0082] The sampling signal terminal 202 is shorter in size than the comparison signal terminal 201 . The specific length can be adjusted according to specific product requirements and is not limited in this application.

[0083] The comparison signal terminal 201 is grounded in the link between the card holder 200 and the PCB board. The short sampling signal terminal 202 is a detection PIN, which will be connected to the startup judgment device of the electronic device on the PCB board. By judging whether the detection PIN is grounded, it is identified whether the memory card 100 is installed in place, and then it is determined whether to start the memory card 100.

[0084] That is to say, compared with the prior art, in order to support hot plugging of the memory card 100, the present application adds an additional detection signal on the card socket 200. The detection signal requires adding a PIN pin and a spring-loaded electrode terminal on the card socket 200 to support its signal transmission to the hot plug start determination device.

[0085] The first grounding pad of the present application first contacts the signal terminal on the card holder, and static electricity can be released first. When the pad assembly of the present application is used in a memory card, the first grounding pad in the present application contacts the comparison signal terminal and the sampling signal terminal at the first time and the third time, respectively, and the function of starting the memory card can be determined according to the two signal terminals to realize hot plugging of the memory card. When the pad assembly of the present application is used in a memory card, secondary high-temperature reflow soldering is not required, which can improve the reliability of the memory card.

[0086] The present application also provides a startup determination device for an electronic device, the device comprising a processor; the processor is connected to a sampling signal terminal 202 and a comparison signal terminal 201 on a card holder 200 provided in the present application.

[0087] When the memory card 100 in the present application is inserted into the card holder 200 for the first time, a comparison signal is acquired through the comparison signal terminal 201 .

[0088] At the third moment when the memory card 100 is completely inserted into the card holder 200 , a start signal is acquired through the sampling signal terminal 202 .

[0089] It is determined to turn on the power supply according to the comparison signal and the start signal to start the memory card 100 .

[0090] The solid state drive SSD in the prior art is soldered with BGA solder balls and does not support plugging and unplugging. In order to support hot plugging, the present application needs to set a startup judgment device (for example, a control circuit) of the electronic device at the PCB end of the SSD circuit. The detection PIN is connected to the control circuit. The working principle of the control circuit is: when the control circuit recognizes that the detection PIN is in contact with the first ground pad, it confirms that the memory card 100 has been installed in place, the system recognizes that the memory card 100 is inserted, and the memory card 100 starts running; when the memory card 100 is inserted and the card holder 200 is not yet in place, except for the detection pin, the other spring electrode terminals have been in contact with the target pad, the detection PIN and GND are open, the memory card 100 does not execute the function, does not output the instruction, and there is no function output for the time being.

[0091] The pad assembly 111 of the present application redesigns the pad position layout according to the characteristics of the high-speed interface signal, and reduces the number of pads to less than dozens of pads in a BGA SSD. The reduced space can be used for circuit design optimization, improving signal design quality, and achieving higher particle integration.

[0092] In summary, the LGA SSD of the present application not only has the advantages of being light, small, large in capacity, and having high-frequency read and write performance, but also supports hot plugging and is easy to replace. Since the LGA hard gold finger pad on the back replaces the solder ball with a certain height, the thickness of the LGA SSD can be further reduced and the integration is higher.

[0093] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A pad assembly, characterized in that: The pad components are distributed on the substrate of the storage card; The pad assembly includes multiple rows of pads; The multiple rows of pads include a first row of pads; the first row of pads includes a first ground pad; the width of the first ground pad is greater than the width of any pad in the first row of pads; the length of the first ground pad is greater than or equal to the length of any pad in the first row of pads; The distance from the center point of the first ground pad to a preset reference line on the substrate is smaller than the distance from the center point of any pad in the first row of pads to the reference line; The straight line direction parallel to the reference line is the width direction of each component of the pad assembly.

2. The pad assembly according to claim 1, characterized in that: The first row of pads is a row of pads having the smallest vertical distance to the reference line among the multiple rows of pads; the first row of pads also includes a plurality of long strip-shaped power pads and a plurality of long strip-shaped second ground pads; The lengths of each of the second grounding pads are equal to the lengths of the first grounding pad, and the center points of the first grounding pad and each of the second grounding pads are on a first straight line parallel to the reference line; The lengths of the power pads are consistent, and the center points of the power pads are located on a second straight line parallel to the reference line; A distance from the first straight line to the reference line is smaller than a distance from the second straight line to the reference line.

3. The pad assembly according to claim 2, characterized in that: The width of the first ground pad is N times the width of the second ground pad; N is an integer greater than or equal to 2; and the length of the first ground pad is equal to the length of each of the power pads.

4. The pad assembly according to claim 2, characterized in that: The plurality of power pads are divided into a corresponding number of power pad units according to the number of planned power networks, and each group of power pad units includes at least two power pads; the plurality of second ground pads are divided into a plurality of groups of second ground pad units, and each group of second ground pad units includes at least one second ground pad; The power pad unit, the second ground pad unit and the first ground pad are arranged in sequence from both ends of the first pad row to the middle.

5. The pad assembly according to claim 4, characterized in that: The first row of pads includes two groups of power pad units, one group of power pad units includes two power pads belonging to a first power network, and the other group of power pad units includes three power pads belonging to a second power network; The first row of pads includes two groups of second ground pad units, one group of the second ground pad units includes one second ground pad, and the other group of the second ground pad units includes two second ground pads.

6. The pad assembly according to claim 2, characterized in that: Also comprising a second row of pads; the vertical distance between the second row of pads and the reference line is greater than the vertical distance between the first row of pads and the reference line; The second row of pads includes at least two groups of mixed pad units; Each group of the mixed pad units includes at least one second ground pad and at least one first signal pad; the second ground pad is arranged close to the first signal pad in the mixed pad unit to which it belongs; the length of the first signal pad is less than the length of the second ground pad; Center points of all the second ground pads and all the first signal pads are on a third straight line parallel to the reference line.

7. The pad assembly according to claim 2, characterized in that: Also comprising a third row of pads; wherein the vertical distance from the third row of pads to the reference line is greater than the vertical distance from the first row of pads to the reference line; The center points of the pads in the third row of pads are arranged at intervals on a fourth straight line parallel to the reference line; The third row of pads includes at least one group of differential signal pads, and a third ground pad is disposed on each side of the differential signal pads; the length of the third ground pad is greater than the length of the differential signal pads.

8. The pad assembly according to claim 7, characterized in that: It also includes a number of rectangular solder resist components that is the same as the number of the third ground pads; the differential signal pads include a positive phase signal pad and a negative phase signal pad; The solder resist component is provided with a plurality of via holes; The wide side of the third ground pad is parallel to a corresponding long side of the solder resist component and the distance between them is less than a preset spacing threshold, and the first wide side of the solder resist component is located on the center line of the positive phase signal pad adjacent to one side of the third ground pad, and the second wide side of the solder resist component is located on the center line of the negative phase signal pad adjacent to the other side of the third ground pad and overlaps with it.

9. The pad assembly according to any one of claims 1 to 8, characterized in that: The substrate includes a first short side and a first long side; an anti-missing corner is set between the first short side and the first long side; the reference line is the first short side, the second short side corresponding to the first short side, or a middle line in the substrate parallel to the first short side.

10. The pad assembly according to any one of claims 1 to 8, characterized in that: Each pad in the pad assembly is a gold finger pad.

11. A printed circuit board, characterized in that: It comprises a substrate; a pad assembly as claimed in any one of claims 1 to 10 is welded on the passive surface of the substrate; The substrate is provided with a plurality of circuit layers; a plurality of device pads are welded on the active surface of the substrate; the device pads are used for welding bare cores, and each of the device pads is connected to a corresponding pad in the pad assembly through the circuits in the plurality of circuit layers and the opened vias.

12. The printed circuit board according to claim 11, characterized in that: Also includes: A plurality of hollowed-out areas are provided in other circuit layers except the determined middle circuit layer; The middle circuit layer is a complete circuit layer.

13. The printed circuit board according to claim 12, characterized in that: The intermediate circuit layer is determined by the following method: According to the fact that the area of ​​each device pad and each pad in the pad assembly is positively correlated with the plane capacitance and inversely correlated with the distance from the reference plane, a signal quality simulation is performed with the minimum plane capacitance as the goal to obtain the intermediate circuit layer; wherein the reference plane is the projection of the pad on the circuit layer.

14. A memory card, characterized in that: The memory card comprises a main control die, at least one flash memory die, a plurality of electronic components and a printed circuit board as claimed in any one of claims 11 to 13; The master bare core, the flash memory bare core and the plurality of electronic components are soldered to the printed circuit board via corresponding device pads on the printed circuit board.

15. The memory card according to claim 14, wherein: The memory card further comprises a plastic package; the master control core, the at least one flash memory core and the plurality of electronic components are all wrapped by the plastic package.

16. A card holder, characterized in that: include: A sampling signal terminal, a comparison signal terminal and a plurality of spring electrode terminals; At a first moment when the memory card as claimed in claim 14 or 15 is inserted into the card holder, the comparison signal terminal starts to contact the first ground pad to output a comparison signal; At a second moment when the memory card is inserted into the card holder, the plurality of spring electrode terminals begin to contact one by one with each pad on the edgeless surface of the printed circuit board in the memory card except the first ground pad; At a third moment when the memory card is inserted into the card holder, the sampling signal terminal starts to contact the first ground pad to output a start signal of the memory card; The first time is earlier than the second time, and the second time is earlier than the third time.

17. The card holder according to claim 16, characterized in that: The length of the comparison signal terminal is greater than the length of the sampling signal terminal.

18. A startup determination device for an electronic device, characterized in that: comprising a processor; the processor being connected to a sampling signal terminal and a comparison signal terminal on the card holder as claimed in claim 16 or 17; When the memory card according to claim 14 or 15 is inserted into the card holder for the first time, a comparison signal is acquired through the comparison signal terminal; At a third moment when the memory card is completely inserted into the card holder, a start signal is acquired through the sampling signal terminal; Turning on power is determined according to the comparison signal and the start signal to start the memory card.

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