Lithium battery protection plate chip frame, packaging body and lithium battery protection plate

Abstract

The utility model discloses a lithium battery protection plate chip frame, a packaging body and a lithium battery protection plate. The lithium battery protection plate chip frame comprises a frame body, a plurality of base islands, two first pins and a plurality of second pins. Wherein the base island is arranged on the frame body; and the first pin is L-shaped and is positioned on one side of the base island. According to the utility model, the two first pins are arranged on one side of the base island so as to surround one side of the base island, so that the chip on the base island has sufficient routing space, the requirement of large current can be met, and the cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of integrated circuit packaging, and in particular to a lithium battery protection board chip frame, a packaging body and a lithium battery protection board. Background Art

[0002] With the development of electronic industry technology, lithium battery applications are becoming more and more widespread in people's daily lives. Among them, the application of lithium battery protection boards, especially single-cell lithium batteries, pursues large current and miniaturization. The chips of lithium battery protection boards generally use SOT23-6, TSSOP8, DFN3 and other packaging forms. Due to the limitations of the SOT23-6 and TSSOP8 structural frames, they cannot meet the needs of large currents. Although DFN3 and other packages can meet the current requirements, the framework and processing are difficult, and the overall cost is high.

[0003] Therefore, the prior art still needs to be improved and developed. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a lithium battery protection board chip frame, a package body and a lithium battery protection board to solve the problem that the chip packaging of the existing lithium battery protection board cannot meet the demand for large current and has high cost.

[0005] The technical solution of the utility model is as follows:

[0006] A lithium battery protection board chip frame, comprising: a frame body, a plurality of base islands, two first pins and a plurality of second pins; wherein,

[0007] The base island is arranged on the frame body;

[0008] The first pin is L-shaped and is located at one side of the base island.

[0009] According to a further configuration of the present invention, the two first pins are symmetrically arranged and respectively distributed along the corners of the base island.

[0010] According to a further configuration of the utility model, the lithium battery protection board chip frame also includes a pad, and the pad is arranged at the bottom of the frame body.

[0011] According to a further configuration of the utility model, 2-4 second pins are provided, wherein the second pins provided opposite to the base island are connected to the base island.

[0012] According to a further configuration of the present invention, four second pins are provided.

[0013] According to a further configuration of the present invention, two base islands are provided.

[0014] A package body comprises a chip and the lithium battery protection board chip frame as described above, wherein the chip is arranged on the base island and is respectively connected to the first pin and the second pin.

[0015] A lithium battery protection board comprises the packaging body as described above.

[0016] The utility model provides a lithium battery protection board chip frame, a package and a lithium battery protection board, wherein the lithium battery protection board chip frame includes: a frame body, a plurality of base islands, two first pins and a plurality of second pins. The base island is arranged on the frame body; the first pin is L-shaped and is located on one side of the base island. The utility model arranges the two first pins on one side of the base island to surround the one side of the base island, so that the chip on the base island has sufficient wiring space, which can not only meet the needs of large current, but also has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary personnel in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the internal frame of the lithium battery protection board chip frame in the utility model Figure 1 .

[0019] Figure 2 This is a schematic diagram of the internal wiring of the double chip package in the utility model. Figure 1 .

[0020] Figure 3 This is a schematic diagram of the internal wiring of a single chip in the utility model. Figure 1 .

[0021] Figure 4 It is a top view of the package body in the utility model Figure 1 .

[0022] Figure 5 It is the bottom view of the package in the utility model. Figure 1 .

[0023] Figure 6 This is a schematic diagram of the internal frame of the lithium battery protection board chip frame in the utility model Figure 2 .

[0024] Figure 7 This is a schematic diagram of the internal wiring of the double chip package in the utility model. Figure 2 .

[0025] Figure 8 This is a schematic diagram of the internal wiring of a single chip in the utility model. Figure 2 .

[0026] Fig. 9 This is a schematic diagram of the internal wiring of a single-chip single MOS tube in the utility model.

[0027] Fig.10 This is a schematic diagram of the internal frame of the lithium battery protection board chip frame in the utility model Figure 3 .

[0028] Fig.11 This is a schematic diagram of the internal wiring of the double chip package in the utility model. Figure 3 .

[0029] Fig.12 It is a top view of the package body in the utility model Figure 2 .

[0030] Fig.13 The bottom view of the package body in the utility model Figure 2 .

[0031] Fig.14 This is a schematic diagram of the internal frame of the lithium battery protection board chip frame in the utility model Figure 4 .

[0032] Fig.15 This is a schematic diagram of the internal wiring of the double chip package in the utility model. Figure 4 .

[0033] Fig.16 The bottom view of the package body in the utility model Figure 3 .

[0034] The marks in the accompanying drawings are: 100, lithium battery protection board chip frame; 110, frame body; 120, base island; 130, first pin; 140, second pin; 150, pad; 200, chip. DETAILED DESCRIPTION

[0035] The utility model provides a lithium battery protection board chip frame, a package body and a lithium battery protection board. In order to make the purpose, technical solution and effect of the utility model clearer and more specific, the utility model is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0036] In the embodiments and patent claims, unless the article is specifically limited in the text, "a", "an", "said" and "the" may also include plural forms. If there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0037] It should be further understood that the term "comprising" used in the specification of the utility model refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when an element is said to be "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can also be an intermediate element. In addition, the "connection" or "coupling" used here can include wireless connection or wireless coupling. The term "and / or" used here includes all or any unit and all combinations of one or more associated listed items.

[0038] Those skilled in the art will understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the utility model belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as the meaning in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0039] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0040] Please also see Figures 1 to 16 The utility model provides a preferred embodiment of a package.

[0041] The utility model provides a package body, which includes a chip 200 and a lithium battery protection board chip frame 100. Figures 1 to 5As shown, the lithium battery protection board chip frame 100 includes: a frame body 110, a plurality of base islands 120, two first pins 130 and a plurality of second pins 140. The base island 120 is arranged on the frame body 110; the first pin 130 is L-shaped and is located on one side of the base island 120. The chip 200 is arranged on the base island 120 and is connected to the first pin 130 and the second pin 140 respectively.

[0042] Specifically, the first pin 130 is an L-shaped lead frame, which is provided in two pieces and is located on one side of the base island 120, and surrounds the base island 120 along the side of the base island 120, and the chip 200 is provided on the base island 120. In this way, there is sufficient wire bonding space between the chip 200 and the first pin 130, and the number of wire bonding is greater than that of a package with the same frame size, so that the conduction capability of the package is stronger, so that the package can meet the demand of large current, and the cost is low.

[0043] The principle that the lithium battery protection board can meet the demand for high current because of the larger wiring space is as follows:

[0044] The overcurrent capacity of the lithium battery protection board is determined by the internal resistance and heat dissipation of the chip. The internal resistance of the chip is the built-in MOS on-resistance R1 plus the package resistance R2. The resistance of 8205 on a normal lithium battery protection board is 40mΩ (milliohms), of which the MOS on-resistance R1 = 34mΩ plus the wire resistance 6mΩ. The normal package is 42um copper wire. Under such a package size framework, each resistor is about 18mΩ, and 6 wires are tied on a single end (in parallel). The actual single-ended resistance is 18 / 6 = 3mΩ. The package resistance R2 at both ends of the input and output is added up to 6mΩ, so the total is 40mΩ. In order to pass a larger current, a chip with a smaller internal resistance is used. When the on-resistance R1 is much larger than the package resistance R2, a MOS chip with a small internal resistance can be used to obtain a lithium battery protection chip with a smaller internal resistance. However, when the on-resistance R1 is also around 6mΩ, the total internal resistance is 12mΩ. Even if the on-resistance R1 is reduced to 3mΩ (the area of ​​the MOS chip must be doubled at this time), the total internal resistance is only reduced from 12mΩ to 9mΩ, and the overall internal resistance is only reduced by 25%.

[0045] In the package provided by the present utility model, Figure 1 As shown, from Figure 1 It can be seen that the two wire positions on the left side of the chip are in an inverted L shape, which can have a larger wire position. The number of wires for SOT23 and TSSOP8 under the same frame size is 6, while the utility model can have 19-20 wires ( Figure 2It is a wiring diagram, which is also the number of wires that can be achieved in actual production). For the same MOS chip with an internal resistance of 3mΩ, the internal resistance obtained by using SOT23 is 3+6=9mΩ. When using the utility model, because there are a total of 19 parallel connections, the single-ended sum is less than 1mΩ, and the entire internal resistance is 3+18 / 19*2=4.9mΩ. The overall internal resistance is only 54% of the original, and the conduction capacity is almost doubled.

[0046] In some embodiments, Figure 1 As shown, the two first pins 130 are symmetrically arranged and respectively distributed along the edges and corners of the base island 120 .

[0047] Specifically, the two first pins 130 are respectively located at the two corner edges on the left side of the base island 120, and the corner parts of the first pins 130 are surrounded by the corners of the base island 120, and one of the first pins 130 is in an inverted L shape, so that the two first pins 130 are symmetrically distributed and surround the left side of the base island 120, so that there is sufficient wiring space between the chip 200 and the first pins 130.

[0048] In some embodiments, Figure 4 , Figure 8 and Fig. 9 As shown, a chip 200 is disposed on the base island 120. Fig. 9 It is a schematic diagram applied to a single MOS tube.

[0049] In some embodiments, Figure 2 , Figure 7 and Fig.11 As shown, two chips 200 can be arranged on the base island 120 .

[0050] In some embodiments, Fig.14 , Fig.15 and Fig.16 As shown, the number of base islands 120 may be two, and a chip 200 is disposed on each of the base islands 120 .

[0051] In some embodiments, Figures 11 to 13 As shown, the number of the second pins 140 is 2-4.

[0052] Specifically, the second pin 140 is located on the right side of the base island 120, that is, on the opposite side of the first pin 130. While allowing multi-line packaging to reduce internal resistance and good heat dissipation, the control pins can be brought out to the maximum extent to provide a simple and convenient cascade application for different lithium battery protection boards. In one implementation, the second pin 140 can be set to 4 to facilitate the signal lead-out of the chip 200, so that the cascaded MOS tubes can be controlled to adapt to different current requirements.

[0053] In some embodiments, Figures 6 to 9 As shown, the second pin 140 disposed opposite to the base island 120 is connected to the base island 120. In this way, by connecting the second pin 140 to the base island 120, a heat dissipation path can be provided to achieve a better heat dissipation effect.

[0054] In some embodiments, Figure 5 , Fig.13 and Fig.16 As shown, the lithium battery protection board chip frame 100 also includes a pad 150 , and the pad 150 is arranged at the bottom of the frame body 110 .

[0055] Specifically, the package provided by the present invention adopts a package form with E, that is, a metal pad is provided at the bottom of the frame body 110, and the pad 150 can be directly connected to the PCB board. The pins of the pad 150 are wide-surface large-pin outputs, which can fit the PCB board, so that the heat can be dissipated in the fastest way. Among them, the pins of the pad 150 and the first pin 130 and the second pin 140 are all power output pins of the chip 200. Like the pins of the pad 150, the first pin 130 and the second pin 140 also adopt wide-surface large-pin outputs, which are suitable for lithium battery protection boards that require good heat dissipation. Fig.16 As shown, the number of the pads 150 may be two, corresponding to the number of the base islands 120 .

[0056] In order to better illustrate the heat dissipation effect, the following is a comparison between the MSOP5 package in the utility model and the commonly used SOT23-6 package on the market at an ambient temperature of 24°C and a power supply of 4V. The comparison data table of the two packages is as follows:

[0057]

[0058] For the same MOS tube, we can take 3A and 5A points for calculation (1A and 2A temperature rise are easily affected by external interference). The calculation process is as follows:

[0059] R 热 =(T2-T1) / I 2 R, where T2 is the maximum temperature of the chip surface after loading, T1 is the ambient temperature, I is the current, and R is the internal resistance.

[0060] When the current is 3A, in this solution:

[0061] R 热1 =(T2-T1) / I 2 R=(48-24) / (3 2*0.02)=24 / 0.18=133° / W;

[0062] When the current is 3A, in the commonly used SOT23-6 on the market:

[0063] R 热2 =(65-24) / (3 2 *0.0228)=41 / 0.2052=199° / W;

[0064] Comparison of thermal resistance between the two: R 热2 / R 热1 =1.49.

[0065] Similarly, it can be calculated under 5A conditions:

[0066] R 热1 =θ / P=(94-24) / 5 2 / 0.02 = 140° / W;

[0067] R 热2 =θ / P=(138-24) / 5 2 / 0.0228=200° / W;

[0068] Comparison of thermal resistance between the two: R 热2 / R 热1 =1.42.

[0069] As can be seen from the above, the thermal resistance of this case is 40% smaller than that of the general package on the market.

[0070] In some embodiments, the present invention further provides a lithium battery protection board, which includes the package body described above. The package body is specifically as described in an embodiment of the package body, and will not be described in detail here.

[0071] In summary, the lithium battery protection board chip frame, package and lithium battery protection board provided by the utility model have the following beneficial effects:

[0072] By arranging the two first pins on one side of the base island to surround the one side of the base island, the chip on the base island has sufficient wiring space, which can not only meet the demand for high current but also has low cost;

[0073] The number of the second pins can be set to multiple, so as to control the cascaded MOS tubes to adapt to different current requirements;

[0074] The second pin is connected to the base island, which can provide a heat dissipation path to achieve better heat dissipation effect;

[0075] The pins of the pad, the first pin and the second pin adopt wide and large pin output, which is suitable for lithium battery protection boards that require good heat dissipation.

[0076] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made according to the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A package for a lithium battery protection board, characterized in that: It includes a chip and a lithium battery protection board chip frame, and the lithium battery protection board chip frame includes: a frame body, a plurality of base islands, two first pins and a plurality of second pins; wherein the base island is arranged on the frame body; the first pin is L-shaped and is located on one side of the base island; the chip is arranged on the base island and is respectively connected to the first pin and the second pin; the two first pins are symmetrically arranged and respectively distributed along the corners of the base island; wherein the two first pins are respectively located at the two corner edges on the left side of the base island, and the corner parts of the first pins are surrounded by the corners of the base island, and one of the first pins is in an inverted L shape, so that the two first pins are symmetrically distributed to surround the left side of the base island.

2. The package according to claim 1, characterized in that: A soldering pad is also included, and the soldering pad is arranged at the bottom of the frame body.

3. The package according to claim 1, characterized in that: The number of the second pins is 2-4.

4. The package according to claim 3, characterized in that: The second pin disposed opposite to the base island is connected to the base island.

5. The package according to claim 4, characterized in that: There are four second pins.

6. The package according to claim 1, characterized in that: There are two base islands.

7. A lithium battery protection board, characterized in that: Comprising the package as described in any one of claims 1 to 6.

Images