Circuit board and electronic device with gold finger connector

Abstract

A circuit board and electronic device with a gold finger connector, comprising: a PCB carrier, an insulating reference layer, and at least one conductive contact. The reference layer partially or completely covers at least one surface of the PCB carrier and includes a first reference portion and a second reference portion. The direction of the first reference portion pointing toward the second reference portion is consistent with the plug-in direction of the gold finger connector. The thickness of the first reference portion is greater than the thickness of the second reference portion. The conductive contact is disposed on the reference layer at at least one end of the PCB carrier. In the above-mentioned circuit board, the reference layer forms a stepped surface for the conductive contact that decreases in height along the plug-in direction, so that the sum of the thickness of the first reference portion and the conductive contact disposed on the surface of the first reference portion is greater than the sum of the thickness of the second reference portion and the conductive contact disposed on the surface of the first reference portion. This prevents the conductive contact from warping or peeling off when the gold finger connector is inserted into a female connector, thereby reducing the risk of short circuits during the gold finger insertion and removal process.

Description

Technical Field

[0001] The present application relates to the technical field of connectors, and in particular to a circuit board and electronic equipment with a gold finger connector. Background Art

[0002] The electrical connection between a functional board and a mainboard, such as a printed circuit board (PCB), typically requires fabricating connecting fingers on the PCB substrate. These fingers then mate with corresponding female connectors to achieve electrical connections between electronic devices. These connecting fingers consist of multiple golden conductive contacts, known as pins. They are called "connecting fingers" because they are gold-plated and arranged like fingers.

[0003] However, with the rapid development of the electronics industry, PCB functional boards are becoming increasingly miniaturized, and the gap between the gold fingers and the female connectors is becoming smaller and smaller, making it increasingly difficult to plug and unplug the gold fingers, and the risk of poor plugging and unplugging of the gold fingers is also increasing.

[0004] like Figure 1A As shown, it is a structural diagram of the gold finger connector in the prior art. Figure 1B Shown Figure 1A The gold finger connector shown is a schematic diagram of a cross-sectional structure cut at AB. The gold finger connector includes a PCB carrier 11 and a plurality of conductive contacts 12 arranged side by side on the surface of the PCB carrier layer. The conductive contacts 12 are the pins of the gold finger. Figure 1B As shown, for the gold finger of this structure, when the gold finger is inserted and removed from the female connector with great force or for a long time, it is easy to cause the hanging gold to lift or peel off. The hanging gold that falls between the pins of the gold finger will cause the risk of short circuit of the pins of the gold finger. Summary of the Invention

[0005] The embodiments of the present application provide a circuit board and an electronic device with a gold finger connector to solve the problem in the prior art that the conductive contacts of the gold finger connector are lifted up or peeled off when inserted into a female connector.

[0006] In a first aspect, an embodiment of the present application provides a circuit board having a gold finger connector, comprising:

[0007] Printed circuit board PCB carrier board;

[0008] an insulating reference layer, the reference layer partially or completely covering at least one surface of the PCB carrier; the reference layer comprising a first reference portion and a second reference portion; the direction in which the first reference portion points to the second reference portion is consistent with the plugging direction of the gold finger connector; the thickness of the first reference portion is greater than the thickness of the second reference portion; and

[0009] At least one conductive contact, the conductive contact being disposed on the reference layer at at least one end of the PCB carrier; the conductive contact being electrically connected to the PCB carrier;

[0010] The sum of the thicknesses of the first reference portion and the conductive contact sheet disposed on the surface of the first reference portion is greater than the sum of the thicknesses of the second reference portion and the conductive contact sheet disposed on the surface of the first reference portion.

[0011] The above-mentioned circuit board forms a stepped surface for the conductive contacts through the reference layer, the height of which decreases along the plugging direction, so that the sum of the thickness of the reference layer and the conductive contacts at the rear end of the gold finger connector is at the front end, and the conductive contacts at the front end are lower than the conductive contacts at the rear end, thereby avoiding the problem of the conductive contacts curling up or peeling off when the gold finger connector is inserted into the female connector, thereby reducing the risk of short circuit during the gold finger plugging and unplugging process.

[0012] Moreover, the structure uses a reference layer to construct the morphology of the conductive contact, which is easier to prepare.

[0013] In one possible implementation, each of the conductive contact pieces includes a first conductive portion and a second conductive portion; the first conductive portion and the second conductive portion are connected; the first conductive portion is arranged on a surface of the first reference portion facing away from the PCB carrier, and the second conductive portion is arranged on a surface of the second reference portion facing away from the PCB carrier; wherein the sum of the thicknesses of the first reference portion and the first conductive portion is greater than the sum of the thicknesses of the second reference portion and the second conductive portion.

[0014] In the above-mentioned gold finger connector, the base layer provides a stepped surface for the conductive contact piece, and this structure is easier to implement.

[0015] In a possible implementation, a thickness difference between the first reference portion and the second reference portion is 10 μm-1 mm.

[0016] In a possible implementation, the second conductive portion includes a first end and a second end; the second conductive portion extends from the second end to the first end along the plugging direction; wherein the thickness of the first end is less than or equal to the thickness of the second end.

[0017] In a possible implementation, the second conductive portion has a uniform thickness or decreases in thickness from the second end portion toward the first end portion.

[0018] In a possible implementation, the thickness of the second conductive portion remains constant or decreases substantially along the plugging direction.

[0019] In a possible implementation, a surface of the second conductive portion facing away from the second reference portion is a combination of one or more of a curved surface, an inclined surface, and a flat surface.

[0020] In a possible implementation, the at least one conductive contact is arranged in a row at intervals substantially perpendicular to the plugging direction.

[0021] In a possible implementation, the at least one conductive contact piece is a plurality of conductive touch screens; and the plurality of conductive contact pieces are arranged in two rows at intervals substantially perpendicular to the plugging direction.

[0022] In a possible implementation, a ratio of the length of the second conductive portion to the total length of the conductive contact piece is 0.9-1 / 3.

[0023] In a second aspect, an embodiment of the present application further provides a method for preparing a circuit board, comprising:

[0024] A printed circuit board (PCB) carrier is provided, wherein the PCB carrier comprises a first area and a second area, and a direction from the first area to the second area is a plugging direction of the gold finger connector;

[0025] forming a reference layer on at least one surface of a printed circuit board (PCB);

[0026] Etching the reference layer located in the second region, whereby the thickness of the reference layer located in the second region after etching is 0 or less than the thickness of the reference layer located in the first region;

[0027] At least one conductive contact is formed on the surface of the etched reference layer facing away from the PCB carrier, wherein the sum of the thickness of the reference layer and the conductive contact located on the surface of the first area is greater than the total thickness of the reference layer and the conductive contact located on the surface of the second area.

[0028] In a possible implementation, forming at least one conductive contact on a surface of the reference layer facing away from the PCB carrier after etching includes:

[0029] Performing metallization on the etched reference layer to form a conductive layer on a surface of the reference layer facing away from the PCB carrier;

[0030] Using the conductive layer as an electrode, electroplating to form a copper layer on the conductive layer;

[0031] patterning the copper layer to form a plurality of copper contacts;

[0032] At least one metal layer is formed on surfaces of the plurality of contact pads.

[0033] In a third aspect, an embodiment of the present application further provides an electronic device, comprising: a main board and a circuit board as described in the first aspect, wherein the main board has a slot; the circuit board is plugged into the slot through the gold finger connector to achieve electrical connection with the main board.

[0034] It is understandable that the preparation method provided in the second aspect and the electronic device provided in the third aspect both include the circuit board with the gold finger connector provided in the first aspect. Therefore, the beneficial effects achievable by these methods can be referenced to the corresponding beneficial effects in the first aspect and will not be further elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1A It is a structural diagram of a gold finger connector in the prior art;

[0036] Figure 1B for Figure 1A The cross-sectional structure diagram of the gold finger connector shown is taken at MN;

[0037] Figure 2A A schematic structural diagram of a circuit board with a gold finger connector provided in an embodiment of the present application;

[0038] Figure 2B for Figure 2A The schematic diagram of the cross-sectional structure of the circuit board shown is taken at MN;

[0039] Figure 3A A schematic structural diagram of another circuit board with a gold finger connector provided in an embodiment of the present application;

[0040] Figure 3B for Figure 3A The schematic diagram of the cross-sectional structure of the circuit board shown is taken at MN;

[0041] Figure 4A A schematic structural diagram of another circuit board with a gold finger connector provided in an embodiment of the present application;

[0042] Figure 4B for Figure 4A The schematic diagram of the cross-sectional structure of the circuit board shown is taken at MN;

[0043] Figure 5A A schematic structural diagram of another circuit board with a gold finger connector provided in an embodiment of the present application;

[0044] Figure 5B for Figure 5AThe schematic diagram of the cross-sectional structure of the circuit board shown is taken at MN;

[0045] Figure 6A A schematic structural diagram of a circuit board with a gold finger connector provided in an embodiment of the present application;

[0046] Figure 6B for Figure 6A The schematic diagram of the cross-sectional structure of the circuit board shown is taken at MN;

[0047] Figure 7 This is an example diagram of the distribution of conductive contacts provided in an embodiment of the present application;

[0048] Figure 8 A schematic flow chart of a method for preparing a circuit board with a gold finger connector provided in an embodiment of the present application;

[0049] Figures 9A-9H This is a schematic structural diagram of a cross-section of a structure formed during the preparation of a circuit board with a gold finger connector provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0051] In this document, "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more than two. "Above" is inclusive; for example, "two or more" includes two.

[0052] In the following, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0053] The orientations mentioned in the embodiments of the present application, such as "upper", "lower", "inside", "outside", "side", "top", "bottom", etc., are only reference to the directions in the accompanying drawings. Therefore, the orientation terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than simply or implying that the indicated device or element must have a specific orientation, be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0054] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "connected", "connected", and "set on..." should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0055] In the description of the embodiment of the present application, the suspended gold is the metal that is extra at the front end of the conductive contact. Its composition is related to the composition of the conductive contact and can be not only gold but also nickel or a mixture thereof.

[0056] like Figure 2A 、 Figure 3A 、 Figure 4A and Figure 5A As shown in FIG, there are several schematic diagrams of circuit board structures with gold finger connectors provided in the embodiments of the present application, such as Figure 2B 、 Figure 3B 、 Figure 4B and Figure 5B They are Figure 2A 、 Figure 3A 、 Figure 4A and Figure 5A The schematic diagram of the cross section of the gold finger connector at MN is shown. Figures 2A-5B As shown, the circuit board with the gold finger connector includes a PCB carrier 21 , a reference layer 22 and at least one conductive contact 23 .

[0057] The PCB carrier 21 may include one or more PCB layers, i.e., one or more wiring layers. The PCB carrier 21 includes two opposing surfaces, namely a first surface 211 and a second surface 212, i.e., the top surface and bottom surface of the PCB carrier 21, respectively. The thickness of the PCB carrier 21 may be 1-10 mm. The number of layers of the PCB carrier 21 may be 2, 4, 8, 10, 12, etc. The PCB carrier 21 may be made of insulating materials such as FR4, bismaleimide-triazineresin (BT), polyphenylene ether, ceramic matrix, polytetrafluoroethylene (PTFE), and polyimide (PI). Gold finger structures may be designed on both the top and bottom surfaces of the PCB carrier 21, with the gold finger structures on both sides being symmetrical.

[0058] In some application scenarios, the PCB carrier board 21 can be composed of multiple layers of PCB copper-clad boards, with insulating boards (such as polypropylene (PP) boards) between the PCB copper-clad boards, and can be a circuit board without connected components (such as memory chips).

[0059] In some application scenarios, the PCB carrier board 21 is coupled with components (such as a network controller) to realize corresponding functions, such as serving as a communication network device. In this case, the PCB carrier board 21 including the gold finger connector is also called a network card.

[0060] In some embodiments, an insulating reference layer 22 is disposed on at least one of the first surface 211 and the second surface 212 of the PCB carrier 21 . Figures 2A-6B Taking the example of setting the reference layer 22 on both surfaces, it should be understood that in other embodiments, the reference layer 22 may be set on only one of the surfaces, such as only on the first surface 211.

[0061] The reference layer 22 can be made of an inorganic insulating material, such as silicon oxide, silicon nitride, etc.; it can also be made of an organic insulating material, such as polypropylene (PP), epoxy resin, polyester resin, phenolic resin, etc.

[0062] like Figures 2A-5B As shown, the reference layer 22 includes a first reference portion 221 and a second reference portion 222 connected to each other. The thickness d1 of the first reference portion is greater than the thickness d2 of the second reference portion. The direction from the first reference portion 221 to the second reference portion 222 aligns with the insertion direction of the gold finger connector. The reference layer 22 can fully cover the surface of the PCB carrier 21.

[0063] It should be understood that the PCB carrier 21 can be divided into a first area and a second area, wherein the first reference portion 221 is disposed on the surface of the first area, and the second reference portion 222 is disposed on the surface of the second area.

[0064] In an achievable manner, the reference layer 22 may only include the first reference portion 221, and the thickness of the second reference portion 222 is 0. In this case, the reference layer 22 partially covers the surface of the PCB carrier 21, such as Figure 6A and Figure 6B shown.

[0065] One or more conductive contacts 23 are spaced apart along a first direction at the ends of the reference layer 22 and the PCB carrier 21. A portion of each conductive contact 23 is located on the surface of the reference layer 22, while another portion is located on the surface of the PCB carrier 21. The first direction is generally perpendicular to the insertion direction of the gold finger connector. Each conductive contact comprises one or more layers of metal or metal alloy.

[0066] Each conductive contact 23 is electrically connected to the circuit inside the PCB carrier 21. For example, the conductive contact 23 located on the first surface 211 of the PCB carrier 21 can be electrically connected to the top wiring layer; the conductive contact 23 located on the second surface 212 of the PCB carrier 21 can be electrically connected to the bottom wiring layer. Each conductive contact 23 includes a first conductive portion 231 and a second conductive portion 232 connected to each other, wherein the first conductive portion 231 is disposed on the surface of the first reference portion 221 facing away from the PCB carrier 21, and the second conductive portion 232 is disposed on the surface of the second reference portion 222 facing away from the PCB carrier 21 or on the surface of the PCB carrier 21 (for example, Figure 6A and Figure 6B The second conductive portion 232 is lower in thickness than the first conductive portion 231. It should be understood that the second conductive portion 232 located on the first surface 211 has a thickness direction that runs from the first surface 211 toward the second conductive portion 232; and the second conductive portion 232 located on the second surface 212 has a thickness direction that runs from the second surface 212 toward the second conductive portion 232.

[0067] In this way, the sum of the thicknesses of the first reference portion 221 and the first conductive portion 231 is greater than the sum of the thicknesses of the second reference portion 222 and the second conductive portion 232, and further, the front end portion of the conductive contact 23 (i.e., the second conductive portion 232) is lower than the rear end portion (i.e., the first conductive portion 231), so as to assist in guiding the insertion of the conductive contact and avoid the problem of the conductive contact curling up or peeling off when the gold finger connector is inserted into the female connector, thereby reducing the risk of short circuit during the gold finger insertion and removal process.

[0068] In the embodiment of the present application, the gold finger connector is the aforementioned gold finger structure. The gold finger structure located at the end includes a reference layer 22 and a conductive contact 23. The gold finger structure comprises a front portion C and a rear portion B. The front portion C includes a second reference portion 222 and a second conductive portion 232, while the rear portion B includes a first reference portion 221 and a first conductive portion 231. The length of the second reference portion 222 is greater than that of the second conductive portion 232. The front portion C can be further divided into a conductive portion A and an insulating portion D, with the insulating portion D extending to the edge of the PCB carrier 21.

[0069] Because the thickness of the second reference portion 222 in the front portion C is lower than the thickness of the first reference portion 221 in the rear portion B, the overall thickness of the rear portion B is smaller than the thickness of the front portion C. This allows the pins of the conductive portion A (i.e., the second conductive portion 232) to assist in inserting the gold finger connector into the female connector. After the gold finger connector is inserted into the female connector, the pins in the rear portion B (i.e., the first conductive portion 231) contact the female connector to transmit electrical signals.

[0070] like Figures 2A-5B The first reference portion 221 and the second reference portion 222 form a step, and the surface of the first reference portion 221 facing away from the PCB carrier and the surface of the second reference portion 222 facing away from the PCB carrier are both substantially parallel to the surface of the PCB carrier 21 to which they are attached.

[0071] In some embodiments, the thickness of the first reference portion 221 is greater than the thickness of the second reference portion 222 , and the thickness difference Δd between the first reference portion 221 and the second reference portion 222 is 0−1 / 3*H, where H is the thickness of the PCB carrier 21 .

[0072] In other embodiments, the surface of the second reference portion 222 facing away from the PCB carrier can be a plane, an inclined surface, a curved surface, etc. If it is a plane, the plane can be parallel to the first surface 211. If it is an inclined surface, the inclined surface forms an angle with the first surface 211. The angle is 0-90°, and for example, the angle is not greater than 45°.

[0073] In some embodiments, the length of the rear portion B can be 0.5-30 mm, the length of the front portion C can be 0.5-10 mm, wherein the length of the conductive portion A is 0.5-10 mm, the length of the insulating portion D is 0-9.5 mm, and the thickness difference Δh between the first reference portion 221 and the second reference portion 222 is 10 μm-1 mm. For example, the length of the rear portion B is 1.33 mm, the length of the front portion C is 1.87 mm, wherein the length of the conductive portion A is 0.67 mm, the length of the insulating portion D is 1.2 mm, and the thickness difference Δh between the first reference portion 221 and the second reference portion 222 is 20 μm.

[0074] In some embodiments, the conductive contact 23 may have a total length of 1 mm to 10 mm, a width of 0.1 mm to 1 mm, and a spacing of 0.2 mm to 2 mm. For example, the conductive contact 23 may have a total length of 2 mm, a width of 0.38 mm, and a spacing of 0.6 mm.

[0075] The conductive contact sheet 23 may be composed of multiple conductive layers, each of which may be made of metal, such as copper, gold, nickel, palladium, platinum, silver, etc., or may be made of conductive films such as indium tin oxide and graphene. Figures 2A-5B As shown, the base layer 22 includes a metallization layer 23a, a copper layer 23b, a nickel layer 23c, and a gold layer 23d, which are sequentially disposed on the surface of the base layer 22. The metallization layer 23a is a layer structure formed by metallizing the surface of the base layer 22 before electroplating the conductive contact 23. In some embodiments, the conductive contact 23 may be prepared using other processes, and the layer structure of the conductive contact 23 may not include the metallization layer 23a.

[0076] The conductive contact piece 23 is divided into two parts according to the position, ie, a first conductive part 231 located on the surface of the first reference part 221 and a second conductive part 232 located on the surface of the second reference part 222 .

[0077] In some embodiments, the length of the first reference portion 221 is greater than the length of the first conductive portion 231, and the length of the second reference portion 222 is greater than the length of the second conductive portion 232. In some embodiments, the second reference portion 222 extends to the edge of the PCB carrier 21. Here, "length" refers to the length along the insertion direction.

[0078] For example, the length of the first conductive portion 231 may be 9 / 10 to 1 / 3 of the total length of the conductive contact 23, and correspondingly, the length of the second conductive portion 232 may be 1 / 10 to 2 / 3 of the total length of the conductive contact 23. It should be understood that the sum of the lengths of the first conductive portion 231 and the second conductive portion 232 is the total length of the conductive contact 23, and both the lengths of the first conductive portion 231 and the second conductive portion 232 are the lengths thereof in the plugging direction.

[0079] like Figures 2A-5B As shown, the surface of the first conductive portion 231 facing away from the PCB carrier 21 is a plane, and its thickness remains consistent.

[0080] like Figure 2A and Figure 2B As shown, the surface of the second conductive portion 232 facing away from the PCB carrier 21 may be a curved surface, and its thickness gradually decreases along the plugging direction.

[0081] like Figure 3A and Figure 3B As shown, the surface of the second conductive portion 232 facing away from the PCB carrier 21 can be a plane parallel to the first surface 211 , and the thickness of the second conductive portion 232 remains unchanged along the plugging direction, so that the conductive contact 23 is stepped.

[0082] Optionally, the second conductive portion 232 includes a first end and a second end; the second conductive portion 232 extends from the second end to the first end along the plugging direction; wherein the thickness of the first end is less than or equal to the thickness of the second end.

[0083] Optionally, the second conductive portion 232 has a uniform thickness or decreases in thickness from the second end portion to the first end portion.

[0084] like Figure 4A and Figure 4BAs shown, the surface of the second conductive portion 232 facing away from the PCB carrier 21 can be an inclined surface. The angle θ1 between the inclined surface and the surface of the second reference portion 222 facing away from the PCB carrier 21 can be between 10° and 80°. The thickness of the second conductive portion 232 gradually decreases along the insertion direction, resulting in a triangular shape.

[0085] The surface of the second conductive portion 232 facing away from the PCB carrier 21 can be a combination of at least one of a plane, an inclined surface, and a curved surface. Figure 5A and Figure 5B The figure shows the connection of a plane and an inclined surface. The plane is parallel to the first surface 211, and the angle θ2 between the inclined surface and the surface of the second reference portion 222 facing away from the PCB carrier 21 (or the first surface 211) can be between 10° and 80°. The thickness of the second conductive portion 232 initially remains constant and then gradually decreases along the insertion direction, resulting in a trapezoidal shape.

[0086] It should be understood that the above Figure 2A-2B 、 Figure 3A-Figure 3B 、 Figure 4A-4B 、 Figure 5A-5B The following description is made by taking an example where the reference layer 22 and the conductive contact sheet 23 are arranged on both the upper and lower surfaces of the PCB carrier board 21 , and the reference layer 22 and the conductive contact sheet 23 are symmetrical in the upper and lower directions.

[0087] It should also be understood that it is not limited to the above Figure 2A-2B 、 Figure 3A-Figure 3B 、 Figure 4A-4B 、 Figure 5A-5B In the structure of the gold finger connector shown, under the premise that the thickness of the front portion A is smaller than that of the rear portion B, the reference layer 22 and the conductive contact piece 23 may also include other deformations, which will not be described here.

[0088] What needs to be explained is that the above Figure 2A 、 Figure 3A 、 Figure 4A 、 Figure 5A Six conductive contacts 23 are exemplarily shown on one side of the gold finger connector. Based on actual application requirements, the gold finger connector may include more or fewer conductive contacts 23.

[0089] For example, see Figure 7 , which is an exemplary diagram of the distribution of a conductive contact provided by an embodiment of the present application, a plurality of conductive contact pieces 23 are arranged at equal intervals, and the length and width of each conductive contact piece 23 are consistent.

[0090] In other embodiments, a plurality of conductive contact pieces 23 are distributed in a row and may be arranged at unequal intervals. The length and width of each conductive contact piece 23 may also be different.

[0091] In other embodiments, the plurality of conductive contact pieces 23 are distributed in two rows and may be arranged at unequal intervals. The length and width of each conductive contact piece 23 may also be different.

[0092] above Figures 2A-6B The circuit board with the gold finger connector may be a functional board, which may be a memory card, a graphics card, a network card, etc.

[0093] The embodiment of the present application also provides an electronic device, which may include a mainboard, a Figures 2A-6B The circuit board described above can be used for memory cards, graphics cards, and network cards. The motherboard has a female connector corresponding to the gold finger connector. The circuit board is inserted into the female connector via the gold finger connector, and then communicates data with other devices or chips on the motherboard, such as a processor. This electronic device can be a terminal such as a mobile phone, smartwatch, virtual reality device, augmented reality device, smart furniture device, or in-vehicle device, or a network device or computing device such as a server or cloud computer.

[0094] Combine as follows Figure 8 The preparation method flow chart of the gold finger connector shown in FIG. Figures 9A-9H The schematic diagram of the cross section of the structure formed during the preparation process is shown, which introduces the above Figures 2A-6B The method for preparing the gold finger connector shown may include but is not limited to some or all of the following steps:

[0095] S01 : providing a PCB carrier 71 , and forming a reference layer 72 on at least one surface of the PCB carrier 71 .

[0096] PCB carrier 71 may include one or more PCB layers, that is, one or more wiring layers. PCB carrier 71 may be formed by laminating at least one PCB substrate to form a PCB stack, or it may be at least one PCB substrate before lamination. At least one surface of some or all of the PCB substrates may include patterned metal (i.e., a wiring layer). This wiring layer may be made of a metal material such as copper. For details regarding PCB carrier 21, see the aforementioned gold finger connector, which will not be repeated here.

[0097] like Figure 9A As shown, the PCB carrier 71 is used as an example for description, comprising a substrate 710 and a top wiring layer 711 and a bottom wiring layer 712 disposed on the upper and lower surfaces of the substrate 710. The PCB carrier 71 includes two opposing surfaces, namely a first surface 713 and a second surface 714, which respectively represent the surface of the top wiring layer 711 and the surface of the bottom wiring layer 712 of the PCB carrier 71.

[0098] like Figure 9AAs shown, two reference layers 72 and a PCB carrier 71 are stacked in sequence and then pressed together to form reference layers 72 on both the first surface 713 and the second surface 714. This embodiment uses the example of forming gold fingers on both the first surface 713 and the second surface 714 to obtain a double-sided gold finger. It should be understood that in other embodiments, the reference layer 72 may be formed on only one surface to obtain a single-sided gold finger.

[0099] Among them, the reference layer 72 can be made of acrylic, ajinomoto buildup film (ABF), BT resin, MIS material, etc., and can also be made of other insulating materials such as silicon oxide, silicon nitride, polypropylene (PP), epoxy resin, polyester resin, phenolic resin, etc.

[0100] S02 : Partially etching the reference layer 72 to form a first reference portion 721 and a second reference portion 722 sequentially arranged along the plugging direction, wherein the second reference portion 722 is thinner than the first reference portion 721 .

[0101] The PCB carrier 71 includes a first area and a second area, and the direction from the first area to the second area is the plugging direction of the gold finger connector. In step S02, the reference layer 72 located on the surface of the second area can be partially etched to form a Figures 2A-5B The gold finger connector shown in FIG. 1 is formed by completely etching the reference layer 72 on the surface of the second region. Figure 6A and Figure 6B The gold finger connector is shown.

[0102] The length of the first reference portion 721 is greater than the length of the second reference portion 722. Figures 2A-5B The length of the first reference portion 221 in the gold finger connector shown is greater than the relevant description of the second reference portion 222 , which will not be repeated here.

[0103] Specifically, a laser or plasma device can be used to partially etch the front portion of the reference layer 72 (the portion that first contacts the female connector during insertion). The etching depth Δh can be 10 μm-1 / 3*H, where H is the total thickness of the PCB carrier 71 and the reference layer 72, to form a stepped reference layer 72. It should be understood that the etching method is not limited to the dry etching method described above, and wet etching can also be used.

[0104] In other embodiments, the etching depth may be changed dynamically to obtain reference layers 72 with different morphologies.

[0105] In another implementation, the reference layer at one end of the PCB carrier may be completely etched to expose the surface of the PCB carrier. In this case, the obtained reference layer 72 only includes the first reference portion 721 .

[0106] S03 : forming a conductive contact 73 on the etched reference layer 72 .

[0107] The conductive contact piece 73 disposed on the surface of the first reference portion 721 is also called the first conductive portion; the conductive contact piece 73 disposed on the surface of the second reference portion 722 is also called the second conductive portion.

[0108] Due to the stepped structure of the reference layer 72, the sum of the thicknesses of the first reference portion 721 and the first conductive portion is smaller than the sum of the thicknesses of the second reference portion 722 and the second conductive portion. Consequently, the front end portion (i.e., the second conductive portion) of the conductive contact 73 is lower than the rear end portion (i.e., the first conductive portion), thereby assisting in guiding the insertion of the conductive contact and avoiding the problem of the conductive contact being lifted or peeled off when the gold finger connector is inserted into the female connector, thereby reducing the risk of short circuit during the gold finger insertion and removal process.

[0109] Figure 9B Taking the formation of the conductive contact 73 on the stepped reference layer 72 as an example, an implementation of step S03 includes but is not limited to the following steps:

[0110] S031: performing metallization processing on the etched reference layer 72 .

[0111] Metallization is the process of forming a conductive layer on the etched reference layer 72. Metallization methods may include, but are not limited to, depositing a conductive material on the surface of the reference layer 72 facing away from the PCB carrier 71 through thin-film deposition processes such as vacuum evaporation and electroless copper deposition to form the conductive layer 73a; or forming the conductive layer 73a on the surface of the reference layer 72 facing away from the PCB carrier 71 through a black hole process, a black shadow process, or a graphene metallization process.

[0112] S032: Using the conductive layer 73a as an electrode, a copper layer is formed on the conductive layer 73a by electroplating.

[0113] The conductive layer 73a is used as an electrode, and a copper ion solution such as copper sulfate is used as an electrolyte to form a copper layer on the conductive layer 73a. The thickness of the copper layer can be between 10 μm and 100 μm, with the actual thickness being controlled according to design requirements. Typically, the surface of the copper layer formed by electroplating, facing away from the conductive layer 73a, is curved and arc-shaped.

[0114] S033: Patterning the copper layer to form multiple conductive wires and multiple copper contacts 73b. The conductive wires (not shown) correspond one-to-one to the copper contacts. The multiple copper contacts 73b are arranged in intervals, with one end of each conductive wire connected to a copper contact and the other end electrically connected to a wiring layer inside or on the surface of the PCB carrier 71.

[0115] S034: forming a solder resist layer on the patterned copper layer to expose the copper contacts 73b.

[0116] It should be understood that the solder resist layer (not shown in the figure) can also be called a window layer or a green oil layer. In step S034, the solder resist layer can cover all areas except the copper contacts.

[0117] S035: Electroplating is performed sequentially to form a nickel layer 73c and a gold layer 73d on the surface of the copper contact piece 73b exposed by the solder resist layer.

[0118] The copper contact piece 73 b and the nickel layer 73 c and the gold layer 73 d on the surface of the copper contact piece 73 b constitute the conductive contact piece 73 .

[0119] It should be understood that the embodiment of the present application takes the structure of the conductive contact 73 as four conductive layers as an example. In other embodiments, the copper contact 73b, the nickel layer 73c and the gold layer 73d can also be replaced by other metal layers, or include fewer or more metal layers.

[0120] In some embodiments, in order to control the morphology of the second conductive portion located on the surface of the second reference portion 722, the copper layer located on the surface of the second reference portion 722 may be etched or cut after the copper layer is formed to obtain the following: Figure 9C The stepped copper layer shown in FIG. 3 can be obtained by further executing S033. Figure 9D The gold finger connector is shown.

[0121] In some embodiments, after forming the copper layer, the copper layer on the surface of the second reference portion 722 is etched or cut to obtain Figure 9E The copper layer with the bevel shown in FIG. 1 can be further obtained by executing S033. Figure 9F The gold finger connector is shown.

[0122] In some embodiments, after forming the copper layer, the copper layer on the surface of the second reference portion 722 is etched or cut to obtain Figure 9G The copper layer shown in FIG. 1 can be obtained by further executing S033. Figure 9H The gold finger connector is shown.

[0123] In one application scenario, the number of PCB layers in PCB carrier 71 is no less than two, and can be, for example, four. The etching depth Δh of reference layer 72 can be 10 μm-1 / 3*H, where H is the thickness of PCB carrier 71. The thickness of the electroplated copper layer is 10 μm-100 μm, the thickness of the nickel layer is 2.5-15 μm, and the thickness of the gold layer is no less than 0.8 μm.

[0124] In another application scenario, the number of PCB layers in the PCB carrier 71 is 8, the total thickness of the PCB carrier 71 is 1.4 mm, the etching depth Δh of the reference layer 72 can be 20 um, the thickness of the copper layer formed by electroplating is 25 um-60 um, the thickness of the nickel layer 73 c is 2.5-15 um, and the thickness of the gold layer 73 d is not less than 0.8 um.

[0125] It should be noted that the flowcharts described in each embodiment of the present invention are merely one embodiment. Without departing from the spirit of the present invention, the steps in each flowchart may be modified or varied in various ways, such as executing the steps in the flowchart in a different order, or deleting, adding, or modifying certain steps.

[0126] The technical terms used in the embodiments of the present invention are only used to illustrate specific embodiments and are not intended to limit the present invention. In this document, the singular forms "a," "the," and "said" are used to include the plural forms, unless the context clearly indicates otherwise. Furthermore, the terms "including" and / or "comprising" used in this specification refer to the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or components.

[0127] It should also be understood that in the various embodiments of the present application, "at least one" or "one or more" refers to one, two, or more than two. References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of the present application include specific features, structures, or characteristics described in conjunction with the embodiment. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized.

[0128] The corresponding structures, materials, acts, and equivalents of all means or steps and function elements in the appended claims, if any, are intended to include any structure, material, or act for performing that function in combination with other explicitly claimed elements. The description of the present invention has been presented for purposes of example and description, but is not intended to be exhaustive or to limit the invention to the form disclosed.

Claims

1. A circuit board with a gold finger connector, characterized in that: include: Printed circuit board PCB carrier board; an insulating reference layer, wherein the reference layer partially or completely covers at least one surface of the PCB carrier; The reference layer includes a first reference portion and a second reference portion; the direction in which the first reference portion points to the second reference portion is consistent with the plugging direction of the gold finger connector; the thickness of the first reference portion is greater than the thickness of the second reference portion; and At least one conductive contact, the conductive contact being disposed on the reference layer at at least one end of the PCB carrier; the conductive contact being electrically connected to the PCB carrier; The sum of the thicknesses of the first reference portion and the conductive contact sheet disposed on the surface of the first reference portion is greater than the sum of the thicknesses of the second reference portion and the conductive contact sheet disposed on the surface of the first reference portion.

2. The circuit board according to claim 1, characterized in that , Each of the conductive contacts includes a first conductive portion and a second conductive portion; the first conductive portion and the second conductive portion are connected; the first conductive portion is arranged on a surface of the first reference portion facing away from the PCB carrier, and the second conductive portion is arranged on a surface of the second reference portion facing away from the PCB carrier; wherein the sum of the thicknesses of the first reference portion and the first conductive portion is greater than the sum of the thicknesses of the second reference portion and the second conductive portion.

3. The circuit board according to claim 2, wherein: The second conductive portion includes a first end and a second end; the second conductive portion extends from the second end to the first end along the plugging direction; wherein the thickness of the first end is less than or equal to the thickness of the second end.

4. The circuit board according to claim 3, wherein: The second conductive portion has a uniform thickness or a thickness that decreases from the second end portion to the first end portion.

5. The circuit board according to claim 3 or 4, characterized in that: A surface of the second conductive portion facing away from the second reference portion is a combination of one or more of a curved surface, an inclined surface, and a flat surface.

6. The circuit board according to any one of claims 1 to 4, characterized in that: The at least one conductive contact is arranged in a row at intervals substantially perpendicular to the plugging direction.

7. The circuit board according to any one of claims 1 to 4, characterized in that: The at least one conductive contact piece is a plurality of conductive contact pieces; the plurality of conductive contact pieces are arranged in two rows at intervals substantially perpendicular to the plugging direction.

8. The circuit board according to any one of claims 1 to 4, characterized in that: The thickness of the second reference portion is 0.

9. The circuit board according to any one of claims 1 to 4, characterized in that: The circuit board is a memory card, a graphics card or a network card.

10. An electronic device, characterized in that: include: A motherboard and a circuit board as described in any one of claims 1 to 9; the motherboard has a slot; the circuit board is plugged into the slot through the gold finger connector to achieve electrical connection with the motherboard.

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