Longitudinal electric connector based on printed circuit board and application thereof

Abstract

The invention discloses a longitudinal electric connecting piece based on a printed circuit board. The longitudinal electric connecting piece comprises a layered insulation structure and a layered metal connecting piece arranged in the layered insulation structure. At least one end of the layered metal connecting piece is provided with an end bonding pad exposed out of the layered insulating structure, and the surface of the end bonding pad is in a wave shape. On the other hand, the invention discloses application of the longitudinal electric connecting piece based on the printed circuit board. The longitudinal electric connecting piece is applied to a power module. According to the invention, the width, spacing and the like of the end pads can be greatly reduced, the number of fan-out pins is effectively increased, the interconnection density is improved, the welding area can be effectively increased, a welding exhaust channel is provided, a welding spot crack propagation path is blocked and the like, and the connection reliability can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-frequency power supply, and in particular relates to a longitudinal electrical connector based on a printed circuit board and an application thereof. Background Art

[0002] With the increasing demand for various artificial intelligence and data processing, global computing power consumption has exploded. Moreover, due to the extremely high size restrictions of these computing units, higher and higher requirements are placed on the floor space, height, efficiency, heat dissipation, and reliability of energy processing units.

[0003] A typical two-stage power supply architecture, the front stage is 48V to 12V (5V), and the back stage is 12V (5V) to the processor's operating voltage, about ~1V. The front stage module usually contains a magnetic component, a transformer, because its voltage conversion is relatively high; the back stage usually uses a buck circuit, which contains a magnetic component, an inductor.

[0004] Since these energy processing units need to receive / output numerous signals, how to achieve high-density and high-reliability interconnection of signals among the energy processing units, avoid interference from adjacent magnetic components and voltage jump points on the signals, and ensure the functional safety of the energy processing units is an issue that needs to be addressed urgently. Summary of the invention

[0005] In view of this, one of the objects of the present invention is to provide a longitudinal electrical connector based on a printed circuit board, which can significantly reduce the width and spacing of the end pads, effectively increase the number of pin fan-outs, improve the interconnection density, effectively increase the welding area, provide a welding exhaust channel, block the solder joint crack propagation path, etc., and effectively increase the connection reliability.

[0006] To achieve the above-mentioned purpose, the present invention provides a longitudinal electrical connector based on a printed circuit board, wherein the longitudinal electrical connector includes a layered insulating structure and a layered metal connector arranged in the layered insulating structure; at least one end of the layered metal connector has an end pad exposed from the layered insulating structure, and the surface of the end pad is wavy.

[0007] Preferably, the longitudinal electrical connector has a first surface and a second surface perpendicular to the thickness direction, and the end pad extends to the first surface and / or the second surface.

[0008] Preferably, the end pads are multiple and arranged in an array, each of the end pads is electrically connected to at least two adjacent layered metal connectors, and the spacing between adjacent end pads is greater than twice the spacing between adjacent layered metal connectors.

[0009] Preferably, a distance between adjacent terminal pads is greater than three times a distance between adjacent layered metal connectors.

[0010] Preferably, the spacing between adjacent layered metal connectors is 20-100 μm, and the spacing between adjacent end pads is 200-500 μm.

[0011] Preferably, the end pad is a layered metal connector formed by electroplating on the end surface.

[0012] Preferably, the height of the longitudinal electrical connector is greater than 1.5 times the thickness of the longitudinal electrical connector.

[0013] On the other hand, the present invention provides an application of the above-mentioned longitudinal electrical connector, wherein the longitudinal electrical connector is used in a power module, wherein the power module includes at least one of the longitudinal electrical connectors and at least one large-volume component, wherein the longitudinal electrical connector is fixedly arranged on at least one side of the large-volume component by a bonding material, and the longitudinal electrical connector and the large-volume component form an assembly.

[0014] Preferably, the power module further includes a top component and a bottom component, the top component includes a top plate and a power chip and a capacitor element arranged on the top plate, and the bottom component includes a bottom plate, and the top plate and the bottom plate are respectively welded to the top surface and the bottom surface of the assembly.

[0015] The beneficial effects of the present invention are:

[0016] (1) Compared with the traditional board edge gold plating process, the width and spacing of the end pads can be greatly reduced, effectively increasing the number of pin fan-outs and improving the interconnection density; the line spacing of the traditional board edge gold plating process is usually greater than 0.6mm, the gold plating width must also be greater than 0.6mm, and the forming stability is poor, and waist drum-shaped spacing often occurs. The line width and line spacing of this embodiment can be easily achieved to be less than 0.5mm, or even less than 0.4mm or 0.3mm.

[0017] (2) The end pads formed directly by electroplating grow vertically and expand horizontally at the same time, so they naturally have a concave and convex wavy structure, which can effectively increase the welding area, provide welding exhaust channels, block the crack propagation path of the solder joint, etc., which can effectively increase the connection reliability;

[0018] (3) The longitudinal electrical connector of the present invention uses PCB as a substrate. When applied to a power module, the loop inductance can be reduced by wiring design, and the signal can be effectively prevented from being interfered with by setting a shielding layer, etc. The present invention can be cut into large pieces during production, which is suitable for batch production, and has a small dimensional tolerance and high consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 to Figure 3 It is a schematic structural diagram of the longitudinal electrical connector disclosed in the present invention;

[0021] 4A to 4F A schematic diagram of a metal end surface and an end pad disclosed in an embodiment of the present invention;

[0022] Figure 5A and Figure 5B A schematic diagram of an electrode of a longitudinal electrical connector disclosed in an embodiment of the present invention;

[0023] Figure 6 and Figure 7 It is a structural schematic diagram of the application of the longitudinal electrical connector disclosed in the embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] This embodiment discloses a longitudinal electrical connector 1 based on a printed circuit board, such as Figure 1A and Figure 1B As shown, Figure 1B for Figure 1A As shown in the AA cross-sectional view, the longitudinal electrical connector 1 includes a layered insulating structure and a layered metal connector 3 arranged in the layered insulating structure; at least one end of the layered metal connector 3 has an end pad 2 exposed from the layered insulating structure, and the end pad 2 is electrically connected to at least two adjacent layered metal connectors 3 and has a wavy surface.

[0026] Specifically: the longitudinal electrical connector 1 has a first surface and a second surface perpendicular to the thickness direction, as well as an upper end face and a lower end face; the layered metal connector 3 can be electrically connected inside the printed circuit board through vias or the like as needed, and the layered metal connector 3 directly forms an end pad 2 at the upper end face / lower end face by electroplating, and the electroplated metal grows vertically and is electrically connected to two or more wiring layers of the printed circuit boards by expanding along the thickness direction of the connector, thereby forming a wavy surface.

[0027] In this embodiment, the end pad 2 extends to the first surface and / or the second surface to further provide side creep tin, further increase the welding strength, and improve the visual inspection of welding quality. In some other embodiments, the end pad 2 may not be extended on the first surface / second surface. The number of wiring layers of the carrier board and the interlayer via connection can be freely set as needed, and the area exposed at the upper end surface / lower end surface of the layered metal connector 3 can also be freely set as needed.

[0028] The manufacturing method of this embodiment is as follows:

[0029] Step 1: Make a motherboard of the printed circuit board, cut it, and expose the metal end surface of the wiring layer at the cut surface of the upper and lower end surfaces of the longitudinal electrical connector 1;

[0030] Step 2: Perform graphic definition on the first surface / second surface (including steps such as forming surface graphic definition by photoresist material), electroplating, and forming end pads 2 at the same time. Since the interlayer spacing of the wiring layers is very small, the electroplated metal on the metal end faces of adjacent wiring layers can be electrically connected by expanding along the thickness direction of the longitudinal electrical connector 1. Since the height of the electroplated metal at the metal end face position exposed by the end face cutting surface is naturally higher than the height of the electroplated metal at the middle position of the adjacent wiring layer, a wavy surface is formed;

[0031] Step 3: Electroplating metal anti-etching layer;

[0032] Step 4: Remove the surface graphic definition layer;

[0033] Step 5: Etch to remove the exposed copper base on the surface;

[0034] step6: Remove the metal anti-etching layer.

[0035] In some other embodiments, steps such as forming through-holes / via electrical connectors on the printed circuit board can be completed in step 1 or step 2.

[0036] In a preferred embodiment, the upper and lower ends of the longitudinal electrical connector 1 can also be pattern-defined, exposing only the area to be electroplated, and sputtering the seed layer to further promote the electrical connection across the wiring layer of the end pad 2. In a preferred embodiment, the slit width of the jig used for pattern definition is less than 1 / 2 of the line width of the metal end surface.

[0037] In a preferred embodiment, if Figure 2A and Figure 2BAs shown, in order to allow the electroplated metal to connect adjacent wiring layers while preventing different pads from short-circuiting each other, when designing the exposed surface layout of the layered metal electrical connector, the distance d2 between adjacent pads (measured in terms of edge spacing) needs to be greater than twice the distance d1 between adjacent wiring layers, preferably at least three times; since the thickness of d1 is usually between 20 and 100 μm, the spacing between adjacent pads is still very small, for example, 200 to 500 μm, and extremely small line width and line spacing (line width and line spacing such as Figure 1A Preferably, the height h of the longitudinal electrical connector 1 is 1.5 times or more than the thickness t.

[0038] The end pad 2 can be provided on both the upper end surface and the lower end surface. Figure 3 As shown, it can also be set only on one of the upper end surface or the lower end surface.

[0039] In a preferred embodiment, the overall shape of the end pad 2 can be adjusted by adjusting the length, arrangement and spacing between adjacent metal layers of the metal end surface when the structure of the printed circuit board is pre-designed to meet different process, electrical and reliability requirements. 4A to 4F As shown, the upper part of the figure is a schematic diagram of the layout of the metal end surface before making the end pad 2, and the lower part of the figure is a schematic diagram of the shape of the obtained finished product.

[0040] like Figure 4A As shown, the shape of the terminal pad 2 may be close to a regular square.

[0041] like Figure 4B As shown, the shape of the end pad 2 can be a rectangle with concave sides, such as Figure 4C As shown, the shape of the end pad 2 can also be a rounded rectangle with convex sides.

[0042] In some other embodiments, it can also be other irregular shapes, such as Figure 4D As shown, the end pads 2 can be arranged in any pattern by arranging and combining the metal end faces to form the end pads 2 in a relative position relationship.

[0043] like Figure 4E As shown, the thickness of the end pad 2 / the thickness of the insulating dielectric layer can be set as needed. The adjacent metal layers of the thin dielectric are interconnected by electroplating to form a metal connection structure. The two adjacent metal layers of the thick dielectric cannot be connected by electroplating due to the large distance. Therefore, a multi-row and multi-column pad structure can be formed on the side wall, thereby increasing the number of pins led out to the outside.

[0044] like Figure 4FAs shown, in some areas, the spacing of the metal end faces along the thickness direction can be made larger than the spacing required for the electroplating to form an electrical interconnection structure by local avoidance, so that the end pads 2 formed by electroplating can be arranged along the thickness direction, and the spacing difference can also be achieved by the inconsistent thickness of some laminated media in the layered insulating structure 3. Therefore, the number of rows / columns of the end pads 2 of the array can be freely set as needed. In order to allow the electroplated metal to connect adjacent wiring layers but not adjacent pads, the distance d2 between adjacent pads along the thickness direction should also be greater than 2 times the distance d1 of adjacent wiring layers. Preferably, d2 is greater than 3 times d1.

[0045] In a preferred embodiment, if Figure 5A and Figure 5B As shown, Figure 5A is a schematic diagram of the layout of the electrodes 21 on the upper end surface of the longitudinal electrical connector 1, Figure 5B Schematic diagram of the layout of the electrodes 21 on the lower end surface of the longitudinal electrical connector 1. When the upper and lower end surfaces of the longitudinal connector 1 are both provided with end pads 2, the number, shape and arrangement position of the electrodes 21 formed on the upper / lower end surfaces can be freely set as needed, further increasing the wiring flexibility. In this embodiment, the number of electrodes on the lower end surface is greater than that on the upper end surface, and the extra electrodes can be used for other components to be bridged by means of the lower end surface of the longitudinal electrical connector 1.

[0046] Compared with the traditional board edge gold plating process, this embodiment can significantly reduce the width and spacing of the end pads 2, effectively increase the number of pin fan-outs and improve the interconnection density; the line spacing of the traditional board edge gold plating process is usually greater than 0.6mm, the gold plating width must also be greater than 0.6mm, and the forming stability is poor, and waist drum-shaped spacing often occurs. The line width and line spacing of this embodiment can be easily achieved to be less than 0.5mm, or even less than 0.4mm or 0.3mm.

[0047] The end pad 2 formed directly by electroplating in this embodiment grows vertically and expands horizontally at the same time, so it naturally has a concave and convex wavy structure, which can effectively increase the welding area, provide a welding exhaust channel, block the expansion path of the solder joint crack, etc., and can effectively increase the connection reliability.

[0048] On the other hand, this embodiment discloses the application of the longitudinal electrical connector 1, such as Figure 6 As shown, the longitudinal electrical connector 1 and the large-volume component 41 of the power module are fixedly connected by bonding materials to form an assembly 4; the top surface and / or the bottom surface of the large-volume component 41 are provided with welding pads. In this embodiment, the height of the longitudinal electrical connector 1 is approximately the same as the height of the large-volume component 41, and further, the surface of the longitudinal electrical connector 1 and the surface of the large-volume component 41 are approximately horizontal.

[0049] In a preferred embodiment, the bonding material is insulating adhesive, SMT patch adhesive, solder, etc.

[0050] After the assembly is formed, further steps such as Figure 7 As shown, the power module also includes a top component and a bottom component 6, the top component includes a top plate 51 and a power chip 52 and a capacitor element 53 arranged on the top plate, and the bottom component 6 includes a bottom plate, and the top plate and the bottom plate are welded to the top surface and the bottom surface of the assembly 4 respectively. The power module that directly supplies power to the computing chip usually adopts a buck circuit, which includes magnetic components, capacitors, power chips, etc. The longitudinal connector of this embodiment can effectively avoid interference of adjacent magnetic components and voltage jump points on the signal through stacking wiring and shielding layer setting, thereby ensuring the functional safety of the energy processing unit and effectively improving the accuracy and stability of various signals.

[0051] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0052] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A longitudinal electrical connector based on a printed circuit board, characterized in that: The longitudinal electrical connector comprises a layered insulating structure and a layered metal connector arranged in the layered insulating structure; at least one end of the layered metal connector has an end pad exposed from the layered insulating structure, and the surface of the end pad is wavy.

2. The longitudinal electrical connector according to claim 1, characterized in that The longitudinal electrical connector has a first surface and a second surface perpendicular to the thickness direction, and the end pad extends to the first surface and / or the second surface.

3. The longitudinal electrical connector according to claim 1, characterized in that The end pads are multiple and arranged in an array, each of the end pads is electrically connected to at least two adjacent layered metal connectors, and the spacing between adjacent end pads is greater than twice the spacing between adjacent layered metal connectors.

4. The longitudinal electrical connector according to claim 3, characterized in that: The spacing between adjacent terminal pads is greater than three times the spacing between adjacent layered metal connectors.

5. The longitudinal electrical connector according to claim 3, characterized in that: The spacing between adjacent layered metal connectors is 20-100 μm, and the spacing between adjacent end pads is 200-500 μm.

6. The longitudinal electrical connector according to claim 1, characterized in that The end pad is a layered metal connector formed by electroplating on the end surface.

7. The longitudinal electrical connector according to claim 1, characterized in that The height of the longitudinal electrical connector is greater than 1.5 times the thickness of the longitudinal electrical connector.

8. Use of a longitudinal electrical connector according to any one of claims 1 to 7, characterized in that: The longitudinal electrical connector is used in a power module, which includes at least one longitudinal electrical connector and at least one large-volume component. The longitudinal electrical connector is fixedly arranged on at least one side of the large-volume component by bonding material, and the longitudinal electrical connector and the large-volume component form an assembly.

9. The use according to claim 8, characterized in that: The power module also includes a top component and a bottom component. The top component includes a top plate and a power chip and a capacitor element arranged on the top plate. The bottom component includes a bottom plate. The top plate and the bottom plate are welded to the top surface and the bottom surface of the assembly respectively.

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