Circuit board connection structure with high length copper pillar and manufacturing method thereof

Abstract

The application provides a manufacturing method of a circuit board connection structure with a high-length copper column. The first copper column, the second copper column and the third copper column are manufactured respectively, and the high-length copper column is manufactured by splicing the first copper column, the second copper column and the third copper column, so as to reduce the problem of empty package or gap of the high-length copper column in the manufacturing process, improve the homogeneity of the high-length copper column, and further improve the stability of signal transmission between the to-be-connected component and the first conductive circuit layer. The application also provides a circuit board connection structure with a high-length copper column manufactured by the method.

Description

Technical Field

[0001] This application relates to the field of circuit boards, and more particularly to a circuit board connection structure with high-length copper pillars and its manufacturing method. Background Technology

[0002] With the advancement of technology, electronic products such as mobile phones and laptops are developing towards higher density and higher integration. In the manufacturing process of electronic products, circuit boards are typically connected to components using long copper pillars. Currently, these copper pillars are generally produced using electroplating. Due to the considerable length of the copper pillars, issues such as voids or gaps can easily occur during manufacturing, reducing the homogeneity of the copper pillars and thus affecting signal transmission between the circuit board and the connected components. Summary of the Invention

[0003] In view of this, this application provides a method for manufacturing a circuit board connection structure with high homogeneity and long copper pillars.

[0004] Additionally, it is necessary to provide a circuit board connection structure with high-length copper pillars manufactured using the above method.

[0005] One embodiment of this application provides a method for manufacturing a circuit board connection structure with high-length copper pillars, including:

[0006] A first substrate is provided, the first substrate including a first dielectric layer and a first copper foil layer located on the surface of the first dielectric layer, and a through hole is formed in the first dielectric layer;

[0007] A first copper pillar is formed on the first copper foil layer, and a second copper pillar is formed in the through hole, and the first copper pillar and the second copper pillar are positioned opposite each other to obtain a second substrate;

[0008] A circuit board is provided, the circuit board comprising a first conductive circuit layer, a second dielectric layer, a second copper foil layer and a first copper plating layer stacked sequentially, and a third copper pillar is provided on the first conductive circuit layer.

[0009] The second substrate and the circuit substrate are stacked together, and the second copper pillar and the third copper pillar are opposite to each other;

[0010] The second substrate and the circuit substrate are hot-pressed to electrically connect the second copper pillar and the third copper pillar;

[0011] The first copper foil layer is etched to form a conductive element, and the conductive element is located between the first copper pillar and the second copper pillar; the first copper plating layer and the second copper foil layer are etched to form a second conductive circuit layer.

[0012] An accommodating groove is formed in the first dielectric layer, and a portion of the first conductive line layer is exposed in the accommodating groove to form a solder pad;

[0013] The components are placed in the receiving groove using a first conductive paste, and the components are electrically connected to the solder pads; and

[0014] The component to be connected is electrically connected to the first copper pillar using a second conductive paste, thereby electrically connecting the component to be connected to the first conductive circuit layer, thus obtaining the circuit board connection structure.

[0015] An embodiment of this application also provides a circuit board connection structure with a high-length copper pillar, including a component to be connected, a first dielectric layer, a first conductive line layer, a second dielectric layer, and a second conductive line layer stacked sequentially.

[0016] The circuit board connection structure includes a first copper pillar, a conductive element, a second copper pillar, and a third copper pillar that are coaxially connected in sequence. The first copper pillar, the conductive element, the second copper pillar, and the third copper pillar are located between the component to be connected and the first dielectric layer. The component to be connected is electrically connected to the first copper pillar through a second conductive paste, so that the component to be connected is electrically connected to the first conductive circuit layer.

[0017] The circuit board connection structure further includes components. A receiving groove is formed in the first dielectric layer, and a portion of the first conductive circuit layer is exposed in the receiving groove to form a solder pad. The components are disposed in the receiving groove by a first conductive paste, and the components are electrically connected to the solder pad.

[0018] This application separately manufactures the first copper pillar, the second copper pillar, and the third copper pillar, and fabricates a high-length copper pillar by splicing the first copper pillar, the second copper pillar, and the third copper pillar together. This reduces the problem of voids or gaps in the fabrication of the high-length copper pillar, thereby improving the homogeneity of the high-length copper pillar and thus improving the stability of signal transmission between the component to be connected and the first conductive circuit layer. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the first substrate provided in an embodiment of this application.

[0020] Figure 2 Is Figure 1 The diagram shows a cross-sectional view of a first copper pillar formed on a first copper foil layer and a second copper pillar formed in a through hole.

[0021] Figure 3 This is a cross-sectional view of a circuit board provided in an embodiment of this application.

[0022] Figure 4It is Figure 2 The second substrate shown and Figure 3 The diagram shows a cross-sectional view of the circuit board after it has been stacked and hot-pressed.

[0023] Figure 5 It is Figure 4 The first copper foil layer is shown being etched, and a cross-sectional view showing the first copper plating layer and the second copper foil layer after etching.

[0024] Figure 6 Is Figure 5 The cross-sectional view shown is of the second conductive line layer after a protective layer has been formed.

[0025] Figure 7 Is Figure 6 The cross-sectional view shown is of the first dielectric layer after the accommodating groove and recess are formed.

[0026] Figure 8 Is Figure 7 The diagram shows a cross-sectional view of the first copper pillar at its end away from the second copper pillar, the sidewalls of the first copper pillar, the sidewalls of the second copper pillar, and the sidewalls of the third copper pillar, with a first surface treatment layer formed thereon, and a second surface treatment layer formed on the solder pad.

[0027] Figure 9 Is Figure 8 The cross-sectional view shown is after the components are installed in the accommodating slot.

[0028] Figure 10 Is Figure 9 The diagram shows a cross-sectional view of the circuit board connection structure obtained after connecting the components to be connected to the first copper pillar.

[0029] Explanation of main component symbols

[0030] Circuit board connection structure 100

[0031] First substrate 10

[0032] First dielectric layer 101

[0033] First copper foil layer 102

[0034] Through hole 1011

[0035] First Bronze Pillar 11

[0036] Second Copper Pillar 12

[0037] Second substrate 20

[0038] Circuit board 30

[0039] First conductive circuit layer 301

[0040] Second dielectric layer 302

[0041] Second copper foil layer 303

[0042] First copper plating layer 304

[0043] Third Copper Pillar 31

[0044] Conductive part 32

[0045] Conductive component 33

[0046] Second conductive circuit layer 34

[0047] Protective layer 40

[0048] Receiving slot 41

[0049] Groove 42

[0050] First surface treatment layer 50

[0051] Second surface treatment layer 51

[0052] Components 60

[0053] First conductive paste 70

[0054] Second conductive paste 71

[0055] 80 parts to be connected

[0056] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0057] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0059] To further illustrate the technical means and effects adopted by this application in achieving its intended purpose, the following detailed description of this application is provided in conjunction with the accompanying drawings and preferred embodiments.

[0060] One embodiment of this application provides a method for manufacturing a circuit board connection structure with a high-length copper pillar, comprising the following steps:

[0061] Step S11, please refer to Figure 1 A first substrate 10 is provided.

[0062] In this embodiment, the first substrate 10 includes a first dielectric layer 101 and a first copper foil layer 102 located on the surface of the first dielectric layer 101.

[0063] The material of the first dielectric layer 101 can be selected from polymer materials such as polyimide (PI), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), and perfluoroalkoxy (PFA). In this embodiment, the material of the first dielectric layer 101 is a liquid crystal polymer.

[0064] A through-hole 1011 is formed in the first dielectric layer 101. The through-hole 1011 penetrates the first dielectric layer 101, and a portion of the first copper foil layer 102 is exposed through the through-hole 1011.

[0065] Step S12, please refer to Figure 2 A first copper pillar 11 is formed on the first copper foil layer 102, and a second copper pillar 12 is formed in the through hole 1011 to obtain the second substrate 20.

[0066] The first copper pillar 11 and the second copper pillar 12 are opposite to each other, and the first copper pillar 11 can be electrically connected to the second copper pillar 12 through the first copper foil layer 102. The end face of the second copper pillar 12 away from the first copper foil layer 102 is approximately flush with the surface of the first dielectric layer 101 away from the first copper foil layer 102.

[0067] In one embodiment, both the first copper pillar 11 and the second copper pillar 12 can be cylindrical, triangular prism, or pentagonal prism. In another embodiment, the end of the first copper pillar 11 furthest from the second copper pillar 12 can be flat-topped, arched, or dished.

[0068] In one embodiment, both the first copper pillar 11 and the second copper pillar 12 can be formed by electroplating or printing copper paste.

[0069] In this embodiment, the distance between the diameters of the two first copper pillars 11 is less than or equal to 3 μm, and the distance between the diameters of the two second copper pillars 12 is less than or equal to 3 μm.

[0070] Step S13, please refer to Figure 3 , and provide circuit board 30.

[0071] In this embodiment, the circuit board 30 includes a first conductive circuit layer 301, a second dielectric layer 302, a second copper foil layer 303, and a first copper plating layer 304, which are stacked sequentially.

[0072] The material of the second dielectric layer 302 may be the same as that of the first dielectric layer 101. For details, please refer to the material of the first dielectric layer 101, which will not be described in detail here.

[0073] A third copper pillar 31 is provided on the first conductive circuit layer 301. The third copper pillar 31 is electrically connected to the first conductive circuit layer 301. In one embodiment, the shape of the third copper pillar 31 may also be cylindrical, triangular prism, or pentagonal prism, etc.

[0074] In this embodiment, the distance between the diameters of the two third copper pillars 31 is less than or equal to 3 μm.

[0075] In this embodiment, the circuit board 30 is provided with a conductive portion 32. The conductive portion 32 may be made of copper.

[0076] Step S14, please refer to Figure 4 The second substrate 20 and the circuit substrate 30 are stacked together, and the second copper pillar 12 and the third copper pillar 31 are positioned opposite each other.

[0077] Step S15: Hot-press the second substrate 20 and the circuit substrate 30 to electrically connect the second copper pillar 12 and the third copper pillar 31.

[0078] Since the second copper pillar 12 and the third copper pillar 31 are electrically connected, the first copper pillar 11 is electrically connected to the third copper pillar 31, thereby making the first copper pillar 11 electrically connected to the first conductive circuit layer 301.

[0079] like Figure 4 As shown, the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 are coaxially arranged. The total height of the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 is greater than 50 μm. The diameters of the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 may be equal or unequal.

[0080] Step S16, please refer to Figure 5 The first copper foil layer 102 is etched to form a conductive element 33, and the conductive element 33 is positioned between the first copper pillar 11 and the second copper pillar 12. The first copper plating layer 304 and the second copper foil layer 303 are etched to form a second conductive line layer 34.

[0081] The first copper pillar 11 is electrically connected to the second copper pillar 12 via the conductive element 33. In this embodiment, the conductive element 33 is made of copper.

[0082] The conductive part 32 is used to electrically connect the first conductive line layer 301 and the second conductive line layer 34, so that the first copper pillar 11 is electrically connected to the second conductive line layer 34.

[0083] The second conductive line layer 34 can be formed by etching through exposure and development.

[0084] Step S17, please refer to Figure 6 A protective layer 40 is formed on the second conductive line layer 34.

[0085] The protective layer 40 is used to protect the second conductive circuit layer 34. In this embodiment, the protective layer 40 may be a cover film (CVL).

[0086] Step S18, please refer to Figure 7 A receiving groove 41 is formed in the first dielectric layer 101, and a groove 42 is formed on the periphery of the first dielectric layer 101 near the second copper pillar 12 and the third copper pillar 31.

[0087] In this embodiment, a portion of the first conductive line layer 301 is exposed in the receiving groove 41 to form a solder pad 43. In this embodiment, a portion of the first conductive line layer 301 is exposed in the recess 42.

[0088] In this embodiment, both the receiving groove 41 and the recess 42 can be formed by laser cutting or chemical etching.

[0089] Step S19, please refer to Figure 8 A first surface treatment layer 50 is formed on the end of the first copper pillar 11 away from the second copper pillar 12, the side wall of the first copper pillar 11, the side wall of the second copper pillar 12 and the side wall of the third copper pillar 31, and a second surface treatment layer 51 is formed on the solder pad 43.

[0090] In this embodiment, both the first surface treatment layer 50 and the second surface treatment layer 51 can be a gold layer, a nickel layer, or a tin layer. The gold layer can be formed by electroplating gold or electroless gold plating, the nickel layer can be formed by electroless nickel plating, and the tin layer can be formed by electroplating tin.

[0091] The first surface treatment layer 50 is used to prevent the oxidation of the first copper pillar 11, the second copper pillar 12 and the third copper pillar 31.

[0092] Step S20, please refer to Figure 9The component 60 is placed in the receiving groove 41 using the first conductive paste 70, and the component 60 is electrically connected to the solder pad 43.

[0093] Since the component 60 is electrically connected to the pad 43, the component 60 is electrically connected to the first conductive line layer 301, thereby making the component 60 electrically connected to the second conductive line layer 34.

[0094] In this embodiment, the component 60 may be a chip, capacitor, resistor, etc. In this embodiment, the first conductive paste 70 may be solder paste.

[0095] Step S21, please refer to Figure 10 The component to be connected 80 is electrically connected to the first copper pillar 11 through the second conductive paste 71, so that the component to be connected 80 is electrically connected to the second conductive circuit layer 34, thereby obtaining the circuit board connection structure 100.

[0096] Specifically, the component to be connected 80 is electrically connected to the first conductive circuit layer 301 through the second conductive paste 71, the first copper pillar 11, the second copper pillar 12 and the third copper pillar 31, and is then electrically connected to the second conductive circuit layer 34 through the conductive part 32.

[0097] In this embodiment, the second conductive paste 71 can also be solder paste. The groove 42 serves to prevent the second conductive paste 71 from overflowing when it melts.

[0098] In this embodiment, the component to be connected 80 may be a circuit board, motherboard, chip, capacitor, resistor, etc.

[0099] Please see Figure 10 An embodiment of this application also provides a circuit board connection structure 100 with a high-length copper pillar, including a component to be connected 80, a first dielectric layer 101, a first conductive line layer 301, a second dielectric layer 302, a second conductive line layer 34 and a protective layer 40 stacked in sequence.

[0100] The material of the first dielectric layer 101 can be selected from polymer materials such as polyimide (PI), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), and perfluoroalkoxy (PFA). In this embodiment, the material of the first dielectric layer 101 is a liquid crystal polymer.

[0101] The material of the second dielectric layer 302 may be the same as that of the first dielectric layer 101. For details, please refer to the material of the first dielectric layer 101, which will not be described in detail here.

[0102] The protective layer 40 is used to protect the second conductive circuit layer 34. In this embodiment, the protective layer 40 may be a cover film (CVL).

[0103] In this embodiment, the circuit board connection structure 100 includes a conductive portion 32. The conductive portion 32 may be made of copper. The conductive portion 32 is used to electrically connect the first conductive circuit layer 301 and the second conductive circuit layer 34.

[0104] In this embodiment, the component to be connected 80 may be a circuit board, motherboard, chip, capacitor, resistor, etc.

[0105] The circuit board connection structure 100 includes a first copper pillar 11, a conductive element 33, a second copper pillar 12, and a third copper pillar 31 that are coaxially connected in sequence. The first copper pillar 11, the conductive element 33, the second copper pillar 12, and the third copper pillar 31 are located between the component to be connected 80 and the first dielectric layer 101.

[0106] like Figure 10 As shown, in this embodiment, the distance between the diameters of the two first copper pillars 11, the distance between the diameters of the two second copper pillars 12, and the distance between the diameters of the two third copper pillars 31 are all less than or equal to 3μm.

[0107] In one embodiment, the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 can all be cylindrical, triangular prism, or pentagonal prism, etc. In one embodiment, the end of the first copper pillar 11 away from the second copper pillar 12 can be flat-topped, arched, or dished, etc.

[0108] The total height of the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 is greater than 50 μm. The diameters of the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 may be equal or unequal.

[0109] In this embodiment, the conductive element 33 is made of copper.

[0110] The component to be connected 80 is electrically connected to the first copper pillar 11 via the second conductive paste 71, thereby electrically connecting the component to be connected 80 to the second conductive circuit layer 34. Specifically, the component to be connected 80 is electrically connected to the first conductive circuit layer 301 via the second conductive paste 71, the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31, and is then electrically connected to the second conductive circuit layer 34 via the conductive portion 32. In this embodiment, the second conductive paste 71 may be solder paste.

[0111] A groove 42 is formed on the periphery of the first dielectric layer 101 adjacent to the second copper pillar 12 and the third copper pillar 31. In this embodiment, a portion of the first conductive line layer 301 is exposed in the groove 42. The third copper pillar 31 is also located within the groove 42. The groove 42 serves to prevent overflow when the second conductive paste 71 melts. A receiving groove 41 is also formed in the first dielectric layer 101, wherein a portion of the first conductive line layer 301 is exposed in the receiving groove 41 to form a solder pad 43.

[0112] The circuit board connection structure 100 further includes a first surface treatment layer 50 and a second surface treatment layer 51. In this embodiment, the first surface treatment layer 50 is located on the end of the first copper pillar 11 away from the second copper pillar 12, the sidewall of the first copper pillar 11, the sidewall of the second copper pillar 12, and the sidewall of the third copper pillar 31. The first surface treatment layer 50 is used to prevent oxidation of the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31. The second surface treatment layer 51 is located on the solder pad 43. In this embodiment, both the first surface treatment layer 50 and the second surface treatment layer 51 can be gold, nickel, or tin.

[0113] The circuit board connection structure 100 also includes a component 60. The component 60 is located in the receiving groove 41 via a first conductive paste 70, and is electrically connected to the solder pad 43. Because the component 60 is electrically connected to the solder pad 43, it is electrically connected to the first conductive circuit layer 301, thereby electrically connecting the component 60 to the second conductive circuit layer 34.

[0114] In this embodiment, the component 60 may be a chip, capacitor, resistor, etc. In this embodiment, the first conductive paste 70 may be solder paste.

[0115] This application separately manufactures the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31, and manufactures a high-length copper pillar by splicing the first copper pillar 11, the second copper pillar 12, and the third copper pillar 31 together, so as to reduce the problem of voids or gaps in the manufacturing process of the high-length copper pillar, thereby improving the homogeneity of the high-length copper pillar, and thus improving the stability of signal transmission between the component to be connected 80 and the second conductive circuit layer 34.

[0116] The above description is merely an optimized implementation of this application, but in actual applications, it should not be limited to this implementation.

Claims

1. A method for manufacturing a circuit board connection structure with high-length copper pillars, characterized in that, include: A first substrate is provided, the first substrate including a first dielectric layer and a first copper foil layer located on the surface of the first dielectric layer, and a through hole is formed in the first dielectric layer; A first copper pillar is formed on the first copper foil layer, and a second copper pillar is formed in the through hole, and the first copper pillar and the second copper pillar are positioned opposite each other to obtain a second substrate; A circuit board is provided, the circuit board comprising a first conductive circuit layer, a second dielectric layer, a second copper foil layer and a first copper plating layer stacked sequentially, and a third copper pillar is provided on the first conductive circuit layer. The second substrate and the circuit substrate are stacked together, and the second copper pillar and the third copper pillar are opposite to each other; The second substrate and the circuit substrate are hot-pressed to electrically connect the second copper pillar and the third copper pillar; The first copper foil layer is etched to form a conductive element, and the conductive element is located between the first copper pillar and the second copper pillar; the first copper plating layer and the second copper foil layer are etched to form a second conductive circuit layer. An accommodating groove is formed in the first dielectric layer, and a portion of the first conductive line layer is exposed in the accommodating groove to form a solder pad; The components are placed in the receiving groove using a first conductive paste, and the components are electrically connected to the solder pads; and The component to be connected is electrically connected to the first copper pillar using a second conductive paste, thereby electrically connecting the component to be connected to the first conductive circuit layer, thus obtaining the circuit board connection structure.

2. The method for manufacturing the circuit board connection structure as described in claim 1, characterized in that, After forming the second conductive line layer, the fabrication method further includes: A groove is formed at the periphery of the first dielectric layer near the second copper pillar and the third copper pillar.

3. The method for manufacturing the circuit board connection structure as described in claim 2, characterized in that, After creating the groove, the manufacturing method further includes: A first surface treatment layer is formed on the end of the first copper pillar away from the second copper pillar, the sidewall of the first copper pillar, the sidewall of the second copper pillar, and the sidewall of the third copper pillar. The second conductive paste is electrically connected to the first copper pillar through the first surface treatment layer.

4. The method for manufacturing the circuit board connection structure as described in claim 1, characterized in that, The component to be connected is a motherboard or circuit board.

5. The method for manufacturing the circuit board connection structure as described in claim 1, characterized in that, The total height of the first copper pillar, the second copper pillar, and the third copper pillar is greater than 50 μm.

6. A circuit board connection structure with high-length copper pillars, characterized in that, It includes the component to be connected, a first dielectric layer, a first conductive line layer, a second dielectric layer, and a second conductive line layer, which are stacked in sequence. The circuit board connection structure includes a first copper pillar, a conductive element, a second copper pillar, and a third copper pillar that are coaxially connected in sequence. The first copper pillar, the conductive element, the second copper pillar, and the third copper pillar are located between the component to be connected and the first dielectric layer. The component to be connected is electrically connected to the first copper pillar through a second conductive paste, so that the component to be connected is electrically connected to the first conductive circuit layer. The circuit board connection structure further includes components. A receiving groove is formed in the first dielectric layer, and a portion of the first conductive circuit layer is exposed in the receiving groove to form a solder pad. The components are disposed in the receiving groove by a first conductive paste, and the components are electrically connected to the solder pad.

7. The circuit board connection structure as described in claim 6, characterized in that, The first dielectric layer has a groove around the periphery of the second copper pillar and the third copper pillar, and the third copper pillar is located in the groove.

8. The circuit board connection structure as described in claim 7, characterized in that, Also includes: A first surface treatment layer is located on the end of the first copper pillar away from the second copper pillar, the side wall of the first copper pillar, the side wall of the second copper pillar, and the side wall of the third copper pillar. The second conductive paste is electrically connected to the first copper pillar through the first surface treatment layer.

9. The circuit board connection structure as described in claim 6, characterized in that, The component to be connected is a motherboard or circuit board.

10. The circuit board connection structure as described in claim 6, characterized in that, The total height of the first copper pillar, the second copper pillar, and the third copper pillar is greater than 50 μm.

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