Circuit board structure

Abstract

A circuit board structure includes a first insulating layer, a first metal layer, a second insulating layer, a second metal layer, a third insulating layer, and a first metal cap. The first insulating layer has a first through-hole. The first metal layer is located on the wall surface of the first through-hole and the surface of the first insulating layer. A second insulating layer fills the first through-hole and has a second through-hole. The second metal layer is located on the wall surface of the second through-hole. The third insulating layer fills the second through-hole and includes a first recess, exposing a portion of the second metal layer. The first metal cap is located in the first recess and connected to the second metal layer. The top of the first metal cap is either lower than or flush with the surface of the first metal layer of the first insulating layer.

Description

Technical Field

[0001] This utility model relates to the field of circuit boards, and specifically to a circuit carrier board structure. Background Technology

[0002] In recent years, with the increasing demand for chips, chip packaging and assembly technologies have also been improved accordingly.

[0003] As chips shrink and their size decreases, the number of chips that can be carried per unit on a circuit board increases. This also means that the circuit board needs denser circuitry to accommodate the chips. Current technology allows for the provision of double-layered circuitry on the circuit board through drilling or redistribution techniques. Utility Model Content

[0004] To accommodate future denser circuitry, a circuit board structure is provided. In some embodiments, the circuit board structure includes a first insulating layer, a first metal layer, a second insulating layer, a second metal layer, a third insulating layer, and a first metal cap. The first insulating layer has a first through-hole penetrating through it. The first metal layer is located on the wall of the first through-hole and on the surface of the first insulating layer. A second insulating layer fills the first through-hole and has a second through-hole penetrating through it. The second metal layer is located on the wall of the second through-hole. The third insulating layer fills the second through-hole and includes a first recess exposing a portion of the second metal layer. The first metal cap is located in the first recess and connected to the second metal layer. The top of the first metal cap is either lower than or flush with the surface of the first metal layer of the first insulating layer.

[0005] In some embodiments, the first metal layer is located on the wall of the first through hole and the upper and lower surfaces of the first insulating layer, and the first metal cap is located on the same side as the upper surface of the first insulating layer.

[0006] Furthermore, in some embodiments, the circuit board structure further includes a second metal cover, and the third insulating layer further includes a second recess. The second recess and the first recess are respectively located on opposite sides of the third insulating layer, the second metal cover is connected to the second metal layer, and the second metal cover and the lower surface of the first insulating layer are located on the same side.

[0007] Furthermore, in some embodiments, the surface of the second metal cover is at a height higher than or level with the first metal layer on the lower surface.

[0008] In some embodiments, the wall surface of the first through hole and the surface of the first insulating layer are rough surfaces.

[0009] In some embodiments, a circuit board structure is also provided. The circuit board structure includes a first insulating layer, a first metal layer, a second insulating layer, and a first metal cap. The first insulating layer has a first through-hole that penetrates the first insulating layer. The first metal layer is located on the wall of the first through-hole. The second insulating layer fills the first through-hole and has a first recess that exposes a portion of the first metal layer. The first metal cap is located in the first recess and is connected to the first metal layer. The top of the first metal cap is at a height lower than or flush with the surface of the first insulating layer.

[0010] In some embodiments, the first insulating layer has an upper surface and a lower surface, and the first metal cap is located on the same side as the upper surface of the first insulating layer.

[0011] Furthermore, in some embodiments, the circuit board structure further includes a second metal cover, and the second insulating layer further includes a second recess, the second recess and the first recess being located on opposite sides of the second insulating layer, and the second metal cover and the lower surface of the first insulating layer being located on the same side.

[0012] Furthermore, in some embodiments, the bottom surface of the second metal cover is at a higher level than the lower surface, or is at the same level as the lower surface.

[0013] In some embodiments, the wall surface of the first through hole is a rough surface.

[0014] As described in the previous embodiments, by placing the first metal cap in the through hole instead of the traditional solder pad that protrudes from the first insulating layer, the allowable tolerance can be reduced, the pitch of the circuit can be further reduced, the overall circuit density can be increased, and the number of chips mounted per unit area can be increased. Attached Figure Description

[0015] Figure 1 This is a partial cross-sectional view of the first embodiment of the circuit board structure;

[0016] Figure 2 This is a partial cross-sectional view of the second embodiment of the circuit board structure;

[0017] Figure 3 This is a partial cross-sectional view of the third embodiment of the circuit board structure;

[0018] Figure 4 This is a partial cross-sectional view of the fourth embodiment of the circuit board structure;

[0019] Figure 5 This is a partial cross-sectional view of the fifth embodiment of the circuit board structure;

[0020] Figure 6 This is a partial cross-sectional view of the sixth embodiment of the circuit board structure;

[0021] Figure 7 This is a partial cross-sectional view of the seventh embodiment of the circuit board structure;

[0022] Figure 8 This is a partial cross-sectional view of the eighth embodiment of the circuit board structure;

[0023] Figure 9 A cross-sectional view of an embodiment of the circuit board structure in practical application;

[0024] Figure 10 This is a cross-sectional view of another embodiment of the circuit board structure in practical application.

[0025] [Symbol Explanation]

[0026] 1: Circuit board structure

[0027] 10: First insulating layer

[0028] 10A: Top surface

[0029] 10B: Lower surface

[0030] 11: First through hole

[0031] 111:Wall

[0032] 20: First metal layer

[0033] 30: Second insulating layer

[0034] 30A: First surface

[0035] 30B: Second surface

[0036] 31: Second through hole

[0037] 311:Wall

[0038] 35: First concave part

[0039] 37:Second recess

[0040] 40: Second metal layer

[0041] 50: Third insulation layer

[0042] 51: First concave part

[0043] 53:Second recess

[0044] 61: First Metal Cap

[0045] 63: Second metal cap

[0046] 631: Bottom surface

[0047] 500: Additional Insulation Layer

[0048] 510: Opening

[0049] 600: Circuit Pattern Layer

[0050] 610: Metal Column

[0051] H1: Height of the first metal layer on the upper surface of the first insulating layer

[0052] H2: Horizontal height of the top of the first metal cap

[0053] H3: Horizontal height of the bottom surface of the second metal cover

[0054] H4: Height of the upper surface of the first insulating layer

[0055] H5: Horizontal height of the top of the first metal cap

[0056] H6: Horizontal height of the bottom surface of the second metal cover Detailed Implementation

[0057] Figure 1 This is a partial cross-sectional view of the first embodiment of the circuit board structure. Figure 2 This is a partial cross-sectional view of the second embodiment of the circuit board structure. (See attached image.) Figure 1 As shown, the circuit board structure 1 includes a first insulating layer 10, a first metal layer 20, a second insulating layer 30, a second metal layer 40, a third insulating layer 50, and a first metal cover 61. The first insulating layer 10 has a first through hole 11, which penetrates the upper surface 10A and the lower surface 10B of the first insulating layer 10. Here, the first insulating layer 10 can be a ceramic substrate, a glass substrate, a glass fiber substrate, a phenolic resin substrate, or it can be an insulating resin layer or a solder resist layer used for circuit redistribution.

[0058] The first metal layer 20 is located on the wall 111 of the first through hole 11 and on the upper surface 10A and lower surface 10B of the first insulating layer 10. The second insulating layer 30 fills the first through hole 11 and has a second through hole 31 that penetrates the first surface 30A and the second surface 30B of the second insulating layer 30. Here, the first surface 30A is substantially coplanar with the upper surface 10A, and the second surface 30B is substantially coplanar with the lower surface 10B. "Substantially" here means within tolerance range.

[0059] The second metal layer 40 is located on the wall 311 of the second through hole 31. The third insulating layer 50 is filled into the second through hole 31, and the third insulating layer 50 includes a first recess 51, exposing a portion of the second metal layer 40. The first metal cap 61 is located in the first recess 51 and is connected to the second metal layer 40. Here, the second insulating layer 30 and the third insulating layer 50 can be made of the same material. They can be formed by first creating a through hole, then plating the second metal layer 40, and finally filling the hole. Alternatively, they can be formed by annular groove cutting, creating an annular groove in the outer shape of the third insulating layer 50, then plating metal to directly form the second metal layer 40 and the first metal cap 61.

[0060] In the first embodiment, the horizontal height H2 of the top of the first metal cover 61 is flush with the height H1 of the first metal layer 20 on the upper surface 10A of the first insulating layer 10. In the second embodiment, the horizontal height H2 of the top of the first metal cover 61 is slightly lower than the height H1 of the first metal layer 20 on the upper surface 10A of the first insulating layer 10. In both the first and second embodiments, the first metal cover 61 and the upper surface 10A of the first insulating layer 10 are located on the same side, and the reference plane for its height is the bottom end of the first metal layer 20 on the lower surface 10B of the first insulating layer 10.

[0061] In other words, the first metal cover 61 can be slightly recessed or flush with the surface of the first insulating layer 10, and is not connected to the first metal layer 20. It is actually used as a solder pad for the circuit layer. Thus, in overall manufacturing, only the tolerances of the first vias 11 and the pitch tolerances between the first vias 11 need to be considered. Without needing to consider the tolerances of the solder pads and the pitch tolerances, the pitch can be further reduced, increasing the circuit density per unit area, which is more conducive to next-generation chip packaging.

[0062] Furthermore, the wall surface 111 of the first through hole 11 and the upper surface 10A and lower surface 10B of the first insulating layer 10 are rough surfaces, which helps the first metal layer 20 to adhere.

[0063] Figure 3 This is a partial cross-sectional view of the third embodiment of the circuit board structure. Figure 4 This is a partial cross-sectional view of the fourth embodiment of the circuit board structure. (See attached image.) Figure 3 and Figure 4 As shown, unlike the first embodiment, the circuit board structure 1 also includes a second metal cover 63. The third insulating layer 50 also includes a second recess 53, which is located on opposite sides of the third insulating layer 50, and the second metal cover 63 is connected to the second metal layer 40. The second metal cover 63 and the lower surface 10B of the first insulating layer 10 are located on the same side.

[0064] For more details, see [link to relevant documentation]. Figure 3 and Figure 4 ,like Figure 3 As shown, the horizontal height H3 of the bottom surface 631 of the second metal cover 63 is flush with the height of the first metal layer 20 on the lower surface 10B. And as... Figure 4 As shown, the horizontal height H3 of the bottom surface 631 of the second metal cover 63 is above the first metal layer 20 on the lower surface 10B. Here, the height is taken as the horizontal reference plane by the first metal layer 20 located on the lower surface 10B. Figure 3 and Figure 4 The structure is more compatible with Figure 1 or Figure 2 The implementation method is adjusted to meet actual specification requirements.

[0065] Figure 5 This is a partial cross-sectional view of the fifth embodiment of the circuit board structure. Figure 6 This is a partial cross-sectional view of the sixth embodiment of the circuit board structure. (See attached image.) Figure 5 and Figure 6 As shown, the circuit board structure 1 includes a first insulating layer 10, a first metal layer 20, a second insulating layer 30, and a first metal cover 61. The first insulating layer 10 has a first through-hole 11 that extends from its upper surface 10A to its lower surface 10B. The first metal layer 20 is located on the wall surface 111 of the first through-hole 11. The second insulating layer 30 fills the first through-hole 11 and has a first recess 35 that exposes a portion of the first metal layer 20. The first metal cover 61 is located in the first recess 35 and is connected to the first metal layer 20.

[0066] like Figure 5 As shown, the horizontal height H5 of the top of the first metal cover 61 is flush with the height H4 of the upper surface 10A of the first insulating layer 10. And as... Figure 6 As shown, the horizontal height H5 of the top of the first metal cover 61 is lower than the upper surface 10A of the first insulating layer 10. The structure provided in the third embodiment allows the circuit board structure 1 to be configured according to holes of different sizes. In this embodiment, the first metal cover 61 and the upper surface 10A of the first insulating layer 10 are located on the same side, and the height reference is based on the lower surface 10B of the first insulating layer 10.

[0067] In this embodiment and the sixth embodiment, the wall surface 111 of the first through hole 11 can also be a rough surface to increase the adhesion of the first metal layer 20. However, for electrical considerations, in the implementation of the structure of the fifth embodiment, the upper surface 10A of the first insulating layer 10 adjacent to the periphery of the first through hole 11 is usually removed.

[0068] Figure 7 This is a partial cross-sectional view of the seventh embodiment of the circuit board structure. Figure 8This is a partial cross-sectional view of the eighth embodiment of the circuit board structure. (See attached image.) Figure 7 and Figure 8 As shown, the circuit board structure 1 also includes a second metal cover 63, and the second insulating layer 30 also includes a second recess 37. The second recess 37 and the first recess 35 are located on opposite sides of the second insulating layer 30, and the second metal cover 63 and the lower surface 10B of the first insulating layer 10 are located on the same side.

[0069] Furthermore, referring to Figure 7 and Figure 8 ,like Figure 7 As shown, in some embodiments, the horizontal height H6 of the bottom surface 631 of the second metal cover 63 is flush with the height of the lower surface 10B. And as... Figure 8 As shown, the horizontal height H6 of the bottom surface 631 of the second metal cover 63 is higher than the lower surface 10B. Here, the height is taken as the horizontal reference plane with the lower surface 10B of the first insulating layer 10 as the reference plane.

[0070] Figure 9 This is a cross-sectional view of an embodiment of the circuit board structure in practical application. Figure 10 This is a cross-sectional view of another embodiment of the circuit board structure in practical application. (See diagram below.) Figure 9 As shown, Figure 9 To apply the third embodiment and perform a practical circuit layout thereon, additional layers can be added at both ends. Openings 510 are provided on the added insulating layer 500, which correspond to the first metal cover 61 and the second metal cover 63 respectively. During electroplating and circuit image transfer, a circuit pattern layer 600 is formed on the added insulating layer 500, and the circuit pattern layer 600 includes metal pillars 610 connected to the first metal cover 61 and the second metal cover 63.

[0071] like Figure 10 The diagram shows the practical application of the seventh embodiment, on which a circuit layout is performed. No additional layers are added here; instead, influence transfer is performed directly. Circuit pattern layers 600 are directly formed on the upper surface 10A and lower surface 10B of the first insulating layer 10. Here, the first metal cover 61, the second metal cover 63, and the second metal layer 40 directly serve as electrical connection channels connecting the upper and lower circuit pattern layers 600.

[0072] In summary, by placing the first metal cover 61 in the first through hole 11 or the second through hole 31, replacing the traditional solder pads that protrude from the first insulating layer 10, the reserved tolerances can be reduced, the pitch of the circuit can be further reduced, the overall circuit density can be increased, and the number of chips mounted per unit area can be increased.

[0073] Although the technical content of this utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit this utility model. Any modifications and refinements made by those skilled in the art without departing from the spirit of this utility model should be included within the scope of this utility model. Therefore, the scope of protection of this utility model shall be determined by the scope defined in the appended claims.

Claims

1. A circuit board structure, characterized in that, Include: A first insulating layer has a first through hole that penetrates the first insulating layer; A first metal layer is located on the wall of the first through hole and the surface of the first insulating layer; A second insulating layer is filled into the first through hole, and the second insulating layer has a second through hole that penetrates the second insulating layer; A second metal layer is located on the wall of the second through hole; A third insulating layer is filled into the second through hole, and the third insulating layer includes a first recess that exposes a portion of the second metal layer; as well as A first metal cap is located in the first recess and connected to the second metal layer. The top of the first metal cap is at a horizontal height lower than or level with the surface of the first metal layer of the first insulating layer.

2. The circuit board structure as described in claim 1, characterized in that, The first metal layer is located on the wall of the first through hole and on an upper and lower surface of the first insulating layer, and the first metal cap is located on the same side as the upper surface of the first insulating layer.

3. The circuit board structure as described in claim 2, characterized in that, It also includes a second metal cap, and the third insulating layer further includes a second recess, the second recess and the first recess being located on opposite sides of the third insulating layer, the second metal cap being connected to the second metal layer, and the second metal cap and the lower surface of the first insulating layer being on the same side.

4. The circuit board structure as described in claim 3, characterized in that, The surface of the second metal cover is at a height higher than or level with the first metal layer on the lower surface.

5. The circuit board structure as described in claim 1, characterized in that, The wall of the first through hole and the surface of the first insulating layer are rough surfaces.

6. A circuit board structure, characterized in that, Include: A first insulating layer has a first through hole that penetrates the first insulating layer; A first metal layer is located on the wall of the first through hole; A second insulating layer is filled into the first through hole, and the second insulating layer has a first recess that exposes a portion of the first metal layer; as well as A first metal cap is located in the first recess and connected to the first metal layer. The top of the first metal cap is at a height lower than or level with the surface of the first insulating layer.

7. The circuit board structure as described in claim 6, characterized in that, The first insulating layer has an upper surface and a lower surface, and the first metal cap is located on the same side as the upper surface of the first insulating layer.

8. The circuit board structure as described in claim 7, characterized in that, It also includes a second metal cover, and the second insulating layer further includes a second recess, which and the first recess are respectively located on opposite sides of the second insulating layer, and the second metal cover and the lower surface of the first insulating layer are located on the same side.

9. The circuit board structure as described in claim 8, characterized in that, The bottom surface of the second metal cover is at a height higher than or level with the lower surface.

10. The circuit board structure as described in claim 6, characterized in that, The wall of the first through hole has a rough surface.

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