Printed circuit board with embedded smd devices

Abstract

This invention discloses a printed circuit board with embedded SMD devices. A printed circuit board (PCB) assembly is also disclosed. The PCB assembly may include a PCB body and a set of through holes disposed within the PCB body. The PCB assembly may further include a set of devices respectively disposed within the set of through holes.

Description

Technical Field

[0001] The embodiments relate to the field of surface mount device technology, and more particularly to printed circuit boards having surface mount devices. Background Technology

[0002] Printed circuit boards (PCBs) typically house electrical components that can be mounted onto them. A common arrangement is called surface mount technology (SMT), where electrical components are placed directly on the surface of the PCB. These devices are often called surface mount devices (SMDs) and can include capacitors, resistors, inductors, diodes, ESD protection devices, semiconductors, or other components. Compared to older through-hole technologies, SMT offers advantages such as smaller components and higher component density.

[0003] PCBs can be found in many electronic or electrical devices, including portable electronic devices, where space considerations dictate efficient PCB design. In view of the above, this embodiment of the present disclosure is provided. Summary of the Invention

[0004] In one embodiment, a printed circuit board (PCB) assembly is provided. The PCB assembly may include a PCB body, a set of through holes disposed within the PCB body, and a set of devices disposed within the set of through holes.

[0005] In another embodiment, a printed circuit board (PCB) assembly is provided. The PCB assembly may include a PCB body comprising a plurality of substrate layers formed of an insulating material. The PCB assembly may further include a plurality of embedded conductive layers arranged alternately between the plurality of substrate layers; and a plurality of device vias disposed within the PCB body, wherein each device via includes a device disposed therein. Attached Figure Description

[0006] Figure 1A A side cross-sectional view of a PCB assembly according to an embodiment of the present disclosure is depicted;

[0007] Figure 1B Depicting Figure 1A Top plan view of the PCB assembly;

[0008] Figure 1C A side cross-sectional view of the reference PCB assembly is depicted;

[0009] Figure 1D Depicting Figure 1C Top plan view of the reference PCB assembly;

[0010] Figure 2AA side cross-sectional view of a PCB assembly according to other embodiments of the present disclosure is depicted; and

[0011] Figure 2B Depicting Figure 2A Top plan view of the PCB components. Detailed Implementation

[0012] This embodiment will now be described more fully below with reference to the accompanying drawings, in which exemplary embodiments are illustrated. The embodiments are not to be construed as limiting oneself to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be exhaustive and complete, and will fully convey its scope to those skilled in the art. In the drawings, similar numerals consistently refer to similar elements.

[0013] In the following description and / or claims, the terms “on,” “covering on,” “set on,” and “above” may be used in the following description and claims. “On,” “covering on,” “set on,” and “above” may be used to indicate that two or more elements are in direct physical contact with each other. Furthermore, the terms “on,” “covering on,” “set on,” and “above” may mean that two or more elements are not in direct contact with each other. For example, “above” may mean that one element is on top of another element without contacting each other, and there may be one or more other elements between the two elements. Additionally, the term “and / or” may mean “and,” it may mean “or,” it may mean “exclusive,” it may mean “one,” it may mean “some, but not all,” it may mean “neither,” and / or it may mean “both,” although the scope of the claimed subject matter is not limited in this respect.

[0014] As described below, this embodiment provides a novel PCB layout in which devices such as conventional surface mount devices (SMDs) are included within the PCB. By including the SMDs within the PCB, the overall height of the PCB assembly including the SMDs is reduced compared to known PCB layouts.

[0015] Figure 1A A side cross-sectional view of a PCB assembly 100 according to an embodiment of the present disclosure is depicted. Figure 1B Depicting Figure 1A Top plan view of PCB assembly 100.

[0016] PCB assembly 100 includes PCB body 102. PCB body 102 may include at least one substrate layer, as shown in substrate layer 104, typically formed of a known electrically insulating material (such as a mixture of polymer resin and glass, ceramic material, etc.).

[0017] In embodiments having multiple substrate layers 104, the different substrate layers 104 may be formed of the same insulating material, or the composition and / or materials of the different substrate layers 104 may differ between the different substrate layers 104. In a non-limiting example, the PCB body 102 may include four substrate layers 104, such as... Figure 1A What is depicted.

[0018] The PCB body 102 may also include one or more embedded conductor layers, shown as embedded layers 106, arranged planarly between adjacent substrate layers in the substrate layer 104. Embedded layers 106 may be patterned. For example, embedded layers 106 may be formed from copper foil, which may be unpatterned.

[0019] In one example, the PCB body 102 can be formed by creating multiple layers (corresponding to substrate layer 104) of epoxy-injected fiberglass board (referred to as prepreg) and alternatingly placing conductive material (such as a metal plate) corresponding to the embedded layer 106 between adjacent prepreg layers. This multilayer stack of alternating layers of substrate layer 104 and embedded layer 106 can then be subjected to high temperature and high pressure to form the PCB body 102 in a cured state. Such manufacturing processes are well known in the art and will not be described in detail herein.

[0020] In a non-limiting example where the PCB body comprises four substrate layers 104, the total thickness of the PCB body 102 may be 1 mm. In this embodiment, the PCB assembly 100 may include any suitable number of devices, which will be collectively referred to herein as SMDs.

[0021] Figure 1A and Figure 1B This embodiment illustrates a configuration in which the PCB body 102 includes a plurality of recesses or holes (which will be referred to as through holes). These through holes act as device vias, meaning that through holes are used to house devices within a given through hole. For simplicity, only through holes 110 and 120 are shown. However, it will be understood that the PCB body 102 may include several or many through holes. Note that through holes such as through holes 110 and 120 may be formed to a specific depth within the PCB body 102 and are not necessarily through holes.

[0022] exist Figure 1A In the embodiments described herein, for the sake of simplicity, vias 110 and 120 are formed with a via depth d from the top surface of the PCB body 102, wherein the via depth is approximately equal to the thickness of the three substrate layers 104 (and includes the thickness of the three embedded layers 106).

[0023] like Figure 1A As shown, a first SMD (referred to as device 112) is disposed within a first via (meaning via 110), while a second device (referred to as device 122) is disposed within a second via (meaning via 120). For example, device 112 could represent a capacitor. Figure 1A In this arrangement, device 112 may have electrodes arranged in a planar configuration and extending parallel to the plane of substrate layer 104. In this configuration, top electrode 114A is arranged to be electrically connected to surface trace 108, while bottom electrode 114B may be connected to embedded layer 106A, such as a copper sheet.

[0024] In various embodiments, device 114 may represent any other suitable device, such as a bare semiconductor die or a molded device. For simplicity, in this configuration, top electrode 124A is disposed on one side of device 122 and is arranged to be electrically connected to surface trace 108, while bottom electrode 124B disposed on the same side of device 122 may be connected to embedded layer 106A.

[0025] exist Figure 1B In one embodiment, through holes 110 and 120 may have a circular cross-section in a top plan view. In other embodiments, the through holes may have different shapes in a plan view. The circular shape of through holes 110 and 120 may be achieved, for example, using known drilling techniques.

[0026] It should be noted that, Figure 1A In this configuration, devices 112 and 122 are embedded within the PCB body 102, meaning that at least a majority of devices 112 and 122 do not extend above the top surface of the PCB body 102. Therefore, a characteristic of the PCB assembly 100 is that the overall height of the PCB is relatively smaller than in known PCB configurations. This overall height is shown as height h, which includes the distance from the lower surface of the PCB body 102 to the highest point of the devices contained within the PCB assembly 100. In a non-limiting example, height h can be equal to the thickness t of the PCB body 102, meaning that no device extends above the upper surface of the PCB body 102. Therefore, in an embodiment where t = 1 mm, h will also be equal to 1 mm. Figure 1A In the illustration, the top electrode 114A and / or the bottom electrode 114B may extend very slightly above the top surface of the PCB body 102, such as by a maximum of tens of micrometers. Therefore, in a non-limiting example, for illustrative purposes only, the thickness t may be equal to 1.00 mm and the height h may be equal to 1.04 mm.

[0027] Figure 1AOne advantage of this embodiment is that the PCB assembly 100 can accommodate multiple SMD devices while maintaining a relatively low overall assembly thickness. To explain this advantage, Figure 1C and Figure 1D The reference PCB assembly is shown in the figure. Figure 1C A side cross-sectional view of the reference PCB assembly 150 is depicted, while Figure 1D Depicting Figure 1C The above is a top plan view of the reference PCB assembly 150. Note that the reference PCB assembly 150 is depicted for illustrative purposes and may not represent any known PCB assembly.

[0028] exist Figure 1C In the example, the layer structure of the PCB body 152 can typically be formed as described above with respect to the PCB body 102, wherein similar components are similarly labeled. However, in this example, the PCB body 152 does not include... Figure 1A and Figure 1B The embodiments shown do not include any device vias. Instead, devices 162 and 172 are disposed on the top surface of the PCB body 152. Device 162 may be, for example, a capacitor or a resistor. Device 162 may be electrically connected to the top trace 158, such as through electrode 164 and solder 166, as shown. Similarly, device 172 may be a bare semiconductor die or a molded device, similar to device 122. Device 172 may also be electrically connected to the top trace 158 using a connector 174, such as solder.

[0029] For comparison purposes, it can be assumed that devices 162 and 172 together perform the same function as devices 112 and 122. Therefore, in operation, reference PCB assembly 150 can perform similarly (but not necessarily identically) to PCB assembly 100. However, in one example, devices 162 and / or 172, disposed on the top surface of PCB body 152, can extend a distance l above the top surface of PCB body 152. Therefore, the total height of reference PCB assembly 150 is denoted as H. In some real-world examples, the distance l representing the height of device 162 or device 172 can be approximately 0.3 mm. Therefore, in an example where the thickness t of PCB body 152 is 1 mm, the height H of reference PCB assembly 150 can be 1.3 mm. In contrast, the height of PCB assembly 100, which provides the same function as reference PCB assembly 150, can be only 1.0 mm. In other words, the height of reference PCB assembly 150 in this example is 30% greater than the height of PCB assembly 100.

[0030] Figure 1A and Figure 1B Another advantage of this configuration is that it is compatible with... Figure 1CCompared to the previous configuration, this can reduce the surface area of ​​the PCB body. For example, assuming that device 122 and device 172 are identical devices with dimensions of 0.6mm × 0.3mm along two different directions, Figure 1A The vertical arrangement of device 122 results in a planar layout area of ​​only 0.3mm × 0.3mm (e.g. Figure 1B (As shown). On the other hand, Figure 1C The horizontal arrangement of device 172 presents a planar layout area of ​​0.3mm × 0.6mm. Figure 1D ), or for Figure 1A Twice the area of ​​the embodiment (see Figure 1D (The dashed lines in the text are used for comparison).

[0031] Figure 2A A side cross-sectional view of a PCB assembly 200 according to an embodiment of the present disclosure is depicted. Figure 2B Depicting Figure 2A Top plan view of PCB assembly 200.

[0032] PCB assembly 200 includes PCB body 202. Similar to PCB body 102, PCB body 202 may include at least one substrate layer, shown as substrate layer 104, as discussed above. PCB body 202 may also include one or more embedded conductor layers, shown as embedded layer 106, as discussed above.

[0033] In a non-limiting example where the PCB body 202 includes four substrate layers 104, the total thickness of the PCB body 202 may also be 1 mm. In this embodiment, the PCB assembly 200 may include any suitable number of devices, which will be collectively referred to herein as SMDs.

[0034] Figure 2A and Figure 2B This embodiment illustrates a configuration in which the PCB body 202 includes a plurality of recesses or holes (which will be referred to as through holes). These through holes act as device vias, as described above. For simplicity, only through holes 210 and 220 are shown. However, it will be understood that the PCB body 202 may include several or many through holes. Note that through holes such as through holes 210 and 220 may be formed to a specific depth within the PCB body 202 and are not necessarily through holes.

[0035] exist Figure 2A In the embodiments described herein, for the sake of simplicity, vias 210 and 220 are formed with a via depth d2 from the top surface of the PCB body 202, wherein the via depth is approximately equal to the thickness of the two substrate layers 104 (and includes the thickness of the two embedded layers 106).

[0036] like Figure 2A As shown, a first SMD (referred to as device 212) is disposed within a first via (meaning via 210), while a second device (referred to as device 222) is disposed within a second via (meaning via 220). For example, device 212 could represent a capacitor. Figure 1A In this arrangement, device 212 may have electrodes arranged in a vertical configuration and extending in a plane perpendicular to substrate layer 104. In this configuration, first electrode 214A and second electrode 214B are respectively arranged to be electrically connected (e.g., by means of solder 216) to embedding layers 106B and 106C, such as copper sheets.

[0037] In various embodiments, device 222 may represent any other suitable device, such as a bare semiconductor die or a molded device. For simplicity, in this configuration, the first lower electrode 224A and the second lower electrode 224B (collectively referred to as electrode 224) are arranged to also be connected to the embedding layer 106C and the embedding layer 106A, respectively.

[0038] exist Figure 2B In one embodiment, through holes 210 and 220 may have rectangular cross-sections in a top plan view. In other embodiments, the through holes may have different shapes in a plan view.

[0039] As Figure 1A In this configuration, devices 212 and 222 are embedded within the PCB body 152, meaning that at least a majority of devices 212 and 222 do not extend above the top surface of the PCB body 152. This overall height is also referred to as height h, which includes the distance from the lower surface of the PCB body 152 to the highest point of the devices contained in the PCB assembly 150 or the top surface of the PCB body 102. In a non-limiting example, height h can be equal to the thickness t of the PCB body 152, meaning that no device extends above the upper surface of the PCB body 152. Therefore, in an embodiment where t = 1 mm, h will also be equal to 1 mm. Figure 2A In the illustration, devices 212 and 222 can be arranged in vias 210 and 220 such that these devices do not extend above the upper surface of the PCB body 152. Therefore, in a non-limiting example, for illustrative purposes only, the thickness t can be equal to 1.00 mm and the height h can also be equal to 1.00 mm.

[0040] Figure 2A and Figure 2BThe advantage of this configuration is that the corresponding vias (via 210 and via 220) can be arranged with a sufficiently large area in the top plan view to accommodate devices 212 and 222, respectively, as shown. Specifically, the longer dimension of device 212, extending between the first electrode 214A and the second electrode 214B, lies parallel to the plane of substrate 104, while the shorter dimension of device 212 extends perpendicular to the plane of substrate 104. Similarly, the longer dimension of device 222 lies parallel to the plane of substrate 104, while the shorter dimension of device 222 extends perpendicular to the plane of substrate 104. This geometry means that vias 210 and 220 can be moved to a shallower depth compared to the depth of vias 110 or 120. The disadvantage is that vias 210 and 220 may have a larger cross-sectional area and may need to be manufactured in a rectangular shape in the top plan view to accommodate devices 212 and 222, respectively.

[0041] In other embodiments of this disclosure, the PCB assembly may be provided with a plurality of through-holes, wherein the depths of the through-holes may differ from one another. Thus, a first through-hole may extend through three layers of the PCB body, while a second through-hole extends through only two layers of the PCB body. Furthermore, the shapes of the through-holes within the PCB body may differ between the different through-holes, wherein the first through-hole presents a rectangular shape in a top plan view, while the second through-hole presents a circular shape.

[0042] While this embodiment has been disclosed with reference to certain embodiments, many modifications, alterations, and changes are possible to the described embodiments without departing from the field and scope of this disclosure as defined in the appended claims. Therefore, this embodiment is not limited to the described embodiments and may have the full scope defined by the language of the following claims and their equivalents.

Claims

1. A printed circuit board (PCB) assembly, comprising: PCB body; A set of through holes, the set of through holes being disposed within the PCB body; as well as A set of devices, wherein the set of devices are respectively disposed in the set of through holes.

2. The PCB assembly according to claim 1, wherein, The PCB body includes: Multiple substrate layers, said multiple substrate layers being formed of an insulating material; and Multiple embedded layers, the multiple embedded layers being formed of conductive material and disposed alternately between adjacent substrate layers in the multiple substrate layers.

3. The PCB assembly according to claim 1, wherein, The set of devices includes a set of surface mount devices.

4. The PCB assembly according to claim 1, wherein, The set of devices does not extend above the top surface of the PCB body.

5. The PCB assembly according to claim 1, wherein, The set of through holes has a circular shape in the top plan view.

6. The PCB assembly according to claim 5, wherein, The PCB body includes: Multiple substrate layers, said multiple substrate layers being formed of an insulating material; and Multiple embedded layers, each formed of a conductive material, are disposed alternately between adjacent substrate layers. In this configuration, at least one electrode of at least one device in at least one of the group of through holes is electrically connected to an embedding layer in the plurality of embedding layers.

7. The PCB assembly according to claim 1, wherein, The set of through holes has a rectangular shape in the top plan view.

8. The PCB assembly according to claim 7, wherein, The PCB body includes: Multiple substrate layers, said multiple substrate layers being formed of an insulating material; and Multiple embedded layers, each formed of a conductive material, are disposed alternately between adjacent substrate layers. In this configuration, at least one electrode of at least one device in at least one of the group of through holes is electrically connected to an embedding layer in the plurality of embedding layers.

9. The PCB assembly according to claim 1, wherein, The set of through holes does not extend through the overall thickness of the PCB body.

10. A printed circuit board (PCB) assembly, comprising: PCB body, the PCB body includes: Multiple substrate layers, said multiple substrate layers being formed of an insulating material; and Multiple embedded conductive layers, the multiple embedded conductive layers being arranged alternately between the multiple substrate layers; and Multiple device vias are disposed within the PCB body, wherein each device via includes a device disposed therein.

11. The PCB assembly according to claim 10, wherein, The device is a surface mount device.

12. The PCB assembly according to claim 10, wherein, The height of the PCB assembly is equal to the thickness of the PCB body.

13. The PCB assembly according to claim 10, wherein, The plurality of device vias have a circular shape in the top plan view.

14. The PCB assembly according to claim 13, wherein, At least one electrode of the device is electrically connected to an embedded layer among the plurality of embedded conductive layers.

15. The PCB assembly according to claim 10, wherein, The plurality of device vias have a rectangular shape in the top plan view.

16. The PCB assembly according to claim 10, wherein, At least one electrode of the device is electrically connected to an embedded layer among the plurality of embedded conductive layers.

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