TWI601467B - Circuit board structure and manufacturing method thereof - Google Patents

Description

Circuit board structure and manufacturing method thereof

The present invention relates to a circuit board structure and a method of fabricating the same, and more particularly to a circuit board structure having a buried component and a method of fabricating the same.

Due to the increasing integration of electronic products, circuit boards used in highly integrated electronic products have changed from one layer to two layers to six layers, eight layers, and even more than ten layers. In order to enable electronic components to be more densely mounted on the printed circuit board. However, as the number of layers of the board increases and the line is dense, the influence of the RC delay or cross talk on the electrical signals transmitted in the board is also increasing. The more obvious. In order to improve the electrical properties of the board, it is necessary to add electronic components to the limited configuration area of the board. However, a normalized passive component with a specific electrical value may not be fully compliant with a particular circuit design, so making the electronic component directly inside the board is a viable solution.

At present, circuit boards generally having embedded components mostly embed electronic components in the manufacturing process of the circuit board. However, if the embedded component is a high power electronic component When the whole machine is running, there may be disadvantages such as high heat causing the terminal product to crash or malfunction.

The present invention provides a circuit board structure having a buried component and capable of providing a good heat dissipation effect.

The present invention provides a method of fabricating a circuit board structure that can produce the above-described circuit board structure.

A circuit board structure of the present invention includes a first dielectric layer, a buried component, a heat pipe, a heat conductive material, a second dielectric layer, and a plurality of heat conducting columns. The first dielectric layer includes a slot. The embedded component is located in the slot of the first dielectric layer and includes an opposite active surface and a back surface. The heat pipe is located in the slot of the first dielectric layer, and the buried component is coplanar with the heat pipe. The thermally conductive material fills the slot of the first dielectric layer and encloses the embedded component and the heat pipe. The second dielectric layer is located on one side of the first dielectric layer and covers the trench, wherein the back surface of the buried component faces the second dielectric layer, and the second dielectric layer includes a plurality of first holes, the embedded component and An orthographic projection of the heat pipe to the plane of the second dielectric layer overlaps the first holes. The heat conducting column is disposed in the first hole of the second dielectric layer, wherein the heat generated by the embedded component and the heat transferred to the heat pipe and the heat conductive material are transmitted through the heat conducting column.

In an embodiment of the invention, the groove is recessed in a surface of the first dielectric layer.

In an embodiment of the invention, the circuit board structure further includes a first Three dielectric layers and vias. The third dielectric layer is on the other side of the first dielectric layer, wherein the active side of the buried component faces the third dielectric layer. The via hole is disposed through the third dielectric layer and is connected to the pad of the embedded component.

In an embodiment of the invention, the heat pipe surrounds the embedded component in a closed or non-closed manner.

In an embodiment of the invention, the ratio (D/t) of the tube diameter (D) of the heat pipe to the thickness (t) of the first dielectric layer is less than or equal to 1.

A method of fabricating a circuit board structure of the present invention includes: providing a first dielectric layer, wherein the first dielectric layer comprises a slot; and configuring a buried component and a heat pipe to slot the first dielectric layer The embedded component is coplanar with the heat pipe, and the embedded component includes an opposite active surface and a back surface; filling a heat conductive material to the first dielectric layer to cover the buried component and the heat pipe Forming a second dielectric layer on one side of the first dielectric layer to cover the trench, wherein the back surface of the buried component faces the second dielectric layer; removing the partial second dielectric layer to form a plurality of a hole in which an orthographic projection of the buried component and the heat pipe to the plane of the second dielectric layer overlaps the first hole; and a plurality of thermally conductive pillars are formed in the first hole of the second dielectric layer, wherein the embedded component The heat generated and the heat transferred to the heat pipe and the heat conductive material can be transmitted through the heat conducting column.

In an embodiment of the present invention, the step of inserting the buried component into the first dielectric layer further includes: disposing a release layer on a side of the first dielectric layer; And the embedded component and the heat pipe are disposed on the release layer, and the embedded component and the heat pipe are located in the slot.

In an embodiment of the invention, after the step of filling the heat conductive material to the trench, the method further comprises: removing the release layer; forming a third dielectric layer on the other side of the first dielectric layer, wherein The active surface of the buried component faces the third dielectric layer; and a via hole is formed on the third dielectric layer, wherein the via is connected to a pad of the buried component.

In an embodiment of the invention, the heat pipe surrounds the embedded component in a closed or non-closed manner.

In an embodiment of the invention, the ratio (D/t) of the tube diameter (D) of the heat pipe to the thickness (t) of the first dielectric layer is less than or equal to 1.

In an embodiment of the invention, the thermally conductive material is non-conductive.

Based on the above, the circuit board structure of the present invention is configured by a heat pipe disposed adjacent to the buried component, and the heat conductive material covers the design of the embedded component and the heat pipe. The heat generated by the embedded component can be transmitted to the heat pipe through the heat conductive material, and the heat pipe The two-phase fluid is contained therein and can be cooled by endothermic vaporization of the two-phase fluid. In addition, the heat conducting column is connected with the heat conductive material, the embedded component and the heat pipe, and the heat generated by the embedded component and the heat transferred to the heat pipe and the heat conductive material can also be transmitted through the heat conducting column to effectively dissipate heat. In addition, since the embedded component is coplanar with the heat pipe, the circuit board structure of the present invention has a relatively thin thickness.

The above described features and advantages of the invention will be apparent from the following description.

10‧‧‧ release layer

100‧‧‧Circuit board structure

110‧‧‧First dielectric layer

112‧‧‧ slotting

120‧‧‧Internal components

122‧‧‧Active surface

124‧‧‧Back

126‧‧‧ pads

130‧‧‧heat pipe

140‧‧‧thermal materials

150‧‧‧Second dielectric layer

152‧‧‧ first hole

160‧‧‧thermal column

170‧‧‧ Third dielectric layer

180‧‧‧through holes

200‧‧‧Manufacturing method of circuit board structure

210~290‧‧‧Steps

S‧‧‧ surface

1 to 6 are schematic views of a method of fabricating a circuit board structure in accordance with an embodiment of the present invention.

FIG. 7 is a flow chart showing a method of fabricating a circuit board structure in accordance with an embodiment of the invention.

1 to 6 are schematic views of a method of fabricating a circuit board structure in accordance with an embodiment of the present invention. FIG. 7 is a flow chart showing a method of fabricating a circuit board structure in accordance with an embodiment of the invention. Please refer to FIG. 7 together with reference to FIG. 1 to FIG. 6. It should be noted that FIG. 1 to FIG. 6 are only schematic diagrams showing the size ratio of each component in the circuit board structure 100 (labeled in FIG. 6). Not limited to this.

A manufacturing method 200 for a circuit board structure of the present embodiment includes the following steps. First, as shown in FIG. 1, a first dielectric layer 110 is provided, wherein the first dielectric layer 110 includes a slot 112 (step 210). . In the embodiment, the trench 112 penetrates through the first dielectric layer 110. In other embodiments, as shown in FIG. 1', the trench 112 may not penetrate the first dielectric layer 110, but only be recessed on the surface S of the first dielectric layer 110.

Next, as shown in FIG. 2, a buried component 120 and a heat pipe 130 are disposed in the trench 112 of the first dielectric layer 110, wherein the buried component 120 is coplanar with the heat pipe 130, and the buried component 120 An opposite active surface 122 and a back surface 124 are included (step 220). In this embodiment, since the trench 112 is penetrated through the first dielectric layer 110, the step 220 of disposing the buried component 120 and the heat pipe 130 further includes: disposing a release layer 10 on the first dielectric layer. One side of 110 (step 222). After that, match The embedded component 120 and the heat pipe 130 are disposed on the release layer 10, and the embedded component 120 and the heat pipe 130 are located in the slot 112 (step 224). In the present embodiment, the heat pipe 130 is provided with a two-phase fluid and can be cooled by endothermic vaporization of the two-phase fluid, which will be further described later.

In the present embodiment, the active surface 122 of the embedded component 120 is in the lower position of FIG. 2, and the back surface 124 is in the upper position of FIG. 2, and the active surface 122 of the embedded component 120 has a plurality of pads 126 thereon. The active face 122 of the embedded component 120 is placed on the release layer 10. Of course, in one embodiment, the slot 112 does not penetrate the first dielectric layer 110, but is only recessed on the surface S of the first dielectric layer 110, and the buried component 120 and the heat pipe 130 may be directly disposed on The bottom of the groove 112 is grooved, and the step of disposing the release layer 10 is omitted.

As shown in FIG. 2, the height of the slot 112 is greater than the thickness of the embedded component 120 and the heat pipe 130. In the present embodiment, the ratio (D/t) of the tube diameter (D) of the heat pipe 130 to the thickness (t) of the first dielectric layer 110 is less than or equal to 1. In the present embodiment, the heat pipe 130 adopts a miniaturized heat pipe, and the size of the pipe through the heat pipe 130 is limited to a certain range, thereby reducing the size of the circuit board structure 100.

In detail, in the present embodiment, by disposing the heat pipe 130 at a position coplanar with the embedded component 120, since the pipe diameter of the heat pipe 130 is smaller than the thickness of the embedded component 120, the circuit board structure 100 is configured with the heat pipe 130 and It does not affect its thickness, but it retains its original thin thickness. Of course, in other embodiments, the diameter of the heat pipe 130 may also be greater than the thickness of the buried component 120. However, since the buried component 120 is coplanar with the heat pipe 130, the thickness of the first dielectric layer 110 is greater than heat. The diameter of the tube 130 can accommodate the embedded element 120 and the heat pipe 130 at the same time. The circuit board structure 100 of the present embodiment has a smaller configuration than the embedded element 120 and the heat pipe 130 are not coplanar but stacked. thickness of. In addition, the miniaturized heat pipe 130 can also reduce the length and width dimensions of the slot 112, and enable other portions of the circuit board structure 100 to be provided at a higher ratio for use by the designer.

3 is a top view of the buried component 120 and the heat pipe 130 surrounding the buried component 120. As shown in FIG. 3, in the present embodiment, the heat pipe 130 has a non-closed shape. Therefore, the heat pipe 130 surrounds the embedded component 120 in a non-closed manner, but in other embodiments, the heat pipe 130 may also be a closed ring. The embedded component 120 is surrounded by a closed form. It should be noted that FIG. 3 only schematically illustrates one form of the heat pipe 130. The shape and diameter of the heat pipe 130 and the ratio of the circumference of the heat pipe 130 are not limited thereto.

Then, as shown in FIG. 4, a heat conductive material 140 is filled into the trench 112 of the first dielectric layer 110 to cover the buried component 120 and the heat pipe 130 (step 230). In the present embodiment, the heat conductive material 140 is flush with the upper and lower surfaces of the first dielectric layer 110, and the heat generated by the embedded component 120 during operation can be transmitted to the heat pipe 130 in the horizontal direction through the heat conductive material 140. The heat pipe 130 is provided with a two-phase fluid, and the two-phase fluid undergoes a phase change to cool down after the heat is absorbed.

It should be noted that in the present embodiment, the heat conductive material 140 is only thermally conductive and not electrically conductive to avoid conduction between the pads 126 of the embedded component 120. The heat conductive material 140 may be a thermal grease, but the type of the heat conductive material 140 is not limited thereto.

Next, as shown in FIG. 5, the heat conductive material 140 is filled to the trench 112. After step 230, the method further includes: removing the release layer 10 (step 270). A second dielectric layer 150 is formed on one side of the first dielectric layer 110 to cover the trench 112, wherein the back surface 124 of the buried component 120 faces the second dielectric layer 150 (step 240). A third dielectric layer 170 is formed on the other side of the first dielectric layer 110, wherein the active surface 122 of the buried component 120 faces the third dielectric layer 170 (step 280). In this embodiment, as shown in FIG. 5 , the second dielectric layer 150 and the third dielectric layer 170 are respectively pressed to the upper and lower opposite sides of the first dielectric layer 110 , and then to the second dielectric layer 150 . Two conductor layers are respectively formed on the upper and third dielectric layers 170.

In this embodiment, step 270 may be performed first, and step 240 and step 280 may be performed at the same time. Of course, step 270 and step 280 may be performed after step 240, or steps may be sequentially performed. After step 280 and step 280, step 240 is performed. In other words, the order of the steps is not limited.

In addition, in one embodiment, if the trench 112 does not penetrate the first dielectric layer 110 but is only recessed on the surface S of the first dielectric layer 110, the configuration of the release layer 10 of step 222 is not required. Step, in this embodiment, step 270 can also be omitted. In addition, in this embodiment, since the trench 112 does not penetrate the first dielectric layer 110, a portion of the first dielectric layer 110 is originally under the trench 112, and thus step 280 is not required. The conductor layer can be formed directly on the lower side of the first dielectric layer 110.

Then, as shown in FIG. 6, the partial second dielectric layer 150 is removed to form a plurality of first holes 152, wherein the orthographic projection of the buried component 120 and the heat pipe 130 to the plane of the second dielectric layer 150 overlaps. These first holes 152 (step 250). Also That is, the position of the first hole 152 on the second dielectric layer 150 corresponds to the position of the buried element 120 and the heat pipe 130. When step 250 is performed, a first hole 152 may be formed on the second dielectric layer 150 by mechanical or laser drilling. Further, in the present embodiment, in addition to the second dielectric layer 150, In addition to drilling the buried component 120 and the heat pipe 130, the thermally conductive material 140 can also be drilled in a location proximate to the buried component 120 and the heat pipe 130.

Next, a plurality of thermally conductive pillars 160 are formed in the first holes 152 of the second dielectric layer 150, wherein the heat generated by the buried component 120 and the heat transmitted to the heat pipe 130 and the heat conductive material 140 are transmitted through the heat conducting column 160 ( Step 260). A via hole 180 is formed on the third dielectric layer 170, wherein the via hole 180 is connected to the pad 126 of the embedded component (step 290). The conductor layer above the second dielectric layer 150 and the conductor layer under the third dielectric layer 170 are then patterned to form a two wiring layer.

In this embodiment, the heat conducting column 160 is disposed in a vertical direction to connect the heat conductive material 140, the embedded element 120 and the heat pipe 130, and the heat generated by the buried element 120 and the heat transferred to the heat pipe 130 and the heat conductive material 140 can also be The heat transfer column 160 is transmitted in the vertical direction to effectively lower the temperature of the circuit board structure 100 of the present embodiment.

In addition, the signal of the buried component 120 can also be transmitted from the pad 126 through the via 180 and the wiring layer under the third dielectric layer 170. In the embodiment, the via hole 180 is a solid metal pillar, or may be a hollow via hole in which a conductive layer is formed in the aperture, or an insulating or non-insulating paste may be inserted therein to dissipate heat, and the via hole 180 is in the form of Without being limited thereto, as long as it can be connected to the pad 126 of the embedded component, can.

Similarly, in the present embodiment, the manufacturing method 200 of the circuit board structure may sequentially perform step 250 and step 260 before performing step 290. Alternatively, step 290 may be performed before step 250 and step 260. The order of the steps is not limited. In addition, in one embodiment, if the trench 112 does not penetrate the first dielectric layer 110 but is only recessed on the surface S of the first dielectric layer 110, the third dielectric layer 170 may not be additionally disposed. The via hole 180 is formed in a portion of the first dielectric layer below the recess, wherein the via hole 180 is connected to the pad 126 of the buried component 120 instead of the step 290.

6 is a schematic diagram of a circuit board structure in accordance with an embodiment of the present invention. Referring to FIG. 6 , the circuit board structure 100 of the present embodiment includes a first dielectric layer 110 , a buried component 120 , a heat pipe 130 , a heat conductive material 140 , a second dielectric layer 150 , and a plurality of heat conducting columns. 160. The first dielectric layer 110 includes a slot 112. The buried component 120 is located in the trench 112 of the first dielectric layer 110 and includes an opposite active surface 122 and a back surface 124. The heat pipe 130 is located within the slot 112 of the first dielectric layer 110, and the buried component 120 is coplanar with the heat pipe 130. The heat conductive material 140 is filled in the trench 112 of the first dielectric layer 110 and covers the buried component 120 and the heat pipe 130. The second dielectric layer 150 is located on one side of the first dielectric layer 110 and covers the trench 112. The back surface 124 of the buried component 120 faces the second dielectric layer 150, and the second dielectric layer 150 includes a plurality of first layers. The hole 152, the orthographic projection of the embedded component 120 and the heat pipe 130 to the plane of the second dielectric layer 150 overlaps the first hole 152. The heat conducting column 160 is disposed on the first hole 152 of the second dielectric layer 150.

With the above-described component arrangement, the heat generated by the embedded component 120 of the circuit board structure 100 in the present embodiment can be transmitted to the heat pipe 130 in the horizontal direction through the heat conductive material 140. The heat pipe 130 is provided with a two-phase fluid, and the two-phase fluid undergoes a phase change to cool down after the heat is absorbed. In addition, the heat conducting column 160 is disposed in a vertical direction to connect the heat conductive material 140, the embedded element 120 and the heat pipe 130, and the heat generated by the buried element 120 and the heat transferred to the heat pipe 130 and the heat conductive material 140 can also pass through the heat conducting column 160. It is transmitted in the vertical direction to effectively lower the temperature of the circuit board structure 100 of the present embodiment.

In summary, the circuit board structure of the present invention is configured by a heat pipe disposed adjacent to the buried component, and the heat conductive material covers the design of the embedded component and the heat pipe, and the heat generated by the embedded component can be transmitted to the heat pipe through the heat conductive material. The heat pipe is filled with a two-phase fluid and can be cooled by endothermic vaporization of the two-phase fluid. In addition, the heat conducting column is connected with the heat conductive material, the embedded component and the heat pipe, and the heat generated by the embedded component and the heat transferred to the heat pipe and the heat conductive material can also be transmitted through the heat conducting column to effectively dissipate heat. In addition, since the embedded component is coplanar with the heat pipe, the circuit board structure of the present invention has a relatively thin thickness.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Circuit board structure

110‧‧‧First dielectric layer

112‧‧‧ slotting

120‧‧‧Internal components

122‧‧‧Active surface

124‧‧‧Back

126‧‧‧ pads

130‧‧‧heat pipe

140‧‧‧thermal materials

150‧‧‧Second dielectric layer

152‧‧‧ first hole

160‧‧‧thermal column

170‧‧‧ Third dielectric layer

180‧‧‧through holes

Claims (10)

A method for fabricating a circuit board structure includes: providing a first dielectric layer, wherein the first dielectric layer comprises a slot; and configuring a buried component and a heat pipe to the slot of the first dielectric layer Internally, wherein the embedded component is coplanar with the heat pipe, and the embedded component includes an opposite active surface and a back surface; filling a heat conductive material to the opening of the first dielectric layer to cover the a buried component and the heat pipe; forming a second dielectric layer on a side of the first dielectric layer to cover the trench, wherein the back surface of the buried component faces the second dielectric layer; Forming a plurality of first holes by the second dielectric layer, wherein the buried element and the orthographic projection of the heat pipe on the plane of the second dielectric layer overlap the first holes; and forming a plurality of heat conduction The first holes are in the second dielectric layer, wherein the heat generated by the embedded component and the heat transferred to the heat pipe and the heat conductive material are transmitted through the heat conducting column. The method for manufacturing a circuit board structure according to the first aspect of the invention, wherein the slot is inserted through the first dielectric layer, and in the step of disposing the embedded component and the heat pipe, further comprising: disposing a release type Laminating on one side of the first dielectric layer; and arranging the buried component and the heat pipe on the release layer, and the buried component and the heat pipe are located in the slot. The manufacturing method of the circuit board structure of claim 2, wherein after the step of filling the thermally conductive material to the grooving, the method further comprises: removing the release layer; forming a third dielectric layer thereon The other side of the first dielectric layer, wherein the active surface of the buried component faces the third dielectric layer; and a via hole is formed on the third dielectric layer, wherein the via hole is connected thereto A pad of the buried component. The method of fabricating a circuit board structure according to claim 1, wherein the heat pipe surrounds the embedded component in a closed or non-closed manner. The method of manufacturing a circuit board structure according to claim 1, wherein a ratio of a diameter of the heat pipe to a thickness of the first dielectric layer is less than or equal to one. A circuit board structure comprising: a first dielectric layer comprising a slot; a buried component located in the slot of the first dielectric layer and including an opposite active surface and a back surface; a heat pipe disposed in the slot of the first dielectric layer, the buried component being coplanar with the heat pipe; a heat conductive material filling the slot of the first dielectric layer and covering the buried component And a heat pipe; a second dielectric layer on one side of the first dielectric layer and covering the trench, wherein the back surface of the buried component faces the second dielectric layer, the second dielectric layer Include a plurality of first holes, the buried element and the plane of the heat pipe to the second dielectric layer The front projection overlaps the first holes; and the plurality of heat conducting columns are disposed on the first holes of the second dielectric layer, wherein heat generated by the buried component is transmitted to the heat pipe and the heat conduction The heat of the material is transmitted through the thermally conductive column. The circuit board structure of claim 6, wherein the slot is recessed on a surface of the first dielectric layer. The circuit board structure of claim 6, further comprising: a third dielectric layer on the other side of the first dielectric layer, wherein the active surface of the embedded component faces the third a dielectric layer; and a via hole extending through the third dielectric layer and connected to a pad of the buried component. The circuit board structure of claim 6, wherein the heat pipe surrounds the buried component in a closed or non-closed manner. The circuit board structure of claim 6, wherein a ratio of a diameter of the heat pipe to a thickness of the first dielectric layer is less than or equal to one.