CN219834461U - Three-dimensional packaging structure - Google Patents

Abstract

The utility model discloses a three-dimensional packaging structure, which comprises a substrate and at least two conductive structures: the substrate is provided with a bonding pad; each conductive structure comprises a conductive post, a first conductive layer and a second conductive layer, wherein the conductive post comprises a first end face and a second end face opposite to the first end face, and the conductive post is electrically connected with the bonding pad through the first end face; the first conductive layer comprises a first surface and a second surface opposite to the first surface, and the first surface of the first conductive layer is electrically connected with the second end face of the conductive column; the second conductive layer comprises a first surface and a second surface opposite to the first surface, the first surface of the second conductive layer is electrically connected with the second surface of the first conductive layer, and the second surface of the second conductive layer is used for being electrically connected with soldering pins of an electronic component to be soldered. The utility model can adjust the position of the bonding pad, better match the bonding leg of the electronic component to be welded, and avoid poor welding.

Description

Three-dimensional packaging structure

Technical Field

The utility model relates to the field of electronic component packaging, in particular to a three-dimensional packaging structure.

Background

When soldering electronic components to printed circuit boards (Printed Circuit Board, PCB) using surface mount technology (Surface Mounted Technology, SMT), stereoscopic packaging is desirable in some cases due to the limited area of the PCB. Some components such as inductors can be soldered with copper pillars on the pads of the PCB, then the copper pillars are fixed by plastic packaging, and then the solder feet of the electronic components are soldered on the copper pillars, as shown in fig. 1.

However, due to the high density and weight of the copper pillar, when the SMT process is used to mount the electronic component, the copper pillar is easy to incline or deviate in the tin brushing reflow process, so that the position of the upper end surface of the copper pillar is not matched with the soldering leg of the electronic component, and poor soldering is caused, as shown in fig. 1.

In addition, when the size of the soldering leg of the electronic component is larger than that of the copper column, the electronic component is attached and offset, the subsequent processing operation is influenced, and the problem of unmatched size can be solved by selecting the copper column with larger cross-section area, but the packaging cost is greatly increased due to higher price of copper. In addition, when the coplanarity of the plurality of solder fillets of the electronic component is poor, a problem of poor soldering of the electronic component may also be caused.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a novel three-dimensional packaging structure which can well solve the problems of mounting offset, poor welding and the like caused by mismatching of a copper column and an electronic component so as to realize good conduction between a substrate bonding pad and the electronic component to be welded.

In order to achieve the above object, the present utility model provides a three-dimensional package structure, including a substrate and at least two conductive structures, the substrate having pads; each conductive structure includes: a conductive post including a first end face and a second end face opposite to the first end face thereof, the conductive post being electrically connected to the pad through the first end face thereof; a first conductive layer including a first surface and a second surface opposite the first surface thereof, the first surface of the first conductive layer being electrically connected to the second end face of the conductive post; the second conductive layer comprises a first surface and a second surface opposite to the first surface, the first surface of the second conductive layer is electrically connected with the second surface of the first conductive layer, and the second surface of the second conductive layer is used for being electrically connected with soldering pins of electronic components to be soldered.

In some embodiments, the second surface of the first conductive layer has an area that is greater than the area of the first surface of the second conductive layer.

In some embodiments, the first surface of the first conductive layer covers the second end face of the conductive post.

In some embodiments, the conductive posts have a cross-sectional area that is less than the footprint area of the electronic component to be soldered.

In some embodiments, each conductive structure corresponds to a solder tail of an electronic component to be soldered.

In some embodiments, the thickness of the first conductive layer is less than the thickness of the second conductive layer.

In some embodiments, the first conductive layer has a thickness of 10-100 microns.

In some embodiments, the at least two conductive structures comprise three or more conductive structures, at least two of the three or more conductive structures having a common first conductive layer.

In some embodiments, the three-dimensional package structure further includes a first package layer, the first package layer being an insulator, the conductive pillars being encapsulated within the first package layer and exposing the second end surfaces of the conductive pillars.

In the above embodiment, the three-dimensional package structure further includes a second package layer, the second package layer is an insulator, and the first conductive layer and the second conductive layer are packaged in the second package layer and expose a second surface of the second conductive layer.

According to the utility model, the conductive column, the first conductive layer and the second conductive layer are arranged in the three-dimensional packaging structure, so that the following technical effects are obtained:

(1) And the positions of the bonding pads are adjusted to better match the bonding pins of the electronic components to be welded, so that poor welding is avoided.

(2) The bonding pads on the substrate can be enlarged to be matched with the bonding pins of the electronic components to be welded, so that the area of the substrate is saved; the conductive posts can also be smaller in size, which is beneficial to cost reduction.

Drawings

FIG. 1 is a schematic diagram of a prior art three-dimensional package structure with copper pillar tilting resulting in mismatch with an inductor leg;

fig. 2 shows a schematic view of a three-dimensional package structure 1 of one embodiment of the present disclosure;

fig. 3 shows a schematic view of a perspective package structure 1 of an embodiment of the present disclosure projected onto a substrate 10;

fig. 4 shows a schematic projection view of a three-dimensional package structure 1 according to another embodiment of the present disclosure on a substrate 10;

FIG. 5 illustrates a flow chart of a method 500 for fabricating a three-dimensional package structure;

fig. 6-12 are schematic diagrams of product structures corresponding to respective steps of the method 500 for manufacturing a three-dimensional package structure shown in fig. 5.

Detailed Description

The following detailed description is presented to facilitate an understanding of those skilled in the art in conjunction with the following examples and figures. In the drawings, like reference numerals generally refer to like elements unless the context indicates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not limiting of the utility model. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the inventive subject matter. It will be readily understood that the aspects of the present disclosure, as generally described and illustrated in the figures herein, could be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated as part of this disclosure.

The utility model provides a three-dimensional packaging structure which comprises a substrate and at least two conductive structures.

Fig. 2 shows a schematic view of a three-dimensional package structure 1 of one embodiment of the present disclosure. In the figure, the three-dimensional package structure 1 comprises a substrate 10 and at least two conductive structures 20. Fig. 3 shows a schematic view of a perspective package structure of an embodiment of the present disclosure projected onto a substrate 10, where the second end face 212 of two conductive posts is included (the first end face of the conductive posts and pads on the substrate are not shown).

The substrate 10 may be a Printed Circuit Board (PCB) or other carrier for supporting electronic components. One side surface of the substrate 10 has pads 11 for soldering the electronic component, two fillets 41 of the electronic component 4 are exemplarily shown in the figure, each of the fillets 41 corresponding to one of the pads 11 on the substrate 10. It should be noted that the bonding pads and the bonding pins may not be in a one-to-one correspondence, for example, the plurality of bonding pads on the substrate may correspond to a bonding pad of an electronic component to be soldered, and the bonding pads are specific to the need. In some embodiments, pads for soldering other electronic components may be further disposed between the substrate pads 11 corresponding to the solder fillets 41, so that other electronic components (not shown in the drawing) may be soldered below the electronic component 4, thereby realizing stacked three-dimensional package and saving substrate area.

Each conductive structure 20 includes a conductive post 21, a first conductive layer 22, and a second conductive layer 23.

The conductive post 21 includes a first end surface 211 and a second end surface 212 opposite the first end surface 211, and the first end surface 211 of the conductive post 21 is soldered to the pad 11, i.e., electrically connected to the pad 11 through the first end surface 211 thereof. The conductive posts 21 may be perpendicular to the substrate 10, and during actual connection, the conductive posts 21 may also tilt or shift, resulting in the conductive posts 21 having an inclination angle with respect to the substrate 10 as shown in fig. 1. The conductive post 21 may be cylindrical, square or rectangular, or any other shape that can be used to make an electrical connection. The conductive pillars 21 may be made of copper, gold, silver, or alloy.

The first conductive layer 22 includes a first surface 221 and a second surface 222 opposite the first surface 221, the first surface 221 of the first conductive layer 22 being electrically connected to the second end face 212 of the conductive post 21. In some embodiments, the first surface 221 of the first conductive layer 22 covers the second end face 212 of the conductive post 21.

In some embodiments, the material of the first conductive layer may be one or more conductive materials such as copper, gold, silver, and the like. Because there may be differences in the specifications (dimensions, spacing, etc.) of the fillets of the electronic components to be soldered in different batches, the second surface of the first conductive layer may be overlaid with conductive posts in order to better match the fillets of the electronic components to be soldered.

In some embodiments, the first conductive layer may be implemented by electroplating, and the thickness of the first conductive layer may be set according to needs, for example, may be set to 10-100 micrometers.

As shown in fig. 2, the second conductive layer 23 includes a first surface 231 and a second surface 232 opposite to the first surface 231 thereof, the first surface 231 of the second conductive layer is electrically connected with the second surface 222 of the first conductive layer, and the second surface 232 of the second conductive layer is used for electrically connecting with the soldering leg 41 of the electronic component 4 to be soldered and matching with the soldering leg 41 of the electronic component to be soldered, that is, the shape and area of the second surface 232 of the second conductive layer 23 are substantially the same as those of the soldering leg 41, so that good electrical connection between the two is achieved. In some embodiments, the area of the second surface 222 of the first conductive layer 22 is greater than the area of the first surface 231 of the second conductive layer 23, and the use of a smaller area for the second conductive layer 23 may save cost and space. In some embodiments, the thickness of the first conductive layer 22 is smaller than the thickness of the second conductive layer 23, and the second conductive layer with a larger thickness may have a higher strength, so as to be capable of more firmly electrically connecting with the solder fillets 41 of the electronic component 4 to be soldered. It should be noted that the second surface of the second conductive layer of the same conductive structure may be electrically connected to one solder tail of the electronic component, or may be electrically connected to two or more solder tails of the same or different electronic components, for example, the second surface of the second conductive layer of the same conductive structure may be electrically connected to both one solder tail of the first electronic component to be soldered and one solder tail of the second electronic component to be soldered, so that the two electronic components are electrically connected through the second surface of the second conductive layer of the conductive structure.

Similarly, in some embodiments, the second conductive layer may be implemented by electroplating, and the material may be one or more conductive materials such as copper, gold, silver, and alloys.

In other embodiments, the cross-sectional area of the conductive post 21 may be set smaller than the solder tail 41 of the electronic component to be soldered in order to save material cost or when the substrate area is smaller and it is difficult to accommodate the solder tail of the electronic component to be soldered.

The three-dimensional packaging structure can well solve the problem that the sizes of the pins of the conductive column 21 and the electronic component to be welded are not matched in the prior art by adding the first conductive layer 22 and the second conductive layer 23. For ease of understanding by those skilled in the art, the following is further described by way of example in fig. 3. The first conductive layer 22 covers the second end face 212 of the conductive post 21, and the area of the first surface 212 or the second surface 222 of the first conductive layer 22 is larger than the area of the second end face 212 of the conductive post 21, so that on one hand, the first conductive layer 22 and the conductive post 21 are well electrically connected, and on the other hand, the arrangement position of the second conductive layer 23 is highly selective, so that the position and the size of the second conductive layer 23 can be set according to the spacing and the size of the soldering leg of the electronic component to be soldered, and the second surface of the second conductive layer 23 can be matched with the soldering leg of the electronic component to be soldered. In the present disclosure, the second conductive layer is matched with the solder fillets of the electronic component to be soldered, which means that the second surface of the second conductive layer corresponding to two or more conductive structures of two or more solder fillets of one electronic component to be soldered is matched with parameters such as positions, pitches, shapes, sizes and the like of the solder fillets of the electronic component, so that after the solder fillets of the electronic component are soldered to the conductive structures, good electrical connection with the conductive pillars can be achieved. For example, the pitch, shape and size of the second surface of the second conductive layer of the conductive structures are the same as the pitch, shape and size of the corresponding fillets of the electronic component.

As shown in fig. 2, in some embodiments, the three-dimensional package structure 1 may include a first package layer 31, where the first package layer is an insulator and may perform insulation, dust prevention, water prevention, oxidation prevention, fixing, and the like, and the package material may be selected from plastics, epoxy, polysulfide, polyurethane, and organosilicon, and the like. The conductive post 21 is encapsulated in the first encapsulation layer 31, but if the conductive post has been displaced before encapsulation, the encapsulation and fixation can only be performed according to the current situation of the conductive post 21, and the second end surface 212 of the conductive post needs to be exposed from the first encapsulation layer 31 so as to be electrically connected to the first surface 221 of the first conductive layer 22.

As shown in fig. 2, in some embodiments, the three-dimensional package structure 1 may further include a second package layer 32, where the second package layer 32 is an insulator and may perform insulation, dust-proof, water-proof, oxidation-proof, fixing, and the like, and the package material may be plastic, epoxy, dry film, or the like.

In some embodiments, the first conductive layer 22 and the second conductive layer 23 are encapsulated in the second encapsulation layer 32 and expose the second surface 232 of the second conductive layer. In other embodiments, only the first conductive layer 22 is encapsulated in the second encapsulation layer 32, and the second conductive layer 23 may not be encapsulated or encapsulated in the third encapsulation layer. But at least the electrical connection of the second surface 222 of the first conductive layer 22 with the first surface 231 of the second conductive layer 23 should be ensured and the second surface 232 of the second conductive layer 23 needs to be exposed for electrical connection with the fillets 41 of the electronic component 4 to be soldered.

Fig. 4 is a schematic view of a perspective view of a package structure on a substrate 10 according to another embodiment of the disclosure, which is different from fig. 3 in that a plurality of conductive structures share a first conductive layer, second end faces 212 of three conductive pillars in a left conductive structure are electrically connected to the first conductive layer 22, and second end faces 212 of three conductive pillars in a right conductive structure are electrically connected to the first conductive layer 22. When a plurality of conductive posts need to be communicated in the circuit design, the structure using the common first conductive layer can conveniently, flexibly and selectively realize the circuit communication between the conductive posts.

The disclosure also provides a method 500 for manufacturing a three-dimensional package structure, as shown in fig. 5, where the method 500 may be used to manufacture the three-dimensional package structure of the disclosure. Fig. 6-12 are schematic diagrams of product structures corresponding to respective steps of the method 500 for manufacturing a three-dimensional package structure shown in fig. 5. The method 500 may be implemented by:

step 510: the first end face of the conductive post is soldered to a pad of the substrate. As shown in fig. 6, the conductive post 21 is soldered on the pad 11 on the substrate 10, that is, the first end surface 211 of the conductive post 21 is soldered to the pad 11.

Step 520: and encapsulating one surface of the substrate connected with the conductive column. As shown in fig. 7, the components on the substrate 10 are protected and encapsulated, and a first encapsulation layer 31 is formed and the conductive pillars 21 are also encapsulated therein. The first encapsulation layer 31 can fix the conductive pillars 21 and other components on the substrate 10 in addition to the waterproof, dustproof, and oxidation-proof effects. The first encapsulation layer 31 may be made of various insulating encapsulation materials, such as epoxy.

Step 530: exposing the second end surface of the conductive post. Since the first encapsulation layer 31 may cover the conductive pillars during encapsulation in step 520, the second end surfaces of the conductive pillars need to be exposed. As shown in fig. 8, the first encapsulation layer 31 may be thinned using a thinning process to expose the second end faces 212 of all of the conductive pillars 21. The thinning may be performed by mechanical cutting, grinding, laser, or a combination thereof, according to the material of the first encapsulation layer 31.

Step 540: and electroplating a first conductive layer on the second end surface of the conductive column. In some embodiments, as shown in fig. 9, the first surface 221 of the first conductive layer 22 covers the second end face 212 of the conductive post 21. In other embodiments, the selective connection between the plurality of conductive pillars 21 may also be achieved by using selective plating to make the plurality of conductive pillars 21 share the first conductive layer 22 according to design requirements (see fig. 4). The thickness of the first conductive layer 22 may be set as desired, for example, 10 to 100 micrometers.

Step 550: the first conductive layer is encapsulated. As shown in fig. 10, the first conductive layer 22 is encapsulated in the second encapsulation layer 32, and the second encapsulation layer 32 can play roles of water resistance, dust resistance, oxidation resistance, damage resistance, and the like. The second encapsulation layer 32 may be made of various insulating encapsulation materials, such as a dry film, and the polymer material can generate a polymerization reaction after being irradiated by ultraviolet rays, so as to form a stable substance attached to the surface and can block electroplating and etching.

Step 560: exposing the second surface of the first conductive layer. Since the second encapsulation layer 32 may cover the first conductive layer during encapsulation at step 550, the second end surface of the first conductive layer needs to be exposed. As shown in fig. 11, the second encapsulation layer 32 is partially removed to expose the second end surface 222 of the first conductive layer 22, and part or all of the second end surface 222 of the first conductive layer 22 may be exposed as needed. Depending on the material used for the second encapsulation layer 32, various modes and combinations of mechanical cutting, grinding, laser, etc. can be used. For example, when the second packaging layer 32 is made of a dry film, a laser method may be selected to remove a portion of the dry film, so as to expose a portion of the second surface 222 of the first conductive layer 22 substantially identical to the corresponding solder tail 41 of the electronic component 4 to be soldered, so as to facilitate subsequent connection of the second conductive layer. When the area of the fillets 41 of the electronic component 4 to be soldered is large or otherwise desired, more or even all of the second surface 222 of the first conductive layer 22 may be exposed.

Step 570: a second conductive layer is electroplated on the second surface of the first conductive layer. The first surface of the second conductive layer may be smaller than the second surface of the first conductive layer, or may be equal to or larger than the second surface of the first conductive layer, according to actual needs. As shown in fig. 12, the first surface 231 of the second conductive layer 23 is smaller than the second surface 222 of the first conductive layer. The second surface 232 of the second conductive layer 23 is for electrical connection with the fillets 41 of the electronic component 4 to be soldered.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art from a reading of the specification, the disclosure, and the drawings, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the terms "a" and "an" do not exclude a plurality. In the practice of the utility model, a single component may perform the functions of several of the features recited in the claims. Any reference signs in the claims shall not be construed as limiting the scope.

Claims (10)

1. The three-dimensional packaging structure is characterized by comprising a substrate and at least two conductive structures, wherein the substrate is provided with a bonding pad; each of the conductive structures includes:

a conductive post including a first end face and a second end face opposite to the first end face thereof, the conductive post being electrically connected to the pad through the first end face thereof;

a first conductive layer including a first surface and a second surface opposite the first surface thereof, the first surface of the first conductive layer being electrically connected to the second end face of the conductive post;

the second conductive layer comprises a first surface and a second surface opposite to the first surface, the first surface of the second conductive layer is electrically connected with the second surface of the first conductive layer, and the second surface of the second conductive layer is used for being electrically connected with soldering pins of electronic components to be soldered.

2. The three-dimensional package structure of claim 1, wherein the second surface of the first conductive layer has an area greater than the first surface of the second conductive layer.

3. The three-dimensional package structure of claim 1, wherein the first surface of the first conductive layer covers the second end surface of the conductive post.

4. The three-dimensional package structure of claim 1, wherein the conductive posts have a cross-sectional area that is smaller than a footprint area of the electronic component to be soldered.

5. The three-dimensional package structure of claim 1, wherein each of the conductive structures corresponds to a solder tail of an electronic component to be soldered.

6. The three-dimensional package structure of claim 1, wherein the first conductive layer has a thickness that is less than a thickness of the second conductive layer.

7. The three-dimensional package structure of claim 6, wherein the first conductive layer has a thickness of 10-100 microns.

8. The three-dimensional package structure of claim 1, wherein the at least two conductive structures comprise three or more conductive structures, at least two of the three or more conductive structures having a common first conductive layer.

9. The three-dimensional package structure of any one of claims 1-8, further comprising a first package layer, the first package layer being an insulator, the conductive pillars being encapsulated within the first package layer and exposing the second end surfaces of the conductive pillars.

10. The package structure of claim 9, further comprising a second encapsulation layer, the second encapsulation layer being an insulator, the first and second conductive layers being encapsulated in the second encapsulation layer and exposing a second surface of the second conductive layer.