Method for manufacturing integrated passive device

Abstract

A method of fabricating an integrated passive device (IPD) is provided. According to the method, a semiconductor manufacturing process is adopted, and first-class passive elements required by the integrated passive device and connecting parts between the first-class passive elements are manufactured on an epoxy resin substrate based on a wafer manufacturing process; and the first type of passive elements comprise a capacitor and a resistor. A plurality of laminated connection layers are arranged according to actual conditions, and a second type passive element-inductor required by the integrated passive device is synchronously manufactured on a part of the laminated connection layers to become a part of the part of the laminated connection layers. Every two adjacent connecting layers are connected through a conductive column and are plastically packaged through a corresponding oxygen resin layer. And exposing the conductive column of the uppermost connecting layer to manufacture a signal connecting part of the integrated passive device. According to the method for manufacturing the integrated passive device, the epoxy resin substrate is adopted to replace a high-resistance silicon or glass substrate, raw materials are easy to obtain and low in price, and the manufacturing cost of the integrated passive device is greatly reduced.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit manufacturing, and in particular to a method for manufacturing an integrated passive device. Background Art

[0002] In various functional circuits (especially RF circuits), a large number of discrete passive components such as capacitors and inductors are often included to form corresponding signal processing circuits (for example, filter circuits, oscillation circuits, etc.). At present, in RF circuits using discrete passive components, discrete passive components account for about 80% of the area and 70% of the cost of the entire RF circuit. Due to the actual demand for passive components in various functional circuits, the development of integrated passive devices (IPD) has been promoted. Using integrated passive devices to replace passive components in functional circuits can not only save the area occupied by discrete passive components in the functional circuit, but also reduce the cost of the entire functional circuit to a certain extent.

[0003] At present, the integrated passive device manufacturing scheme usually uses high-resistance silicon or glass as the substrate. When using high-resistance silicon as the substrate, polyimide (PI) or benzocyclobutene (BCB) is required as the passivation layer, which is relatively expensive. If glass is used as the substrate, the manufacturing process is more difficult due to the fragility of glass. Based on the above shortcomings of the existing integrated passive device manufacturing scheme, how to simultaneously reduce the difficulty and cost of manufacturing integrated passive devices has become the main direction for the industry to improve the manufacturing process. Summary of the invention

[0004] In view of the high manufacturing cost and difficult manufacturing process of existing integrated passive devices, this application proposes a new solution for manufacturing integrated passive devices. This solution uses low dielectric constant epoxy resin as a substrate and combines it with wafer manufacturing process to manufacture integrated passive devices. Based on the technical solution provided by this application, not only can the cost of manufacturing integrated passive devices be effectively reduced, but the manufacturing and packaging of integrated passive devices are uniformly based on epoxy resin, which greatly reduces the manufacturing cost and difficulty.

[0005] The new solution for manufacturing an integrated passive device provided by the present application is implemented as: a method for manufacturing an integrated passive device (IPD). The method comprises: A temporary substrate is provided, and a temporary bonding layer is coated on one surface of the temporary substrate; on the temporary bonding layer, the first type of passive components required for the integrated passive device are manufactured based on a wafer manufacturing process, and the first type of passive components include resistors and capacitors.

[0006] A plurality of first conductive posts are manufactured so that each connection end of each element in the first type of passive elements is electrically connected to different first conductive posts respectively; a first epoxy resin layer is manufactured so as to cover the temporary bonding layer and encapsulate all the first conductive posts and all the first type of passive elements.

[0007] The temporary substrate is removed by a debonding process, the first epoxy resin layer is turned over, an epoxy resin base is made on the side of the first epoxy resin layer that was originally in contact with the temporary substrate, and the structure composed of the epoxy resin base and the first epoxy resin layer is turned over again.

[0008] A plurality of stacked connection layers are made on the top of the first epoxy resin layer, a second conductive column is made on the top of each stacked connection layer, and each stacked connection layer and the second conductive column thereon are encapsulated with an epoxy resin layer; the lower end of each stacked connection layer is connected to the upper end of the conductive column on the adjacent connection layer below it, and the uppermost epoxy resin layer is thinned to expose the upper end of the conductive column therein. All of the above epoxy resin layers are made by a plastic encapsulation process. Preferably, the temporary substrate is glass or silicon.

[0009] Furthermore, the first type of passive components required for the integrated passive device are manufactured on the temporary bonding layer, including: manufacturing a first connection layer on the temporary bonding layer based on a wafer manufacturing process, and manufacturing the first type of passive components on the first connection layer; wherein the resistors in the first type of passive components are manufactured synchronously with the first connection layer and serve as a part of the first connection layer.

[0010] Correspondingly, the manufacturing of a plurality of first conductive pillars so that each connection end of each element in the first type of passive elements is electrically connected to different first conductive pillars is achieved by manufacturing first conductive pillars at corresponding positions of the upper plate of each capacitor in the group of passive elements and the upper end of the first connection layer so that any connection end of each element in the first type of passive elements is electrically connected to the corresponding first conductive pillar.

[0011] Furthermore, the method further comprises: manufacturing the second type of passive components required for the integrated passive device in part of the stacked connection layers, wherein the second type of passive components are manufactured synchronously with the corresponding stacked connection layers and serve as a part of the corresponding stacked connection layers. The second type of passive components include inductors.

[0012] Furthermore, the method further comprises: before making each connection layer, thinning each epoxy resin layer to expose the upper end of the conductive pillar and the upper end of the inductor. Preferably, the epoxy resin layer is thinned by a grinding process to expose the corresponding conductive pillar.

[0013] Furthermore, the temporary bonding layer is made of temporary bonding glue. Accordingly, the debonding process includes at least one of the following: laser debonding, mechanical debonding or thermal debonding.

[0014] Further, all the conductive pillars are copper pillars with polygonal, circular or elliptical bottom surfaces. Preferably, the cross-section of the upper end of all the conductive pillars is larger than the cross-section of the lower end thereof.

[0015] Furthermore, the method further includes: making an exposed pad, solder ball or bump to connect the conductive column in the uppermost epoxy resin layer. The integrated passive device uses the pad, solder ball or bump as an electrical connection terminal, which can be easily integrated into a PCB in the future and form a corresponding functional circuit in conjunction with other devices.

[0016] The method for manufacturing an integrated passive device provided by the present application uses low dielectric constant epoxy resin as a substrate and a plastic encapsulation layer, which can effectively reduce the parasitic capacitance effect between metal wires. In addition, using epoxy resin instead of high-resistance silicon or glass as a substrate can not only greatly reduce the manufacturing cost of the integrated passive device, but also greatly reduce the difficulty of the manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1-Figure 11 In one embodiment, a cross-sectional schematic diagram of an integrated passive device manufactured by the method provided in the present application after relevant steps. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] The number of plastic encapsulation layers, the number of connection layers, and the number of conductive columns in the technical solution provided by this application are not limited to the numbers given in the solution examples, and the number of layers can be reasonably adjusted according to the design scheme of the integrated passive device. Among them, the size of the epoxy resin substrate is not limited to 8 inches, 12 inches, etc., and the shape is not limited to round, square, etc. That is, the shape and size of the epoxy resin substrate in this case are not too limited. Figure 1-Figure 11 In one embodiment, a schematic diagram of the changes in the cross section at the same position of an integrated passive device manufactured using the method provided by the present application is shown.

[0021] In this embodiment, the present application provides a method for manufacturing an integrated passive device (IPD), comprising the following steps: Step S1: Provide a temporary substrate and coat a temporary bonding layer on one surface of the temporary substrate. Figure 1 As shown, a temporary substrate 10 is provided, and a temporary bonding layer 20 is made on the temporary substrate 10 using a temporary bonding adhesive. The temporary substrate 10 can be made of glass or silicon. Since the temporary substrate 10 only serves as a temporary support and will be peeled off later, the material for making the temporary substrate 10 is not limited to glass or silicon.

[0022] Step S2: On the temporary bonding layer, based on the wafer manufacturing process, the first type of passive components required for the integrated passive device are manufactured, and the first type of passive components include resistors and capacitors. Obviously, the first type of passive components are not limited to resistors and capacitors, but can also be passive components such as diodes for signal processing.

[0023] Furthermore, manufacturing the first type of passive components required for the integrated passive device on the temporary bonding layer includes: manufacturing a first connection layer on the temporary bonding layer based on a wafer manufacturing process, and manufacturing the first type of passive components on the first connection layer. The resistors in the first type of passive components are manufactured synchronously with the first connection layer and serve as a part of the first connection layer. The first connection layer can not only conveniently realize the electrical connection between the first type of passive components, but also support the first type of passive components.

[0024] like Figure 2 As shown, a first connection layer 11 is manufactured on a side of the temporary bonding layer 20 away from the temporary substrate 10 based on a wafer manufacturing process, and a number of first-type passive components required for integrated passive devices are manufactured on the first connection layer 11 . Figure 2 The passive component 30 is a capacitor, and the passive component 40 is a resistor.

[0025] Step S3, a first conductive column is made at a corresponding position on the upper plate of the capacitor in each first-category passive component and the first connection layer, so that each connection end of each component in the first-category passive component is electrically connected to a different first conductive column. The first conductive column and the first connection layer are used to establish an electrical connection relationship between passive components in an integrated passive device.

[0026] like Figure 3 In the cross section shown, the first conductive column 12 is arranged on the upper end surface of the capacitor 30 and the upper end surface of the connecting layer 11. The cross section of the first conductive column 12 can be polygonal, circular or elliptical. The upper end cross section of the first conductive column is arranged to be larger than the lower end cross section, so that the first conductive column can be firmly fixed in the first epoxy resin layer. The subsequent remaining conductive columns are arranged in the same manner as the first conductive column.

[0027] Step S4: prepare a first epoxy resin layer to encapsulate all the first type passive components and the first conductive pillars. Figure 4 As shown, a first epoxy resin layer 100 is formed by a plastic packaging process to encapsulate all the first type passive components and all the first conductive pillars 12 .

[0028] Step S5, removing the temporary substrate by a debonding process, flipping the first epoxy resin layer, making an epoxy resin base on the side of the first epoxy resin layer that was originally in contact with the temporary substrate, and then flipping the structure composed of the first epoxy resin layer and the epoxy resin base again. Figure 4 As shown, after the temporary substrate 10 is removed by a debonding process, the first epoxy resin layer 100 is flipped over, and an epoxy resin base 101 is made on the end surface of the first epoxy resin layer 100 that was originally in contact with the temporary substrate 10 by a molding process; then the structure formed by the first epoxy resin layer 100 and the epoxy resin base 101 is flipped over again.

[0029] Step S6, thinning the first epoxy resin layer to expose the upper end of the first conductive column. Figure 5 As shown, the first epoxy resin layer 100 is thinned by a grinding process to expose the upper end surface of the first conductive column 12 so as to facilitate subsequent fabrication of a stacked connection layer to achieve electrical connection.

[0030] Step S7, making a second connection layer (i.e., a stacked connection layer) connected to the upper end of the first conductive column. Further, the second type of passive component-inductor required by the integrated passive device is made in part of the stacked connection layer. The second type of passive component-inductor is made synchronously with the corresponding stacked connection layer and becomes a part of the corresponding stacked connection layer.

[0031] like Figure 6As shown, the lower end surface of the second connection layer 21 is electrically connected to the exposed upper end of the first conductive column 12 ; and a second type of passive component, an inductor 23 , is fabricated on the second connection layer 21 , so that the inductor 23 becomes a part of the second connection layer 21 .

[0032] Step S8, making a second conductive column at a position corresponding to the upper end of the second connection layer. Figure 7 As shown, the second conductive column 22 is disposed on the upper end of the second connection layer 21 , and its shape is the same as that of the first conductive column 12 .

[0033] Step S9: using a second epoxy resin layer to plastic-encapsulate the second connection layer and the second conductive pillars thereon, and thinning the second epoxy resin layer to expose the upper ends of the second conductive pillars.

[0034] like Figure 8 As shown, the second epoxy resin layer 200 is used to plastic-encapsulate the second connection layer 21 and the second conductive pillars 22 thereon, and the second epoxy resin layer 200 is thinned by a grinding process to expose the upper ends of the second conductive pillars 22 .

[0035] Step S10: fabricate a third connection layer (laminated connection layer) connected to the upper end of the second conductive pillar, and fabricate a third conductive pillar at a corresponding position on the upper end of the third connection layer to further establish an electrical connection relationship between passive components in the integrated passive device. Fig. 9 As shown, a third connection layer 31 is manufactured on the upper end of the second conductive pillar 22 , and a third conductive pillar 32 is disposed on the upper end of the third connection layer 31 .

[0036] Obviously, the number of stacked connection layers can be set according to actual needs, and the number of the second type of passive components can also be set in the corresponding stacked connection layers according to actual needs.

[0037] Step S11, using a plastic encapsulation process to form a third epoxy resin layer to encapsulate the third connection layer and the third conductive column thereon; thinning the third epoxy resin layer to expose the upper end of the third conductive column (the first conductive column). In the above embodiment, the effect of the third epoxy resin layer 300 is as follows: Fig.10 shown.

[0038] Step S12: fabricating a metal column as an electrical signal connection terminal of the integrated passive device at the exposed upper end of the third conductive column. Fig.10 As shown, the fabricated metal column 4 includes a copper layer 41 , a nickel layer 42 and a silver-tin layer 43 .

[0039] It is worth noting that the integrated passive device manufactured in the above embodiment has only three connection layers. In fact, the technical solution provided in this application does not limit the number of connection layers and conductive pillars thereon. The technicians sequentially set the corresponding number of stacked connection layers and conductive pillars according to actual needs, and then use the corresponding epoxy resin layer for plastic sealing.

[0040] Specifically, according to actual needs, a person skilled in the art sequentially manufactures a plurality of stacked connection layers and a conductive column on each connection layer at the exposed upper end of the first conductive column, and manufactures an epoxy resin layer that encapsulates each connection layer and the conductive column thereon. The lower end of each of the connection layers is connected to the upper end of the conductive column manufactured on the adjacent connection layer below it, and the lower end of the lowest connection layer is connected to the upper ends of the plurality of first conductive columns. Finally, the uppermost epoxy resin layer is thinned to expose the upper ends of the conductive columns therein.

[0041] In addition, the specific shape of the electrical signal connection terminal of the integrated passive device is not limited to the metal pillar in the above embodiment. In fact, under ball metallization (UBM), bump (BUMP) or pad is also a commonly used electrical signal connection terminal. At the same time, the material of the electrical signal connection terminal can be any metal material with good conductivity.

[0042] The technical solution provided by the present application adopts low dielectric constant epoxy resin as the substrate and the plastic sealing layer, replacing the high-resistance silicon or glass used in the existing integrated passive device manufacturing process.

[0043] The technical solution provided by the present application can not only reduce the cost and difficulty of manufacturing integrated passive devices, but also reduce the parasitic capacitance effect between metal wires inside the integrated passive devices. It has a strong application prospect and is particularly suitable for large-scale manufacturing of integrated passive devices with specific functions.

Claims

1. A method for manufacturing an integrated passive device (IPD), characterized in that, The method comprises: A temporary substrate is provided, and a temporary bonding layer is coated on one surface of the temporary substrate; on the temporary bonding layer, a first type of passive components required for the integrated passive device is manufactured based on a wafer manufacturing process, and the first type of passive components include resistors and capacitors; Making a plurality of first conductive pillars so that each connection end of each element in the first type of passive elements is electrically connected to different first conductive pillars respectively; making a first epoxy resin layer so that it covers the temporary bonding layer and encapsulates all the first conductive pillars and all the first type of passive elements; The temporary substrate is removed by a debonding process, the first epoxy resin layer is turned over, an epoxy resin base is formed on the side of the first epoxy resin layer that was originally in contact with the temporary substrate, and the structure composed of the epoxy resin base and the first epoxy resin layer is turned over again; A plurality of stacked connection layers are made on the top of the first epoxy resin layer, a second conductive column is made on the top of each stacked connection layer, and each stacked connection layer and the second conductive column thereon are encapsulated with an epoxy resin layer; the lower end of each stacked connection layer is connected to the upper end of the conductive column on the adjacent connection layer below it, and the uppermost epoxy resin layer is thinned to expose the upper end of the conductive column therein.

2. The method according to claim 1, characterized in that The first type of passive components required for the integrated passive device are manufactured on the temporary bonding layer, comprising: manufacturing a first connection layer on the temporary bonding layer based on a wafer manufacturing process, and manufacturing the first type of passive components on the first connection layer; wherein the resistors in the first type of passive components are manufactured synchronously with the first connection layer and serve as a part of the first connection layer.

3. The method according to claim 2, characterized in that The method of making a plurality of first conductive pillars so that each connection end of each element in the first type of passive elements is electrically connected to different first conductive pillars is implemented as follows: a first conductive pillar is made at a corresponding position of the upper plate of each capacitor in the group of passive elements and the upper end of the first connection layer so that any connection end of each element in the first type of passive elements is electrically connected to the corresponding first conductive pillar.

4. The method according to any one of claims 1 to 3, characterized in that The method also includes: manufacturing the second type of passive components required for the integrated passive device in some stacked connection layers, wherein the second type of passive components are manufactured synchronously with the corresponding stacked connection layers and serve as a part of the corresponding stacked connection layers; the second type of passive components include inductors.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: before forming each connection layer, thinning each epoxy resin layer to expose the upper end of the conductive column therein.

6. The method according to claim 5, characterized in that The temporary substrate is glass or silicon.

7. The method according to claim 1, characterized in that The temporary bonding layer is made of temporary bonding glue.

8. The manufacturing method according to claim 7, characterized in that: The debonding process includes at least one of the following: laser debonding, mechanical debonding or thermal debonding.

9. The method according to claim 1, characterized in that The cross-sections of all the conductive pillars are polygonal, circular or elliptical.

10. The method according to claim 9, characterized in that The cross-sections of the upper ends of all the conductive pillars are larger than the cross-sections of the lower ends thereof.

11. The method according to claim 5, characterized in that The epoxy resin layer is thinned by a grinding process to expose the corresponding conductive pillars.

12. The method according to any one of claims 1 to 4, characterized in that The method further comprises: making an exposed solder pad or solder ball or bump to connect the conductive column in the uppermost epoxy resin layer.

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