Inductor packaging structure and packaging method thereof

Abstract

The invention discloses an inductor packaging structure and a packaging method thereof, comprising the following steps: a bottom line manufacturing step: electroplating a plurality of bottom lines on a bottom encapsulation layer, wherein the plurality of bottom lines are arranged horizontally; an intermediate column forming step: the end of each bottom line is vertically electroplated with an intermediate column; a connecting column forming step: electroplating the connecting column while electroplating the bottom line and the intermediate column, wherein the top surface of the connecting column is coplanar with the top surface of the intermediate column; a top line manufacturing step: encapsulating and horizontally grinding to expose the top surfaces of the connecting column and the intermediate column, electroplating a plurality of top lines between the intermediate columns, and electrically connecting the B end of a top line located at the edge of the arrangement with the connecting column through an electroplating process, wherein the bottom line, the intermediate column, the connecting column and the top line constitute a spiral coil with electrical input at one end and electrical output at the other end, and the process flow of the invention can flexibly form a spiral coil by electroplating around a special-shaped magnetic core.

Description

Technical Field

[0001] The present invention belongs to the technical field of inductor packaging, and in particular relates to an inductor packaging structure and a packaging method thereof. Background Art

[0002] Inductors have the characteristics of high quality, high energy storage and low resistance. Commonly used inductors are mainly wire-wound inductors and stacked inductors. Among them, wire-wound inductors have high inductance accuracy, low loss (i.e. large Q value), large allowable current, strong inheritance of manufacturing process, simple and low cost; stacked inductors have good magnetic shielding, high sintering density and good mechanical strength.

[0003] In the field of semiconductor or other chip device packaging, inductors are often needed in circuits to form stacked structures. As the package size continues to develop and progress in the direction of miniaturization or even miniaturization, the size of the stacked structure also needs to adapt to new developments. The inductors that occupy a larger volume in the stacked structure need to be further optimized to reduce the volume while ensuring the inductor performance.

[0004] However, among the commonly used types of inductors, the inductance of a wire-wound inductor is generated by the interaction between the current and the magnetic field in the coil, and the inductance is related to many factors, such as the number of turns of the inductor coil, the winding method, the size of the magnetic core, etc. Therefore, in order to ensure the inductance of a wire-wound inductor, its volume is generally large and its external dimensions are limited, which is not suitable for high-density board layout and packaging environments with high requirements for volume and space; and a stacked inductor, also known as a non-wire-wound inductor, is a structure in which multiple layers of internal coils are stacked horizontally, and each layer is electrically connected to form an exposed electrode structure, and a magnetic core can also be placed at the center point around the coil. Since the coil is placed horizontally and then stacked vertically up and down, the stacked inductor has a certain thickness, which makes it difficult to meet the requirements of miniaturized patches. At the same time, its multi-coil design leads to a relatively complex manufacturing process and a high production cost.

[0005] Therefore, it is urgent to design an inductor packaging structure and a packaging method thereof to solve the above problems. Summary of the invention

[0006] In order to solve the above problems in the prior art, the present invention provides an inductor packaging structure and a packaging method thereof.

[0007] The inductor structure packaging method comprises the following steps:

[0008] The bottom line manufacturing steps are as follows: electroplating a plurality of bottom lines on the bottom encapsulation layer, and the plurality of bottom lines are arranged horizontally;

[0009] Intermediate pillar formation step: an intermediate pillar is vertically plated at the end of each bottom line

[0010] The connecting column forming step includes: electroplating the connecting column while electroplating the bottom line and the middle column, and the top surface of the connecting column is coplanar with the top surface of the middle column;

[0011] The top-layer circuit manufacturing steps are as follows: encapsulating and horizontally grinding to expose the top surfaces of the connecting pillars and the middle pillars, electroplating multiple top-layer circuits between the middle pillars, and electrically connecting the B end of a top-layer circuit located at the edge of the arrangement with the connecting pillars through an electroplating process. The bottom-layer circuit, the middle pillar, the connecting pillars and the top-layer circuit form a spiral coil with electrical input at one end and electrical output at the other end.

[0012] Product unit production steps: Continue encapsulation, the top layer circuit is completely encapsulated in the encapsulation material, and the encapsulation material is vertically cut at the product cutting line position to obtain separated product units.

[0013] Furthermore, in the bottom layer circuit production step, a conductive bottom block is encapsulated inside the bottom encapsulation layer, and after encapsulation, the top surface of the encapsulation is horizontally ground to expose the top surface of the conductive bottom block, and an electrical connection is achieved between the A end of a bottom layer circuit located at the edge of the arrangement and one of the conductive bottom blocks through an electroplating process.

[0014] Furthermore, in the step of forming the connection pillar, the bottom end of the connection pillar is electrically connected to the conductive bottom block.

[0015] Furthermore, in the product unit manufacturing step, the encapsulation layers of all steps in the packaging method finally form a packaging body, the bottom surface of the conductive bottom block of the product unit is flush with and exposed to the bottom surface of the packaging body, and the two conductive bottom blocks serve as the electrical input terminal and electrical output terminal of the packaging body respectively.

[0016] Furthermore, in the intermediate column forming step, two sections of the intermediate column connected together are formed through two electroplating, encapsulation and grinding processes.

[0017] Furthermore, between the connecting column forming step and the top-layer circuit making step, there is also a magnetic core mounting step: the electroplated middle column has a certain height to form a spatial groove for accommodating the magnetic core, the magnetic core is mounted in the middle part of the spatial groove, and is encapsulated and horizontally ground to expose the top surfaces of the connecting column and the middle column.

[0018] An inductor packaging structure includes a packaging body, wherein the packaging body encapsulates:

[0019] The bottom layer circuit is encapsulated at the bottom of the package body, and a plurality of bottom layer circuits are arranged in a horizontal direction;

[0020] The middle column and the connecting column, the middle column is vertically plated at the end of each bottom line, the connecting column and the middle column and the bottom line are plated at the same time, and the top surface of the connecting column after electroplating is coplanar with the top surface of the middle column;

[0021] Top-layer circuits: electroplate multiple top-layer circuits between the ends of the middle pillars, and electrically connect the B ends of the top-layer circuits at the edge of the arrangement to the connecting pillars through an electroplating process;

[0022] The bottom layer circuit, the middle column, the connecting column and the top layer circuit constitute a spiral coil with electrical input at one end and electrical output at the other end.

[0023] Furthermore, the package body also encloses two conductive bottom blocks, the bottom surface of the conductive bottom block is flush with and exposed to the bottom surface of the package body, and the two conductive bottom blocks serve as the electrical input terminal and electrical output terminal of the package body respectively.

[0024] Furthermore, an A end of a bottom layer circuit located at the edge of the arrangement is electrically connected to one of the conductive bottom blocks through an electroplating process.

[0025] Furthermore, the bottom end of the connecting column is electrically connected to another conductive bottom block.

[0026] Furthermore, the intermediate column is formed by two electroplating, encapsulation and grinding processes.

[0027] Furthermore, a magnetic core is enclosed in the package, and the magnetic core is arranged between the bottom layer circuit and the top layer circuit.

[0028] The present invention:

[0029] 1. The process can flexibly electroplate around the special-shaped magnetic core to form a spiral coil, and finally form an inductor package, which can achieve the inductance performance while meeting the requirements of small inductance structure volume, and can solve the problem that special-shaped magnetic cores are difficult to form inductors;

[0030] 2. Through multiple electroplating and encapsulation process between each electroplating, the shape, structure and size of the column plated each time can be flexibly controlled. After the bottom column is electroplated and encapsulated, the column is electroplated again. The two parts of the column can be set to different sizes to ensure that there is enough contact area between the middle column, the connecting column and the encapsulation material to prevent separation from the encapsulation material;

[0031] 3. Effectively avoid the difficulty of electroplating when the column height is high, and the process is simple, efficient and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 One of the process flow charts of the bottom layer circuit manufacturing steps of an inductor structure packaging method of the present invention;

[0033] Figure 2 The second process flow chart of the bottom layer circuit manufacturing step of the inductor structure packaging method of the present invention;

[0034] Figure 3The third process flow chart of the bottom layer circuit manufacturing step of the inductor structure packaging method of the present invention;

[0035] Figure 4 One of the process flow charts of the steps of forming the intermediate pillar and the connecting pillar in the inductor structure packaging method of the present invention;

[0036] Figure 5 The second process flow chart of the steps of forming the intermediate pillar and the connecting pillar of the inductor structure packaging method of the present invention;

[0037] Figure 6 The third process flow chart of the steps of forming the intermediate pillar and the connecting pillar of the inductor structure packaging method of the present invention;

[0038] Figure 7 The fourth process flow chart of the steps of forming the intermediate pillar and the connecting pillar of the inductor structure packaging method of the present invention;

[0039] Figure 8 The fifth process flow chart of the steps of forming the intermediate pillar and the connecting pillar of the inductor structure packaging method of the present invention;

[0040] Fig. 9 FIG6 is a sixth process flow chart of the steps of forming the intermediate pillar and the connecting pillar of the inductor structure packaging method of the present invention;

[0041] Fig.10 One of the process flow charts of the magnetic core mounting step of an inductor structure packaging method of the present invention;

[0042] Fig.11 The second process flow chart of the magnetic core mounting step of the inductor structure packaging method of the present invention;

[0043] Fig.12 One of the process flow charts of the top-layer circuit manufacturing steps of an inductor structure packaging method of the present invention;

[0044] Fig.13 The second process flow chart of the top-layer circuit manufacturing step of the inductor structure packaging method of the present invention;

[0045] Fig.14 The third process flow chart of the top-layer circuit manufacturing step of the inductor structure packaging method of the present invention;

[0046] Fig.15 The fourth process flow chart of the top-layer circuit manufacturing step of the inductor structure packaging method of the present invention;

[0047] Fig.16 A process flow chart of steps for manufacturing a product unit of an inductor structure packaging method of the present invention;

[0048] Fig.17 It is a three-dimensional diagram of an inductor packaging structure of the present invention.

[0049] Explanation of the markings in the figure: 1. Package body; 2. Bottom layer circuit; 3. Middle column; 4. Connecting column; 5. Top layer circuit; 6. A end; 7. B end; 8. Conductive bottom block; 9. Magnetic core. DETAILED DESCRIPTION

[0050] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can imagine various embodiments of the present invention. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or limitation of the technical solution of the present invention. On the contrary, the purpose of providing these embodiments is to enable those skilled in the art to understand the present invention more thoroughly.

[0051] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the innovative concept of the present invention.

[0052] When an inductor is used in the packaging field, it is necessary to combine the inductor with the shell, that is, to encapsulate the inductor. The role of the encapsulation is mainly reflected in: protecting the inductor components, improving stability and reliability, and realizing flexible control of the size, shape, end face and other requirements of the inductor components to adapt to different application scenarios. The existing inductors are mainly used in the chip packaging field in winding and stacked types. Due to their large size, limited size, relatively complex manufacturing process, high production cost, and unsuitable for high-density board layout and packaging environments with high volume and space requirements; therefore, it is necessary to design an inductor packaging structure and its packaging method to solve the existing problems.

[0053] In order to better understand the purpose, structure and function of the present invention, the following Figure 1 -Attached Fig.17 , a further detailed description is given of an inductor packaging structure and a packaging method thereof proposed in the present invention.

[0054] Please see attached Figure 1 -Attached Fig.16 The inductor structure packaging method comprises the following steps:

[0055] The bottom line 2 manufacturing step is: electroplating a plurality of bottom line 2 on the bottom encapsulation layer, and the plurality of bottom line 2 are arranged in a horizontal direction;

[0056] The middle pillar 3 forming step: the middle pillar 3 is vertically electroplated at the end of each bottom line 2;

[0057] The step of forming the connecting column 4 is as follows: the connecting column 4 is electroplated while the bottom line 2 and the middle column 3 are electroplated, and the top surface of the connecting column 4 is coplanar with the top surface of the middle column 3;

[0058] The steps of manufacturing the top-layer circuit 5 are as follows: encapsulating and horizontally grinding to expose the top surfaces of the connecting pillars 4 and the middle pillars 3, electroplating multiple top-layer circuits 5 between the middle pillars 3, and electrically connecting the B end 7 of a top-layer circuit 5 located at the edge of the arrangement with the connecting pillar 4 through an electroplating process, and the bottom-layer circuit 2, the middle pillar 3, the connecting pillar 4 and the top-layer circuit 5 form a spiral coil with electrical input at one end and electrical output at the other end;

[0059] Product unit production steps: Continue encapsulation, the top layer circuit 5 is completely encapsulated in the encapsulation material, and the encapsulation material is vertically cut at the product cutting line position to obtain a separated product unit.

[0060] Among them, as attached Figure 1 -Attached Figure 3 In the manufacturing steps of the bottom line 2 shown in the figure, first, a substrate is provided. The substrate can be a glass substrate, a silicon substrate or a metal substrate commonly used in the technical field, or other suitable materials; an adhesive layer is adhered to the surface of the substrate, and a conductive bottom block 8 is adhered to the corresponding area through the adhesive layer. The corresponding area is determined by the preset area during the actual product design, and the number of the conductive bottom blocks 8 is not limited. It is designed according to the capacity of the substrate. In the drawings of this application, 8 are set as an example. The other two are blocked by the front two in the cross-sectional view. After the conductive bottom block 8 is adhered, the conductive bottom block 8 is encapsulated by an encapsulation process, and the top surface of the encapsulation is horizontally mechanically ground until the top surface of the conductive bottom block 8 is exposed (as shown in the attached figure). Figure 1 As shown), at this time, the encapsulation material and the conductive bottom block 8 form a whole, namely the bottom encapsulation layer.

[0061] The bottom line 2 is formed on the top surface of the ground bottom encapsulation layer by electroplating process, and multiple bottom lines 2 are arranged in the horizontal direction. In the present application, multiple bottom lines 2 are evenly arranged in the horizontal direction, and each bottom line 2 is parallel to each other and extends along the horizontal direction of the top surface of the bottom encapsulation layer by oblique electroplating (such as the attached Figure 3 As shown in the figure, the inclined bottom line 2 can lengthen the bottom line 2 as much as possible within the same space range, increase the performance of the inductor structure, such as the increase of inductance, and can also increase the contact area between the bottom line 2 and the encapsulation material to prevent the bottom line 2 from falling off and causing a short circuit or open circuit; similarly, the top line 5 is also arranged in this way, and the width, length and spacing distance of the bottom line 2 and the top line 5 can be formulated according to the actual product design and flexibly controlled according to the electroplating process.

[0062] In other embodiments, due to the flexibility of the electroplating process, the bottom line 2 and the top line 5 can also be arranged irregularly, which is determined according to the actual product characteristics or the mounted special-shaped magnetic core. The special-shaped magnetic core refers to a magnetic core with an irregular shape structure relative to regular shapes such as block cores, strip cores, ring cores, etc. This type of magnetic core mainly serves specific needs. The process flow of the present application can flexibly electroplate around the special-shaped magnetic core to form a spiral coil, while meeting the requirement of a small volume of the inductor structure.

[0063] After the bottom line 2 is electroplated, the A end 6 of a bottom line 2 located at the edge of the arrangement is electrically connected to the top surface of one of the conductive bottom blocks 8 through the electroplating process, and the first connecting column electrically connected is electroplated on the top surface of the other conductive bottom block 8. The two electroplating processes can be performed simultaneously (as shown in the attached figure). Figure 2 As shown), the top surface of the electroplated first connecting column is flush with the top surface of the bottom layer line 2.

[0064] Among them, as attached Figure 4 -Attached Fig. 9 In the step of forming the intermediate pillar 3 and the connecting pillar 4, a first intermediate pillar perpendicular to the bottom line 2 is vertically electroplated at the end of the bottom line 2, and a second connecting pillar flush with the top surface is electroplated at the same time as the first intermediate pillar is electroplated, and the bottom end of the second connecting pillar is electroplated and connected with the top end of the first connecting pillar (as shown in the attached figure). Figure 4 As shown, attached Figure 5 For attachment Figure 4 ).

[0065] After the electroplating of the first intermediate pillar and the second connecting pillar is completed, the encapsulation material is used to continue encapsulation on the basis of the bottom encapsulation layer until the encapsulation top surface completely encapsulates the first intermediate pillar and the second connecting pillar top surface, and the encapsulation top surface is horizontally mechanically polished until the top surface of the first intermediate pillar and the second connecting pillar is exposed (such as the attached Figure 6 As shown, attached Figure 7 For attachment Figure 6 ).

[0066] The second intermediate column and the third connecting column are electroplated on the top surfaces of the exposed first intermediate column and the second connecting column. The second intermediate column is electroplated and connected to the first intermediate column as a whole to form a complete intermediate column 3. The third connecting column is electroplated and connected to the second connecting column as a whole (as shown in the attached figure). Figure 8 As shown, attached Fig. 9 For attachment Figure 8The top view of the figure shows that the shape, structure and size of the column plated each time can be flexibly controlled by electroplating twice and encapsulation process is interposed between the two electroplating processes. The bottom column is electroplated and encapsulated before the column is electroplated again. The two parts of the column can be set to different sizes to ensure that there is enough contact area between the middle column 3 and the connecting column 4 and the encapsulation material to prevent separation from the encapsulation material. For example, the cross-sectional area of ​​the exposed top surface of the bottom column (first middle column) is inconsistent with the cross-sectional area of ​​the bottom surface of the top column (second middle column), which means that part of the cross-sectional area is in direct contact with the encapsulation material. After the column is electroplated as a whole, the middle column 3 is clamped with the encapsulation material to effectively prevent separation from the encapsulation material. The structure is stable. The third connecting column and the second connecting column can also be designed in this way. Moreover, the difficulty of electroplating when the column height is high is effectively avoided. The process is simple, efficient and safe.

[0067] Among them, as attached Fig.10 -Attached Fig.11 In the step of mounting the magnetic core 9, according to the actual specific characteristics of the inductor product, after electroplating the connecting pillars 4 and the intermediate pillars 3 and before encapsulating the connecting pillars 4 and the intermediate pillars 3, a spatial groove for accommodating the magnetic core 9 can be formed between the intermediate pillars 3 with a certain height, and the magnetic core 9 can be mounted in the spatial groove (as shown in the attached figure). Fig.10 As shown, attached Fig.11 For attachment Fig.10 ), the present application takes a magnetic core of conventional shape and size as an example, the middle column 3 is evenly distributed on both sides of the magnetic core 9, and for an irregularly shaped magnetic core 9, the shape and size of the magnetic core 9 are irregular, and the positions of the connecting column 4 and the middle column 3 can be designed according to the structure of the magnetic core 9, and then the magnetic core 9 is electroplated and mounted, which also ensures that the middle column 3 is evenly distributed on both sides of the magnetic core 9. The present application can solve the problem that the irregularly shaped magnetic core 9 is difficult to form an inductor; the magnetic core 9 is made of a variety of materials, such as a magnetic powder core, a sendustine core 9, a ferrite core 9, a manganese-zinc ferrite core 9, a nickel-zinc ferrite core 9, etc. The top height of the magnetic core 9 after mounting is lower than the height of the middle column 3.

[0068] After adding the magnetic core 9 to the inductor coil, the inductance can be greatly improved. After adding the magnetic core 9, the inductance of the inductor with the same geometric size and number of turns will be thousands of times higher than that without the magnetic core. Compared with the air-core inductor, the inductor with the magnetic core 9 will have hysteresis loss or eddy current loss. In order to improve this problem, while selecting a magnetic core of a more suitable material, the coil and the magnetic core 9 are both encapsulated by the electroplating method of the present application, and the encapsulation material is spaced between the magnetic core 9 and the coil (the spiral coil is formed by the A end 6, the bottom line 2, the middle column 3, the top line 5, the B end 7, the connecting column 4 and the conductive bottom block 8). Although the encapsulation material slightly affects the inductance due to its material characteristics, it can greatly reduce the hysteresis loss and eddy current loss.

[0069] Inductor is an important passive component, widely used in various electronic circuits. Its function is to store and release electrical energy through the principle of electromagnetic induction. Its specific functions are:

[0070] 1. Limit the rate of change of current: Inductance has the function of preventing sudden changes in current. When the current in the circuit changes, the inductor will generate electromagnetic induction force to prevent the change of current, that is, the magnetic core and coil will generate self-inductance or mutual inductance, thereby smoothing the current waveform and preventing sudden changes in current. This plays an important role in the filter circuit of the DC power supply, which can reduce the current ripple and make the power supply output more stable.

[0071] 2. Energy storage: Inductors have the ability to store electrical energy. When the current on the inductor changes, electrical energy will be stored in the inductor. When the current change stops, the stored electrical energy will be released. That is, when the magnetic core is working in the circuit, the current passes through the coil and generates a magnetic field around the coil. Due to the magnetic field, the magnetic core will gradually magnetize and store magnetic energy, thus playing a role of energy storage. This plays an important role in the filter circuit in the AC power supply, which can balance the current waveform and provide stable power output.

[0072] 3. Impedance change: Inductors have impedance change characteristics for AC current. When AC current passes through an inductor, the impedance of the inductor to the current will change with the frequency. The impedance presented by the inductor coil to the current signal utilizes the self-inductance of the coil. This plays an important role in frequency selective circuits, which can select signals of specific frequencies to pass through and suppress signals of other frequencies.

[0073] Among them, as attached Fig.12 -Attached Fig.15 The manufacturing steps of the top circuit 5 are shown in the figure, encapsulating the middle column 3, the connecting column 4 and the magnetic core 9, and grinding the top surface of the encapsulation horizontally by mechanical grinding until the top surface of the middle column 3 and the connecting column 4 are exposed. At this time, the magnetic core 9 is encapsulated in the encapsulation material (as shown in the figure). Fig.12 As shown, attached Fig.13 For attachment Fig.12 ), the exposed middle pillar 3 is directly electroplated to form a top-layer circuit 5, and the B end of a top-layer circuit 5 located at the edge of the arrangement is electrically connected to the exposed connection pillar 4 through an electroplating process (as shown in the attached figure). Fig.14 As shown, attached Fig.15 For attachment Fig.14 The bottom line 2, the middle column 3, the connecting column 4 and the top line 5 constitute a spiral coil with electrical input at one end and electrical output at the other end, and the magnetic core 9 is arranged in the middle part of the spiral coil.

[0074] Among them, as attached Fig.16As shown in the product unit manufacturing steps, the electroplated top layer circuit 5 is further encapsulated, and the encapsulation process of each step finally forms an integral package body 1. After the encapsulation material is solidified, the substrate is peeled off and removed. The adhesive layer can be removed by chemical corrosion, mechanical peeling, chemical mechanical polishing (CMP), mechanical grinding, thermal baking, etc., so that the substrate is peeled off, and the bottom surface of the conductive bottom block 8 is flush with the bottom surface of the package body 1 and exposed. The encapsulation material is vertically cut at the product cutting position to obtain a separated product unit (such as the attached Fig.16 As shown), since the present application sets 8 conductive bottom blocks 8 on the substrate, the 8 conductive bottom blocks 8 respectively constitute the electrical input terminal and the electrical output terminal of the package body 1 of four groups of product units, and each group of product units is provided with two conductive bottom blocks 8, the electrical input terminal inputs electricity, and respectively outputs electricity through the A terminal 6, the bottom line 2, the middle column 3, the top line 5, the B terminal 7, the connecting column 4, and the electrical output terminal, and the product unit is finally welded and mounted on the corresponding working area through the conductive bottom block 8 on the bottom.

[0075] If the conductive bottom block 8 flush with the bottom surface of the package body 1 is directly welded in the working area, the size, shape and number of the conductive bottom block 8 need to be designed so that the package body 1 and the welding area have sufficient welding area and stress points to ensure that the force of the package body 1 is balanced after welding and the structure is stable.

[0076] According to the welding situation, the exposed protruding solder feet can continue to be electroplated on the bottom surface of the exposed conductive bottom block 8 to ensure the welding effect, so as to avoid the inability to observe tin creeping during welding of the conductive bottom block 8 that is flush with the bottom surface of the package body 1, resulting in the inability to judge the welding effect and prone to open circuit or short circuit. The exposed protruding solder feet raise the welding point of the conductive bottom block 8 of the package body 1, which is convenient for observing tin creeping during welding and ensuring the welding quality.

[0077] All the steps of the electroplating process used in this application are to first form electroplating protection on the surface through exposure and development photolithography technology, and then form a metal seed layer in the area to be electroplated by sputtering or sinking. The metal seed layer is copper or copper alloy, iron, iron alloy, nickel, nickel alloy, tungsten and other metal materials. The metal seed layer is to ensure the bonding force between the subsequent electroplated metal and the plastic packaging material, and at the same time provide a surface for the conductive ions to adhere to the electroplating to ensure the electroplating effect. The use of photoresist in the electroplating process is also a technical common sense in the field, and the metal material for electroplating can be set according to the material of the inductor coil.

[0078] All steps using packaging technology in this application use plastic packaging material injection molding combined with molding or transfer molding to form the package. The plastic packaging material used in this application is EMC (epoxy resin plastic packaging material), which has low cost and good curing performance. Other materials may also be used, such as one or more of polyimide resin, benzocyclobutene resin, polybenzoxazole resin, polyethylene, etc.

[0079] By the above-mentioned inductor structure packaging method, an inductor packaging structure (such as the attached Fig.17 As shown), the packaging structure includes a packaging body 1, and the packaging body 1 encapsulates:

[0080] A bottom layer circuit 2, the bottom layer circuit 2 is encapsulated at the bottom of the package body 1, and a plurality of bottom layer circuits 2 are arranged in a horizontal direction;

[0081] The middle column 3 and the connecting column 4, the middle column 3 is vertically electroplated at the end of each bottom line 2, the connecting column 4 and the middle column 3 and the bottom line 2 are electroplated at the same time, and the top surface of the connecting column 4 after electroplating is coplanar with the top surface of the middle column 3;

[0082] Top-layer circuit 5, multiple top-layer circuits 5 are electroplated between the ends of the middle pillars 3, and the B ends 7 of the top-layer circuits 5 at the edge of the arrangement are electrically connected to the connecting pillars 4 through an electroplating process;

[0083] The bottom line 2, the middle column 3, the connecting column 4 and the top line 5 form a spiral coil with electrical input at one end and electrical output at the other end.

[0084] At the same time, two conductive bottom blocks 5 are also encapsulated in the package body 1. The bottom surface of the conductive bottom block 5 is flush with and exposed to the bottom surface of the package body 1. The two conductive bottom blocks 8 serve as the electrical input terminal and the electrical output terminal of the package body 1 respectively. The A end 6 of a bottom line 2 located at the edge of the arrangement is electrically connected to one of the conductive bottom blocks 8 through an electroplating process. The bottom end of the connecting column 4 is electrically connected to the other conductive bottom block 8. The middle column 3 is formed through two electroplating, encapsulation, and grinding processes. A magnetic core 9 is also encapsulated in the package body 1, and the magnetic core 9 is arranged between the bottom line 2 and the top line 5.

[0085] The present application: The process flow can flexibly electroplate a spiral coil around the irregularly shaped magnetic core 9, while meeting the requirement of a small volume of the inductor structure, and can solve the problem that the irregularly shaped magnetic core 9 is difficult to form an inductor; through two electroplating times and an encapsulation process in between the two electroplating times, the shape, structure, and size of the column electroplated each time can be flexibly controlled, and the bottom column is electroplated and encapsulated before being electroplated again. The two parts of the column can be set to different sizes to ensure that there is sufficient contact area between the middle column 3, the connecting column 4 and the encapsulation material to prevent separation from the encapsulation material, effectively avoiding the difficulty of electroplating when the column height is high, and the process is simple, efficient, and safe.

[0086] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present invention are within the scope of protection of the present invention.

Claims

1. A method for packaging an inductor structure, characterized in that: The following steps are involved: The bottom line manufacturing steps are as follows: electroplating a plurality of bottom lines on the bottom encapsulation layer, wherein the plurality of bottom lines are arranged in a horizontal direction; The intermediate pillar forming step: an intermediate pillar is vertically electroplated at the end of each bottom line, and the intermediate pillar is divided into a first intermediate pillar and a second intermediate pillar; The connecting column forming step includes: electroplating the connecting column while electroplating the bottom line and the middle column, the connecting column includes a first connecting column, a second connecting column and a third connecting column, electroplating the first connecting column of the same height while electroplating the bottom line, electroplating the second connecting column whose top surface is flush with the first middle column while electroplating the first middle column at the end of each bottom line, continuing to encapsulate on the basis of the bottom encapsulation layer by the encapsulation material, making an encapsulation top surface to completely encapsulate the top surfaces of the first middle column and the second connecting column, horizontal mechanical grinding on the encapsulation top surface until the top surfaces of the first middle column and the second connecting column are exposed, continuing to electroplate the second middle column and the third connecting column on the top surfaces of the exposed first middle column and the second connecting column, the second middle column and the first middle column are connected to form an integral middle column by electroplating, the first connecting column, the third connecting column and the second connecting column are connected to form an integral connecting column by electroplating, and the top surface of the connecting column is coplanar with the top surface of the middle column; The top-layer circuit manufacturing steps are as follows: encapsulating and horizontally grinding to expose the top surfaces of the connecting pillars and the middle pillars, electroplating multiple top-layer circuits between the middle pillars, and electrically connecting the B end of a top-layer circuit located at the edge of the arrangement with the connecting pillars through an electroplating process. The bottom-layer circuit, the middle pillar, the connecting pillars and the top-layer circuit form a spiral coil with electrical input at one end and electrical output at the other end. Product unit production steps: Continue encapsulation, the top layer circuit is completely encapsulated in the encapsulation material, and the encapsulation material is vertically cut at the product cutting line position to obtain separated product units.

2. The inductor structure packaging method according to claim 1, characterized in that: In the bottom layer circuit manufacturing step, a conductive bottom block is encapsulated inside the bottom encapsulation layer, and after encapsulation, the top surface of the encapsulation is horizontally ground to expose the top surface of the conductive bottom block, and an A end of a bottom layer circuit located at the edge of the arrangement is electrically connected to one of the conductive bottom blocks through an electroplating process.

3. The inductor structure packaging method according to claim 2, characterized in that: In the step of forming the connection column, the bottom end of the connection column is electrically connected to the conductive bottom block.

4. The inductor structure packaging method according to claim 3, characterized in that: In the product unit manufacturing step, the encapsulation layers of all steps in the packaging method finally form a packaging body, the bottom surface of the conductive bottom block of the product unit is flush with and exposed to the bottom surface of the packaging body, and the two conductive bottom blocks serve as the electrical input terminal and electrical output terminal of the packaging body respectively.

5. The inductor structure packaging method according to claim 1, characterized in that: In the intermediate column forming step, two sections of the intermediate column connected together are formed through two electroplating, encapsulation and grinding processes.

6. The inductor structure packaging method according to claim 1, characterized in that: Between the connecting column forming step and the top-layer circuit making step, there is also a magnetic core mounting step: the electroplated middle column has a set height to form a spatial groove to accommodate the magnetic core, the magnetic core is mounted in the middle part of the spatial groove, and the top surfaces of the connecting column and the middle column are exposed by encapsulating and horizontally grinding.

7. An inductor packaging structure, comprising a packaging body, characterized in that: The package contains: The bottom layer circuit is encapsulated at the bottom of the package body, and a plurality of bottom layer circuits are arranged in a horizontal direction; Intermediate columns and connecting columns, the intermediate columns are divided into first intermediate columns and second intermediate columns, the connecting columns include first connecting columns, second connecting columns and third connecting columns, the first connecting columns of equal height are plated while the bottom line is plated, the second connecting columns whose top surfaces are flush with the first intermediate columns are plated on the first connecting columns while the first intermediate columns are plated at the ends of each bottom line, the encapsulation material is used to continue encapsulating on the basis of the bottom encapsulation layer, the encapsulation top surface is made to completely encapsulate the top surfaces of the first intermediate columns and the second connecting columns, the encapsulation top surface is horizontally mechanically ground until the top surfaces of the first intermediate columns and the second connecting columns are exposed, the second intermediate columns and the third connecting columns are further plated on the exposed top surfaces of the first intermediate columns and the second connecting columns, the second intermediate columns and the first intermediate columns are connected to form an integral intermediate column by electroplating, the first connecting columns, the third connecting columns and the second connecting columns are connected to form an integral connecting column by electroplating, the intermediate columns are vertically plated at the ends of each bottom line, the connecting columns, the intermediate columns and the bottom lines are plated simultaneously, and the top surfaces of the connecting columns after electroplating are coplanar with the top surfaces of the intermediate columns; Top-layer circuits: electroplate multiple top-layer circuits between the ends of the middle pillars, and electrically connect the B ends of the top-layer circuits at the edge of the arrangement to the connecting pillars through an electroplating process; The bottom layer circuit, the middle column, the connecting column and the top layer circuit constitute a spiral coil with electrical input at one end and electrical output at the other end.

8. The inductor packaging structure according to claim 7, characterized in that: The package body also contains two conductive bottom blocks, the bottom surface of the conductive bottom blocks is flush with and exposed to the bottom surface of the package body, and the two conductive bottom blocks serve as the electrical input terminal and the electrical output terminal of the package body respectively.

9. The inductor packaging structure according to claim 8, characterized in that: The A end of a bottom layer line located at the edge of the arrangement is electrically connected to one of the conductive bottom blocks through an electroplating process.

10. The inductor packaging structure according to claim 9, characterized in that: The bottom end of the connecting column is electrically connected to another conductive bottom block.

11. The inductor packaging structure according to claim 7, characterized in that: The intermediate column is formed by two electroplating, encapsulation and grinding processes.

12. The inductor packaging structure according to claim 7, characterized in that: The package also contains a magnetic core, which is arranged between the bottom layer circuit and the top layer circuit.

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