Package substrate, method of manufacturing the same, and package substrate heat dissipation detection system and method

Abstract

The application provides a packaging substrate, a preparation method thereof, and a packaging substrate heat dissipation detection system and method. The preparation method of the packaging substrate comprises the following steps: S11, providing a support plate attached with a detachable film; S12, preparing a first metal block on the detachable film by using a dry process; S13, forming a first dielectric layer on the detachable film and the first metal block to encapsulate the first metal block, so that a packaging substrate structure is obtained; S14, forming a first metal seed layer on the surface of the packaging substrate structure; S15, forming a first metal disc and a first circuit on the first metal seed layer; S16, removing the support plate through the detachable film, and reversing the packaging substrate structure; and S17, sequentially forming a second metal seed layer, a second metal disc and a second circuit on the surface of the packaging substrate structure. Compared with a traditional manual copper block embedding process, the application can effectively avoid the problems of low alignment accuracy, substrate delamination, board explosion and yield reduction, and the process method is environmentally friendly and low in cost, so that the application is conducive to popularization.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing, and in particular to a packaging substrate, its preparation method, and a heat dissipation detection system and method for the packaging substrate. Background Technology

[0002] With the development of modern society, especially with the advent of the 5G era, electronic products are becoming increasingly multifunctional and highly integrated. High-power electronic components such as high-frequency radio frequency (RF) and power amplifiers place increasingly higher demands on the heat dissipation capabilities of packaging substrates. This has spurred the development of high-density and diversified substrate heat dissipation structure designs. High-frequency, high-speed substrates, which possess high-speed, low-power, and high-quality signal transmission capabilities, need to adapt to the high power consumption performance of high-frequency, high-power components. If the power consumption inside the substrate is high and the heat dissipation structure is small, the overall heat of the substrate will rise sharply. Furthermore, due to the different thermal expansion coefficients of the materials within the board, different degrees of expansion will occur between the materials after absorbing heat, inducing different internal stresses, resulting in problems such as delamination, blistering, and board bursting. Long-term operation can easily lead to a decline in the electrical performance of the substrate or even damage. Therefore, solving the heat dissipation problem of packaging substrates is particularly important.

[0003] This led to the development of a copper-embedded block technology, which directly embeds a highly thermally conductive metal block, such as copper, within the substrate to solve the heat dissipation problem of the packaging substrate. The core steps in the traditional manufacturing process of a copper-embedded block substrate include: material preparation—preparation of the copper embedding trench—embedding the copper block—lamination—removal of excess adhesive. While the copper-embedded block technology can improve the heat dissipation of the substrate to some extent, some problems can also arise during the manufacturing process, such as:

[0004] 1) Embedding copper blocks in the substrate is a manual operation, which is not efficient. Moreover, the alignment during embedding is difficult to control accurately, and there are height differences between the two ends of the copper block and the board surface. For example, the copper block may be concave or convex, making it difficult to achieve stable control.

[0005] 2) During the lamination process, the prepreg or dielectric layer has flow properties under high temperature conditions. After the copper block is embedded and laminated, a layer of resin glue will cover the copper block. The resin glue cannot be completely removed in subsequent processes, and the residual resin glue will affect the reliability of the product.

[0006] 3) The bonding force between the high thermal conductivity copper block and the dielectric layer or the substrate in the core board is not good. After heat dissipation and heating, the different thermal expansion coefficients of the materials lead to increased stress, which can easily cause quality problems such as delamination and board bursting.

[0007] In view of the above, it is necessary to provide a packaging substrate and its preparation method, as well as a packaging substrate heat dissipation detection system and method, to solve the problems in the existing copper block technology that avoid many problems in the traditional copper block process, such as the height difference between the copper block and the carrier board, glue overflow, delamination, board bursting and other quality problems. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a packaging substrate and its preparation method, as well as a packaging substrate heat dissipation detection system and method, so as to solve the problems in the prior art of copper block embedding technology, which avoids many problems in the traditional copper block embedding process, such as the height difference between the copper block and the carrier board, glue overflow, delamination, board bursting and other quality problems.

[0009] To achieve the above and other related objectives, the present invention provides a method for preparing a packaging substrate, the method comprising:

[0010] S11: Provides a support plate with a removable membrane;

[0011] S12: A first metal block is prepared on the dissociable membrane using a dry process;

[0012] S13: A first dielectric layer is formed on the detachable film and the first metal block to encapsulate the first metal block and obtain a packaged substrate structure;

[0013] S14: A first metal seed layer is formed on the surface of the packaging substrate structure;

[0014] S15: A first metal disk and a first circuit are formed on the first metal seed layer;

[0015] S16: Remove the support plate through the removable membrane and reverse the packaging substrate structure;

[0016] S17: A second metal seed layer, a second metal disk, and a second circuit are sequentially formed on the surface of the above-mentioned packaging substrate structure, wherein the first metal seed layer, the first metal disk, and the first circuit are located on opposite sides of the packaging substrate structure, and the packaging substrate is obtained.

[0017] Optionally, when the height of the packaging substrate is less than that of a packaging substrate with a preset height, steps S12 to S15 are repeated at least once after step S15 until the packaging substrate with the preset height is formed.

[0018] Optionally, when the step of forming the metal block is repeated multiple times, the type of the metal block is divided into through-type metal block and semi-embedded metal block.

[0019] Optionally, the method for preparing the packaging substrate further includes a step of performing a solder resist process on the upper and lower surfaces of the packaging substrate to protect the outer layer structure of the packaging substrate from oxidation.

[0020] Optionally, the first metal block is a copper block, and the height of the copper block ranges from 5μm to 80μm.

[0021] Optionally, the dry process is 3D printing technology.

[0022] Optionally, the printing material used to prepare the first metal block by the 3D printing technology is one of a mixed slurry including conductive silver and copper particles or a pure metal nano slurry.

[0023] Optionally, the method for preparing the first metal block further includes: firstly, when forming the first dielectric layer, the top of the first dielectric layer is higher than the first metal block; then, a through-hole heat dissipation hole is formed in the first dielectric layer above the first metal block, and the hole is filled to form a metallization layer; or a ring of ink fence is first formed around the first metal block to be printed, and then the first metal block is printed, and the ink fence is removed; or a dry film is attached to the removable film, then exposed and developed, and then the first metal block is printed, and the dry film is removed.

[0024] The present invention also provides a packaging substrate, which is prepared by any one of the packaging substrate preparation methods described above.

[0025] The present invention also provides a heat dissipation detection system for a packaging substrate, the heat dissipation detection system for a packaging substrate includes: a packaging substrate, a heat-generating component, a thermocouple, a computer, and an infrared thermal imager; one end of the thermocouple is connected to the heat-generating component mounted on the packaging substrate, and the other end is connected to the computer.

[0026] The present invention also provides a method for detecting heat dissipation of a packaging substrate, the method comprising:

[0027] S21: Provides a heat dissipation detection system for the packaging substrate;

[0028] S22: The thermocouple collects the thermal energy of the heating element and then converts it into electrical energy, which is displayed on the computer.

[0029] S23: Collect temperature data of the heating element using the infrared thermal imager;

[0030] S24: Record and organize the above data, and conduct comparative analysis.

[0031] As described above, the packaging substrate and its preparation method, as well as the packaging substrate heat dissipation detection system and method of the present invention, have the following beneficial effects:

[0032] The support plate of this invention is reusable, reducing cost waste and effectively avoiding problems such as warping and jamming caused by excessive thinness or expansion / contraction of the packaging substrate during production. The metal block of this invention can directly contact the removable membrane, and the dielectric layer is laminated after the metal block is prepared, resulting in better adhesion and increased reliability of the packaging substrate. After removing the removable membrane, there is no residual adhesive from the dielectric layer on the surface of the metal block, avoiding the height difference problem between the metal block and the dielectric layer. This invention uses a dry process to prepare the metal block, reducing wastewater generation, mitigating environmental pollution, and making it more environmentally friendly. Compared to the traditional manual copper embedding process, this invention can effectively avoid problems such as low alignment accuracy, substrate delamination, and board bursting that reduce yield. It offers greater flexibility and versatility in fabrication, shorter production cycles, and higher production efficiency. The circuit layers of this invention are fabricated using an additive method, which, compared to previous subtractive or semi-additive methods, allows for finer circuitry and pads. The embedded metal blocks in the packaging substrate of this invention provide excellent heat dissipation, extending the lifespan of subsequently connected heat-generating components. Furthermore, the heat dissipation detection method for the packaging substrate of this invention offers advantages such as fast detection speed, low cost, high versatility, and ease of operation. Attached Figure Description

[0033] Figure 1 The diagram shows a flow chart of the method for preparing the packaging substrate of the present invention.

[0034] Figure 2 The diagram shown is a structural schematic of the packaging substrate of the present invention.

[0035] Figures 3 to 12 The diagram shows the structural schematics of each step in the preparation method of the packaging substrate of the present invention.

[0036] Figures 13 to 20 The diagram shows the structural schematics of the various steps in the methods for preparing the first metal block according to the present invention.

[0037] Figure 21 The diagram shows a flowchart of the heat dissipation detection method for the packaging substrate of the present invention.

[0038] Component designation explanation

[0039] 10 Support Plates

[0040] 20. Dissociable membrane

[0041] 31 First metal block

[0042] 32 Second metal block

[0043] 41 First dielectric layer

[0044] 42 Second dielectric layer

[0045] 51 First Seed Layer

[0046] 52 Second Seed Layer

[0047] 60 dry film

[0048] 71 First Metal Disk

[0049] 72 First Route

[0050] 73 Second Metal Disk

[0051] 74 Second Route

[0052] 75 Third Metal Disk

[0053] 76 Third Route

[0054] 81 ventilation holes

[0055] 82 Filling holes

[0056] 90 Ink Fence Detailed Implementation

[0057] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0058] Please see Figures 1 to 21 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0059] Example 1

[0060] like Figure 1 and Figure 2 As shown, this embodiment provides a method for preparing a packaging substrate, the method comprising the following steps:

[0061] S11: Provide a support plate 10 with a removable membrane 20 attached;

[0062] S12: A first metal block 31 is prepared on the dissociable membrane 20 using a dry process;

[0063] S13: A first dielectric layer 41 is formed on the detachable film 20 and the first metal block 31 shown, so as to encapsulate the first metal block 31 to obtain a packaged substrate structure;

[0064] S14: A first metal seed layer 51 is formed on the surface of the packaging substrate structure;

[0065] S15: A first metal disk 71 and a first circuit 72 are formed on the first metal seed layer 51;

[0066] S16: Remove the support plate 10 through the removable membrane 20 and reverse the encapsulation substrate structure;

[0067] S17: A second metal seed layer 52, a second metal disk 73, and a second line 74 are sequentially formed on the surface of the packaging substrate structure, wherein the first metal seed layer 51, the first metal disk 71, and the first line 72 are located on opposite sides of the packaging substrate structure, and the packaging substrate is obtained.

[0068] The support plate 10 in this embodiment is reusable, reducing cost waste and effectively preventing warping and jamming problems caused by the thinness or expansion / contraction of the packaging substrate during production. The first metal block 31 in this embodiment can directly contact the removable membrane 20. After preparing the first metal block 31, the first dielectric layer 41 is pressed together, resulting in better adhesion and increased reliability of the packaging substrate. After removing the removable membrane 20, there is no residual adhesive from the first dielectric layer 41 on the surface of the first metal block 31, avoiding high adhesion between the first metal block 31 and the first dielectric layer 41. The present embodiment employs a dry process to prepare the first metal block 31, which reduces wastewater generation, mitigates environmental pollution, and is more environmentally friendly. Compared to the traditional manual copper block embedding process, this embodiment can effectively avoid problems such as low alignment accuracy, substrate delamination, and board bursting that reduce yield. The preparation is more flexible and versatile, with a shorter production cycle and higher production efficiency. The circuit layer in this embodiment is prepared using an additive method, which, compared to the previous subtractive or semi-additive methods, can achieve finer circuits and pads. The packaging substrate in this embodiment has good heat dissipation due to the embedded metal block, which also extends the service life of the heat-generating components that are connected later.

[0069] See Figures 1 to 12 The following description, in conjunction with the accompanying drawings, further illustrates this embodiment.

[0070] like Figure 1 S11 and Figure 3 As shown, as an example, step S11 is performed first, providing a support plate 10 with a removable membrane 20 attached.

[0071] The support plate 10 has a certain rigidity, sufficient to support other structures formed on its surface. The removable membrane 20 attached to the support plate 10 is used in subsequent processes to facilitate the removal of the support plate 10. The thickness of the support plate 10 and the thickness of the removable membrane 20 are not limited and can be set according to actual needs, as long as they meet the above requirements. The support plate 10 is made of one or more of inorganic materials, organic polymers, etc. Furthermore, the support plate 10 is reusable, reducing cost waste to a certain extent.

[0072] like Figure 1 S12 and Figure 4 As shown, as an example, step S12 is then performed to prepare a first metal block 31 on the dissociable membrane 20 using a dry process.

[0073] The dry process is 3D printing technology, which is relatively green and environmentally friendly. The printing material used to prepare the first metal block 31 by the 3D printing technology is either a mixed slurry including conductive silver and copper particles or a pure metal nano-slurry. The slurry utilization rate is high, which will not lead to a lot of waste, thus making the overall cost lower. When printing the first metal block 31 by the 3D printing technology, printing and laser sintering can be performed simultaneously, or printing can be performed first and then sintering and solidifying. The forming method can be set according to actual needs and is not limited here.

[0074] The shape of the first metal block 31 in this embodiment can be set according to the actual situation and is not limited here. It can be one or more of the following: cuboid, cylindrical, and polygonal prism. In this embodiment, in order to ensure that the heat dissipation effect of each layer is the same, it is preferred to use the same shape. Taking the cuboid shape as an example, the cross-sectional length × width range is 1mm × 1mm to 20mm × 20mm. Due to the heat dissipation effect of the first metal block 31 on the packaging substrate and the limitation of the 3D printing method, its height is limited, and the height range is 5μm to 80μm. In this embodiment, due to the heat dissipation effect and low cost of copper, the first metal block 31 is preferably made of copper.

[0075] like Figure 1 S13 and Figures 5 to 6 As shown, as an example, step S13 is then performed to form a first dielectric layer 41 on the removable film 20 and the first metal block 31 to encapsulate the first metal block 31 and obtain a packaged substrate structure.

[0076] A first dielectric layer 41, also called an insulating layer, is laminated onto the resolvable film 20 and the first metal block 31. This can include all insulating dielectric layers of the PCB. The first dielectric layer 41 is made of one or more of the following materials: epoxy resin, polyimide, polymaleimide triazine resin, polyphenylene ether or polytetrafluoroethylene, glass, quartz, or silicon dioxide. Lamination is performed using hot pressing or vacuum lamination. The first dielectric layer 41 becomes fluid during lamination, thus filling the gaps between the first metal blocks 31. It should be noted that after lamination, the height of the first dielectric layer 41 needs to be greater than the height of the first metal blocks 31 (e.g., ...). Figure 5 (As shown).

[0077] like Figure 6 As shown, the top layer of the above structure undergoes physical polishing or grinding and plasma dry etching processes to expose the top of the first metal block 31. Simultaneously, the ends of the first metal block 31 printed by the 3D printing method are ground away, resulting in a complete columnar shape for the first metal block 31. After grinding the above structure, a small amount of residual adhesive from the first dielectric layer 41 will remain on the top surface of the first metal block 31. Appropriate surface treatment, such as plasma treatment or chemical adhesive removal, can be performed to increase the surface roughness and cleanliness of the structure, thereby increasing the adhesion between the first metal seed layer 51 and the substrate surface.

[0078] like Figure 1 S14 and Figure 7 As shown, as an example, step S14 is then performed to form a first metal seed layer 51 on the surface of the packaging substrate structure.

[0079] The material of the first metal seed layer 51 is one or a combination of two or more of titanium, copper and titanium-tungsten alloy; the process method for forming the first metal seed layer 51 is chemical copper plating or sputtering.

[0080] like Figure 1 S15 and Figures 8 to 9 As shown, as an example, step S15 is then performed: a first metal disk 71 and a first line 72 are formed on the first metal seed layer 51.

[0081] A pattern transfer process is performed on the first metal seed layer 51, including the steps of film application, exposure, and development. First, a dry film 60 is applied to the first metal seed layer 51. After exposure and development, metal is electroplated on the developed pattern. After electroplating, the applied dry film is removed, and the first metal seed layer 51 under the dry film is flash-etched away. At this point, the first metal disk 71 and the first circuit 72 are formed. It should be noted that the first metal disk 71 is located at the end of the first metal block 31, and its cross-section is larger than that of the first metal block 31 to avoid short circuits in the packaging substrate due to misalignment of the first metal block 31. The developed groove can be circular, square, or polygonal, depending on actual needs, and is not limited here. The shape of the developed groove is also the shape of the cross-section of the first metal disk 71 and the first circuit 72. The two shapes can be the same or different. In this embodiment, the material of the first metal disk 71 and the first circuit 72 is preferably copper.

[0082] like Figure 1 S16 and Figure 10 As shown, as an example, step S16 is then performed, in which the support plate 10 is removed by the removable membrane 20, and the encapsulation substrate structure is reversed.

[0083] Laser or physical dissociation can be performed from the support plate 10 away from the dissociable membrane 20 to separate the dissociable membrane 20 and the support plate 10 from the first metal block 31, and at the same time, the packaging substrate structure can be reversed by 180°.

[0084] like Figure 1 S17 and Figure 11 As shown, as an example, step S17 is performed last, in which a second metal seed layer 52, a second metal disk 73, and a second line 74 are sequentially formed on the surface of the packaging substrate structure. The first metal seed layer 51, the first metal disk 71, and the first line 72 are located on opposite sides of the packaging substrate structure, and the packaging substrate is obtained.

[0085] Using the same method as steps S14 and S15 above, the second metal seed layer 52, the second metal disk 73, and the second circuit 74 are sequentially formed on the surface of the packaging substrate structure.

[0086] The process for forming the second metal seed layer 52 is a chemical electroless copper plating process or a sputtering process. The material of the second metal seed layer 52 is one of titanium, copper and titanium-tungsten alloy. The materials used for the first metal seed layer 51 and the second metal seed layer 52 may be the same or different. In this embodiment, considering the need to maintain the same heat dissipation effect of the overall structure, the same material is preferred.

[0087] The process used to form the second metal disk 73 and the second line 74 is also a pattern transfer process. The second metal disk 73 is located at the other end of the first metal block 31. Other requirements are the same as in step S15 above, and have been described in detail, so they will not be repeated here.

[0088] like Figure 12 As an example, when the height of the packaging substrate is less than the preset height of the packaging substrate, steps S12 to S15 are repeated at least once to form the second metal block 32, the third metal disk 75, and the third line 76 until the packaging substrate reaches the preset height.

[0089] It should be noted that the second metal block 32 is formed directly on the first metal disk 71, and the second dielectric layer 42 is formed on the first dielectric layer 41 and the first metal block 31 to encapsulate the second metal block 32. A third metal seed layer 53 is formed on the surface of the above-mentioned packaging substrate structure, and a third metal disk 75 and a third circuit 76 are formed on the third metal seed layer 53. The process methods and materials involved in the repeated steps are the same as those in steps S12 to S15, which have been described in detail above and will not be repeated here.

[0090] As an example, when the step of forming the metal block is repeated multiple times, the type of the metal block is divided into through-type metal block and semi-buried metal block.

[0091] The encapsulation substrate is prepared using an addition method, and the metal blocks can be formed repeatedly. When all the metal blocks formed in the encapsulation substrate penetrate the entire encapsulation substrate, all the metal blocks are the through-type metal blocks (e.g., ...). Figure 12 (as shown); when the metal block in the packaging substrate is not entirely present in every dielectric layer during the formation process, the metal block is the semi-buried metal block. When preparing the semi-buried metal block, the step of preparing the metal block only needs to be omitted in a certain dielectric layer of the packaging substrate.

[0092] As an example, the method for preparing the packaging substrate further includes a step of performing a solder resist process on the upper and lower surfaces of the packaging substrate to protect the outer layer structure of the packaging substrate from oxidation.

[0093] The outer structure of the packaging substrate consists of metal disks and circuits, such as the first metal disk 71 and the first circuit 72 and the second metal disk 73 and the second circuit 74 in this embodiment. The solder mask process can protect them from oxidation and ensure the yield of the packaging substrate before use.

[0094] like Figures 13 to 18 As shown, as an example, the method for preparing the first metal block further includes: when forming the first dielectric layer 41, the top of which should be higher than the first metal block 31; then forming heat dissipation holes above the first metal block 31 and filling the holes to form a metallization layer; or forming an ink barrier 90 around the first metal block 31 to be printed before printing the first metal block and removing the ink barrier 90; or attaching a dry film 60 to the removable film 20, then exposing and developing it before printing the first metal block 31 and removing the dry film 60.

[0095] like Figures 13 to 14 As shown, in a preferred embodiment, after the first metal block 31 is prepared on the dissociable membrane 20, the first dielectric layer 41 is pressed together. After pressing, the top of the first dielectric layer 41 is higher than the height of the first metal block 31. Then, a through-hole is formed above the first metal block 31. The diameter of the through-hole is at least 20 μm, which becomes the heat dissipation hole 81 (e.g., Figure 13 As shown), after the heat dissipation holes are formed, holes 82 are filled (as shown). Figure 14 As shown in the diagram, a metallization layer is formed. The material used for the via filling 82 is the same as that used for the first metal block 31. The via filling is performed using an electroplating process. The subsequent manufacturing process of the packaging substrate can also follow the above steps. The blind holes on the first metal block 31 serve as the heat dissipation holes 81. The number of blind holes, the hole diameter, and the height of the electroplated metal inside the holes all affect the total thermal conductivity of the first metal block 31. Theoretically, the more holes per unit area, the larger the hole diameter, and the thicker the electroplated metal inside the holes, the better the thermal conductivity. Therefore, a comprehensive consideration is required in actual manufacturing. The above parameters are not limited here. The optimal number of holes and hole diameter are designed on the first metal block 31 per unit area to ensure both good thermal conductivity and that the electroplated metal can fill the blind holes completely, ensuring the flatness and solderability of the subsequent chip pad surface. It should be noted that the height of the electroplated metal inside the holes, i.e., the top of the first dielectric layer 41, is higher than the height of the first metal block 3. This method of forming the first metal block 31 eliminates the need for grinding and cleaning the top of the first dielectric layer 41, allowing for direct attachment of heat-generating devices to its surface, resulting in better heat dissipation.

[0096] like Figures 15 to 17As shown, in another preferred embodiment, in order to make the shape of the first metal block 31 more regular and precise, an ink grid 90 is first formed around the first metal block 31 to be printed (e.g., ...). Figure 15 As shown), the ink grid 90 can also be printed using the 3D printing technology. The shape and height of the ink grid 90 can be set according to the preset shape and height of the first metal block 31, and are not limited here. After the ink grid 90 is formed, the first metal block 31 can be printed (e.g., ...). Figure 16 (As shown). Besides resulting in a more regular and precise shape for the first metal block 31, this method also simplifies the removal process; the ink fence 90 can be removed by soaking it in a film-removing solution whose main component is sodium hydroxide. Figure 17 As shown in the figure, the first metal block 31 is now complete. The subsequent manufacturing process of the packaging substrate can also be carried out according to the above steps.

[0097] like Figures 18 to 20 As shown, in another preferred embodiment, to make the shape of the first metal block 31 more regular and precise, the first metal block 31 is prepared by a pattern transfer process, a dry film 60 is attached to the removable film 20 to form a dry film layer, and then exposure and development are performed to develop grooves at the positions where the first metal block 31 needs to be embedded (e.g., Figure 18 As shown), the first metal block 31 is printed in the developing tank (as shown). Figure 19 (As shown). The shape and height of the developed groove can be set according to the preset shape and height of the first metal block 31, and are not limited here. It can be a circular groove, a square groove, or a polygonal groove, that is, the shape of the first metal block 31 is not limited. After the first metal block 31 is cured and formed, the dry film 60 around the first metal block 31 can be removed in a film-removing solution whose main component is sodium hydroxide (e.g., Figure 20 As shown in the figure, the first metal block 31 is now complete. The subsequent manufacturing process of the packaging substrate can also be carried out according to the above steps.

[0098] In addition to directly using the 3D printing technology to prepare the first metal block 31, the first metal block 31 prepared by the above three methods can all be used as preparation methods for the through-type metal block and the semi-embedded metal block.

[0099] Example 2

[0100] This embodiment provides a specific example of a method for preparing a packaging substrate, which includes the following steps:

[0101] A support plate 10 with the removable membrane 20 is provided. The support plate 10 has a certain rigidity, and the removable membrane 20 can be physically decomposed and peeled off. In this embodiment, the thickness of the support plate 10 is 1 mm, and the thickness of the removable membrane 20 is 10 μm.

[0102] The first metal block 31 is printed on the removable membrane 20 using the 3D printing technology. In this embodiment, the first metal block 31 is a copper block used to dissipate heat from the packaging substrate. The copper block is rectangular in shape with a length, width, and height of 3mm × 3mm × 40μm. Laser sintering is performed simultaneously with the printing of the copper block. The printing material used in the 3D printing technology includes a mixed paste of conductive silver particles and copper. The mixed paste has better heat dissipation performance.

[0103] The first dielectric layer 41 is formed on the removable film 20 and the copper block by hot pressing. The material of the first dielectric layer 41 is an epoxy resin. During the hot pressing process, its fluidity fills the gaps between the copper blocks, and the top of the first dielectric layer 41 is higher than the top of the copper blocks. The surface of the top of the first dielectric layer 41 is ground by physical grinding, exposing the copper blocks and grinding away the ends of the printed copper blocks, so that the copper pillar has a complete cuboid shape. After grinding the above structure, there will still be a small amount of residual adhesive left by the first dielectric layer 41 on the top surface of the copper blocks. In this embodiment, a plasma treatment process is used to remove the adhesive residue, which increases the roughness and cleanliness of the above structure surface, and also increases the adhesion between the first metal seed layer 51 and the substrate surface.

[0104] Titanium and copper are sputtered onto the surface of the aforementioned packaging substrate structure to form a first metal seed layer 51. The sputtered first metal seed layer 51 can be a nanometer-scale titanium metal layer and a copper metal layer. Due to the high conductivity and adhesion of the titanium metal layer, and its good thickness flatness, the subsequently formed circuitry can be firmly bonded to the first dielectric layer 41. In this embodiment, the thickness of the sputtered titanium metal layer is 20 nm, and the thickness of the sputtered copper metal layer is 300 nm. The copper metal is mainly used to adjust the electroplating impedance, making the sputtered first metal seed layer 51 more uniform.

[0105] The first metal seed layer 51 is subjected to a pattern transfer process, including film application, exposure and development. After development, pattern electroplating is performed, followed by film removal. After film removal, the underlying first metal seed layer 51 is flash-etched away, thus forming the first metal disk 71 and the first circuit 72. The materials of the first metal disk 71 and the first circuit 72 are also copper, which is consistent with the material of the first metal block 31.

[0106] After the above-described substrate structure is prepared, the above steps can be repeated to continue printing copper blocks, the second metal disk 73, and the second circuit 74 on the first metal disk 71. The height of the copper blocks printed each time is similar, and the process methods and material types involved are the same as those in the above steps, which have been described in detail and will not be repeated here. If each dielectric layer of the packaging substrate is provided with copper blocks, the type of copper blocks is a through-type copper block. If the copper blocks are not present in all dielectric layers, the copper blocks are semi-embedded copper blocks. In this embodiment, the copper blocks are through-type copper blocks.

[0107] After the second metal disk 73 and the second circuit 74 are prepared, laser dissociation is performed from the support plate 10 away from the removable film 20 to separate the removable film 20 and the support plate 10 from the copper block. After separation, the substrate structure is flipped 180°, and the third metal disk 75 and the third circuit 76 are sequentially formed on the upper surface of the flipped structure. The first metal seed layer 51, the first metal disk 71 and the first circuit 72 are located on opposite sides of the packaging substrate structure, and the second metal seed layer 52, the second metal disk 73 and the second circuit 74 are located on opposite sides of the packaging substrate structure. The process methods and material types involved in the preparation are the same as those in the above steps and have been described in detail, so they will not be repeated here, thus obtaining a complete packaging substrate.

[0108] Finally, a solder mask process is performed on the upper and lower surfaces of the packaging substrate to protect the outer first metal disk 71 and the first line 72, and the third metal disk 75 and the third line 76 from oxidation.

[0109] In this embodiment, the method for preparing the copper block further includes three methods: 1. After preparing the copper block on the removable film 20, the dielectric layer is pressed together. After pressing, the top of the dielectric layer is higher than the height of the copper block. The heights of the copper block and the dielectric layer are 40 μm and 70 μm, respectively. Then, the dielectric layer above the copper block is laser-processed to form a through-hole heat dissipation hole 81 with a diameter of 20 μm and a depth of 30 μm. Electroplated copper is then used to fill the heat dissipation hole 81 to form a thin layer of metallized copper; 2. An ink barrier 90 is first formed around the area where the first copper block needs to be printed. The ink barrier 90 can also be printed using the 3D printing technology. The shape and height of the ink grid 90 can be the same as the preset shape and height of the first copper block. After the ink grid 90 is formed, the copper block can be printed. The ink grid 90 can be removed by soaking in a film-removing solution with sodium hydroxide as the main component, and the copper block is obtained. 3. The copper block is prepared by a pattern transfer process. A dry film 60 is attached to the removable film 20 to form a dry film layer. Then, exposure and development are performed. A groove is developed at the position where the copper block needs to be embedded. The copper block is printed in the developed groove. The shape and height of the developed groove can be the same as the preset shape and height of the copper block. After the copper block is cured and formed, the dry film layer around the copper block can be removed in a film-removing solution with sodium hydroxide as the main component.

[0110] Example 3

[0111] like Figure 2 As shown, this embodiment provides a packaging substrate, which is obtained by the preparation method of Embodiment 1. The packaging substrate includes:

[0112] A dielectric layer containing a metal block, the metal block penetrating the dielectric layer vertically;

[0113] Metal disks and circuits are sequentially disposed on the upper and lower surfaces of the dielectric layer. A metal seed layer is also disposed between the dielectric layer, the metal disks and the circuits. The metal disks are located at both ends of the metal block, and the cross-section of the metal disks is larger than that of the metal block.

[0114] Example 4

[0115] This embodiment provides a heat dissipation detection system for a packaged substrate, used to detect the heat dissipation of the packaged substrate described in Embodiment 3. The heat dissipation detection system includes a packaged substrate, a heat-generating component, a thermocouple, a computer, and an infrared thermal imager. One end of the thermocouple is connected to the heat-generating component mounted on the packaged substrate, and the other end is connected to the computer.

[0116] Example 5

[0117] like Figure 21 As shown, this embodiment provides a method for detecting heat dissipation of a packaging substrate, which includes the following steps:

[0118] like Figure 21 As shown in S21, as an example, a heat dissipation detection system for a packaged substrate as described in claim 4 is provided;

[0119] The packaging substrate in the heat dissipation detection system can be a packaging substrate including a region containing a metal block and a region not containing a metal block, or it can be two packaging substrates, one with a region containing a metal block and the other without a metal block, with no other differences except for the metal block, for comparative detection. In this embodiment, a packaging substrate including a region containing a metal block and a region not containing a metal block is used.

[0120] The heating element can be either a chip or a resistor, and can be set according to the actual situation. There is no restriction here, but in this embodiment, the resistor is preferred.

[0121] like Figure 21 As shown in S22, as an example, the thermocouple collects the thermal energy of the heating element and then converts it into electrical energy displayed on the computer.

[0122] One end of the thermocouple is connected to the resistor mounted on the packaging substrate, and the other end is connected to the computer. It collects the heat energy on the resistor and converts it into electrical energy displayed on the computer. It also needs to be connected to a power source to conduct the circuit of the mounted resistor. After working for a period of time, the temperature distribution will tend to stabilize.

[0123] like Figure 21 As shown in S23, as an example, the infrared thermal imager is used to collect temperature data of the heating element.

[0124] Simultaneously connect the infrared thermal imager. After the simple detection system is connected, power can be supplied. After working for a period of time, once the infrared thermal image of the resistor stabilizes, temperature data can be collected. Different colors in the infrared thermal image represent different temperatures; the brighter the color, the higher the temperature. The right side of the infrared thermal image will have colors representing different temperatures, called color scales.

[0125] like Figure 21 As shown in S24, as an example, the above data is recorded, organized, and compared.

[0126] Once the temperature distribution of the resistors stabilizes, the temperature data of the resistors is collected and statistically analyzed. This detection method can achieve different levels of detection, such as different copper block sizes, etc., to analyze the temperature difference and thus determine the optimal copper block heat dissipation combination. In this embodiment, only the temperature difference between the resistors in the metal block area and the non-metal block area of ​​the packaging substrate is detected. The data clearly shows that the packaging substrate with the metal block area below the resistor has lower heat than the packaging substrate without the metal block area.

[0127] In summary, the present invention provides a packaging substrate and its preparation method, as well as a packaging substrate heat dissipation detection system and method. The preparation method of the packaging substrate includes: S11: providing a support plate with a removable film; S12: preparing a first metal block on the removable film using a dry process; S13: forming a first dielectric layer on the removable film and the first metal block to encapsulate the first metal block, thereby obtaining a packaging substrate structure; S14: forming a first metal seed layer on the surface of the packaging substrate structure; S15: forming a first metal disk and a first circuit on the first metal seed layer; S16: removing the support plate through the removable film and reversing the packaging substrate structure; S17: sequentially forming a second metal seed layer, a second metal disk, and a second circuit on the surface of the packaging substrate structure, wherein the first metal seed layer, the first metal disk, and the first circuit are located on opposite sides of the packaging substrate structure, and the second metal seed layer, the second metal disk, and the second circuit are located on opposite sides of the packaging substrate structure, thereby obtaining the packaging substrate. The support plate of this invention is reusable, reducing cost waste and effectively avoiding problems such as warping and jamming caused by excessive thinness or expansion / contraction of the packaging substrate during production. The metal block of this invention can directly contact the removable membrane, and the dielectric layer is laminated after the metal block is prepared, resulting in better adhesion and increased reliability of the packaging substrate. After removing the removable membrane, there is no residual adhesive from the dielectric layer on the surface of the metal block, avoiding the height difference problem between the metal block and the dielectric layer. This invention uses a dry process to prepare the metal block, reducing wastewater generation, mitigating environmental pollution, and making it more environmentally friendly. Compared to the traditional manual copper embedding process, this invention effectively avoids problems such as low alignment accuracy, substrate delamination, and board bursting that reduce yield. It offers greater flexibility and versatility in fabrication, shorter production cycles, and higher production efficiency. The circuit layers of this invention are fabricated using an additive method, which, compared to previous subtractive or semi-additive methods, allows for finer circuitry and pads. The embedded metal blocks in the packaging substrate of this invention improve heat dissipation, extending the lifespan of subsequently connected heat-generating components. Furthermore, the heat dissipation detection method for the packaging substrate of this invention offers advantages such as fast detection speed, low cost, high versatility, and ease of operation. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and possesses high industrial applicability.

[0128] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a packaging substrate, characterized in that, The method for preparing the packaging substrate includes: S11: Provides a support plate with a removable membrane; S12: A first metal block is prepared on the dissociable membrane using a dry process. The height of the first metal block ranges from 5 μm to 80 μm, and the length × width of the cross-section ranges from 1 mm × 1 mm to 20 mm × 20 mm, in order to serve a heat dissipation function. The dry process is 3D printing technology. The printing material used to prepare the first metal block by the 3D printing technology includes a mixed slurry of conductive particles silver and copper or a pure metal nano slurry. When printing the first metal block by the 3D printing technology, printing and laser sintering are performed simultaneously, or printing is performed first and then sintering and solidifying to form the shape. S13: A first dielectric layer is formed on the detachable film and the first metal block to encapsulate the first metal block, thereby obtaining a packaged substrate structure; wherein, the method for preparing the first metal block further includes: First, when forming the first dielectric layer, the top of the first dielectric layer is higher than the first metal block. Then, a through-hole heat dissipation hole is formed in the first dielectric layer above the first metal block, and the hole is filled to form a metallization layer; or, an ink fence is first formed around the first metal block to be printed, then the first metal block is printed, and the ink fence is removed; or, a dry film is pasted on the removable film, then exposed and developed, then the first metal block is printed, and the dry film is removed. S14: A first metal seed layer is formed on the surface of the packaging substrate structure; S15: A first metal disk and a first circuit are formed on the first metal seed layer; S16: Remove the support plate through the removable membrane and reverse the packaging substrate structure; S17: A second metal seed layer, a second metal disk, and a second circuit are sequentially formed on the surface of the packaging substrate structure, wherein the first metal seed layer, the first metal disk, and the first circuit are located on opposite sides of the packaging substrate structure, and the second metal seed layer, the second metal disk, and the second circuit are located on opposite sides of the packaging substrate structure, thereby obtaining the packaging substrate. When the height of the packaging substrate is less than that of the packaging substrate with a preset height, steps S12 to S15 are repeated at least once after step S15 until the packaging substrate with the preset height is formed; when the step of forming the metal block is repeated multiple times, the type of the metal block is divided into a through-type metal block and a semi-embedded metal block. The method for preparing the packaging substrate further includes a step of performing a solder resist process on the upper and lower surfaces of the packaging substrate to protect the outer layer structure of the packaging substrate from oxidation.

2. The method for preparing the packaging substrate according to claim 1, characterized in that: The first metal block is a copper block.

3. A packaging substrate, characterized in that, The packaging substrate includes a packaging substrate prepared by the method for preparing a packaging substrate as described in any one of claims 1 to 2.

4. A heat dissipation detection system for a packaged substrate, characterized in that, The heat dissipation detection system of the packaging substrate includes: the packaging substrate as described in claim 3, a heat-generating component, a thermocouple, a computer, and an infrared thermal imager; one end of the thermocouple is connected to the heat-generating component mounted on the packaging substrate, and the other end is connected to the computer.

5. A method for detecting heat dissipation of a packaged substrate, characterized in that, The heat dissipation detection method for the packaging substrate includes: S21: Provide the heat dissipation detection system for the packaging substrate as described in claim 4; S22: The thermocouple collects the thermal energy of the heating element and then converts it into electrical energy, which is displayed on the computer. S23: Collect temperature data of the heating element using the infrared thermal imager; S24: Record and organize the above data, and conduct comparative analysis.

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