Packaging substrate

Abstract

The present invention provides a packaging substrate and a method for manufacturing the same, which have improved thermal stability, electrical stability, and electrical conductivity, due to the low content of eluted impurities or the ratio of specific impurities being within a certain range. [Solution] A packaging substrate 100 comprising a glass wafer 20, a number of vias 25 arranged on the glass wafer, copper electrodes 40 arranged on the vias or surface of the glass wafer, and an insulating layer 30 covering the vias or copper electrodes, wherein the eluted impurities include P and Zn. The content of the eluted impurities is an analytical value obtained by adding 70 mol% nitric acid to the packaging substrate, preparing an analytical solution by pre-treating it in a graphite block at 200 degrees Celsius for 16 hours, and analyzing the analytical solution with an ICP-MS equipped (Nexlon2000 model product from PerkinElmer) in accordance with the KSM0025:2008 test method, where the P content (by mass) is 1,500 ppb or less and the Zn content (by mass) is 500 ppb or less.

Description

Technical Field

[0001] Embodiment examples relate to packaging substrates and the like.

Background Art

[0002] In the manufacture of electronic components, the process of forming circuits on a semiconductor wafer is called the front-end process (FE), and the process of assembling the formed wafer so that it can be used in an actual product is called the back-end process (BE). The packaging process is included in the back-end process.

[0003] As four core technologies of the semiconductor industry that have enabled the recent rapid development of electronic products, there are semiconductor technology, semiconductor packaging technology, manufacturing process technology, and software technology. Semiconductor technology has evolved into various forms such as sub-micron line widths in nanometer units, over ten million cells, high-speed operation, and a large amount of heat dissipation. However, the technology to perfectly package this relatively has not been sufficiently supported. Therefore, the electrical performance of a semiconductor may sometimes be determined by the packaging technology and the electrical connections thereby, rather than the performance of the semiconductor technology itself.

[0004] As materials for packaging substrates, ceramics or resins are applied. In the case of a ceramic substrate such as a silicon substrate, it is not easy to mount high-performance high-frequency semiconductor elements because of its high resistance value or high dielectric constant. In the case of a resin substrate, relatively high-performance high-frequency semiconductor elements can be mounted. However, there is a limit to reducing the wiring pitch.

[0005] Recently, glass substrates can be applied as high-end packaging substrates. By forming through-holes in the glass substrate and applying a conductive substance to these through-holes, the wiring length between the element and the motherboard can be shortened, and excellent electrical characteristics can be achieved.

[0006] As related prior art, there is Korean Patent Publication No. 10-2023-0038664 and the like. [Overview of the project] [Problems that the invention aims to solve]

[0007] The purpose of this embodiment is to provide a packaging substrate with a low impurity content and a method for manufacturing the packaging substrate. [Means for solving the problem]

[0008] To achieve the above objective, a packaging substrate according to one embodiment is a packaging substrate comprising: a glass wafer; a number of vias disposed on the glass wafer; copper electrodes disposed on the vias or on the surface of the glass wafer; and an insulating layer covering the vias or the copper electrodes.

[0009] The packaging substrate contains P and Zn as eluted impurities.

[0010] The content of the eluted impurities is the analytical value obtained by adding 70 mol% nitric acid to the packaging substrate, pre-treating it in a graphite block at 200 degrees Celsius for 16 hours to prepare an analytical solution, and analyzing the analytical solution using an ICP (inductively coupled plasma)-MS (Nexlon2000 model product manufactured by Perkin Elmer) in accordance with the KS M 0025:2008 test method.

[0011] The P content (by mass) may be 1,500 ppb or less.

[0012] The Zn content (by mass) may be 500 ppb or less.

[0013] A seed layer may be further included beneath the copper electrode.

[0014] The seed layer may contain copper and titanium.

[0015] The insulating layer may include polymer resin and inorganic particles.

[0016] The inorganic particles can include silica.

[0017] The polymer resin can include any one selected from the group consisting of an epoxy resin, an acrylic resin, a urethane resin, and combinations thereof.

[0018] The packaging substrate is generally in a polyhedral shape.

[0019] The polyhedron may be a hexahedron. Two or more cut surfaces of the hexahedron may be exposed. The polyhedron may have cut surfaces where 2 to 6 surfaces are exposed.

[0020] The glass wafer can be borosilicate plate glass.

[0021] The eluted impurities can further include Si and B.

[0022] The ratio of the content of Si to the content of B (by mass) can be 1:5 to 7.

[0023] The analytical values of the eluted impurities can include the intensity of B and the intensity of F.

[0024] The ratio of the intensity of the F peak to the intensity of the B peak can be 50 or less.

[0025] The eluted impurities can further include B and Ti.

[0026] The ratio of the content of B to the content of Ti (by mass) can be 1:50 to 70.

[0027] The eluted impurities can further include Al.

[0028] The content of Al (by mass) can be 900 ppb or less.

[0029] The elution impurities may further contain B.

[0030] The ratio of the content of B (by mass) to the content of Zn (by mass) may be 1:2 to 5.

[0031] The ratio of the content of B (by mass) to the content of P (by mass) may be 1:5 to 30.

Advantages of the Invention

[0032] The packaging substrate according to the embodiment has a low content of elution impurities or the content ratio of specific impurities is within a defined range, so that a packaging substrate with improved thermal stability, electrical stability, electrical conductivity, etc. can be provided.

Brief Description of the Drawings

[0033] [Figure 1] FIG. 1 is a conceptual diagram for explaining the structure of a packaging substrate according to an embodiment in cross-section.

Best Mode for Carrying Out the Invention

[0034] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings so that those having ordinary knowledge in the technical field to which the embodiments belong can easily implement them. However, the embodiments can be realized in various different forms and are not limited to the embodiments described here. The same reference numerals are given to similar parts throughout the specification.

[0035] Throughout this specification, the term "these combinations" included in the Markush-type expressions means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expressions, and means including one or more selected from the group consisting of the said components.

[0036] Throughout this specification, terms such as “First,” “Second,” or “A,” “B” are used to distinguish identical terms from one another. Furthermore, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0037] In this specification, "~system" may mean that the compound contains a compound corresponding to "~" or a derivative of "~".

[0038] In this specification, the meaning of B being located on A means either B being in direct contact with A, or B being located on A with other layers located between them, and is not limited to B being in contact with the surface of A.

[0039] In this specification, the meaning of B being connected to A means either that A and B are directly connected, or that A and B are connected through other components between them, and is not limited to the direct connection of A and B unless otherwise specified.

[0040] In this specification, unless otherwise specified, singular expressions are interpreted to include singular or plural, as interpreted in the context.

[0041] A packaging substrate is composed of various materials such as supports, electrodes, and insulators arranged in a predetermined shape, and it serves to support semiconductor elements. It also acts as a medium connecting semiconductor elements to a power source, and rectifies the current transmitted to the semiconductor elements, thereby improving the stability of electronic equipment.

[0042] The packaging substrate has a basic form in which an electrically conductive pattern (electrodes) is formed on a support substrate, and an insulating layer is placed on top, although the position and thickness of the electrodes (including the form of vertical and horizontal electrodes) may be changed depending on the design.

[0043] Recently, packaging substrates are being designed with increasingly fine lines and integrated configurations. To realize this, it is important to form electrodes finely and accurately, but impurity control also becomes even more crucial.

[0044] For example, if a specific element placed in region A easily diffuses into region B and affects the function of region B, the performance of the packaging substrate may deteriorate. Therefore, the effects of such impurities must be carefully considered not only immediately after the manufacturing of the packaging substrate, but also in the actual usage environment, and overall, it is necessary to ensure more stable properties.

[0045] Figure 1 is a conceptual diagram illustrating the cross-sectional structure of a packaging substrate in one example. The specific example will be described below with reference to Figure 1.

[0046] A packaging substrate 100 according to one embodiment includes a glass wafer 20, a number of vias 25 arranged on the glass wafer 20, copper electrodes 40 arranged on the vias 25 or on the surface of the glass wafer 20, and an insulating layer 30 covering the vias 25 or the copper electrodes 40.

[0047] The glass wafer 20 may be made of flat glass, including semiconductor-grade flat glass. For example, the glass wafer 20 may be borosilicate-based flat glass. Borosilicate is a glass containing silica and boron trioxide. Examples of commercially available products include those sold by Schott, Corning, and AGC, but the glass wafer 20 in this example is not limited to these.

[0048] A number of vias 25 may be arranged on the glass wafer 20.

[0049] The via 25 is a passage that penetrates the glass wafer 20 and connects the top and bottom surfaces, and can be filled with electrodes or the like, as described later.

[0050] Via 25 can be formed by applying methods such as etching or melting.

[0051] For example, defects may be formed on the glass wafer 20 by a laser or the like, followed by wet etching.

[0052] The electrode may, for example, be a copper electrode 40. The copper electrode refers to a copper plating layer, a copper alloy layer, etc., arranged in a predetermined electrode form, and should not be interpreted as being limited to an electrode made of copper. In other words, in this concrete example, a copper electrode is used as an example of an electrically conductive layer. Although it is referred to as a copper electrode, it is described as representative of a metallic electrically conductive layer applied to a packaging substrate, and is interpreted in a broad sense that includes copper, not as an electrode made of copper. Furthermore, the scope of the patent does not exclude the inclusion of materials other than copper, as long as it does not impair the idea of ​​the present invention.

[0053] The copper electrodes may, for example, be manufactured by a plating method. For example, electroless copper plating may be used, but is not limited to this.

[0054] The copper electrode may be plated after applying a seed layer, if necessary, before the plating process. The seed layer promotes the formation of the plating layer, and examples include, but are not limited to, an inorganic seed layer such as a titanium-containing sputtered layer or an organic seed layer containing copper seeds.

[0055] The insulating layer is formed during the process of forming the copper electrodes 40 and serves to prevent short circuits between the copper electrodes 40.

[0056] The insulating layer can be made of a mixture of inorganic particles and polymer resin.

[0057] For example, the inorganic particles may be silica particles.

[0058] Exemplary, the polymer resin may include any one selected from the group consisting of epoxy resins, acrylic resins, urethane resins, and combinations thereof.

[0059] The insulating layer may, for example, be made of ABF (Ajinomoto Build-up Film), but is not limited to this.

[0060] In this concrete example, the impurity content of the packaging substrate 100 can be measured by eluted impurities.

[0061] The content of the eluted impurities was determined by preparing an analytical solution by adding 3 ml of 70 mol% nitric acid to 0.43 g of the packaging substrate 100 and pre-treating it in a graphite block at 200 degrees Celsius for 16 hours. This analytical solution was then analyzed using an ICP (inductively coupled plasma)-MS (Nexlon2000 model product manufactured by Perkin Elmer) in accordance with the KS M 0025:2008 test method. The program used for the analysis was the program provided by the manufacturer (program name: Syngistix for ICP-MS, version: 3.2), and the standard mode was applied.

[0062] The packaging substrate 100 contains P and Zn as eluted impurities.

[0063] Specifically, the content of P (by mass, the same applies hereinafter) may be 1,500 ppb or less. The content of P may also be 1,400 ppb or less, 1,300 ppb or less, 1,200 ppb or less, 1,100 ppb or less, or 1,000 ppb or less. The content of P may also be 200 ppb or more, 300 ppb or more, 400 ppb or more, 500 ppb or more, or 600 ppb or more.

[0064] The phosphorus (P) is thought to originate from polymer layers placed on the packaging substrate, such as the insulating layer and resist layer. Furthermore, P can contribute to improving thermal stability and chemical resistance. When the P content in the eluted impurities is within the aforementioned range, the thermal stability of the insulating layer of the substrate can be improved. Additionally, chemical durability can be further improved even when the packaging substrate is repeatedly exposed to high-temperature environments. Along with this, by maintaining the strength, conductivity, and processability of the electrodes within a certain range, a packaging substrate with even greater physical superiority can be obtained.

[0065] The zinc (Zn) content (by mass, the same applies hereinafter) may be 500 ppb or less. The zinc content may also be 450 ppb or less, 400 ppb or less, 350 ppb or less, or 300 ppb or less. The zinc content may also be 200 ppb or more, or 220 ppb or more.

[0066] Zn can prevent corrosion of metal components such as electrodes. Zn can prevent oxidation and protect metal materials in electrodes, such as copper, which can affect the electrical resistance and signal transmission efficiency of the electrodes, thereby improving circuit stability. When the Zn content in the eluted impurities is within the aforementioned range, the electrode peel stability and heat resistance are maintained within a certain range, resulting in a packaging substrate with even greater physical properties.

[0067] The eluted impurities may include Si.

[0068] The Si (silicon) content may be 120 ppb or less, 110 ppb or less, 100 ppb or less, 90 ppb or less, 80 ppb or less, 70 ppb or less, 60 ppb or less, 50 ppb or less, 40 ppb or less, or 30 ppb or less. The Si content may be 3 ppb or more, 5 ppb or more, or 7 ppb or more.

[0069] Si is one of the main components of glass wafers. Furthermore, Si is one of the components of silica used as inorganic particles in the insulating layer. When the Si content in the eluted impurities is within the aforementioned range, a packaging substrate with stable physical properties and minimal detachment of inorganic components can be obtained.

[0070] The eluted impurity may include B (boron).

[0071] The content of B may be 250 ppb or less, 220 ppb or less, 180 ppb or less, 150 ppb or less, 120 ppb or less, 110 ppb or less, 100 ppb or less, 90 ppb or less, 80 ppb or less, or 70 ppb or less. The content of B may be 10 ppb or more, 20 ppb or more, 30 ppb or more, 40 ppb or more, or 50 ppb or more.

[0072] B is one of the main components of glass wafers. When the content of B in the eluted impurities is within the range described above, a packaging substrate with stable physical properties and minimal detachment of inorganic components can be obtained.

[0073] The eluted impurities may include Ti (titanium).

[0074] The Ti content may be 7,000 ppb or less, 6,500 ppb or less, 6,000 ppb or less, 5,500 ppb or less, or 5,000 ppb or less. The Ti content may be 1,000 ppb or more, 1,500 ppb or more, 2,000 ppb or more, 2,500 ppb or more, or 3,000 ppb or more.

[0075] The Ti is thought to originate from one of the elements used in the electrode formation process. After forming seed layers and other components, unnecessary parts may be removed or retained as needed. When the Ti content in the eluted impurities is within the range described above, a packaging substrate with high integration density and excellent durability can be obtained.

[0076] The eluted impurity may include Al (aluminum).

[0077] The Al content may be 900 ppb or less, 800 ppb or less, 700 ppb or less, 600 ppb or less, 500 ppb or less, 400 ppb or less, or 300 ppb or less. The Al content may be 50 ppb or more, 60 ppb or more, 70 ppb or more, 80 ppb or more, 90 ppb or more, or 100 ppb or more.

[0078] Al can be applied to electrodes, electrode seed layers, and other components. Al can influence the signal and power redistribution of the redistribution layer, which is related to the electrical performance of the substrate. Furthermore, by forming an oxide film (Al2O3) that suppresses the occurrence of electrode corrosion and damage, it helps to maintain stable long-term performance, and depending on the placement, it is thought to aid in heat dissipation. When the Al content in the eluted impurities is within the range described above, the durability of the electrodes is improved, and a packaging substrate with superior physical properties can be obtained.

[0079] In the eluted impurities, the ratio of the Si content to the B content (by mass) may be 1:5 to 7. Alternatively, the ratio may be 1:5.5 to 6.5. When such a ratio is present, a packaging substrate with excellent mechanical and electrical stability can be obtained.

[0080] In the eluted impurities, the ratio of the content of B to the content of Ti (by mass) may be 1:50 to 70. The ratio may also be 1:52 to 68, or 1:55 to 63. When such a ratio is present, a packaging substrate with excellent electrical stability can be obtained.

[0081] In the eluted impurities, the ratio of the content of B (by mass) to the content of Zn (by mass) may be 1:2 to 5. The ratio may also be 1:2.5 to 4.5, or 1:3 to 4. When such a ratio is present, a packaging substrate with excellent electrical and mechanical stability can be obtained.

[0082] In the eluted impurities, the ratio of the content of B (by mass) to the content of P (by mass) may be 1:5 to 30. The ratio may also be 1:8 to 25, or 1:10 to 20. When such a ratio is present, a packaging substrate with excellent processing stability and electrical stability can be obtained.

[0083] In the eluted impurities, the ratio of the content of B (by mass) to the content of Al (by mass) may be 1:1 to 5. The ratio may also be 1:1.5 to 4, or 1:2.5 to 3.5. When such a ratio is present, a packaging substrate with excellent electrical stability and thermal stability can be obtained.

[0084] The eluted impurities may include F.

[0085] In the analytical values ​​of the eluted impurities, the intensity of F relative to the intensity of B should be below a certain ratio. Specifically, the ratio of the intensity of the peak of F relative to the peak of B may be 50 or less. The intensity ratio may also be 45 or less, 40 or less, 37 or less, or 36 or less. The intensity ratio may also be 1 or more, 15 or more, or 25 or more.

[0086] F is thought to originate from hydrofluoric acid or other substances applied during the etching or cleaning process. Since F is considered to be one of the causes of delamination between the glass wafer and the electrode, and between the glass wafer and the insulating layer, it is advisable to remove it thoroughly. When the ratio of the strengths is within the range described above, the occurrence of delamination of the packaging substrate during the manufacturing or use process can be substantially suppressed, and a packaging substrate with improved durability can be obtained.

[0087] The aforementioned eluted impurities can be measured using an analytical solution obtained by pre-treating 100 samples of packaging substrates.

[0088] The packaging substrate 100 is typically a rectangular plate with thickness, and may have an overall hexahedral shape. Electrodes and insulating layers may be formed on the top and bottom surfaces. A cover layer 60 may be placed on top of the substrate to provide insulation and expose the electrodes at predetermined positions. The cover layer 60 may be a polyimide layer, but is not limited to this. The cover layer 60 may also be a solder resist layer, but is not limited to this.

[0089] Depending on its size, the packaging substrate 100 can be used directly in the production of the analytical solution. For example, the packaging substrate 100 may be cut to an appropriate size before being used in the production of the analytical solution. The cutting can be performed using a method applicable to dicing the packaging substrate. Laser cutting may also be used for this cutting; however, the cutting method is not limited to these.

[0090] For example, at least two of the remaining four surfaces, excluding the top and bottom surfaces, may be in a configuration where the cross-section is exposed. For example, at least a portion of the glass wafer, insulating layer, and cover layer may be exposed in the cross-section.

[0091] The following describes an example of the experiment.

[0092] Redistribution lines were placed on a borosilicate glass wafer having a core with a thickness of approximately 500 μm or more. The redistribution lines were formed by repeatedly laminating and etching, depending on the method used to form them, and conventional methods were applied. A titanium sputtered layer was used as the seed layer, ABF (manufactured by Ajinomoto Co., Ltd.) was used as the insulating layer, and copper plating was used for the copper electrode layer. Cleaning was performed a sufficient number of times at each stage, in accordance with Korean Published Patent No. 10-2023-0038664.

[0093] The packaging substrate with the above configuration was used as a sample cut using a glass knife, measuring 1 cm wide, 1 cm long, and weighing 0.43 g.

[0094] The sample was pretreated with approximately 3 ml of nitric acid in a graphite block at 200 degrees Celsius for 16 hours. The solution was then taken and qualitative analysis was performed using the analytical solution. The analysis was performed using ICP (inductively coupled plasma)-MS equipment in accordance with the general rules for mass spectrometry KS M 0025:2008. The temperature during analysis was approximately 24 degrees Celsius and the relative humidity was 64%.

[0095] The aforementioned equipment was a Nexlon2000 model manufactured by Perkin Elmer, and the analysis program was version 3.2 of the Syngistix for ICP-MS program provided by the manufacturer. The analysis was performed in Standard Mode. The detection range was 0.001 ppb or higher.

[0096] The measurement results showed that in the case of Cu, the high concentration resulted in an over-range reading.

[0097] The intensity of P was 4,704,002, and the concentration (in ppb) was 924.992.

[0098] The intensity of Zn was 2,875,872, and the concentration (in ppb) was 246.577.

[0099] The Si intensity was 250872550, and the concentration (in ppb) was 11.563.

[0100] The intensity of B was 1,780,351, and the concentration (in ppb) was 68.828.

[0101] The intensity of Ti was 179196692, and the concentration (in ppb) was 4054.503.

[0102] The intensity of Al was 14637243, and the concentration (in ppb) was 201.417.

[0103] The intensity of F was 60556883.

[0104] The B content relative to the Si content was approximately 5.95.

[0105] The ratio of Ti to the B content was approximately 58.9.

[0106] The B content relative to the Si content was approximately 5.95.

[0107] The P content relative to the B content was approximately 13.5.

[0108] The Zn content relative to the B content was approximately 3.58.

[0109] The Al content relative to the B content was approximately 2.93.

[0110] The strength of F, relative to the strength of B, was approximately 34 times greater.

[0111] Packaging substrates possessing these characteristics can maintain excellent physical properties even in operating environments where heating and cooling are repeatedly performed, thereby providing high-performance packaging substrates.

[0112] The aforementioned measurement values ​​are obtained by taking a sample of a packaging substrate from which the elements, capsule layer, and / or leads have been removed, in cases where leads are separately placed on the packaging substrate or elements are mounted on it. Specifically, the values ​​are obtained using a sample in which a glass substrate, a redistribution layer, and a cover layer (PI layer on top and solder resist layer on the bottom) are placed.

[0113] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, utilizing the basic concepts of the present invention as defined in the appended claims, also fall within the scope of the present invention. [Explanation of Symbols]

[0114] 20 glass wafers 25 Beer 30 Insulating layer 40 copper electrode 60 Cover layer 100 Packaging substrates

Claims

1. Glass wafers and A number of vias arranged on the glass wafer, A copper electrode disposed on the via or the surface of the glass wafer, A packaging substrate comprising an insulating layer covering the via or the copper electrode, The aforementioned packaging substrate contains P and Zn as eluted impurities. The content of the eluted impurities is an analytical value obtained by adding 70 mol% nitric acid to the packaging substrate, pre-treating it in a graphite block at 200 degrees Celsius for 16 hours to prepare an analytical solution, and analyzing the analytical solution using an ICP (inductively coupled plasma)-MS (Nexlon2000 model product manufactured by Perkin Elmer) in accordance with the KSM 0025:2008 test method. The content of P (by mass) is 1,500 ppb or less. A packaging substrate having a Zn content (by mass) of 500 ppb or less.

2. A seed layer is further included beneath the copper electrode. The seed layer contains copper and titanium, The insulating layer comprises a polymer resin and inorganic particles. The inorganic particles include silica, The packaging substrate according to claim 1, wherein the polymer resin comprises one selected from the group consisting of epoxy resin, acrylic resin, urethane resin, and combinations thereof.

3. The aforementioned packaging substrate has an overall polyhedral shape, The packaging substrate according to claim 1, wherein two or more cross-sectional faces of the polyhedron are exposed.

4. The packaging substrate according to claim 1, wherein the glass wafer is a borosilicate glass plate.

5. The eluted impurities further include Si and B, The packaging substrate according to claim 4, wherein the ratio of the Si content to the B content (by mass) is 1:5 to 7.

6. The analytical values ​​of the eluted impurities include the intensity of B and the intensity of F. The packaging substrate according to claim 4, wherein the ratio of the intensity of the peak of F to the peak of B is 50 or less.

7. The eluted impurities further include B and Ti, The packaging substrate according to claim 4, wherein the ratio of the content of B to the content of Ti (by mass) is 1:50 to 70.

8. The aforementioned eluted impurity further contains Al, The packaging substrate according to claim 1, wherein the Al content (by mass) is 900 ppb or less.

9. The eluted impurity further contains B, The packaging substrate according to claim 1, wherein the ratio of the content (by mass) of B to the content (by mass) of Zn is 1:2 to 5.

10. The packaging substrate according to claim 6, wherein the ratio of the content (by mass) of B to the content (by mass) of P is 1:5 to 30.

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