JP6273873B2 - Manufacturing method of glass interposer substrate - Google Patents

Description

The present invention is a substrate for converting the terminal arrangement density of electronic devices, the method for manufacturing at least a glass interposer board including a glass layer, in particular, glass interposer board having a through conductor in the glass layer It relates to the manufacturing method.

  In recent years, in order to simplify the mounting of a semiconductor chip component on a large wiring board (motherboard), an electronic device in which a semiconductor chip is attached to an interposer substrate that converts a terminal arrangement into a coarse pitch is often used. Although the interposer substrate mainly functions to change the terminal arrangement density, it can also be used to relieve stress caused by the difference in thermal expansion coefficient between the semiconductor chip itself and the wiring substrate.

  Semiconductors are mainly made of silicon. On the other hand, wiring boards are made of organic materials such as epoxy resin, so the difference in coefficient of thermal expansion is large. A large stress in the shear direction is generated on the member for mechanically mechanical connection, which affects reliability. Therefore, by interposing the interposer substrate, the semiconductor chip and the wiring substrate are buffered in terms of the coefficient of thermal expansion.

  As an example of an interposer substrate, there is a substrate material made of silicon similar to a semiconductor chip instead of an organic material. In the case of a silicon material, the technology cultivated in the semiconductor manufacturing process can be utilized as a method for forming fine wiring including through conductors, so that it is very useful. However, since it is disadvantageous in terms of cost compared to organic materials, it is considered that there is a limit to expanding its use.

  In this respect, an interposer substrate using glass, which is an inorganic material like silicon, as a substrate material is considered to be very promising because of its material cost. A point to keep in mind when using glass is that the processing technology applied to silicon cannot be used. Furthermore, the point which considers cost and reliability also about the electrically-conductive material with which the through-hole for comprising a through-conductor is filled, and through-hole itself are mentioned. One example of a wiring board having a through conductor in a glass layer is disclosed in the following prior art.

WO2005 / 034594

The present invention has been made in consideration of the above circumstances, in the manufacturing method of a glass interposer board comprising at least the glass layer to a substrate for converting the terminal arrangement density of electronic devices, the through conductors and to provide a process for producing a glass interposer board capable of improving reliability.

For example, a glass interposer substrate according to one aspect includes a first surface and a second surface opposite to the first surface, and a hole penetrating from the first surface to the second surface is provided. The first diameter, which is the diameter of the first surface, is larger than the second diameter, which is the diameter of the hole, on the second surface, and the hole is between the first surface and the second surface. A glass base layer in which the diameter has a minimum value at any of the positions, and the third diameter, which is the minimum value, is smaller than the first diameter, and the inside of the hole in the base layer And a conductor provided in contact with the upper and lower surfaces of the longitudinal conductor, which is a surface connected to the first surface and the second surface of the base layer. It comprises.

  In other words, this interposer substrate is characterized by the diameter of the holes provided in the glass base layer that it has, and further characterized by the fact that the conductive composition is positioned inside the holes to make a longitudinal conductor. There is. First, the hole provided in the base layer has a diameter on the first surface larger than that on the second surface. Thereby, when it is going to fill with an electroconductive composition from the 1st surface which has a big diameter, it has an appropriate shape. If the filling property is poor, the shape reliability of the vertical conductor (through conductor) deteriorates, but this can be effectively prevented.

  Further, this hole is a hole whose diameter has a minimum value at any position between the first surface and the second surface. By doing in this way, even after the conductive composition is filled and cured and contracted, it can be reliably prevented from falling out of the hole. That is, the penetrating hole is a hole different from a simple taper shape, so that the conductive composition is supported by the inner wall of the hole above and below the position having the minimum value of the hole diameter and does not fall off. Therefore, it is possible to greatly improve defects due to dropout and improve the formation reliability of the vertical conductor (through conductor).

  Moreover, the manufacturing method of the interposer board | substrate which is another aspect of this invention irradiates the laser beam which has predetermined | prescribed 1st power with respect to a glass-made base layer from the surface side, and is 1st on the back surface side. A step of forming a laser processing recess, and laser processing is performed by irradiating the base layer with laser light having a second power weaker than the first power, from the surface side, and performing the laser processing. A step of forming a second laser processing recess having a deep processing recess; and a laser beam having a third power weaker than the first power and stronger than the second power with respect to the base layer. Performing a laser processing by irradiating from the side, forming a through hole in which the second laser processing recess is made to penetrate the back surface, and a smoothed surface by hydrofluoric acid processing the inner wall surface of the through hole of the base layer Forming a step; A step of filling a conductive composition from the back side of the base layer into the through-hole of the base layer having a smoothed surface to form a longitudinal conductor, and on the front surface and the back surface of the base layer Providing a conductor so as to come into contact with the upper and lower surfaces of the longitudinal conductor, which is a continuous surface.

  This manufacturing method is one aspect for manufacturing the interposer substrate. In this manufacturing method, at least three stages of laser processing are performed on the glass base layer, whereby the diameter on the back surface is larger than the diameter on the front surface and at any position between the back surface and the front surface. A through-hole having a minimum diameter can be formed. After the formation of the through hole, the inner wall surface is smoothed, and then the conductive composition is filled from the back surface side to form the vertical conductor, and further, the vertical conductor that is a surface connected to the front surface and the back surface of the base layer A conductor is provided so as to be in contact with the upper and lower surfaces.

  Moreover, the manufacturing method of the interposer board | substrate which is another aspect of this invention is the process of irradiating a laser beam with respect to a glass-made base layer, forming a through-hole, and with respect to the said base layer which has the said through-hole. Then, a hydrofluoric acid bath having a depth that is in contact with one side of the base layer and does not reach the other side is performed until a predetermined first time elapses, and from the one side to the middle of the depth of the through hole. A step of expanding the diameter of the through-hole, and the base layer having the diameter of the through-hole extended from the one surface to the middle of the depth of the through-hole, in contact with the other surface of the base layer Performing a hydrofluoric acid bath having a depth not reaching the surface until a second time shorter than the first time elapses, and expanding the diameter of the through hole from the other surface to the depth of the through hole And the diameter of the through hole is expanded from the one surface and the other surface A step of filling a conductive composition into the through-hole of the layer from the one surface side of the base layer to form a longitudinal conductor, and connecting the one surface and the other surface of the base layer Providing a conductor so as to be in contact with the upper and lower surfaces of the vertical conductor, which is a surface.

  This manufacturing method is another mode for manufacturing the above-described interposer substrate. In this manufacturing method, first, a through hole is formed by laser processing as a pilot hole in the base layer. Then, a hydrofluoric acid bath having a depth that is in contact with one side of the base layer and does not reach the other side is performed until a predetermined time has elapsed, and the diameter of the through hole from one side to the depth of the through hole is determined. spread. Subsequently, a hydrofluoric acid bath having a depth that contacts the other surface of the base layer and does not reach one surface is performed until a shorter time elapses, and the diameter of the through hole from the other surface to the middle of the depth of the through hole is determined. spread. As a result, a through hole can be formed in which the diameter on one surface is larger than the diameter on the other surface, and the diameter has a minimum value at any position between the one surface and the other surface. After forming the through-hole, the conductive composition is filled from one side to form a vertical conductor, and the upper and lower surfaces of the vertical conductor, which are surfaces connected to the front and back surfaces of the base layer, are contacted. A conductor is provided on.

  ADVANTAGE OF THE INVENTION According to this invention, it is a board | substrate for converting the terminal arrangement density of an electronic device, Comprising: In the glass interposer board | substrate containing at least a glass layer, and its manufacturing method, the reliability of a penetration conductor can be improved.

Sectional drawing which shows typically the structure of the interposer board | substrate which is one Embodiment. FIG. 3 is a process diagram showing a manufacturing process of the interposer substrate shown in FIG. FIG. 3 is a continuation diagram of FIG. 2, and a process diagram showing a manufacturing process of the interposer substrate shown in FIG. 1. FIG. 4 is a process diagram showing a manufacturing process of the interposer substrate shown in FIG. 1 different from those shown in FIG. 2 and FIG. 3. Sectional drawing which shows typically the structure of the interposer board | substrate which is another embodiment. Typical sectional drawing which shows an example (an example of a through-hole shape) which can be used instead of the glass base layer 11 shown in FIG. 1, FIG. FIG. 6 is a schematic cross-sectional view showing an example (an example of a through-hole shape) of a glass base layer that can be used in place of the glass base layer 11 shown in FIGS. 1 and 5, which is different from that shown in FIG. 6. 6 is a schematic cross-sectional view showing an example of a glass base layer (an example of a through hole shape) that can be used instead of the glass base layer 11 shown in FIGS. Figure.

  As an embodiment of the present invention, the position where the base layer has the third diameter in the hole is closer to the second surface as viewed from the intermediate position between the first surface and the second surface of the base layer. It can be said that it is the base layer currently arrange | positioned. Such a hole shape is a better shape in terms of the filling property of the conductive composition.

  Further, as an embodiment, the position where the base layer has the third diameter in the hole is arranged on the first surface side when viewed from an intermediate position between the first surface and the second surface of the base layer. It is possible to be a base layer that is made. Such a hole shape is a better shape with respect to preventing the conductive composition from falling off after curing shrinkage.

  Further, as an embodiment, the base layer may be a base layer in which a change in diameter before and after the position having the third diameter in the hole is made smooth. This is a characteristic aspect when the base layer is made of a single layer made of glass. Since it is a single layer (that is, not a bonded layer), it can be easily processed so that the change in the diameter of the hole is smooth in the penetration direction.

  As an embodiment, the hole of the base layer may be a hole whose diameter decreases in the depth direction from the first surface on the first surface. In this way, when the hole is a hole whose diameter decreases in the depth direction, particularly in the first surface, it becomes an opening shape into which a paste-like object can be easily introduced. Get better.

  As an embodiment, the hole of the base layer may be a hole whose diameter decreases in the depth direction from the second surface on the second surface. Thus, when the hole is a hole whose diameter decreases in the depth direction particularly on the second surface, the effect of being supported by the inner wall of the hole so that the conductive composition does not fall off is enhanced. Therefore, the formation reliability of the vertical conductor (through conductor) can be further improved.

  As an embodiment, a gap may be formed between the inner wall surface of the hole of the base layer and the vertical conductor. This is an aspect in which the curing shrinkage of the conductive composition generated when the longitudinal conductor is formed of the conductive composition is left as it is. Even if there is a gap, there is no problem in functionality as a longitudinal conductor.

  Based on the above, embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a configuration of an interposer substrate according to an embodiment. As shown in the figure, this interposer substrate includes a glass base layer 11, resin layers (interlayer insulating layers) 12, 13, 14, 15, via-hole plated vias 21a, 21c, 22a, 22c, and wiring patterns 21b, 21d. , 22b, 22d, nickel gold plating layer 22e, longitudinal conductor (through conductor) 31, solder resist (protective film) 41, 42, and solder ball 51.

  As an outline, this interposer substrate is mounted with a semiconductor chip (not shown) by, for example, flip chip bonding using a portion of the nickel gold plating layer 22e on the upper surface in the drawing as a connection land, while a solder ball on the lower surface in the drawing. 51 is a structure that can be entirely surface-mounted on another larger resin wiring board (not shown). The arrangement pitch of the lands having the nickel gold plating layer 22e is a narrow pitch corresponding to that of a terminal (not shown) of the semiconductor chip, and the solder balls 51 are arranged at a wider pitch. The interposer substrate simplifies mounting of semiconductor chip components with a narrow terminal pitch on a large wiring substrate (such as a mother board).

  The connection land having the nickel gold plating layer 22e is electrically connected to the wiring pattern 22d, the via hole plating via 22c, the wiring pattern 22b, the via hole plating via 22a, the vertical conductor 31, the via hole plating via 21a, and the wiring pattern 21b. In addition, the solder ball 51 is electrically connected to the via hole plating via 21c and the wiring pattern 21d.

  While the above-described longitudinal and lateral conductor portions exist, the glass base layer 11, the resin layers 12 to 15, and the solder resists 41 and 42 are insulators. Can be arranged (or protected) as desired. Among the insulators, the glass base layer 11 is a layer corresponding to a core layer using glass as the name suggests, and has a coefficient of thermal expansion considerably smaller than that of a resin material, so that a semiconductor chip ( The stress caused by the difference in coefficient of thermal expansion between the wiring board (not shown) and the wiring board (not shown) can be greatly reduced.

  The vertical conductor 31 provided through the glass base layer 11 is a conductor made of a conductive composition disposed in a via hole 11 a formed through the glass base layer 11. In particular, the vertical cross-sectional shape of the via hole 11a formed through the glass base layer 11 has a shape as shown in the figure, so that the longitudinal conduction among the deterioration of reliability conceivable in the interposer substrate. The deterioration of reliability due to the body 31 is greatly improved. The conductive composition is a well-known composition in which fine metal particles (for example, silver particles) are dispersed in a thermosetting resin and have conductivity as a whole.

  The via hole 11a has at least the following conditions in terms of shape. That is, the diameter of the via hole 11a on the lower surface (first surface) of the glass base layer 11 is larger than the diameter of the via hole 11a on the upper surface (second surface) of the glass base layer 11, and between the lower surface and the upper surface. In any of the positions, the diameter has a minimum value (it may be said that there is a “neck”), and the minimum value is smaller than the diameter on the lower surface. In addition, about the via hole 11a, it has arrangement | positioning of the glass base layer 11 so that the side which has the big diameter may be turned to the side with the solder ball 51. FIG. This is because, in general, the fineness required for conductor formation is coarser on the side where the solder balls 51 are located than on the side where the nickel gold plating layer 22e is present. .

  If the diameter of the lower surface of the via hole 11a is larger than the diameter of the upper surface, it is very difficult to fill the paste-like conductive composition from the lower surface of the figure, which has a large diameter. Is preferable. This is because, in the via hole 11a, an area that becomes blind when filling is hardly formed, and the paste is naturally guided from the lower surface side toward the inner side. If the filling property is poor, the shape reliability of the longitudinal conductor 31 deteriorates, but this is effectively prevented.

  In addition, according to the diameter of the via hole 11a having a minimum value at any position between the lower surface and the upper surface, the following effects can be obtained. After the conductive composition is filled in the via hole 11a as described above, it is dried in the drying process and further thermally cured, and thus shrinkage occurs (in the drawing, the longitudinal conductor 31 is drawn in consideration of this point). ing). If the via hole 11a has a minimum diameter as described above, it can be reliably prevented from falling off the via hole 11a even after the conductive composition is cured and contracted. This is because the cured conductive composition is supported in a planar shape by the inner wall surface of the hole above and below the position having a minimum diameter. That is, unlike a tapered shape that does not have a minimum diameter between the lower surface and the upper surface, defects due to falling off during the manufacturing process can be greatly improved, and the formation reliability of the vertical conductor 31 can be greatly improved.

  The minimum value of the diameter of the via hole 11a is usually smaller than the small diameter on the upper surface of the glass base layer 11 as shown in the figure, but is not necessarily smaller than the diameter on the upper surface. Even if it is configured to be smaller than a large diameter at least on the lower surface, the above two great effects can be obtained. An example of this is the shape shown in FIG. FIG. 8 will be described later.

  Although one embodiment has been described above, supplementary explanation will be given below. The structure of the resin layers 12 to 15 which are wiring interlayer insulation layers, and conductors that are in contact with or electrically connected to the longitudinal conductor 31 (wiring pattern 22d, via hole plating via 22c, wiring pattern 22b, via hole plating via 22a, via hole) For the configurations of the inner plating via 21a, the wiring pattern 21b, the via hole inner plating via 21c, and the wiring pattern 21d), various known configurations can be used. The number of insulating layers and wiring patterns can be arbitrarily selected as necessary.

  For example, the via-hole plated via may be replaced with a via made of a conductive composition. For the wiring pattern, in addition to subtractive formation by etching a metal foil (for example, copper foil), additive formation such as application of a conductive paste (for example, metal nanopaste) or formation by plating can be employed. Various known materials can be used for the specific material of the resin layer and the specific material of each conductor.

  As for the conductor that is in direct contact with the vertical conductor 31, even if it is arranged so as to cover all the upper and lower surfaces of the vertical conductor 31 connected to the lower surface and the upper surface of the glass base layer 11, as shown in FIG. There is no problem. However, in this case, the longitudinal conductor 31 contains the resin, but all the components disposed around the longitudinal conductor 31 can be a material that does not contain the resin. The gas and moisture escape route is closed, which affects reliability. From this point, as shown in FIG. 1, the conductors (via-hole plated vias 21 a and 22 a) that are in direct contact with the vertical conductor 31 are formed so as to avoid covering all of the upper and lower surfaces of the vertical conductor 31. It is preferable to do this.

  In addition, a gap is generated between the longitudinal conductor 31 and the inner wall surface of the via hole 11a due to curing shrinkage of the conductive composition. This gap can be said to have caused a large material difference between the longitudinal conductor 31 and the glass base layer 11. These are also greatly different in thermal expansion coefficient, and the longitudinal conductor 31 is about 4 to 5 times larger, but there is a preferable aspect because it can be a space for buffering thermal deformation due to a gap.

  The via hole 11a is formed by forming a metal (for example, copper) plating layer on the inner wall surface in addition to the vertical conductor 31 made of the conductive composition facing the glass material of the inner wall surface as it is. Then, the longitudinal conductor 31 may be formed by filling the conductive composition. In this way, a lower resistance can be formed as the longitudinal conductor. However, if the diameter of the portion of the conductive composition is not changed in order to maintain the filling property, the vertical conductor is enlarged in the horizontal direction by the formation thickness of the plating layer. It should be noted that this leads to a decrease in the arrangement density.

  Next, an example of a process for manufacturing the interposer substrate shown in FIG. 1 will be described below. 2 and 3 are process diagrams showing a main manufacturing process of the interposer substrate shown in FIG. 2 and 3, the same or equivalent parts as those shown in FIG. 1 are denoted by the same reference numerals.

  First, as shown in FIG. 2A, a recess 11 h 1 is formed in the glass base layer 11. More specifically, a laser beam with a predetermined power is irradiated from the surface (upper surface in the drawing) side of the glass base layer 11, and the rear surface side is processed so that the focal point of the laser beam is formed near the rear surface.

  Next, as shown in FIG. 2B, laser processing is performed by irradiating a laser beam having a power weaker than the above power from the surface side of the glass base layer 11 to deepen the above-described laser processing indent. . More specifically, the focal point of the laser beam is moved more inward in the depth direction of the glass base layer 11, and the power is further weakened at that time. As a result, as shown in the drawing, the diameter 11h2 is formed in the depth direction.

  Subsequently, as shown in FIG. 2C, the recess 11h2 is penetrated by laser machining to form a machining hole (through hole) 11h3. More specifically, the power of the laser beam when penetrating is stronger than the power of the laser beam when the deepest portion of the recess 11h2 shown in FIG. 2B is formed, and in FIG. It is assumed that the power is weaker than the power of the laser beam when the indentation 11h1 shown is formed. The focal point is formed near the back surface of the glass base layer 11.

  2A to 2C, the thickness of the glass base layer 11 (assumed thickness is 50 μm to 1000 μm, typically 500 μm, for example) and the focus quality of the laser light Depending on the situation, it can be done in several steps. In the case shown in the drawing, processing is performed in five stages. It can be performed in three steps at the minimum. Further, processing may be performed so that the focal position is moved continuously and the power of the laser beam is changed continuously (or stepwise).

  After the machining hole 11h3 is formed, next, as shown in FIG. 2D, the inner wall surface is smoothed (via hole 11a). More specifically, the whole glass base layer 11 is immersed using, for example, hydrofluoric acid. By such smoothing, the microcrack on the inner wall surface of the processing hole 11h3 that may be generated by laser processing can be removed, and the glass base layer 11 having good stability can be obtained. Further, the diameter change is smoothly processed in the through direction in the constricted portion of the via hole 11a.

  Once the via hole 11a has been formed, next, as shown in FIG. 3A, the via hole 11a is filled with a conductive composition 31a. The filling direction is from the via hole 11a side (lower side in the drawing) having a larger diameter, as shown. As described above, this is because the paste-like conductive composition 31a is more easily filled from the side having the larger diameter. More specifically, such filling can be efficiently performed by screen printing using a screen plate having pits at the same position as the via hole 11a.

  After the conductive composition 31a is filled in the via hole 11a, the conductive composition 31a is then dried and further thermally cured. Regarding thermal curing, there is a surface that is cured by the heat required when the resin layers 12 to 15 (see FIG. 1) are formed (laminated) thereafter, and therefore may be incomplete at this point. The conductive material 31a is dried and cured to become the vertical conductor 31.

  The above is the manufacturing process regarding the glass base layer 11 portion. Thereafter, a resin layer 12 to 15 (see FIG. 1) and a laminated portion including each conductor can be formed using a known process.

  Next, FIG. 4 is a process diagram showing a manufacturing process of the interposer substrate shown in FIG. 1, which is different from those shown in FIGS. In FIG. 4, the same or equivalent parts as shown in FIG.

  First, as shown in FIG. 4A, a through hole 11 g 1 is formed as a pilot hole in the glass base layer 11. More specifically, for example, it is formed by irradiating laser light from the lower surface of the glass base layer 11 in the figure. The through-hole 11g1 obtained by this laser processing has a tendency that the diameter on the lower side in the figure is slightly larger and the diameter becomes smaller as it goes upward as a property of laser processing.

  Next, as shown in FIG.4 (b), the diameter is expanded to the depth in the middle of the through-hole 11g1. More specifically, with respect to the glass base layer 11 having the through hole 11g1, for example, a hydrofluoric acid 61 bath having a depth that is in contact with one surface (the lower surface in the drawing) of the base layer 11 and does not reach the other surface. By performing until a predetermined time elapses, the diameter from one surface to the middle of the depth of the through hole 11g1 is expanded (hydrofluoric acid treatment through hole 11g2). At this time, it is preferable to assist the process of expanding the diameter of the through hole 11g1 by irradiating the processing part with ultrasonic waves having a frequency of MHz and circulating the hydrofluoric acid located in the through hole 11g1.

  Next, as shown in FIG.4 (c), the diameter is expanded also about the part with a small diameter in the hydrofluoric-acid process through-hole 11g2. More specifically, conversely, a hydrofluoric acid 62 bath having a depth that is in contact with the other surface of the glass base layer 11 and does not reach one surface is performed until a time shorter than the above time elapses. The diameter up to the middle of 11g2 is expanded (hydrofluoric acid treatment hole 11g3 [= 11a]). Also at this time, it is preferable to assist the process of expanding the diameter of the through hole 11g2 by irradiating the machining site with ultrasonic waves having a frequency of MHz and circulating the hydrofluoric acid located in the through hole 11g2.

  After the via hole 11a is formed in the glass base layer 11 as described above, it is the same as the description with reference to FIG. The manufacturing method shown in FIG. 4 is likely to have fewer steps than the manufacturing method shown in FIGS. 2 and 3, but in terms of controllability for forming the via hole 11a in a desired shape. The manufacturing method shown in FIGS. 2 and 3 is considered to be superior. This is because the method shown in FIG. 4 uses wet etching in terms of controlling the shape of the via hole 11a, and therefore it is considered that there is a limit to the control.

  Next, an interposer substrate according to another embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing a configuration of an interposer substrate according to another embodiment, and the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals. The description is omitted unless there is a matter to be added.

  In this interposer substrate, the vertical cross-sectional shape of the via hole 11aa is different from that of the via hole 11a in FIG. More specifically, in the via hole 11a shown in FIG. 1, the position having the constriction in the via hole 11a is arranged on the upper surface side in the drawing as viewed from the intermediate position between the lower surface and the upper surface of the glass base layer 11. On the contrary, in this interposer substrate, a constriction is formed on the lower surface side of the figure when viewed from the middle of the glass base layer 11.

  The difference in effect due to the difference in shape is considered as follows. In other words, the one shown in FIG. 1 is considered to be better in terms of the filling property of the conductive composition into the via hole. This is because the distance in the depth direction to reduce the diameter is long as viewed from the direction of filling the conductive composition. On the other hand, with respect to preventing the conductive composition from falling off after curing shrinkage, the one shown in FIG. 5 is considered better. Regarding the possibility of dropping downward in the figure, the one shown in FIG. 5 has a larger support area by the inner wall.

  Therefore, regarding the position of the constriction, both the filling property of the conductive composition and the prevention of falling off after curing shrinkage are taken into consideration, and the defective rate due to them is antagonized so that each has a low defect rate that is good to some extent. Can be set appropriately. Although not mentioned at all in the above description, in order to easily obtain the glass base layer 11 having the via holes 11a and 11a1 having the neck as shown in FIGS. 1 and 5, the two layers are bonded together. A method of forming the glass base layer 11 is also conceivable. In this case, a two-layer glass plate in which a simple tapered hole is formed is bonded. Regarding the glass base layer obtained by pasting, it is still necessary to consider from the filling property of the conductive composition and prevention of falling off after curing shrinkage, and as a consideration there is a position in the depth direction of the constriction. does not change. In this case, the position of the constriction is determined by the ratio of the thicknesses of the two layers.

  In addition, as an operational and effective difference due to the difference in the vertical cross-sectional shape of the via hole, the escape of gas and moisture using the longitudinal conductor 31 as a source of the form shown in FIG. 1 from the form shown in FIG. May be slightly better. This is because the portion of the longitudinal conductor 31 having a larger diameter is considered to be a large source of gas and moisture, but in the form shown in FIG. 1, the volume occupied by that portion below the constriction is illustrated. This is because the large-diameter side of the via hole 11a exists in the vicinity of that portion, which is larger than that in the configuration shown in FIG. The contact area between the lower surface, which is the surface of the longitudinal conductor 31 on the large diameter side of the via hole 11a, and the resin layer 12 is the contact area between the upper surface, which is the surface of the longitudinal conductor 31 on the small diameter side, and the resin layer 14. It can be made larger and can contribute to escape of gas and moisture.

  Next, a further modification example of the shape of the via hole formed in the glass base layer 11 will be described. FIG. 6 is a schematic cross-sectional view showing an example of a glass base layer (an example of a through hole shape) that can be used in place of the glass base layer 11 shown in FIGS. 1 and 5.

  In the example shown in FIG. 6, the shape of the via hole 11a1 is different from that of the via hole 11a shown in FIG. Have. That is, the via hole 11a shown in FIG. 1 has a diameter that decreases from the lower surface in the depth direction on the lower surface in the figure, whereas the via hole 11a1 shown in FIG. The diameter increases in the direction. Other features are unchanged as a via hole.

  Even in the shape of the via hole 11a1, it is considered that the practical usefulness in terms of filling property of the conductive composition and prevention of falling off after curing shrinkage can be maintained. However, the via hole 11a1 may be slightly inferior in terms of the filling property of the conductive composition as compared to the via hole 11a shown in FIG.

  Next, FIG. 7 shows an example of a glass base layer (an example of a through-hole shape) that can be used in place of the glass base layer 11 shown in FIGS. 1 and 5, which is different from that shown in FIG. It is typical sectional drawing.

  In the example shown in FIG. 7, the shape of the via hole 11a2 is different from that of the via hole 11aa shown in FIG. Have. That is, the via hole 11aa shown in FIG. 5 has a diameter that decreases from the upper surface in the depth direction on the upper surface in the figure, whereas the via hole 11a2 shown in FIG. The diameter increases in the direction. Other features are unchanged as a via hole.

  Even in the shape of the via hole 11a2, it is considered that practical usefulness in terms of filling property of the conductive composition and prevention of falling off after curing shrinkage can be maintained. However, there is a possibility that the via hole 11a2 may be slightly inferior in terms of preventing the conductive composition from falling off after curing shrinkage compared to the via hole 11aa shown in FIG. This is because the via hole 11a2 has a reduced support area of the inner wall surface when the conductive composition is about to fall off in the downward direction in the figure.

  Next, FIG. 8 is an example of a glass base layer (an example of a through-hole shape) that can be used in place of the glass base layer 11 shown in FIGS. 1 and 5, which is different from those shown in FIGS. 6 and 7. It is a typical sectional view showing.

  In the example shown in FIG. 8, the shape of the via hole 11a3 is different from that of the via hole 11aa shown in FIG. . That is, the diameter of the constricted portion of the via hole 11aa shown in FIG. 5 is smaller than the diameter of the upper surface of the glass base layer 11, but the diameter of the constricted portion of the via hole 11a3 shown in FIG. It is larger than the diameter on the upper surface (however, smaller than the diameter on the lower surface of the glass base layer 11). In terms of shape, the via hole 11a3 shown in FIG. 8 can be regarded as a modification of the via hole 11a2 shown in FIG.

  Even in the shape of the via hole 11a3, it is considered that practical usefulness in terms of filling property of the conductive composition and prevention of falling off after curing shrinkage can be maintained. However, there is a possibility that the via hole 11a3 is slightly inferior to the via hole 11aa shown in FIG. 5 in terms of preventing the conductive composition from falling off after curing shrinkage. This is because the via hole 11a3 has a reduced support area of the inner wall surface when the conductive composition is about to fall down in the illustrated downward direction.

  On the other hand, when the via hole 11a3 is compared with the via hole 11a2 shown in FIG. 7, it is considered that the via hole 11a3 is improved in terms of the filling property of the conductive composition and is somewhat inferior in terms of preventing the falling off after curing shrinkage. This point can be understood by considering the shape based on the matters described so far.

  The method of forming the via holes 11a1, 11a2, and 11a3 as shown in FIGS. 6 to 8 can be realized by using multi-stage laser processing as shown in FIG.

  DESCRIPTION OF SYMBOLS 11 ... Glass base layer, 11a, 11aa, 11a1, 11a2, 11a3 ... Via hole, 11h1, 11h2 ... Laser processing hollow, 11h3 ... Laser processing hole (through-hole), 11g1 ... Through-hole, 11g2, 11g3 ... Hydrofluoric acid treatment through-hole , 12, 13, 14, 15 ... resin layer (interlayer insulating layer), 21a, 22a ... via hole plated via, 21b, 22b ... wiring pattern, 21c, 22c ... via hole plated via, 21d, 22d ... wiring pattern, 22e ... nickel gold plating layer, 31 ... longitudinal conductor (through conductor), 31a ... conductive composition (before drying), 41, 42 ... solder resist (protective film), 51 ... solder ball, 61, 62 ... hook acid.

Claims (2)

Irradiating a glass base layer with laser light having a predetermined first power from the front side to form a first laser processing recess on the back side;
Laser processing is performed by irradiating the base layer with laser light having a second power that is weaker than the first power from the surface side, and the second laser processing in which the first laser processing recess is deepened. Forming a recess;
Laser processing is performed by irradiating the base layer with laser light having a third power that is weaker than the first power and stronger than the second power from the surface side, and the second laser processing indentation is performed. Forming a through hole penetrating through the back surface;
Forming a smoothed surface by hydrofluoric acid treatment of the inner wall surface of the through hole of the base layer;
Filling the through hole of the base layer having the smoothed surface with a conductive composition from the back side of the base layer to form a longitudinal conductor;
Providing a conductor so as to come into contact with the upper and lower surfaces of the longitudinal conductor, which is a surface connected to the front surface and the back surface of the base layer. A method for producing a glass interposer substrate. Irradiating a glass base layer with laser light to form a through hole; and
A hydrofluoric acid bath having a depth that is in contact with one side of the base layer and does not reach the other side of the base layer having the through hole is performed until a predetermined first time elapses. Expanding the diameter of the through hole from the middle of the depth of the through hole,
A hydrofluoric acid bath having a depth that is in contact with the other surface of the base layer and does not reach the one surface with respect to the base layer in which the diameter of the through hole is expanded from the one surface to the middle of the depth of the through hole Performing a second time shorter than the first time, and expanding the diameter of the through hole from the other surface to the middle of the depth of the through hole;
A longitudinal conductor is formed by filling a conductive composition from the one surface side of the base layer into the through hole of the base layer in which the diameter of the through hole is expanded from the one surface and the other surface. Forming a step;
And a step of providing a conductor so as to contact the upper and lower surfaces of the longitudinal conductor, which is a surface connected to the one surface and the other surface of the base layer.

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