JP2011204889A - Interposer substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interposer substrate reduced in deformation of the substrate for fixing a measuring terminal, allowing the measuring terminal to accurately measure electric characteristics of a part serving as a semiconductor chip, and facilitating recognition of an alignment mark.SOLUTION: Since a principal plane of the interposer substrate made of ceramics has a bottomed hole as the alignment mark and a bottom surface of the bottomed hole is recessed to deepen toward the center, the strength of the interposer substrate is increased in comparison with a case that the alignment mark is a through-hole and hence deflection of a product is suppressed, thereby attaining highly accurate positioning. Since a nearly flat area of the bottom surface of the bottomed hole is small, reflection light for image recognition is reduced, and the contrast between the alignment mark and the principal plane is increased, thereby improving the recognizability of the alignment mark.

Description

  The present invention relates to an interposer substrate that is a probe card component used for electrical characteristic testing of a wafer on which a large number of semiconductor elements are formed.

  Inspecting the electrical characteristics of circuits formed on semiconductor wafers used in CPUs (Central Processing Units), MPUs (Microprocessor Units), flash memories, etc. This is done using a probe card.

  FIG. 4 is a schematic cross-sectional view showing a configuration for inspecting electrical characteristics of a semiconductor chip using a conventional probe card.

The probe card 100 shown in FIG. 4 is a probe pin type vertical probe card, and the probe pin 102 fixed to the terminal 103a of the wiring board 103 formed on the support member 104 guides the probe pin 102. The electrical characteristics of a large number of semiconductor chips 111 are inspected at once by contacting the lead electrodes 112 of the wafer 110 on which a large number of semiconductor chips 111, which are to be tested, are placed through the through holes 101a of the member 101. is there.

However, the probe card 100 is provided with a bent portion so that a large number of the probe pins 102 are in contact with the respective lead electrodes 112, but the semiconductor card 111 is further integrated. As a result, the pitch between the lead electrodes 112 is becoming narrower, and when the bent probe pins 102 are used, the probe pins 102 are likely to come into contact with each other, resulting in an electrical short circuit failure. .

Therefore, instead of the conventional probe pin type vertical probe card, a vertical probe card that does not use the probe pin 102 is obtained by using a micro processing technique called MEMS (Micro Electro Mechanical Systems) (for example, a photolithography method). The method is being adopted.

  FIG. 5 is a schematic cross-sectional view showing a configuration for inspecting electrical characteristics of a semiconductor chip using a conventional MEMS vertical probe card.

The probe card 200 in FIG. 5 includes an ST substrate (space transformer) 204, a wiring substrate 203 formed on the ST substrate 204, and an interposer substrate 201 having a through hole 201b. A terminal 203a is formed on the wiring board 203, and the terminal 203a and a measurement terminal 202 formed on the main surface of the interposer substrate 201 by a microfabrication technique of MEMS are electrically connected by a bonding wire 205 that passes through a through hole 201b. It is tied. Then, the measurement terminals 202 are in contact with the lead electrodes 112 of the wafer 110 on which a large number of semiconductor chips 111 that are to be inspected are placed, whereby the electrical characteristics of the large number of semiconductor chips 111 are inspected at a time. .

In assembling a vertical probe card using such a MEMS processing technique, the measurement terminals 202 of the interposer substrate 201 and the terminals 203a formed on the wiring substrate 203 of the ST substrate 204 are used.
Are electrically connected by the bonding wire 205, but the measurement terminal 202 is so fine that it cannot be visually recognized, and the bonding wire 205 drawn out of the wiring board 203 and the measurement terminal 202 are accurate. Therefore, the through hole 201a provided in the interposer substrate 201 is conventionally used as an alignment mark for position recognition.

In order to position using such an alignment mark, light is emitted from the light source toward the alignment mark, and the irradiated light is reflected by the main surface of the interposer substrate 201 around the through hole 201a. Is imaged with a CCD camera, the image is binarized with an image processing device, and the center position in the radial direction of the through hole 201a is obtained.
This is done by recognizing the exact position of the interposer substrate 201. As an alignment mark for such positioning, a projection, a through hole, a bottomed hole, or the like is used.

  In Patent Document 1, a positioning mark provided on a plane is read with a CCD camera, and a positioning mark that can determine a reference point based on the data obtained as a result is a plurality of positioning marks. A positioning mark composed of a mark element is described, and it is described that such a mark element is a bottomed hole. According to this, since one positioning mark is composed of a plurality of mark elements, each mark element can be made small enough to be accurately read by a CCD camera, while these small mark elements are collected. The size of the positioning mark configured in this manner can be made comparable to that of a conventional positioning mark. Therefore, when the positioning mark is roughly aligned with the CCD camera, the positioning mark can be easily captured without increasing the magnification of the CCD camera to reduce the depth of focus and without narrowing the field of view. it can. Therefore, the alignment operation can be performed efficiently.

JP 2000-112151 A

However, in assembling the ST substrate 204 and the interposer substrate 201 of the probe card 200 employed in the MEMS type vertical probe card, alignment for positioning with the interposer substrate 201 is required in order to accurately align the bonding wires 205. Although the through hole 201a is provided as a mark, the wiring on the wiring board 203 is further complicated by the high integration of the semiconductor chip 111, and if the through hole 201a is used for the alignment mark, the wiring on the ST board 204 is used. The incident light is reflected through the through-hole 201a, and the difference in brightness of the image between the main surface of the interposer substrate 201 and the through-hole 201a is reduced, resulting in a problem of adversely affecting the alignment mark position recognition. It was.

  In addition, even if an attempt is made to position the ST mark with the bottom hole of the positioning mark proposed in Patent Document 1, the reflected light reflected from the bottom of the hole is not reflected in the image of the main surface of the interposer board. There remains a problem that the difference between brightness and darkness disappears and the position recognition of the alignment mark is adversely affected, and no solution has been described.

  The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide an interposer substrate capable of accurately recognizing a position in an assembly process of a MEMS type vertical probe card.

  The interposer substrate of the present invention is characterized in that it has a bottomed hole as an alignment mark on the main surface of the interposer substrate made of ceramics, and the bottom surface of the bottomed hole is a concave shape that becomes deeper toward the center. To do.

The interposer substrate of the present invention is characterized in that, in the above configuration, the bottom surface of the bottomed hole is conical or pyramidal.

  The interposer substrate of the present invention is characterized in that, in any of the above-described configurations, L / D is 1 to 4, where D is the inner diameter of the bottomed hole and L is the depth. .

  Moreover, the interposer substrate according to the present invention is characterized in that, in any of the above-described configurations, the arithmetic average roughness Ra of the bottom surface of the bottomed hole is larger than the arithmetic average roughness Ra of the main surface of the interposer substrate. Is.

  Since the interposer substrate of the present invention has a bottomed hole as an alignment mark on the main surface of the interposer substrate made of ceramics, and the bottom surface of the bottomed hole has a concave shape that becomes deeper toward the center, the probe card In the assembly process, when the wiring board of the ST board and the measurement terminal of the interposer board are electrically connected by the bonding wire, the reflected light from the wiring of the ST board does not enter the CCD camera. Furthermore, by making the bottom surface of the bottomed hole deeper toward the center, the reflected light from the bottom surface of the bottomed hole can be reduced from being reflected to the CCD camera. The difference from the reflected light of the main surface of the interposer substrate becomes clear, and the image recognition accuracy of the alignment mark can be improved.

  Further, when the bottom surface of the bottomed hole is conical or pyramidal, the interposer substrate of the present invention can reflect light from the bottom surface of the bottomed hole compared to the case where the bottom surface of the bottomed hole is flat. Since it can be reduced, the difference from the reflected light of the main surface of the interposer substrate around the bottomed hole becomes clear, and the image recognition accuracy of the alignment mark can be improved.

  Also, the interposer substrate of the present invention has a bottomed hole with an inner diameter of D and a depth of L. When L / D is 1 to 4, the light reflected by the bottom face toward the center of the alignment mark Therefore, the difference from the reflected light of the main surface of the interposer substrate around the bottomed hole becomes clear, and the image recognition accuracy of the alignment mark can be improved.

  According to the interposer substrate of the present invention, when the arithmetic average roughness Ra of the bottom surface of the bottomed hole is larger than the arithmetic average roughness Ra of the main surface of the interposer substrate, the interposer around the bottomed hole The difference from the reflected light of the main surface of the substrate becomes clear, and the image recognition accuracy of the alignment mark can be improved.

It is a schematic sectional drawing which shows an example of the structure which test | inspects the electrical property of a semiconductor chip using the probe card which has the interposer board | substrate of this invention. The example of the bottomed hole of the interposer board | substrate of this invention is shown, (a)-(c) is a concave longitudinal cross-sectional view with the bottom face deepening toward the center, (d)-(f) are respectively It is a schematic top view which shows the shape of the bottom face of the bottomed hole of (a)-(c). (A) and (b) are longitudinal sectional views showing a shape with a flat bottom surface, and (c) and (d) are examples of (a) or (b) respectively. It is a schematic top view which shows the shape of the bottom face of a bottom hole. It is a schematic sectional drawing which shows the structure which test | inspects the electrical property of a semiconductor chip using the conventional probe card. It is a schematic sectional drawing which shows the structure which test | inspects the electrical property of a semiconductor chip using the conventional vertical probe card of a MEMS system.

  Examples of embodiments of the interposer substrate of the present invention will be described below.

  FIG. 1 is a schematic cross-sectional view showing an example of a configuration for inspecting electrical characteristics of a semiconductor chip using a probe card having an interposer substrate of the present invention.

  The probe card 10 in FIG. 1 has an ST substrate (space transformer) 4, a wiring substrate 3 formed on the ST substrate 4, and an interposer substrate 1 having a through hole 1b. A terminal 3a is formed on the wiring board 3, and the terminal 3a and a measurement terminal 2 formed on the main surface of the interposer substrate 1 by a microfabrication technique of MEMS are electrically connected by a connection 5 through a through hole 1b. It is.

  This measurement terminal 2 is an alternative to the probe pin of the conventional prob card, and by contacting the electrical signal from the probe card 10 with the lead electrode 112 drawn on the wafer 110 from the semiconductor chip 111 which is the test object, The inspection of electrical characteristics of a large number of semiconductor chips 111 is performed at once.

  The measurement terminal 2 formed on the interposer substrate 1 is so fine that it cannot be visually recognized, and the bonding wire 5 drawn from the wiring substrate 3 of the ST substrate 4 through the through hole 1b of the interposer substrate 1 is measured. When electrically connecting to the terminal 2, accurate bonding can be performed by recognizing an image of the bottomed hole 1 a provided in the main surface of the interposer substrate 1 as an alignment mark.

And in order to position using the bottomed hole 1a as such an alignment mark, light is irradiated from the light source toward the bottomed hole 1a, and the irradiated light is an interposer substrate 201 around the bottomed hole 1a. The reflected light reflected by the main surface is picked up by a CCD camera, the image is subjected to binarization processing by an image processing device, and the center position in the radial direction of the bottomed hole 1a is obtained. The precise position of the interposer substrate 1 is recognized.

  The interposer substrate 1 of the present invention has a bottomed hole 1a as an alignment mark on the main surface of the ceramic interposer substrate 1, and the bottom of the bottomed hole 1a is deepened toward the center. It is important that

  FIG. 2 shows an example of a bottomed hole of the interposer substrate of the present invention, wherein (a) to (c) are concave longitudinal sectional views with the bottom surface deepening toward the center, and (d) to (f). These are the schematic top views which show the shape of the bottom face of the bottomed hole of (a)-(c), respectively.

  As shown in FIGS. 2A and 2D, the bottomed hole 1a of the interposer substrate 1 of the present invention has a concave shape with the bottom surface deeper toward the center on the main surface of the interposer substrate 1 made of ceramics. Since the bottom hole 1a is provided, even if the light emitted from the light source for positioning reaches the bottom surface of the bottomed hole 1a, a part of the reflected light is irregularly reflected, so that the remaining light is reflected light. As shown in FIG. For this reason, since it becomes easy to distinguish from the light reflected by the main surface of the interposer substrate 1 and picked up by the CCD camera, the position of the bottomed hole 1a can be easily recognized and The problem that the position cannot be recognized is reduced. Further, the strength of the interposer substrate is increased as compared with the case where the alignment mark is a through hole, and the bending of the product is suppressed, so that highly accurate positioning can be performed.

  Moreover, it is preferable that the bottom face of the bottomed hole 1a of the interposer substrate 1 of the present invention is conical or pyramidal.

  The bottomed holes 1a shown in FIGS. 2 (b) and (e) are conical, and the bottomed holes 1a shown in FIGS. 2 (c) and (f) are pyramid-shaped. Compared to the concave bottomed hole 1a shown in (d), as the apex of the cone or pyramid on the bottom surface is approached, the irradiated light is more likely to be diffusely reflected. Since the bottom surface of the bottom hole 1a has less reflected light, the light reflected by the main surface of the interposer substrate 1 and picked up by the CCD camera more than the bottomed hole 1a having a concave bottom surface that is deeper toward the center. It is preferable because it can be easily distinguished from. As for the pyramid, a triangular pyramid having a small conical surface is more preferable because reflected light is reduced.

  Further, when the inner diameter of the bottomed hole 1a of the present invention is D and the depth is L, L / D is preferably 1 to 4.

  At this time, when the bottomed hole 1a is conical, D is the diameter of the shape formed in the opening, and when the bottomed hole 1a is a pyramid, D is the circumscribed shape formed in the opening. The diameter of the circle. L is the dimension from the opening of the bottomed hole 1a to the deepest part.

In the interposer substrate 1 in which the measurement terminals 2 are formed by the microfabrication technology of MEMS, the measurement terminals 2 are formed with high density, so that the diameter D of the bottomed hole 1a that is an alignment mark is naturally required to be small, and is currently 0.1 mm. Those in the range of ~ 0.3 mm are the mainstream and are becoming 0.1 mm or less. Further, since the accuracy of the bottomed hole 1a is important, the bottomed hole 1a is processed into the sintered ceramic. In this case, from the viewpoint of productivity, the depth L of the bottomed hole 1a is preferably as shallow as possible, and L / D is preferably 4 or less. At that time, the depth L is preferably 1/3 to 1/30 of the thickness of the interposer substrate 1, and preferably 0.1 mm to 1.0 mm. The L / D of the bottomed hole 1a is preferably 1 to 4, but since this reduces the reflected light reflected from the bottom surface of the bottomed hole 1a, the reflected light from the main surface of the interposer substrate 1 and the CCD This is because the image captured by the camera can be easily distinguished and the position of the bottomed hole 1a can be easily recognized. When L / D is less than 1, the amount of reflected light incident on the CCD camera increases, so the difference from the reflected light from the main surface of the interposer substrate 1 decreases, and the recognition level of the position of the bottomed hole 1a decreases. Tend to. Further, if L / D exceeds 4, the bottomed hole 1a becomes deep, and the machining cost tends to increase.

  The ceramic material for forming the interposer substrate 1 of the present invention is a single material selected from silicon nitride, boron nitride, zirconia, mullite, mica, aluminum nitride, alumina, silica, cordierite or magnesia, or a combination thereof. A composite material manufactured by the above method may be used.

Next, an example of the manufacturing method for obtaining the alignment mark of the interposer substrate 1 of the present invention will be described.
First, the alumina powder is 8 mass% to 95 mass%, and the balance is 100 mass parts so as to be silicon oxide (SiO ₂ ) powder. Further, calcium carbonate ( Each powder of CaCO ₃ ) and magnesium carbonate (MgCO ₃ ) and a predetermined amount of at least one powder of chromium oxide, cobalt oxide, manganese oxide and iron oxide are added as colorants to obtain a mixed powder. Then, this mixed powder is put into a rotary mill together with water as a solvent, and mixed and ground with alumina balls for 24 hours. In addition, what is necessary is just to make the average particle diameter after mixing grinding | pulverization into 1 micrometer or more and 3 micrometers or less. In addition, calcium carbonate (CaCO ₃ ) and magnesium carbonate (MgCO ₃ ), which are sintering aids, are burned down during the firing of carbon dioxide (CO ₂ ), which is part of the constituent components, and calcium oxide (CaO). , It will be present as magnesium oxide (MgO).

Next, after adding polyvinyl alcohol, polyethylene glycol, and an acrylic resin as a molding binder so as to be 6% by mass in total with respect to 100% by mass of the mixed powder, they are mixed to form a slurry. And a sheet | seat is shape | molded by the doctor blade method using this slurry, and it can be set as a molded object by punching out this sheet | seat with the metal mold | die of a predetermined shape, or giving a laser processing.

  Moreover, what is necessary is just to make a sheet | seat into various shapes, for example, disk shape, square plate shape by cutting or laser processing etc. as needed. And the sintered compact used as the interposer board | substrate 1 can be obtained by putting the molded object processed into various shapes into a baking furnace, and hold | maintaining at 1550 degreeC or more and 1650 degrees C or less for 8 hours or more and 12 hours or less.

  The through hole 1b can be obtained by subjecting the obtained sintered body to drilling, ultrasonic processing, laser processing, or water jet processing.

  Furthermore, the bottomed hole 1a can be obtained by subjecting the obtained sintered body to blast polishing, etching, drilling by machining, ultrasonic drilling, laser processing or water jet processing.

  2 (a) and 2 (d) may be processed by blast polishing, etching, laser processing or water polishing if the bottomed hole 1a has a concave shape. FIGS. 2 (b) and 2 (e) 2 may be processed by machining drilling, ultrasonic drilling, laser processing, or water jet processing, and if it is a pyramid shape shown in FIGS. 2C and 2F, ultrasonic drilling is performed. Can be obtained.

  In order to accurately form the position accuracy of the bottomed hole 1a, which is an alignment mark, and to improve productivity, the bottomed hole 1a having a concave or conical shape is well machined, and the bottomed hole 1a has a pyramid shape. Is preferably ultrasonic drilling.

  Moreover, about thickness processing, the interposer board | substrate 1 of predetermined | prescribed thickness can be obtained by performing the surface grinding process or the lapping process by WA, GC, or diamond.

  Examples of the present invention will be specifically described below, but the present invention is not limited to the following examples.

First, aluminum oxide powder having an average particle size of 2.0 μm and silicon oxide, mullite, calcium oxide, and magnesium oxide powders were prepared. Then, a mixed powder in which the contents of aluminum oxide and silicon oxide are weighed so as to be 78.0% by mass and 14.0% by mass of ceramics, respectively, and the balance is a powder composed of mullite, calcium oxide and magnesium oxide. The mixture was put into a rotary mill together with water as a solvent and mixed with ceramic balls made of aluminum oxide having a purity of 99.5% for 3 hours.

Next, after adding polyvinyl alcohol, polyethylene glycol, and an acrylic resin as a molding binder so as to be 10% by mass in total with respect to 100% by mass of the mixed powder, they were mixed to obtain a slurry. And the sheet | seat was shape | molded by the doctor blade method using this slurry, and the molded object was obtained by punching out this sheet | seat with the metal mold | die of a predetermined shape.

  Next, after putting this compact into a firing furnace, it was held at a firing temperature of 1580 ° C. for 3 hours to obtain a sintered body to be the interposer substrate 1 of the present invention having a thickness of 3 mm and a diameter of 200 mm.

Next, a bottomed hole 1a serving as a plurality of alignment marks and a bonding wire 5 are drawn out from the ST substrate 4 to the main surface side of the interposer substrate 1 in the sintered body serving as the interposer substrate 1 having a diameter of 200 mm. The through hole 1b was produced. The shape of the bottomed hole 1a and its dimensions are as shown in Table 1, and 1000 samples were prepared for each.

  Hereinafter, the processing method of the bottomed hole 1a will be described.

Sample No. Nos. 1 and 2 are comparative examples. The bottomed hole 1a has a concave bottom surface and is flat. 2 has a flat bottom surface and an R-shaped curved surface at the corner of the bottom surface. All of these processing methods are based on machining drill processing. Using a machining drill processing apparatus manufactured by Sodick Hightech Co., Ltd., model name: HS-430, the rotation speed is 10,000 rpm, and the cutting depth is 5 μm. did. Moreover, the tip of the drill used what can process a flat surface, and the material of the tool used super hard material. And the diameter D of the bottomed hole 1a was 0.1 mm, and the depth L was 0.2 mm.

Next, sample No. Reference numerals 3 to 7 are samples of the present invention, in which the bottom surface of the bottomed hole 1a is conical, and the processing method is the same as that of the comparative example. However, the tool was changed according to the shape of the bottomed hole. The diameters D of the bottomed holes 1a are all 0.1 mm. 3 is 0.06mm,
Sample No. 4 is 0.10 mm, sample no. 5-1, 0.2 mm, Sample No. 6 is 0.4 mm, sample no. 7 was 0.5 mm.

Next, sample No. 8 to 12 are also samples of the present invention, and the bottom of the bottomed hole 1a has a pyramidal shape, and the processing methods are all by ultrasonic drilling, manufactured by JEOL Ltd. Model name: Using a UM-150C ultrasonic drilling machine, with a frequency of 25 KHz, an amplitude of 5 μm, a feed rate of 5 mm / min, and diamond grains with a grain size of 4-8 μm. It was. In the ultrasonic drilling, the workpiece is made to vibrate up and down to form the bottomed hole 1a, and the tool is made of a super hard material and the tip shape is a pyramid shape.

Next, thickness processing was performed on both surfaces of the main surface of the interposer substrate 1. The purpose of the thickness processing is to remove burrs on the surface of the bottomed hole 1a and the through hole 1b. First, surface grinding is performed. The surface grinding device is model name: MSG-250H manufactured by Mitsui High-Tech Co., Ltd.
No. 1 was used, a resin diamond with abrasive grains of No. 200 was used, the rotation speed was 3000 rpm, and the cutting depth was 0.01 mm. Next, lapping is performed using a model name: DSM 16B-5L / P-V, manufactured by SPEED FAM CO, LTD, with abrasive grains of 1000 and a rotation speed of 60 rpm for 30 minutes. The main surface was ground by 0.02 mm.

  The depth L of the bottomed hole 1a shown in Table 1 is a dimension after thickness processing.

  Next, a test was performed on the accuracy of image recognition of the bottomed hole 1a which is an alignment mark of the interposer substrate 1.

  First, 41 bottomed holes 1a of the interposer substrate 1 are formed in one substrate, and the position of each bottomed hole 1a is the center position of the origin of the dimension value of the interposer substrate 1 and It becomes hole coordinates. The bottomed hole 1a used for the test is a bottomed hole 1a formed at the origin position.

  Then, illumination and a CCD camera were set in the vertical direction of the main surface where the bottomed hole 1a of the interposer substrate 1 was formed, and the bottomed hole 1a of each sample was imaged.

The illumination uses a ring name of VH-Z100R / W made by Keyence Corporation, CC
As the D camera, a model name manufactured by Keyence Corporation: VHX-1000 having a pixel number of 2.11 million was used. The reference hole coordinates for evaluating the accuracy of the hole coordinates based on the binarized data of the captured image were based on the dimension values measured with a laser microscope. The laser microscope was performed with a maximum output of 0.9 mW of a 658 nm red laser using a model name: VK-8700 manufactured by Keyence Corporation.

Next, an image obtained by imaging the bottomed hole 1a located at the center of the interposer substrate 1 is binarized at a commonly used threshold value of 50% (127 gradations), and the binarized data is used to binarize the bottomed hole 1a. The hole coordinates were calculated, and the positional accuracy of the bottomed hole 1a of each sample by image recognition was evaluated based on the error from the hole coordinates obtained with the laser microscope.

  When the hole position of the bottomed hole 1a is within 2 μm with respect to the data of the laser microscope, it was judged as a non-defective product, and a product exceeding 2 μm was regarded as defective. If the defect rate of each sample is 0%, the evaluation is excellent and ◎, the evaluation of 0% to 0.2% or less is good and the evaluation exceeds 0.2%, and the result is rejected and X. Is shown in Table 1.

  As can be seen from the results in Table 1, sample No. In Nos. 1 and 2, the defect rate at the hole position of the bottomed hole 1a was 10% higher, and the evaluation was “poor”. This is because the bottom surface of the circular bottomed hole 1a is flat or the bottom surface of the bottomed hole 1a is flat in the laser microscope because the bottom surface of the bottomed hole 1a is flat. However, in the image processing, the irradiated light hits the bottom surface, and most of the reflected light is incident on the CCD camera, and the brightness of the reflected light from the edge of the bottomed hole 1a and the main surface is dark and dark. The difference is small, and therefore the positional accuracy of the binarized image data is lowered.

Sample No. which is an example of the present invention. 3 to 12, the defect rate at the hole position of the bottomed hole 1a was 0.2% or less, which was excellent の or good ○. This is because the bottomed hole 1a has a circular or square outer peripheral shape, but since the bottom surface is concave toward the center, the irradiated light hits the bottom surface concave toward the center and diffusely reflects. However, since the incident light to the CCD camera radiated to the outside of the bottomed hole 1a can be suppressed, the difference in brightness between the reflected light of the edge of the bottomed hole 1a and the main surface becomes large, and the binarized image data The position accuracy can be improved.

Further, the relationship between the diameter D and the depth L of the bottomed hole 1a is one or more sample Nos. In 4-7 and 9-12, the above-mentioned defect rates were all 0%, and the hole position evaluation was excellent ◎. However, sample no. 7 and 12 had a depth L of 0.5 mm, and the processing time of the bottomed hole 1a was long, so the overall evaluation was ◯. Therefore, it can be said that L / D is preferably 1 to 4.

  Next, the sample No. used in Example 1 was used. Using the same interposer substrate 1 as 5-1 and the bottomed hole 1a of the same size, the accuracy of the hole position of the bottomed hole 1a by image recognition when the surface roughness of the bottom surface of the bottomed hole 1a is changed Confirmed. Samples having the arithmetic average roughness Ra of the bottom surface of the bottomed hole 1a shown in Table 2 were prepared.

Here, the surface roughness was measured according to JIS B 0601 (2001) with a measuring instrument using a laser microscope manufactured by Keyence Corporation (model name: VK-8700). The measurement length at this time was set to 0.1 mm, respectively, and the arithmetic average roughness (Ra) was measured. In addition, each sample was produced with different surface roughness by changing the number of revolutions of the grinding wheel for drilling by machining and the holding time of spark-out (the state in which the grinding wheel is held with zero cutting and finishing processing). . The results are shown in Table 2.

  As can be seen from the results in Table 2, the sample Nos. 1 and 2 have the same or smaller arithmetic average roughness (Ra) of the bottom surface of the bottomed hole 1a than the arithmetic average roughness (Ra) of the main surface of the interposer substrate 1. In 5-2 and 5-3, the defect rates at the hole positions of the bottomed hole 1a were 0.7% and 0.8%, and the evaluation was good, but the arithmetic average roughness (Ra ), The arithmetic average roughness (Ra) of the bottom surface of the bottomed hole 1a is larger. In 5-1 and 5-5, the defect rate at the hole position of the bottomed hole 1a was 0%, and the evaluation was excellent.

  This is because the bottom surface of the bottomed hole 1a is rougher than the surface roughness of the main surface of the interposer substrate 1, so that the reflected light on the bottom surface is more diffusely reflected and enters the CCD camera. The difference between the reflected light and the reflected light of the main surface becomes large, and when the image is binarized, it becomes a clear bottomed hole 1a and can be an alignment mark with high positional accuracy.

1: Interposer board 1a: Bottomed hole 1b: Through hole 2: Measurement terminal 3: Wiring board 3a: Terminal 4: ST board (space transformer)
5: Bonding wire
10: Probe card
110: Wafer
111: Semiconductor chip
112: Lead electrode

Claims (4)

An interposer substrate having a bottomed hole as an alignment mark on a main surface of an interposer substrate made of ceramics, the bottom surface of which is deeper toward the center. The interposer substrate according to claim 1, wherein a bottom surface of the bottomed hole has a conical shape or a pyramid shape. The interposer substrate according to claim 1 or 2, wherein L / D is 1 to 4, where D is an inner diameter of the bottomed hole and L is a depth. The interposer substrate according to any one of claims 1 to 3, wherein the arithmetic average roughness Ra of the bottom surface of the bottomed hole is larger than the arithmetic average roughness Ra of the main surface of the interposer substrate.

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