JP2006292726A - Inspection substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection substrate of high density that can integrally and electrically inspect the circuit of a high-density semiconductor device in batch, which is formed on a semiconductor wafer, with high accuracy. <P>SOLUTION: A terminal 2 for inspection is formed on the top surface of an insulating substrate 3 and the central part of the top surface of the terminal 2 is dented lower than the outer circumferential part, in the inspection substrate 1, where an exterior connection terminal 5 is formed which is electrically connected to the terminal 2 at the lower part of the insulating substrate 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection substrate for collectively measuring and inspecting electrical characteristics of electronic components such as semiconductor elements.

  Conventionally, a semiconductor device mounted with a semiconductor element is supplied with the semiconductor element and the lead frame electrically connected by wire bonding, and then housed and sealed in a resin sealed or ceramic container, and is externally printed. It was mounted on the board. In recent years, a configuration in which a semiconductor element called a flip chip is directly mounted on a ceramic substrate or a printed board is becoming mainstream due to a demand for downsizing of a semiconductor device.

  For a semiconductor element having a large-scale integrated circuit formed on a semiconductor wafer such as a Si wafer at the same time, an almost constant ratio is caused by an electrical failure caused by adhesion of foreign matters from the initial stage of production on the semiconductor wafer. It includes electrical connections and defective electrical characteristics. In addition, conventionally, electrical inspection or the like has been performed after the semiconductor wafer has been cut into individual semiconductor elements, so that there has been a problem that inspection time and cost are very long.

  In order to solve these problems, there has been proposed a probe card capable of performing an electrical inspection of a large number of semiconductor elements at the same time as a semiconductor wafer (see Patent Document 1 below).

  As this probe card, there is a conventional cantilever type probe card. This cantilever type consists of metal needles radially extending around a circular through hole opened in the center of the printed circuit board. This cantilever type probe card has a problem that the number of semiconductor elements that can be inspected simultaneously is smaller than the limit of the number of metal needles.

  In addition, there is a probe card (inspection board) using a wiring board. In this inspection substrate, terminals formed on the inspection substrate and probe pins are electrically connected, and the semiconductor element and the probe pins are brought into contact with each other to perform an electrical inspection. Therefore, many probe pins can be connected to the metal needle of the cantilever type probe card on the inspection substrate, and at the same time, a large number of semiconductor elements can be inspected collectively. The inspection board is manufactured as follows.

  First, a through hole for establishing electrical conduction between the upper and lower surfaces is formed in the ceramic green sheet, and a conductive paste made of tungsten (W) is printed and applied to the through hole and the wiring pattern portion of the ceramic green sheet.

  Next, this ceramic green sheet is laminated so that the wiring patterns are electrically connected, and sintered at a temperature of about 1500 ° C.

  Since the ceramic inspection substrate manufactured in this way is sintered at a temperature of about 1500 ° C., the size of the ceramic green sheet shrinks to about 80%. For this reason, the inspection substrate to be obtained is designed in advance in consideration of shrinkage due to sintering. However, due to variations in the raw materials for ceramic green sheets, molding of the ceramic green sheets, and variations in the firing temperature in the furnace when firing the ceramic green sheets, the dimensions of the test substrate and the probe pin connection terminals on the surface Variation in the shrinkage of the inspection substrate occurs at the position.

  In order to solve such a problem, the following Patent Document 2 proposes a ceramic inspection substrate having a probe pin connection terminal formed on the surface of the substrate after firing by a thin film forming technique.

According to this, since the fine wiring pattern is formed on the fired substrate by the thin film forming technique, the position accuracy of the probe pin connection terminal becomes very good, and the probe pin is finely connected to the probe pin connection terminal. , And can be arranged with high accuracy with respect to absolute coordinates. Therefore, the probe pins arranged with high accuracy can be connected with high accuracy to terminals formed on a large number of semiconductor elements simultaneously formed on the semiconductor wafer. As a result, a large number of semiconductor elements formed simultaneously on the semiconductor wafer can be obtained. Electrical measurement and inspection can be performed with high accuracy.
Japanese Patent Laid-Open No. 7-231019 Japanese Patent Laid-Open No. 11-160356

  In recent years, semiconductor wafers have become larger, and accordingly, there is also a demand for higher density in an inspection board that performs electrical measurement inspection of a large number of semiconductor elements simultaneously formed on a semiconductor wafer with high accuracy. As the dimensions of the connection terminals become smaller, the distance between the terminals has become very narrow.

  When probe pins are connected to such a high-density inspection board, there is a problem that accurate electrical measurement inspection cannot be performed. In other words, the probe pin that contacts the terminal has a generally cylindrical or hemispherical tip and is mainly made of hard metal. Therefore, when the probe pin is brought into contact with the terminal for electrical inspection measurement, the probe pin is There is a problem that the probe pin is easily slipped, and the probe pin easily deviates from the terminal formed to have a small size due to high density, and a complete connection between the probe pin and the terminal cannot be secured. Further, when the probe pin slides on the terminal, the metal of the terminal is easily scraped, and there is a problem in that the metal scraps electrically short-circuit the terminals for connecting the probe pins that are very close to each other due to high density.

  Therefore, the inspection substrate of the present invention has been completed in view of the above problems, and its purpose is to perform a high-precision electrical inspection of high-density semiconductor element circuits formed on a semiconductor wafer. An object of the present invention is to provide a high-density inspection substrate that can be used.

  The inspection board according to the present invention is the inspection board in which the inspection terminal is formed on the upper surface of the insulating substrate and the external connection terminal electrically connected to the inspection terminal is formed on the lower surface of the insulating substrate. The center part of the upper surface of the terminal for use is recessed lower than the outer peripheral part.

  In the inspection substrate of the present invention, preferably, the upper surface of the inspection terminal is recessed so as to gradually become deeper from the outer peripheral portion toward the central portion.

  The inspection board of the present invention is preferably characterized in that the periphery of the inspection terminal is surrounded by an insulator that is the same as the uppermost portion of the inspection terminal or higher than the uppermost portion.

  In the inspection substrate of the present invention, preferably, the insulator includes an organic substance.

  In the inspection board of the present invention, preferably, the insulator covers an outer peripheral portion of the inspection terminal and reaches an outer peripheral portion of the recess.

  The inspection board of the present invention is an inspection board in which an inspection terminal is formed on the upper surface of the insulating substrate and an external connection terminal electrically connected to the inspection terminal is formed on the lower surface of the insulating substrate. By making the center part of the upper surface recessed lower than the outer peripheral part, the probe pin can be stopped at the outer peripheral part of the inspection terminal even if the probe pin slips when the probe pin comes into contact with the inspection terminal. Therefore, electrical connection can be made with high accuracy.

  In addition, even if the probe pin slides and the inspection terminal is scraped and metal scraps are generated, it can be easily collected on the inspection terminal with the central portion depressed, and the adjacent inspection terminals are electrically short-circuited. Can be effectively prevented.

  In the inspection board of the present invention, preferably, the probe pin is brought into contact with the inspection terminal by surrounding the periphery of the inspection terminal with an insulator that is the same as or higher than the uppermost portion of the inspection terminal. At this time, even if the probe pin is slightly removed from the inspection terminal, the periphery is surrounded by an insulator, so that force is applied to pull the probe pin into the inspection terminal, and electrical connection is made with higher accuracy. Can do.

  In addition, it is possible to make it easier for metal scrap generated by the side slip of the probe pin to accumulate on the inspection terminal, and to effectively prevent an electrical short circuit between adjacent inspection terminals.

  In the inspection substrate of the present invention, preferably, the insulator contains an organic substance, thereby facilitating the processability of the inspection substrate, supplying the inspection substrate at a lower cost, and removing the chip of the insulating substrate due to contact with the probe pin. It can be effectively prevented.

  In the inspection substrate of the present invention, preferably, the insulator covers the outer peripheral portion of the inspection terminal and reaches the outer peripheral portion of the recess, so that the inspection terminal can be securely fixed to the insulating substrate.

  Next, the inspection board of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an example of an embodiment of an inspection board of the present invention. In the figure, 1 is an inspection substrate, 2 is an inspection terminal for connecting probe pins, 3 is an insulating substrate, 4 is an insulator, and 5 is an external connection terminal for connection to an external electric circuit.

Here, the insulating substrate 3 is made of various ceramics such as alumina (Al ₂ O ₃ ) ceramics, mullite (3Al ₂ O ₃ .2SiO ₂ ) ceramics, aluminum nitride (AlN) ceramics, and glass ceramics. When a ceramic substrate is used in this way, through-hole conductors can be formed by simultaneous firing, which is excellent in mass productivity and is made of highly rigid ceramics. Therefore, the insulating substrate 1 and a semiconductor wafer on which a large number of semiconductor elements are formed are connected to probe pins. When connecting via the probe pin, it is possible to effectively prevent the probe pin from sinking into the insulating substrate 3 and causing a connection failure of the probe pin.

  The insulating substrate 3 is made of tetrafluoroethylene resin (polytetrafluoroethylene; PTFE), tetrafluoroethylene / ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer resin; ETFE), tetrafluoroethylene / perfluoro. A substrate made of a fluororesin such as an alkoxyethylene copolymer resin (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin; PFA), a substrate made of a glass epoxy resin, a substrate made of a resin such as polyimide, or the like may be used. When such a resin is used, the dielectric constant of the insulating substrate 3 is low, and the high-frequency signal transmission property of 100 MHz or higher is excellent, so that it is suitable for electrical inspection measurement of high-frequency semiconductor elements.

  The insulating substrate 3 may be provided with wiring conductors such as wiring conductor layers and through-holes inside or on the surface, whereby the inspection terminal 2 and the external connection terminal 5 can be electrically connected. .

Here, when the insulating substrate 1 is made of, for example, alumina ceramics, first, an appropriate organic solvent or solvent is added to the raw material powder such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), and magnesia (MgO). The mixture is added and mixed to form a slurry, which is formed into a sheet by a conventionally known doctor blade method, calendar roll method or the like to obtain a ceramic green sheet (hereinafter also referred to as a green sheet).

  Thereafter, a printing paste in which tungsten is a main component and an organic solvent and a solvent are added to the green sheet is printed by screen printing or the like. In addition, the previous printing paste is embedded in the through-holes that have been drilled in order to ensure electrical continuity between the upper and lower surfaces of the green sheet, and the like, and then stamped into a predetermined shape and laminated as necessary. This is manufactured by firing at a temperature of about 1500 ° C.

  Next, the upper and lower surfaces of the insulating substrate 3 are polished using alumina abrasive grains, and the arithmetic average roughness (Ra) is about 0.1 μm or less in order to stably form a thin film for terminals and wiring conductors. It is good to do.

  An inspection terminal 2 for connecting probe pins is formed on the upper surface of the insulating substrate 3. An external connection terminal 5 is formed on the lower surface of the insulating substrate 3. And in the test | inspection board | substrate 1 of this invention, the upper surface of the terminal 2 for a test | inspection becomes deep gradually from the outer peripheral part toward the center part. As a result, when the probe pin is brought into contact with the inspection terminal 2, the probe pin can be stopped at the outer peripheral portion of the inspection terminal 2 even if the probe pin slides sideways. can do.

  Further, even if the probe pin slides and the inspection terminal 2 is scraped and metal scrap is generated, it can be easily collected on the inspection terminal 2 having a depressed central portion, and the adjacent inspection terminals 2 are electrically connected to each other. Can be effectively prevented from short-circuiting.

  The height difference between the central portion and the outer peripheral portion on the upper surface of the inspection terminal 2 is preferably 5 to 45 μm. If it is less than 5 μm, it is likely that it is difficult to stop the probe pin at the outer peripheral portion of the inspection terminal 2 against the side slip of the probe pin. On the other hand, if it exceeds 45 μm, the difference between the thickness of the central portion of the inspection terminal 2 and the thickness of the outer peripheral portion becomes large, and the electrical characteristics easily change depending on the contact position of the probe pin.

  These inspection terminals 2 and external connection terminals 5 are formed by a thin film forming method, a metallization method using a printing paste, a method of patterning by etching a metal foil, a method of transferring a patterned metal foil, a plating method, or the like. Is done. Moreover, you may combine these formation methods.

  In the case of a thin film formation method, a sputtering method, a vapor deposition method, a CVD method, or the like can be used. For example, on the polished main surface of the insulating substrate 1, an adhesion metal layer made of a titanium (Ti) layer having a thickness of about 0.1 μm or the like by a sputtering method, a titanium (Ti) -tungsten (W) alloy layer having a thickness of about 2 μm. Are formed by sequentially forming a diffusion prevention layer made of the above and the like and a main conductor layer made of a copper (Cu) layer having a thickness of about 52 μm and the like, and patterning them by the photolithography method and the etching method.

  In order to prevent oxidation of the surface of the main conductor layer made of Cu layer or the like, the surface of the main conductor layer is electrolessly plated with a nickel (Ni) plating layer having a thickness of 2 μm and a gold (Au) plating with a thickness of 0.2 μm. The layers should be deposited sequentially.

  In the case of a metallization method using a printing paste, a metal paste containing at least one of W, molybdenum (Mo), manganese (Mn), or Cu may be formed by patterning by a screen printing method and sintering. good.

  It can also be formed by etching and patterning a metal foil. In that case, a metal foil such as Cu previously deposited on the insulating substrate 1 is used for inspection by a photolithography method using a dry film or the like and an etching method. Terminal 2 and external connection terminal 5 are formed. Alternatively, it may be formed by transferring a previously patterned metal foil onto the insulating substrate 1.

  In the case of forming by a plating method, a Cu plating layer by an electroless plating method, a Cu plating layer by an electrolytic plating method, or the like is formed and patterned to form.

  The thickness of the inspection terminal 2 and the external connection terminal 5 is preferably 0.5 μm to 50 μm. If the thickness is less than 0.5 μm, the conduction resistance value tends to be high, and if it exceeds 50 μm, it is difficult to process into a fine wiring pattern. Become.

  Further, after forming the insulator 4 and the resist layer on the peripheral portion of the inspection terminal 2, the upper surface is removed from the outer peripheral portion by performing mechanical or chemical or a combination of both. It can be formed so as to become gradually deeper toward the center. As the upper surface shape, for example, in the longitudinal section of the inspection terminal 2, the upper surface can be a concave shape such as an arc shape, the outer peripheral portion is an arc shape, and the central portion is a flat concave shape (see FIG. 1). .

  In the inspection board according to the present embodiment, the upper surface of the inspection terminal 2 is recessed so as to gradually become deeper from the outer peripheral portion toward the central portion, but the center is provided by providing a step between the outer peripheral portion and the central portion. The part may be recessed below the outer peripheral part. Regardless of whether the height of the upper surface of the inspection terminal 2 is changed gently or steeply from the outer peripheral portion to the central portion, the central portion may be recessed lower than the outer peripheral portion on the upper surface of the inspection terminal 2. If possible, even if the probe pin slides when the probe pin is brought into contact with the inspection terminal 2, the probe pin can be stopped at the outer peripheral portion of the inspection terminal 2.

  Preferably, the periphery of the inspection terminal 2 is surrounded by an insulator 4 that is the same as or higher than the uppermost portion of the inspection terminal 2. Thus, when the probe pin is brought into contact with the inspection terminal 2, the probe pin is pulled into the inspection terminal 2 because the periphery is surrounded by the insulator 4 even if the probe pin is slightly detached from the inspection terminal 2. A force is applied to the wire and electrical connection can be made with higher accuracy.

  Moreover, the metal scrap produced by the side slip of the probe pin can be easily collected on the inspection terminal 2, and an electrical short circuit between the adjacent inspection terminals 2 can be more effectively prevented.

  The insulator 4 is made of ceramics, resin, or the like, and may be the same material as the insulating substrate 3 or may be different. Preferably, organic substances such as polyimide, BCB (benzocyclobutene), epoxy resin, and fluorine resin are used. Thereby, the workability of the inspection substrate 1 can be facilitated, the inspection substrate 1 can be supplied at a lower cost, and chipping of the insulating substrate 3 due to contact with the probe pins can be effectively prevented. In addition to the organic substance, the insulator 4 may include an inorganic filler that suppresses the coefficient of thermal expansion of the organic substance.

  Such an insulator 4 can be formed by applying to the insulating substrate 3 using a spin coat method, a roll coat method, a die coat method, a printing method, or the like. Alternatively, it may be formed by depositing a resin processed into a film on the insulating substrate 3. The insulating substrate 3 can also be shaped like the insulator 4 by digging down by grinding or microblasting.

  In addition, it is preferable that the opening edge portion surrounding the inspection terminal 2 of the insulator 4 has an inclined surface whose upper surface becomes lower as it approaches the inspection terminal 2. As a result, even if the probe pin comes in contact with the inspection terminal 2 slightly deviating from the inspection terminal 2, the probe pin can be well guided on the inspection terminal 2 along the inclined surface of the insulator 4, and a more accurate electrical inspection can be performed. Measurements can be made.

  Further, the insulator 4 may cover the outer periphery of the inspection terminal 2 and reach the outer periphery of the recess. That is, the insulator 4 may be formed so as to cover the periphery of the inspection terminal 2 from the peripheral portion of the inspection terminal 2, leaving a recessed central portion on the upper surface of the inspection terminal 2. Thus, by forming the insulator 4 not only on the peripheral portion of the inspection terminal 2 but also on a partial region of the upper surface of the inspection terminal 2, the inspection terminal 4 is securely fixed to the insulating substrate 3. Can do.

  Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.

It is sectional drawing which shows an example of embodiment of the test | inspection board | substrate of this invention.

Explanation of symbols

1: Inspection board 2: Inspection terminal 3: Insulation board 4: Insulator 5: External connection terminal

Claims (5)

In the inspection board formed by forming an inspection terminal on the upper surface of the insulating substrate and forming an external connection terminal electrically connected to the inspection terminal on the lower surface of the insulating substrate, a central portion of the upper surface of the inspection terminal Inspection board characterized in that is recessed below the outer periphery. The inspection substrate according to claim 1, wherein an upper surface of the inspection terminal is recessed so as to gradually become deeper from an outer peripheral portion toward a central portion. 3. The inspection substrate according to claim 1, wherein the periphery of the inspection terminal is surrounded by an insulator that is the same as or higher than the uppermost portion of the inspection terminal. The inspection substrate according to claim 3, wherein the insulator includes an organic substance. 5. The inspection substrate according to claim 3, wherein the insulator covers an outer peripheral portion of the inspection terminal and reaches an outer peripheral portion of the recess.

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