JP4618415B2 - IC chip and non-contact IC card manufacturing method - Google Patents

Description

  The present invention relates to a method for bonding thin plates, a method for manufacturing an IC chip and a non-contact IC card, and a bonding apparatus, and more particularly to a method for bonding a thinned wafer to a reinforcing plate in a step of manufacturing a non-contact IC card.

  Non-contact IC cards are used in various fields, mainly for applications such as railway ticket gates, and are expected to be applied in many fields in the future. The non-contact IC card is configured by sandwiching a communication antenna and a semiconductor chip (IC chip) between predetermined sheets. An IC chip is configured such that a chip body in which a laminated film constituting a circuit is formed on a substrate such as silicon is supported by a reinforcing plate usually made of stainless steel. The reinforcing plate protects the chip body so that the chip body is not excessively deformed, and has a function as a heat sink that absorbs heat generated from the chip body.

  Various IC chip manufacturing methods have been proposed. As one of them, first, the back surface of a wafer on which a large number of chip bodies are formed is thinned, and then the thinned wafer is used as a reinforcing plate. There is a method in which the chip body is diced together with the reinforcing plate and then separated into individual IC chips. The thickness of the wafer affects the thickness of the non-contact IC card, which is the final product, and the wafer can be made as thin as possible for the purpose of ensuring flexibility against bending that occurs during use of the non-contact IC card. Desirably, some are currently 0.1 mm or less.

  Among these, the step of bonding the thinned wafer to the reinforcing plate is performed as follows. First, the reinforcing plate is held by an adhesive jig such as rubber or urethane, and an adhesive is applied to the surface of the reinforcing plate by a screen printing technique or the like. As the adhesive, a thermosetting adhesive such as an epoxy resin is often used (see Patent Document 1). Since epoxy resin is liquid at room temperature, it is applied relatively uniformly.

  Next, the wafer is similarly held by a jig made of rubber or the like, the reinforcing plate and the wafer are opposed to each other, and are in close contact with each other. At this time, if the reinforcing plate and the wafer are brought into intimate contact with air mixed in the adhesive, bubbles in the adhesive may remain in the cured adhesive, resulting in a decrease in adhesive strength and poor adhesion. There is. Therefore, there is a case where bonding is performed after the bubbles in the adhesive are degassed by vacuuming (see Patent Documents 2 and 3).

Next, the epoxy resin is cured by heating in a close contact state, and the reinforcing plate and the wafer are bonded. Thereafter, both jigs are removed, and the bonding step is completed. The heating is performed at 120 ° C. for 2 hours, for example.
JP-A-6-151657 JP 2001-127026 A JP-A-6-151265

  However, the prior art has the following problems. First, in the apparatuses disclosed in Patent Documents 2 and 3, the adhesion between the reinforcing plate and the wafer and the curing of the adhesive are performed in the same apparatus, but the curing of the adhesive requires a long time. The number of wafers that can be processed by one apparatus is limited, and work efficiency deteriorates. Therefore, when using a thermosetting adhesive, it is also conceivable that the bonded body of the reinforcing plate and the wafer is taken out from the apparatus as it is in close contact, and a plurality of bonded bodies are put together in a high temperature furnace and cured. However, at this point, the adhesive is not yet cured, and the wafer is thinned and extremely fragile, so the force received from the adhesive jig when removing it from the jig The wafer itself may be pulled away from the reinforcing plate and damaged.

  This invention is made | formed in view of this subject, and it aims at providing the method etc. which adhere | attach a thin plate efficiently, preventing the breakage | damage of a thin plate.

The IC chip manufacturing method of the present invention is an IC chip manufacturing method in which one surface of a chip body is bonded to a reinforcing plate . The IC chip manufacturing method of the present invention is predetermined for each of a step of forming a wafer in which a plurality of chip bodies are two-dimensionally arranged on a substrate, a step of thinning the wafer, a reinforcing plate and the wafer. When the center is matched and when the reinforcing plate and the wafer are overlapped at a predetermined relative angle, the chip body is included in the corresponding section divided by the groove. A step of forming grooves in a two-dimensional manner, aligning the centers of the wafer and the reinforcing plate, and adjusting the relative angle between the wafer and the reinforcing plate to the angle at which each chip body is included in each section; A bonding step of bonding the reinforcing plate to each other, and a step of cutting the bonded wafer / reinforcing plate assembly along the groove and separating it into individual IC chips. In the bonding step, the surface on which the chip body of the thinned wafer is formed is the first back surface, the surface opposite to the first back surface is the first bonding surface, and the surface of the reinforcing plate on which the grooves are formed is the second surface. An adhesion step for bonding a wafer and a reinforcing plate by sandwiching an adhesive between the first and second adhesive surfaces, with an adhesive surface and a surface opposite to the second adhesive surface as a second back surface, the second adhesive surface of, applying an adhesive, comprising the steps of: by the action of negative pressure to the first back, towards the first adhesive surface downward, for supporting the wafer in the first back, A negative pressure is applied to the second back surface, the second bonding surface is directed upward, and the reinforcing plate is supported by the second back surface, and then the first and second bonding are performed via an adhesive. a temporary bonding step of provisionally bonding by contacting the surfaces with each other, thereafter, curing the adhesive, to adhere the wafer and a reinforcing plate Luz Tsu has a flop, the. In the temporary bonding step, before the first and second bonding surfaces are brought into contact with each other via the adhesive, the light penetrating the wafer and the reinforcing plate is projected, and the resulting transmitted light is transmitted through the groove of the reinforcing plate. And adjusting the relative angle between the wafer and the reinforcing plate while confirming the shadow of the chip body.

  Thus, by applying a negative pressure to the first back surface and the second back surface, the first thin plate and the second thin plate have a negative pressure in a state where the first and second adhesive surfaces are in contact with each other. If these negative pressures are released, the holding force is released. For this reason, even when the adhesive is not sufficiently cured when the holding force is released, unnecessary force is prevented from being applied to the first thin plate and the second thin plate.

  The temporary bonding step may include a step of applying a negative pressure having a vacuum level lower than the negative pressure acting on the first and second back surfaces to the first and second bonding surfaces. This prevents bubbles from being mixed into the adhesive, and also allows the first thin plate and the second thin plate to be held by negative pressure.

  Here, the differential pressure between the negative pressure acting on the second adhesive surface and the negative pressure acting on the first and second back surfaces is preferably 6700 Pa or more.

  The temporary bonding step may include a step of bringing the bonding surfaces into contact with each other after the adhesive is in a semi-cured state.

  The non-contact IC card manufacturing method of the present invention includes the steps of manufacturing an IC chip by the above method, mounting the IC chip on the antenna substrate together with the communication antenna, and the IC chip and the communication on the antenna substrate. Forming a protective film covering the antenna, and covering the protective film and the antenna substrate with an exterior sheet.

  As described above, according to the method for bonding thin plates of the present invention, since the thin plate such as a thinned wafer is held by negative pressure, the thin plates are bonded efficiently while preventing damage to the thin plates. be able to. Furthermore, by applying a negative pressure to the adhesive surface, air bubbles are prevented from being mixed into the adhesive, and high adhesive strength can be realized.

  Hereinafter, the method for bonding thin plates of the present invention will be described with reference to the drawings, taking a method for manufacturing a non-contact IC card as an example. In the present specification, the thin plate includes a film or thin film. FIG. 1 is a conceptual side sectional view of a bonding apparatus used in the present invention. The bonding apparatus 1 has an airtight and transparent chamber 2 and has an upper jig 3 and a lower jig 4 provided inside thereof in a manner facing each other. A removable lid 23 is provided on the upper portion of the chamber 2, and the upper jig 3 is attached to the lid 23. The lid 23 is provided with three viewing windows 24 at substantially equal angles on a virtual circle centered on the upper shaft 5. Since the opening of the observation window 24 is covered with glass, the airtightness of the chamber 2 is not affected. The upper jig 3 and the lower jig 4 are made of transparent glass, and the openings 33 and 34 are provided facing each other. The openings 33 and 34 are covered with the wafer W and the reinforcing plate H, respectively, thereby forming a closed space. Recesses 31, 32 are provided. The depth of the recess 31 to which the wafer W is attached is 0.02 mm or less in order to prevent negative pressure destruction of the wafer W. The upper shaft 5 and the lower shaft 6 are connected to the recesses 31 and 32, respectively. The upper shaft 5 and the lower shaft 6 are provided at the center positions of the upper jig 3 and the lower jig 4, respectively, extend vertically, and are aligned coaxially. A partition plate may be appropriately provided in the recesses 31 and 32 so that the wafer W and the reinforcing plate H are in close contact with the upper jig 3 and the lower jig 4. Moreover, you may cover the opening part of the recessed parts 31 and 32 with the cover in which many fine holes were provided. The upper shaft 5 can be moved up and down along the axial direction and rotated around the axis by a drive mechanism (not shown), and the lower shaft 6 is fixed. However, the upper shaft 5 may be fixed, the lower shaft 6 may be movable, or both may be movable. The upper shaft 5 and the lower shaft 6 pass through the top plate and bottom plate of the chamber 2 by appropriate sealing means (not shown), and have air flow paths 51 and 52 that are respectively connected to the recesses 31 and 32 inside. is doing.

  The bonding apparatus 1 also has vacuum pumps 7, 8 and 9 outside the chamber 2. The vacuum pumps 7, 8, and 9 can be general rotary vacuum pumps, and need not be high-performance pumps that can realize a high vacuum. The vacuum pump 9 is directly connected to the side wall of the chamber 2. The vacuum pumps 7 and 8 are connected to the air flow paths 51 and 52, respectively.

  A vent pipe 21 that can be opened to the atmosphere by opening and closing a valve 22 is connected to the chamber 2. Vent pipes 53 and 54 that can be opened to the atmosphere by opening and closing valves 55 and 56 are connected to the air flow paths 51 and 52, respectively.

  The chamber 2 is further provided with a light source 11 that emits light toward the lower jig 4 on the back side (lower side) of the lower jig 4. The light emitted from the light source 11 may be a light having a visible light component similar to natural light, or may be an infrared ray having excellent transparency. In addition, if the chamber 2 is set as a dark room to block natural light, the selection range of light can be expanded.

  Next, a method for manufacturing a non-contact IC card using this apparatus will be described. As a method for manufacturing an IC card, a method in which a wafer on which a large number of chip bodies are formed is thinned, separated into individual chip bodies, and then a reinforcing plate is bonded can be considered. However, this method requires separate grinding and cleaning of the back surface of the separated chip body. In addition, since thinned wafers are susceptible to flashing and chipping during cutting, it is necessary to apply a reinforcing tape in advance before cutting, and to peel the reinforcing tape after cutting in a reinforced state. is there. For these reasons, it is difficult to improve productivity by the above method.

  On the other hand, the manufacturing method described below is characterized in that after the wafer is thinned, it is bonded to a reinforcing plate in advance, and then the whole reinforcing plate is cut and separated into individual IC chips. For this reason, it is possible to perform cleaning in a batch on the wafer. In addition, since the reinforcing plate is bonded before the wafer is cut, the reinforcing plate can also function as a reinforcing tape, and a step of attaching or peeling the reinforcing tape for cutting becomes unnecessary. In addition, as will be described later, grooves are formed in advance in two orthogonal directions on the reinforcing plate, and the chip body is placed in a section surrounded by the grooves so that the positions of the chips are aligned and bonded. In this case, it is only necessary to cut along the groove, and the cutting process can be rationalized. For these reasons, the productivity can be greatly improved. In addition, since the groove is formed in advance and the cutting amount is small, a merit that adverse effects on the chip body due to mechanical strain and heat during cutting can be minimized can also be expected. Below, the detail of this manufacturing method is demonstrated based on the flowchart of FIG.

  (Step 61) First, a wafer W having a large number of chip bodies C formed on a circular silicon substrate K is manufactured, and then an acceptance inspection of the wafer W is performed as necessary to select defective wafers W. FIG. 3 shows a plan view of the wafer. The chip bodies C are two-dimensionally arranged on the circular silicon substrate K. The size of each chip body C is about 4 mm × 5 mm in one example, and the distance between the centers of the chip bodies C is about 5.08 mm × 6.08 mm. This center-to-center distance is preliminarily matched with the center-to-center distance (described later) between the sections B of the reinforcing plate H. As a result, when the wafer W and the reinforcing plate H are aligned as described later, each chip body C is included in each compartment B. The bonding surface W1 where the wafer W is bonded to the reinforcing plate H is the back surface of the wafer W where the chip body C is not formed.

  (Step 62) Next, the back surface which is the bonding surface W1 of the wafer W is polished. The wafer W has a thickness of about 0.65 mm in one example, but the thickness is reduced to some extent by, for example, mechanical polishing, and finally finished by chemical etching, and is thinned to about 0.05 mm in one example.

  (Step 63) Next, an adhesive is applied to the reinforcing plate H, and the reinforcing plate H is mounted on the lower jig 4 of the bonding apparatus 1. FIG. 4 shows a plan view of the reinforcing plate. The reinforcing plate H is a circular thin plate made of stainless steel and has a diameter that is about the same as the diameter of the wafer W and a thickness of about 0.1 to 0.2 mm. However, the influence of the thickness difference is small. On one surface of the reinforcing plate H, a groove G having a width of about 0.08 mm is formed vertically and horizontally. As will be described later, the width is determined with a margin for cutting. The dimension of the section B partitioned by the groove G is about 5 mm × 6 mm, and therefore the center-to-center distance between the sections B is about 5.08 mm × 6.08 mm.

  5 and 6 show the detailed structure of the groove. The groove G may be either a groove G1 having a cut through the reinforcing plate H or a groove G2 in which a portion to be the groove is thinned with respect to the surroundings. As shown in detail in FIG. 5, the groove G <b> 1 has, on each side of the section B, a cut 81 that penetrates the reinforcing plate H in the thickness direction and two bridge portions 82 that are connected to the adjacent section B. The thickness of each bridge part 82 is the same as the thickness of the reinforcement board H, and the width | variety 83 is about 0.2-0.5 mm. 5A is a plan view of the groove G1, and FIGS. 5B and 5C are sectional views taken along lines bb and cc in FIG. 5A, respectively. (The same applies to FIG. 6). As shown in detail in FIG. 6, the groove G <b> 2 is smaller than the thickness of the reinforcing plate H around each side of the section B. The wall thickness 84 of the groove G2 is preferably 0.03 mm or less. This is because the thickness of the stainless steel 84 is suppressed as much as possible from the fact that stainless steel itself is extremely poor in machinability and is likely to emit a burr and to prevent the grinding stone from being reduced or damaged. Furthermore, as a modification of the groove G1, a configuration in which a large number of bridge portions are provided intermittently in a perforation shape may be used. In this case, the width of the bridge portion constituting the perforation is 0.15 mm, preferably 0.08 mm or less. By providing the grooves G1 and G2, the cutting amount of the grooves can be suppressed, and the cutting speed can be improved.

  This step is performed in more detail in the following substeps. First, an adhesive is applied to the adhesive surface H1 of the reinforcing plate H by screen printing technology. The coating thickness depends on the thickness of the reinforcing plate H, but is, for example, about 0.005 to 0.04 mm. Since epoxy resin is liquid at room temperature, a uniform coated surface can be obtained by screen printing. At this time, the application surface of the epoxy resin is allowed to stand for a predetermined time so that the adhesive is in a semi-cured state. By making the adhesive semi-cured, the adhesive strength of the adhesive is enhanced. This adhesive force is smaller than the final adhesive force obtained by curing, but larger than the adhesive force immediately after application. As a result, an adhesive force that can be taken out from the chamber 2 while the bonded body of the wafer W and the reinforcing plate H is temporarily bonded can be obtained.

  In addition, in order to confirm that the semi-cured state has been reached, a dummy thin film similar to the chip body is attached to the periphery of the wafer, etc., which is not related to the bonding of the chip body, and the thin film is moved or the adhesive moves You may make it confirm adhesive force by seeing.

  Further, when the reinforcing plate H having the groove G1 is used, it is desirable to use an adhesive having a large viscosity and surface tension. In this case, the adhesive is applied to the entire surface of the adhesive surface H1 of the reinforcing plate H including the groove G1, but the adhesive does not drop downward from the groove G1 due to viscosity and surface tension, and the adjacent section B. A bridge can be formed between the groove G1 and the groove G1. As a result, negative pressure can be effectively applied to the back surface of the adhesive surface H1 of the reinforcing plate H as will be described later. The viscosity is preferably 35,000 mPa · s or more at 25 ° C. Even if the adhesive flows out to the back surface, it is not completely cured, so it can be easily wiped off with an alcohol-based or ketone-based general solvent before entering the chamber 2 or after removing from the chamber 2. be able to. Further, since the side surface other than the portion provided with the bridge portion is rubbed against the grindstone at the time of cutting, the adhesive adhered to the side surface is also cleaned at this time.

  Next, the lid 23 of the chamber 2 is opened, and the reinforcing plate H to which the adhesive is applied is placed in the chamber 2. The reinforcing plate H is set on the lower jig 4. When the reinforcing plate H provided with the groove G2 is used, the surface on which the groove G2 is formed is directed upward as the bonding surface H1 with the wafer W. When the reinforcing plate H provided with the groove G1 is used, the surface on which the groove G1 is formed is directed to the upper side regardless of which direction is used, and therefore the direction is not limited.

  Next, the wafer W is attached to the upper jig 3 so that the surface of the wafer W on which the chip body C is formed faces the upper jig 3. The relative angle with respect to the reinforcing plate H is roughly matched using an orientation flat provided on the wafer W (a linear portion provided on a part of the outer periphery of the wafer).

  Next, the valves 55 and 56 are closed, the vacuum pumps 7 and 8 are started, and the air in the recesses 31 and 32 is drawn through the air flow paths 51 and 52. As a result, the wafer W is adsorbed and supported by the upper jig 3 and the reinforcing plate H is adsorbed and supported by the lower jig 4.

  (Step 64) Next, the wafer W is bonded to the reinforcing plate H. First, the lid 23 is set in the chamber 2 with the wafer W held by the upper jig 3. Since the lid 23 is accurately positioned with respect to the chamber 2, the wafer W and the reinforcing plate H face each other centering each other. Next, the lid 23 is closed, and the relative angle between the wafer W and the reinforcing plate H is adjusted. Specifically, first, the light source 11 is turned on, and light is irradiated from the back surface of the lower jig 4. Although the lower jig 4 is relatively thick, it is made of glass and therefore transmits light. The reinforcing plate H at the upper part of the lower jig 4 does not allow light to pass through the general part sufficiently, but transmits part of the transmitted light from the groove G1 (because the groove is also thinned in the case of the groove G2, Part of the transmitted light is transmitted from the groove G2.) Since the epoxy resin adhesive on the reinforcing plate H is also light transmissive, it transmits light. Since the wafer W existing over the space is thinned to about 0.05 mm, a part of the transmitted light is transmitted. However, since the portion where the chip body C is formed is slightly thicker than the surroundings, When it receives, it becomes a shadow. Further, the upper jig 3 transmits light in the same manner as the lower jig 4. As a result, when the light source 11 is viewed from the viewing window 24, the groove G of the reinforcing plate H shines as shown in FIG. Is done. At this time, the relative angle θ between the wafer W and the reinforcing plate H is usually an angle other than zero. Note that only the portion indicated by a circle in the figure can actually be seen from the viewing window 24, but by making the diameter of the viewing window 24 sufficiently larger than the size of the section B, at least 1 from any viewing window 24. Since the two sections B can be seen completely and are confirmed by at least three viewing windows 24, the relative angle θ can be correctly recognized.

  Next, the upper jig 3 is lowered and stopped at a position where a slight gap remains between the wafer W and the reinforcing plate H. The upper jig 3 is rotated around the upper shaft 5 to adjust the relative angle θ between the wafer W and the reinforcing plate H. Specifically, the upper jig 3 is rotated while observing the direction of the groove G of the reinforcing plate H and the direction of the chip body C, and each chip body C is included in each corresponding section B, that is, the chip body C. The upper jig is rotated to such an angle that the whole area enters the section B. In this way, since the relative angle between the wafer W and the reinforcing plate H is adjusted using light, no special device other than the light source 11 and the observation window 24 is required, which is very inexpensive. Further, since the adjustment can be made while directly confirming the relative angle between the wafer W and the reinforcing plate H, the adjustment can be made visually and directly, and the adjustment accuracy is high.

  FIG. 7B shows a state where the angle between the two is accurately adjusted and the relative angle θ becomes zero. At this time, a cutting allowance for cutting the wafer W into each IC chip is about 0.04 to 0.05 mm as an actual cutting allowance when a whetstone having a width of 0.03 mm is used, for example. On the other hand, since the width of the groove G is about 0.08 mm, there is a margin of about 0.015 to 0.02 mm on both sides of the cutting allowance. Since the relative angle θ may be adjusted within this margin, it is not necessary to make a very precise adjustment. Therefore, as shown in FIGS. 7C and 7D, the relative angle θ may be slightly shifted to an angle other than zero.

  Although the wafer W and the reinforcing plate H are described here as being circular, they may be other than circular. That is, when the center point is determined in advance for each of the reinforcing plate and the wafer, the center points coincide with each other, and when the reinforcing plate and the wafer are overlapped at a predetermined relative angle, the projection surface of each chip body is The relationship included in each corresponding section divided by the groove may be sufficient.

  Next, the valve 22 is closed, the vacuum pump 9 is activated, and the pressure in the chamber 2 is reduced. This operation is performed for the first purpose of preventing air contamination due to fine irregularities on the surface of the adhesive. That is, meshes at the time of screen printing remain uneven in the adhesive, and are not completely flat. When the wafer W is brought into contact in this state, the air staying in the concave portion cannot be removed, and bubbles remain on the adhesion surface with the wafer W, which greatly affects the adhesion force. By setting the negative pressure, the air in the concave portion is released, so that bubbles are less likely to remain. This operation is also performed to degas the air mixed in the adhesive by negative pressure. Although the adhesive is in a semi-cured state, defoaming is possible by applying a negative pressure.

  Thereafter, the upper jig 3 is further lowered to bring the wafer W and the reinforcing plate H into contact with each other. Thereby, the wafer W and the reinforcing plate H are defoamed and temporarily bonded by an adhesive having a certain degree of adhesive force.

  Next, the vacuum pumps 7, 8, and 9 are stopped, the valves 22, 55, and 56 are opened, the vent pipes 21, 53, and 54 are opened to the atmosphere, and the pressure in the chamber 2 and the recesses 31 and 32 is returned to the atmospheric pressure. . As a result, the adsorption force between the wafer W and the upper jig 3 and between the reinforcing plate H and the lower jig 4 is lost, and the wafer W and the lower jig 4 are released from these jigs. On the other hand, since the wafer W and the reinforcing plate H are temporarily bonded with an adhesive, the wafer W and the reinforcing plate H can be taken out from the chamber 2 while maintaining the temporary bonded state. At this time, since the suction force of the wafer W is released by releasing the negative pressure, no unnecessary force is applied to the wafer W from the upper jig 3.

  Next, the bonded body of the temporarily bonded wafer W and the reinforcing plate H is placed in a high-temperature furnace and heated at a temperature for a predetermined time. In one example, it was confirmed that sufficient adhesion was generated when heated at 120 ° C. for about 2 hours.

  (Step 65) Next, the bonded body of the bonded wafer W and the reinforcing plate H is cut vertically and horizontally along the groove G of the reinforcing plate H. When cutting, the combined body may be held in advance on the cutting substrate. As described above, since the groove G is provided in the reinforcing plate H, the cutting amount can be reduced, the cutting speed is improved, and the life of the grindstone is also extended. As a result, the combined body of the wafer W and the reinforcing plate H is separated into each IC chip provided with the reinforcing plate.

  (Step 66) Thereafter, the IC chip is cleaned, the cutting substrate is removed, and an appearance inspection is performed.

  (Step 67) Then, the completed IC chip is mounted on the antenna substrate together with the communication antenna, a protective film covering the IC chip and the communication antenna is formed on the antenna substrate, and the protective film and the antenna substrate are packaged. Cover with a sheet to complete the contactless IC card.

  Here, it supplements about the conditions for making an adhesive agent into a semi-hardened state. By going through the semi-cured state, the final adhesive force must not be insufficient, and sufficient adhesive force must be generated in the subsequent curing step. Here, the condition is defined as that a sufficient final adhesive force can be obtained under a heating condition of 120 ° C. for 2 hours after the semi-cured state, and the conditions under which this condition is satisfied were examined. As a result, it was found that various combinations of heating temperature and heating time can be selected for the semi-cured state. As an example, the above conditions are satisfied by heating at 120 ° C. for 15 minutes, 100 ° C. for 20 minutes, 90 ° C. for 30 minutes, and 80 ° C. for 45 minutes. In addition, the above conditions are satisfied even when left at room temperature of 25 ° C. for 300 minutes.

  Next, it supplements about the required pressure (vacuum degree). First, evacuation of the chamber 2 is performed in order to release the bubbles of the adhesive as described above. Therefore, the necessary negative pressure is about 48 KPa (vacuum degree of about 400 mmHg) as an absolute pressure (hereinafter the same) is sufficient, and in the examples, it is about 14.7 KPa (vacuum degree of about 650 mmHg). The evacuation of the recesses 31 and 32 is performed for fixing the wafer W and the reinforcing plate H to the upper jig 3 and the lower jig 4. The pressure required for this is determined by a relative value with respect to the pressure in the chamber 2, and a differential pressure of about 6700 Pa (50 mmHg) with respect to the pressure in the chamber 2 is sufficient. For this reason, in an Example, it was set as about 8 KPa (vacuum degree of about 700 mmHg). In this way, the degree of vacuum does not need to be so high. Therefore, if the degree of vacuum is too high due to the performance and capacity of the vacuum pump 6, the volume of the chamber 2, and airtightness, the valve 22 is partially opened. You may drive while. Further, since the vacuum pumps 7 and 8 are for the purpose of forming a differential pressure with the chamber 2, when the vacuum pumps 7 and 8 are first activated, a lower degree of vacuum is set. An operation method in which the degree of vacuum of 32 is gradually increased may be used.

  The effects of the present invention are summarized as follows.

  First, when bonding the thinned wafer to the reinforcing plate, the adhesive is vacuum defoamed and mutually contacted while fixing the wafer to the jig with negative pressure, so there is a possibility that an excessive force will be applied to the wafer after contact Reduces the risk of wafer damage. Since the wafer is fixed with a negative pressure, it can be held in a flat shape even when the wafer is warped due to stress during thinning of the wafer. In addition, since the adhesive is allowed to stand for a certain period of time before being brought into contact with a semi-cured state, a certain amount of adhesive force is obtained before the adhesive is heat-cured, and the bonded body of the wafer and the reinforcing plate is temporarily bonded. Can be moved. For this reason, combined with the above-mentioned effect, the combined body of the wafer and the reinforcing plate can be put in another high-temperature furnace to be cured at a high temperature, and the work efficiency is increased.

  Further, the positioning of the wafer and the reinforcing plate at the time of bonding can be performed only by adjusting the relative angle between the wafer and the reinforcing plate. When grooves are put in the reinforcing plate in advance, positioning in the x and y2 directions is required. However, since only the relative angle needs to be adjusted by aligning the central axes of each other, adjustment work is reduced and the device itself is inexpensive. It becomes.

  As mentioned above, the case where the thinned wafer is applied to the manufacturing method for bonding the thinned wafer to the reinforcing plate has been described in detail. However, the present invention can be applied to the case where the thinned wafer is bonded to another arbitrary plate-like plane. Can be widely applied. For example, in order to cut the thinned wafer when adopting the above-described procedure of first separating the wafer into each chip body and then fixing each chip body to the reinforcing plate after thinning the wafer, as described above. It is necessary to apply a reinforcing tape to the wafer in advance. In this case, the reinforcing tape is thinner than the above-described reinforcing plate, but the reinforcing tape can be attached to the wafer in the same manner as described above. Furthermore, the present invention can also be applied to the manufacture of hybrid ICs that bond ICs together.

It is a notional side sectional view of the bonding apparatus of the present invention. It is a flowchart which shows the procedure of the adhesion | attachment method of the thin plates of this invention. It is a top view of a wafer. It is a top view of a reinforcement board. It is a partial detail drawing of the groove | channel of a reinforcement board. It is a partial detail drawing of the groove | channel of a reinforcement board. It is a visual recognition image at the time of adjusting the relative angle of a wafer and a reinforcement board. It is a visual recognition image at the time of adjusting the relative angle of a wafer and a reinforcement board. It is a visual recognition image at the time of adjusting the relative angle of a wafer and a reinforcement board. It is a visual recognition image at the time of adjusting the relative angle of a wafer and a reinforcement board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bonding apparatus 2 Chamber 3 Upper jig 4 Lower jig 5 Upper shaft 6 Lower shaft 7, 8, 9 Vacuum pump 11 Light source 31, 32 Recess 33, 34 Opening W Wafer K Silicon substrate C Chip body W1 Bonding surface H Reinforcement Plate G Groove B Section H1 Bonding surface

Claims (5)

A method for producing an IC chip, wherein one surface of a chip body is bonded to a reinforcing plate,
Forming a wafer in which a plurality of chip bodies are two-dimensionally arranged on a substrate;
Thinning the wafer;
When the predetermined centers of the reinforcing plate and the wafer are aligned with each other and the reinforcing plate and the wafer are overlapped at a predetermined relative angle, the chip bodies are divided by grooves. Forming the grooves two-dimensionally in the reinforcing plate so as to be included in each corresponding section;
The centers of the wafer and the reinforcing plate are made to coincide with each other, and the relative angle between the wafer and the reinforcing plate is adjusted to the angle at which each chip body is included in each section, and the wafer and the reinforcing plate Bonding step, and
Cutting the bonded body of the bonded wafer and the reinforcing plate along the groove and separating them into individual IC chips;
Have
In the bonding step, a surface of the thinned wafer on which the chip body is formed is a first back surface, a surface opposite to the first back surface is a first bonding surface, and the reinforcing plate is formed with the grooves. The wafer and the reinforcing plate are sandwiched with an adhesive between the first and second adhesive surfaces, with the second adhesive surface being the second adhesive surface and the opposite surface of the second adhesive surface being the second rear surface. Bonding step for bonding,
Applying the adhesive to the second adhesive surface of the reinforcing plate;
Supporting a negative pressure on the first back surface, supporting the wafer on the first back surface with the first adhesive surface facing downward;
Applying a negative pressure to the second back surface, with the second adhesive surface facing upward, and supporting the reinforcing plate on the second back surface;
Thereafter, a temporary bonding step of bringing the first and second bonding surfaces into contact with each other via the adhesive and temporarily bonding them,
Thereafter, the step of curing the adhesive and bonding the wafer and the reinforcing plate,
The temporary bonding step projects light penetrating the wafer and the reinforcing plate before bringing the first and second bonding surfaces into contact with each other via the adhesive, and the resulting reinforcing plate A method of manufacturing an IC chip, comprising: adjusting a relative angle between the wafer and the reinforcing plate while confirming transmitted light transmitted through the groove and a shadow of the chip body.   The temporary bonding step includes a step of applying a negative pressure having a vacuum level lower than the negative pressure acting on the first and second back surfaces to the first and second bonding surfaces. A method for producing an IC chip as described in 1. above.   The IC chip manufacturing method according to claim 2, wherein a differential pressure between a negative pressure acting on the second adhesive surface and a negative pressure acting on the first and second back surfaces is 6700 Pa or more.   4. The IC chip manufacturing method according to claim 1, wherein the temporary bonding step includes a step of bringing the adhesive surfaces into contact with each other after the adhesive is in a semi-cured state. 5. Producing an IC chip by the method according to any one of claims 1 to 4,
Mounting the IC chip together with a communication antenna on an antenna substrate;
A method of manufacturing a non-contact IC card, comprising: forming a protective film covering the IC chip and the communication antenna on the antenna substrate; and covering the protective film and the antenna substrate with an exterior sheet.

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