JP4193885B2 - Multi-chip mounting method - Google Patents

Description

  The present invention relates to a multichip mounting method on a substrate.

With the miniaturization and thinning of semiconductor chips and electronic components, the circuits and electrodes used for these have become denser and higher definition. Since connection of such a fine electrode is difficult by soldering, recently, a method using an adhesive has been frequently used. In this case, the conductive particles are mixed in the adhesive and pressure-bonded to obtain electrical connection in the thickness direction of the adhesive (for example, Japanese Patent Application Laid-Open No. 55-104007). In some cases, electrical connection is obtained by direct contact of fine irregularities on the electrode surface (for example, JP-A-60-262430). The connection method using these adhesives can be connected at a relatively low temperature, and since the connection part is flexible, it is excellent in reliability. In addition, when using a film-like or tape-like adhesive, it has a certain thickness. Since it can be supplied in a long shape, the mounting line can be automated, or a simple process such as heat and pressure can be used to achieve mechanical fixation at the same time by bonding and bonding the chip and substrate electrodes together. Etc. are attracting attention. In recent years, a multi-chip module (MCM) has been attracting attention by developing the above-described method and mounting a large number of chips on a relatively small substrate at high density. In this case, it is common to first form an adhesive layer on the substrate, then peel off the separator, if any, and then place the substrate electrode and the chip electrode facing each other and align and bond them together. The formation of the adhesive layer on the chip side has not been studied because it is complicated in terms of apparatus because it needs to be formed in a smaller chip area than the substrate. As chips used for MCM, there are many types (hereinafter referred to as chips) such as a semiconductor chip, an active element, a passive element, a resistor, and a capacitor.
Japanese Patent Laid-Open No. 55-104007 JP 60-262430 A Japanese Examined Patent Publication No. 61-27902 Japanese Patent Publication No. 4-30742 JP-A 63-276237 Japanese Patent Laid-Open No. 2-199847

  There are many types of chips used for MCM, and there are many types of chip sizes (area, height) accordingly. For this reason, unprecedented problems are caused by the method of forming the adhesive layer on the substrate and the method of thermocompression bonding with the substrate when connecting to the substrate. That is, when the adhesive is in the form of a film, the adhesive width (tape width) must be different for each chip size. However, since MCM mounts a plurality of chips at a high density on a small substrate, there is little space for mounting and it is difficult to employ various tape widths. In addition, there are many types of tape widths and material management is difficult, and the mounting equipment requires each device such as driving, crimping, and winding for each tape width, which increases the installation space and increases the cost. This causes inconveniences such as For this reason, it has been attempted to mount chips of various sizes after forming an adhesive layer on the entire surface of the substrate (Japanese Patent Publication No. 61-27902), but the process of removing the remaining adhesive in the non-connection portion is troublesome. In addition, since the adhesive layer is excessively used for parts other than the mounting portion, there is a disadvantage that the cost is increased. In addition, since the adhesive is formed on the entire surface of the substrate, the heat at the time of connection affects the adjacent chip mounting part. For example, the reaction of the thermosetting adhesive is promoted and the adjacent part is mounted before mounting the chip. It becomes easy to cause the connection failure of the adjacent chip due to the adhesive becoming soft due to the connection temperature even after the chip is mounted or the adhesive becomes unusable. This is also true when removing a defective chip after mounting the chip, and it is difficult to remove the adhesive due to the reaction of the thermosetting adhesive, making it difficult to remove the defective chip. On the other hand, as an attempt to form an adhesive layer of approximately the same size as the chip, an attempt to form an adhesive layer in a wafer state and perform full dicing can be found in, for example, Japanese Patent Publication No. 4-30742. Preparing various types of wafers with different adhesives for each type has drawbacks such as a long life in the storage stability of the adhesive and complicated process management. Attempts to improve the pitch by which an adhesive can be formed only at the tip of the top of the protruding electrode (also referred to as a bump) of the chip can be found in Japanese Patent Laid-Open Nos. 63-276237 and 2-199847. However, both of them form an adhesive only on the top of the protruding electrode, the bonding area with the substrate is only in the vicinity of the protruding electrode, the bonding force is weak, and the connection reliability is insufficient. As a countermeasure against this, in order to form an adhesive other than the top of the protruding electrode, additional means such as injecting an underfill material is required, which increases the number of processes and increases the cost. In addition, when the chip height is different or when mounting on both sides of the substrate, the heating method is generally used in the conventional press method that presses the molds installed in parallel and the pressure roll method installed in parallel. Pressurization is not performed uniformly, and connection of fine electrodes is impossible. The present invention has been made in view of the above disadvantages, and provides a new multichip mounting method.

The present invention is [1] a multichip mounting method comprising the following steps.
(1) using a film-like adhesive layer composed of a curable material, a plurality of attached adhesive agent obtained by forming a film-like adhesive layer of the size substantially the same area of the electrode forming surface of the chip on the electrode surface before SL chip A step of obtaining a chip as an adhesive-attached chip formed by adhering the chip with adhesive formed on the electrode-forming surface of the chip on the separator with the adhesive layer ;
(2) A step of aligning the electrodes of the plurality of adhesive-attached chips to be connected to the electrodes of the substrate, respectively,
(3) A step of simultaneously heat-pressing the electrodes of the plurality of chips and the electrodes of the substrate that have completed the alignment of the electrodes between the electrodes to be connected to obtain electrical connection of the plurality of chips to the same substrate.
The present invention is also [2] a multichip mounting method comprising the following steps.
(1) using a film-like adhesive layer composed of a curable material, a plurality of attached adhesive agent obtained by forming a film-like adhesive layer of the size substantially the same area of the electrode forming surface of the chip on the electrode surface before SL chip A step of obtaining a chip as an adhesive-attached chip formed by adhering the chip with adhesive formed on the electrode-forming surface of the chip on the separator with the adhesive layer ;
(2) A step of aligning the electrodes of the plurality of adhesive-attached chips to be connected to the electrodes of the substrate, respectively,
(3) The electrodes of the plurality of chips and the electrodes of the substrate, which have been aligned, are thermocompression bonded between the electrodes to be connected so that the reaction rate of the adhesive is 30% or less, and the electrical connection between the electrodes is established. Inspection process,
(4) Inspecting and, if defective, peeling the chip and making a similar connection with a new chip,
(5) A step of obtaining the electrical connection of a plurality of chips on the same substrate by simultaneously press-bonding the electrode of the chip inspected for electrical connection and the electrode of the substrate between the electrodes to be connected at or above the activation temperature of the curing agent.
Further, the present invention is [3] the multichip mounting method according to [1] or [2] above, wherein the thermocompression bonding between the chip and the substrate is performed under hydrostatic pressure in a sealed container.
Also, the present invention is [4] chip with adhesive, the adhesive layer obtained by forming on the separator is brought into contact with the electrode surface of the chip, the adhesive layer along the chip size by heating from the back of the chip A cohesive force lowering line is formed, and an adhesive layer having approximately the same size as the chip is peeled off from the separator and transferred to the chip. [1] to [3] This is a chip mounting method.
In addition, the present invention provides a [ 5 ] chip with an adhesive by using a cutting jig along the outer shape of the chip while bringing the adhesive layer formed on the separator into contact with the electrode surface of the chip and applying pressure from the back surface of the chip. The multichip according to any one of the above [1] to [3], wherein at least part of the adhesive layer in the thickness direction is cut and an adhesive layer having approximately the same size as the chip is transferred to the chip. Implementation method.

  According to the present invention, an adhesive can be accurately formed on the electrode surfaces of chips having different sizes, and a plurality of chips having different sizes can be mounted at a time, so that MCM can be efficiently manufactured. became.

  The present invention will be described below with reference to the drawings showing embodiments. FIG. 1 is a schematic sectional view for explaining one embodiment of the present invention. FIG. 1A is a part of a thermocompression bonding apparatus. For example, an adhesive tape 6 composed of an adhesive layer 4 and a separator 5 is interposed between a heating head 2 capable of fixing the chip 1 by adsorption or the like and a surface plate 3. Exists. Here, the adhesive layer 4 is disposed so as to face the electrode forming surface of the chip 1. The adhesive tape 6 may be brought into close contact with the surface plate 3 by suction or the like, or may be able to run in a state where tension is applied by rolls (not shown) before and after the surface plate 3. Further, the adhesive layer 4 can be peeled off from the separator 5, and it becomes easier by fixing the separator 5 by adhesion or tension. By pressing between the heating head 2 and the surface plate 3, the adhesive layer 4 larger than this is brought into contact with the electrode forming surface of the semiconductor chip 1. The size of the adhesive layer 4 is preferable because selection of the maximum chip size among a plurality of chips used in the MCM can be applied to other chips and is easy to handle. At this time, it is preferable to select the smaller of the vertical and horizontal sides of the chip because the tape width can be reduced and the space of the apparatus can be reduced. The width of the adhesive layer 4 (generally the tape width) may be almost the same as the chip size as shown in FIG. 2A, or slightly larger than the chip size as shown in FIG. It is. Further, it is possible to take out two or more rows as shown in FIG. 2C, and these are selected in consideration of handling property and mass productivity. In FIG. 1A, since the heating head 2 is heated to a predetermined temperature, it is heated directly from the back surface of the electrode forming surface of the chip 1 and the adhesive layer along the chip size is preferentially heated. At this time, the adhesive around the chip 1 has little heat propagation and low thermal conductivity, so the film is kept almost unheated. However, the adhesive layer 4 adhered to the chip 1 is reduced in viscosity by heating. Alternatively, the film strength is improved by transferring and integrating with the chip 1 due to the increase in adhesiveness. Therefore, a cohesive force decreasing line of the adhesive layer 4 along the size of the chip 1 is formed. At this time, the heating temperature of the head 2 is such that the adhesive layer 4 softens and flows (preferably 1000 poise or less, more preferably 100 to 10 poise), and the adhesive curing reaction does not start or is in a low state (reaction) The rate is preferably 20% or less, and is appropriately selected depending on the adhesive system used. It is more preferable that the heating temperature of the head 2 is not higher than the activation temperature of the latent curing agent described later, since the storage stability of the chip with adhesive is improved.

  FIG. 1B is a view in which the heating head 2 is separated from the surface plate 3, but the adhesive layer 4 having approximately the same size as that of the chip 1 due to the cohesive force reduction line of the adhesive layer along the size of the chip 1. Can be formed on the chip 1 by transfer. The adhesive layer 4 on the surface plate 3 exists in a form in which the adhesive layer 4 transferred to the chip 1 is removed, but the film shape is maintained by the remaining adhesive layer 4 and the separator 5 and is removed or run. A new adhesive surface can be placed on the surface plate 3 by moving. In the case of FIG. 1, since a chip with an adhesive is obtained by peeling the adhesive layer 4 from the separator 5, it can be connected to the substrate as it is and can be made into a continuous MCM. At the time of storage, a separator may be formed again on the adhesive surface. In FIG. 1, if various chips are placed on the tape in advance by temporary connection or the like, the chip can be effectively applied as a chip with an adhesive when the chip is peeled off from the tape. In this case, since various chips can be sequentially supplied and continuously supplied as chips with an adhesive, the productivity is high and effective.

  FIG. 3 is a schematic cross-sectional view illustrating another embodiment of the present invention for obtaining a chip with an adhesive. FIG. 3 shows a part of the crimping apparatus, and an adhesive tape 6 composed of an adhesive layer 4 and a separator 5 exists between the pressure head 8 and the surface plate 3 on which the chip 1 is fixed by suction or the like. Here, the adhesive tape 6 may be brought into close contact with the surface plate 3 by suction or the like, or may be able to run in a state where tension is applied by rolls before and after the surface plate 3 (not shown). A cutting jig 7 is disposed on the pressure head 8. The blades of the cutting jig 7 are formed around the size of the chip 1, but may be two sides if the tape width and the chip size are substantially equal. A part or all of the adhesive layer 4 in the thickness direction is cut by the cutting jig 7, and the adhesive layer 4 having approximately the same size as the chip 1 is attached to the chip 1. At this time, the pressure head 8 may be in a state where it is not heated. In this case, since the room temperature operation is possible, trouble of the adhesive due to heat can be prevented. Further, heating to a predetermined temperature is more preferable because the working condition width can be expanded and the adhesiveness of the adhesive layer 4 can be increased due to a synergistic effect with the case of the heat in FIG. The cutting jig 7 can use a cutting tool such as metal or ceramics, or an energy beam such as heat, ultraviolet light, or laser. The height when the cutting jig 7 is a blade and is cut by pressing, that is, the distance from the connection surface of the chip 1 is determined in consideration of the depth of cut into the adhesive layer 4 or the separator 5, but the adhesive layer 4 Is preferable because the chip with adhesive is easily separated from the adhesive layer 4. In this case, continuous productivity is improved by making the cutting jig 7 storable in the pressure head 8 and making it a mechanism that can move up and down. 1 and 3, by placing a cushion layer 11 of rubber or the like between the surface plate 3 and the separator 5 as shown in FIG. 4, the chip with adhesive having a size along the outer edge of the chip size is further provided. It is more preferable because it is easily available.

  The chip | tip with an adhesive agent obtained by the above is demonstrated using FIGS. In any case, a film adhesive having substantially the same area as the chip is present on the entire surface of the electrode surface of the chip so as to cover an electrode portion (not shown). (A) of FIG. 5 is a basic structure of the chip | tip with an adhesive agent, and the semiconductor chip 1 and the adhesive bond layer 4 are the same magnitude | sizes. (B) to (c) are slightly larger than the semiconductor chip 1 and are effective for adjusting the optimum adhesive amount after connection to the substrate. The size range is preferably about chip size ± 30% from the shape stability of the chip with adhesive, and more preferably the same size. In the present invention, these (a) to (c) are included and expressed as substantially the same size as the semiconductor chip. (D) is a case where the separator 5 is formed in the adhesive layer 4, and is preferable from the viewpoint of preventing adhesion of dust or the like to the adhesive surface during storage. 6A to 6B show the case of a chip having a protruding electrode 12, and FIG. 6C shows the case of a chip without a protruding electrode. Moreover, (a) and (b) are the cases where the adhesive contains the conductive particles 14, and (c) is the case where the conductive particles are not included. The presence or absence of these protruding electrodes and conductive particles in FIG. 6 can be combined alternately. FIG. 7A shows an application configuration of a chip with an adhesive, and a plurality of chips with an adhesive, in which a film-like adhesive having approximately the same size as the chip covers the entire surface of the chip on which electrodes are formed. Is independently a chip series with an adhesive formed on a separator, and can be wound as a continuous tape. Further, as shown in FIG. 7B, the adhesive layer 4 can be formed on the separator 5 independently along the chip size. In these cases, by forming various chips on the separator in the order of mounting on the substrate, for example, the chips with adhesive can be continuously supplied, so that productivity is high and effective. The above chip with adhesive can be applied to single chip mounting. A multichip mounting method using the chip will be described below. First, the electrode of the chip with adhesive to be connected and the electrode of the substrate are aligned using a microscope or an image storage device. At this time, the use of the alignment mark is also effective. Next, heat and pressure are applied between the electrodes to be connected to obtain a conductive connection of a plurality of chips to the same substrate. As a condition for heating and pressurizing, it is effective to improve productivity if a plurality of pieces are pressed at the same time. In addition to using a normal press as a heating and pressing method, a method using hydrostatic pressure using an autoclave or the like is also effective as a uniform heating and pressing method particularly when the thickness and size of the chips are different. The hydrostatic pressure as used in the field of the present invention refers to a state in which a constant pressure acts on the external surface of an object perpendicularly. Here, although the chip area is generally 2 to 20 mm square, the thickness of the connection portion is 1 mm or less, and most is 0.1 mm or less, so that the chip area is overwhelmingly large and pressure in the electrode connection direction can be obtained. It is also possible to conduct a continuity test between the electrodes to be connected during heating and pressing. Since the adhesive can be inspected for continuity in an uncured state or in an insufficient curing reaction, the repair work is easy. At this time, it is preferable that the reaction rate of the adhesive is about 30% or less because it is easy to achieve a repair work for the solvent. Further, when the reaction rate of the adhesive is less than 10%, it is preferable to use pressurization in combination because the electrode is not sufficiently fixed. As described above, a multi-chip module (MCM) is obtained in which a plurality of chips 1 having various shapes and sizes are mounted on a relatively small substrate 9 with high density using the adhesive layer 4 as shown in FIG. Examples of the substrate 9 to which the present invention can be applied include plastic films such as polyimide and polyester, composites such as glass fiber / epoxy, semiconductors such as silicon, inorganic substrates such as glass and ceramics, and the like.

  As the adhesive layer 4 used in the present invention, thermoplastic materials and materials that are cured by heat or light can be widely applied. Since these are excellent in heat resistance and moisture resistance after connection, application of a curable material is preferable. Among them, epoxy adhesives that contain latent curing agents and acrylic adhesives that contain radical curing agents such as peroxides can be cured in a short time, have good connection workability, and are adhesive in terms of molecular structure. It is particularly preferable because it is excellent. The latent curing agent has a relatively clear active point of reaction initiation due to heat and pressure, and is suitable for the present invention involving a heat and pressure process. As latent curing agents, there are imidazole series, hydrazide series, boron trifluoride-amine complex, amine imide, polyamine salt, onium salt, dicyandiamide, etc., and modified products thereof. These may be used alone or in combination of two or more. Can be used as a body. These are so-called ion polymerizable catalyst-type curing agents such as anion or cation polymerization type, and are preferable because they are easy to obtain fast curability and require less chemical equivalent consideration. Among these, imidazole-based compounds are non-metallic, are less likely to cause electrolytic corrosion, and are particularly preferable in terms of reactivity and connection reliability. In addition, polyamines, polymercaptans, polyphenols, acid anhydrides, and the like can be used as the curing agent, and the catalyst-type curing agent can be used in combination. In addition, a microcapsule type curing agent having a curing agent as a core and a surface coated with a polymer substance or an inorganic substance can achieve both contradictory properties of long-term storage and rapid curing. As for the active temperature of the hardening | curing agent of the adhesive agent used for this invention, 40-200 degreeC is preferable. If the temperature is lower than 40 ° C., the temperature difference from the room temperature is small and a low temperature is required for storage. If the temperature exceeds 200 ° C., other members are thermally affected at the time of connection. More preferred. The activation temperature in the present invention is indicated by an exothermic peak temperature when the temperature is raised from room temperature to 10 ° C./minute using a DSC (differential scanning calorimeter) as a sample of a mixture of an epoxy resin and a curing agent. The active temperature is determined in consideration of these because the low temperature side tends to have better reactivity but lower storage stability. In the present invention, the preservability of the chip with adhesive is improved by a heat treatment below the activation temperature of the curing agent, and good multichip connection is obtained above the activation temperature. Therefore, it is preferable to adjust the melt viscosity so that a cohesive force lowering line is formed below the curing agent activation temperature.

  It is preferable to add conductive particles and a small amount of insulating particles to these adhesive layers 4 because they act as a thickness maintaining material during heating and pressurization during the manufacture of the chip with adhesive. In this case, the ratio of conductive particles or insulating particles is about 0.1 to 30% by volume, and 0.5 to 15% by volume for anisotropic conductivity. As the adhesive layer 4, a multi-layer component in which an insulating layer and a conductive layer are separately formed can be applied. In this case, since the resolution is improved, high-density electrode connection is possible. Examples of the conductive particles include metal particles such as Au, Ag, Pt, Co, Ni, Cu, W, Sb, Sn, and solder, carbon, graphite, etc., and these conductive particles are used as a core material or non-conductive. A core material made of a polymer such as glass, ceramics, plastic, etc., coated with a conductive layer made of the above-described material may be used. Furthermore, insulating coating particles formed by coating a conductive material with an insulating layer, and combined use of conductive particles and insulating particles such as glass, ceramics, and plastics can be applied because the resolution is improved. The particle diameter of the conductive particles is preferably not less than 15 μm, more preferably 7 to 1 μm, in order to secure one or more, preferably as many particles as possible, on a minute electrode. If it is less than 1 μm, it is difficult to contact the electrode surface. In addition, it is preferable that the conductive material has a uniform particle size because there is little outflow from between the electrodes. Among these conductive particles, those in which a conductive layer is formed on a polymer core material such as plastic, and hot-melt metal such as solder are deformable by heating or pressurization, and contact with a circuit for connection This is preferable because the area is increased and the reliability is improved. In particular, when a polymer is used as a nucleus, it does not show a melting point like solder, so that the softening state can be widely controlled by the connection temperature, and it is easy to cope with variations in electrode thickness and flatness, which is particularly preferable. Also, for example, in the case of hard metal particles such as Ni and W, or particles having a large number of protrusions on the surface, the conductive particles will bite into the electrode or wiring pattern, so even when an oxide film or a contamination layer exists on the electrode surface This is preferable because a low connection resistance is obtained and reliability is improved.

  According to the multichip mounting method of the present invention, chips with adhesives having different sizes can be mounted on the substrate, so that it is easy to mount a large number of chips on a small area substrate. According to the present invention, by using a chip in which a necessary amount of adhesive layer is formed for each chip, the tape width is smaller than when using a different adhesive tape for each chip size. Simplification is possible. Further, compared to the case where an adhesive layer is formed on the entire surface of the substrate, there is no influence of heat and pressure on adjacent chips and adhesives, and it is economical because unnecessary adhesives are not used. According to a preferred embodiment of the present invention, since a latent curing agent is contained in the adhesive, a chip with an adhesive can be obtained by a heat treatment not higher than the activation temperature of the curing agent, so that the storage stability of the adhesive is improved and the activity is improved. A connection with excellent reliability of the multichip can be obtained above the temperature. According to the multi-chip mounting method using hydrostatic pressure of the present invention, the pressure in the sealed container is constant, so that a large number of MCMs can be processed at the same time, so that mass production is highly effective. Further, since the medium is heated with a gas or liquid, an expensive metal mold is not required, and various adhesives such as heat, moisture and anaerobic can be applied depending on the type of medium. In addition, when a long time is required for curing the adhesive, a large number can be produced by one operation. According to the multi-chip mounting method of the present invention, a continuity test can be performed before the adhesive is fully cured, so that when the defective connection portion is found, the adhesive is in an insufficient curing reaction. The chip peeling and the subsequent cleaning with a solvent such as acetone are very simple and the repair work is easy. Moreover, the chip | tip series with an adhesive agent which formed the chip | tip with an adhesive agent on the separator can be formed in order of the mounting to a board | substrate, and is effective for the improvement of productivity. According to the manufacturing method of the chip with adhesive, the adhesive layer can be easily formed with a cohesive force lowering line near the chip by heating the chip, and the adhesive layer can be peeled off from the separator. A chip-sized chip with an adhesive is obtained. Further, by setting this temperature below the activation temperature of the curing agent, it can be used stably without affecting the storage stability of the adhesive. According to the method of manufacturing a chip with adhesive, a chip with adhesive of a chip size can be obtained relatively easily by cutting at least a part of the adhesive layer in the thickness direction with a cutting jig along a very simple chip shape. It is done.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
(Example 1)
(1) Preparation of adhesive layer The ratio of liquid epoxy resin (epoxy equivalent 185) containing phenoxy resin (high molecular weight epoxy resin) and microcapsule type latent curing agent is 30/70, and a 30% solution of ethyl acetate is used. Obtained. To this solution, 2% by volume of conductive particles in which a Ni / Au 0.2 / 0.02 μm thick metal coating was formed on polystyrene particles having a particle size of 3 ± 0.2 μm were added and mixed and dispersed. This dispersion was applied to a separator (silicone-treated polyethylene terephthalate film, thickness 40 μm) with a roll coater and dried at 100 ° C. for 20 minutes to obtain an adhesive film having a thickness of 20 μm. The activation temperature by DSC of this adhesive film was 120 ° C., and the viscosity of the model blend from which the curing agent was removed was measured with a digital viscometer HV-8 (manufactured by Reska Co., Ltd.). The viscosity at 100 ° C. was 800 poise. It was. This adhesive film was cut together with a separator to obtain a tape-like product having a width of 2 mm.

(2) Manufacture of chip with adhesive layer The tape-like material obtained in (1) is mounted on the chip mounting device AC-SC450B (COB connection device manufactured by Hitachi Chemical Co., Ltd.) with the adhesive surface facing up. Tension was applied to the object with the rolls before and after the surface plate, and it was possible to run in close contact with the surface plate. An IC chip for evaluation (silicon substrate, 2 × 10 mm, thickness 0.5 mm, 300 gold electrodes of 50 μmφ and 20 μm height called bumps are formed on the two long sides) was fixed to the heating head by suction. With the above configuration, the heating head was set to 110 ° C., and after thermocompression bonding to the adhesive surface of the tape-like material at 5 kg / cm ² for 3 seconds, the heating head was raised to release the pressure, and the heating head was separated from the surface plate. . At this time, the actual temperature of the adhesive at the tip of the IC chip was 102 ° C. at the maximum. As described above, a chip with an adhesive was obtained by peeling off the adhesive layer substantially equal to the chip size from the separator. In the same manner, a total of four chips with an adhesive having an IC chip size of 5 × 5 mm (tape width 5.5 mm) and two 10 mmφ (tape width 10.5 mm) were obtained. Although the bump pitches of these chips are different, the bump height and the silicon substrate thickness are the same.

(3) Connection 15 mm × 25 mm and 0.8 mm thick glass epoxy board (FR-4 grade) on a 18 μm high copper circuit, and the circuit edge is the bump pitch of the IC chip of (2) above. The chip with adhesive was placed on a glass epoxy substrate having connection electrodes corresponding to the above, and the whole was connected at once at 150 ° C., 20 kgf / mm ² for 15 seconds after alignment of the electrodes by the CCD camera. The chip height is almost equal, and a 100μm thick polytetrafluoroethylene sheet is used as a cushioning material between the chip and the heating head, so an MCM in which four chips with adhesive are connected at once is obtained. It was.
(4) Evaluation The electrode of each chip and the substrate electrode could be connected well. Since the adhesive exists only in the vicinity of the chip, there was almost no unnecessary adhesive on the substrate surface.

(Example 2)
Although it is the same as that of Example 1, the preparation methods of the chip | tip with an adhesive agent were changed. That is, this is a method having a cutting jig in the pressure head, and the tape width is 10 mm. In the case of a 2 × 10 mm chip, the cutting jig was a heater wire made of nichrome wire and provided on four sides. The pressure head was brought to room temperature without heating. Since the cutting jig was a heater wire, the depth of cut into the separator could be all layers, and a chip with a separator on the adhesive surface was obtained. Other chips could form adhesives as well. In the case of a 10 mmφ chip, a heater wire having a cutting jig inner diameter of 11 mmφ was used. Also in this case, the electrode of each chip and the substrate electrode could be connected well. Since the adhesive exists only in the vicinity of the chip, there was almost no unnecessary adhesive on the substrate surface.

(Example 3)
Although it is the same as that of Example 2, in the manufacturing method of the chip | tip with an adhesive bond layer, the heating head was set to 70 degreeC. The cutting jig was a razor blade. Also in this case, the chip | tip with an adhesive layer was obtained easily, and adhesion | attachment of the adhesive agent to a chip | tip was easy by using together a cutting jig and a heating means. Compared with Example 1, it was possible to lower the heating temperature.

Example 4
Although it is the same as that of Example 1, the manufacturing method of the chip | tip with an adhesive bond layer was changed. That is, various chips are preliminarily connected (100 ° C., 5 kg / cm ² , thermocompression bonding for 3 seconds) on a tape (width 10.5 mm) in advance, and the various chips are arranged in order as shown in FIG. Then, in the same manner as in Example 1, an adhesive-attached chip was obtained in which an adhesive layer substantially equal to the chip size was peeled from the separator. In this case, the separation from the separator was easy, and the chips were obtained in the order of mounting, so the productivity was extremely high. The electrode of each chip and the substrate electrode could be connected well.

(Example 5)
The chip with adhesive obtained in Example 4 was temporarily connected again to the continuous separator with the interval between adjacent chips set to 1 mm to obtain a chip series with an adhesive layer as shown in FIG. Productivity was extremely high because the chips could be removed from the separator in the order of mounting. The electrode of each chip and the substrate electrode could be connected well. Further, the chip series with an adhesive layer can be wound around a reel core having an outer diameter of 55 mm and can be stored compactly, so that refrigerated storage after work is easy. The electrode of each chip and the substrate electrode could be connected well.

(Example 6)
Same as Example 1, but the type of adhesive was changed. That is, no conductive particles were added. Also in this case, the electrode of each chip and the substrate electrode could be connected well. This is because the bumps of the chip and the connection electrodes of the glass epoxy substrate are in direct contact and fixed with an adhesive.

(Example 7)
Although it is the same as that of Example 1, after obtaining the chip | tip with an adhesive agent, the intermediate | middle test process which test | inspects the electrical connection between electrodes was provided. First, in Example 6, the connection resistance at each connection point was measured with a multimeter while pressurizing after 2 seconds at 150 ° C. and 20 kgf / mm ² . Similarly, it removed from the connection apparatus after the connection under the conditions of 150 ° C., 20 kgf / mm ² and 4 seconds. Since the adhesive has been cured by heat and pressure, each IC chip is temporarily fixed to the substrate side and tested in the same manner under no pressure. In both cases, one IC chip was abnormal. Therefore, when the abnormal chip was mechanically peeled off and the same connection as described above was performed with a new chip, both were satisfactory. In both cases, since the adhesive was in a state where the curing reaction was insufficient, chip peeling and subsequent cleaning using a solvent were extremely simple, and repair work was easy. When the reaction rate of the adhesive was examined by the calorific value by DSC, it was 7% in the former and 20% in the latter. After the above energization inspection process and repair process, connection was further performed at 150 ° C., 20 kgf / mm ² and 15 seconds. Both examples showed good connection characteristics. After the adhesive is cured, it is extremely difficult to remove the chip and to clean it with a solvent. However, the repair work is easy even when a large number of chips exist on a narrow substrate as in this embodiment. It was.

(Comparative example)
Although it is the same as that of Example 1, the adhesive film with a separator was cut | judged according to chip size and affixed on the electrode formation surface. Since the chip is small, it takes a long time to attach it accurately, and it takes 20 minutes or more to produce one MCM, which is inefficient compared with the case of Example 1 within 1 minute.

(Example 8)
Although it is the same as that of Example 1, it was set as the method by a hydrostatic pressure as a means of the heat pressurization at the time of a connection. A chip with adhesive is placed on a glass epoxy board, and the chip temporary board after positioning of the electrode by the CCD camera is placed in a pressure cooker and cooled to room temperature after 120 minutes of air pressure treatment at 120 ° C and 20 kg / cm ² . I took it out. In the present embodiment, since a uniform pressure is applied regardless of the height of each chip, it is not necessary to use the cushioning material used in the first embodiment. In addition, a large number of MCMs can be processed simultaneously in accordance with the capacity of the pressure cooker.

Example 9
Similar to Example 1, but the separator was changed to polytetrafluoroethylene (thickness 80 μm). When the same evaluation as in Example 1 was performed, the edge of the adhesive at the end of the chip could be transferred sharply with a shape closer to the chip size. This is probably because the separator is more flexible than that of Example 1 so that the adhesive can be cut along the edge of the chip. Here, both elastic moduli are polytetrafluoroethylene 40kgf / mm < ² > with respect to 200kgf / mm < ² > of a polyethylene terephthalate film.

(Example 10)
Although it is the same as that of Example 1, the chip | tip with an adhesive agent was produced by mounting the silicone rubber whose thickness is 0.5 mm between a separator and a surface plate. In this case, compared with Example 1, the edge of the adhesive at the end of the chip could be transferred sharply with a size closer to the chip size. This is probably because silicone rubber acts as a cushioning material. Even when a soft rubber layer is present under the separator, the thickness of the adhesive formed on the electrode surface is controlled by the height of the bumps and conductive particles, so about 4 μm on the bumps. It was formed to have a thickness of about 20 μm.

(A), (b) is a cross-sectional schematic diagram explaining the process of the Example of this invention. (A)-(c) is a top view which shows the width | variety of the adhesive agent of this invention, and the example of an arrangement | sequence of a chip | tip. The cross-sectional schematic diagram explaining the other Example of this invention. The cross-sectional schematic diagram explaining the other Example of this invention. The cross-sectional schematic diagram which shows the structure of the chip | tip with an adhesive agent in this invention. The cross-sectional schematic diagram which shows the structure of the chip | tip with an adhesive agent in this invention. (A), (b) is a cross-sectional schematic diagram which shows the structure of the chip | tip series with an adhesive agent in this invention. The perspective view of MCM which mounted the chip | tip with an adhesive agent of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chip component 2 Heating head 3 Surface plate 4 Adhesive layer 5 Separator 6 Adhesive tape 7 Cutting jig 8 Pressure head 9 Substrate 10 Insulating layer 11 Cushion layer 12 Projection electrode 13 Wiring layer 14 Conductive particle

Claims (5)

Using the multi-chip mounting method (1) comprising a cured material film adhesive layer consisting of the following steps, forming a film-like adhesive layer of the size substantially the same area of the electrode forming surface of the chip on the electrode surface before SL chip A plurality of chips with adhesive formed by attaching the chip with adhesive formed with the film-like adhesive layer on the electrode forming surface of the chip onto the separator with the adhesive layer. Obtaining as a chip chain ,
(2) A step of aligning the electrodes of the plurality of adhesive-attached chips to be connected to the electrodes of the substrate, respectively,
(3) A step of simultaneously heat-pressing the electrodes of the plurality of chips and the electrodes of the substrate that have completed the alignment of the electrodes between the electrodes to be connected to obtain electrical connection of the plurality of chips to the same substrate. Using the multi-chip mounting method (1) comprising a cured material film adhesive layer consisting of the following steps, forming a film-like adhesive layer of the size substantially the same area of the electrode forming surface of the chip on the electrode surface before SL chip A plurality of chips with adhesive formed by attaching the chip with adhesive formed with the film-like adhesive layer on the electrode forming surface of the chip onto the separator with the adhesive layer. Obtaining as a chip chain ,
(2) A step of aligning the electrodes of the plurality of adhesive-attached chips to be connected to the electrodes of the substrate, respectively,
(3) The electrodes of the plurality of chips and the electrodes of the substrate, which have been aligned, are thermocompression bonded between the electrodes to be connected so that the reaction rate of the adhesive is 30% or less, and the electrical connection between the electrodes is established. Inspection process,
(4) Inspecting and, if defective, peeling the chip and making a similar connection with a new chip,
(5) A step of obtaining the electrical connection of a plurality of chips on the same substrate by simultaneously press-bonding the electrode of the chip inspected for electrical connection and the electrode of the substrate between the electrodes to be connected at or above the activation temperature of the curing agent.   The multichip mounting method according to claim 1 or 2, wherein the thermocompression bonding of the chip and the substrate is performed under hydrostatic pressure in a sealed container.   The chip with adhesive is made by bringing the adhesive layer formed on the separator into contact with the electrode surface of the chip and heating from the back surface of the chip to form a cohesive force reduction line of the adhesive layer along the chip size. The multichip mounting method according to any one of claims 1 to 3, wherein an adhesive layer having substantially the same size as the above is peeled off from the separator and transferred to a chip. A chip with an adhesive is formed by bringing an adhesive layer formed on a separator into contact with the electrode surface of the chip, and pressing at least one thickness direction of the adhesive layer with a cutting jig along the outer shape of the chip while applying pressure from the back surface of the chip. The multichip mounting method according to any one of claims 1 to 3, wherein the portion is cut and an adhesive layer having approximately the same size as the chip is transferred to the chip.

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