JP2017163060A - Thermocompression bonding apparatus and thermocompression bonding method - Google Patents

Abstract

An object of the present invention is to provide a thermocompression bonding apparatus and a thermocompression bonding method capable of reducing the thermocompression-bonding failure by uniformizing the temperature distribution of the heating temperature at the joining portion while maintaining the equipment in a compact structure. When a circuit component (second member) is joined to a circuit board (first member) by thermocompression bonding, the thermocompression bonding tool has a thermocompression bonding tool for thermocompression bonding the circuit component to the circuit board. The first hot air nozzle that blows hot air on the joint portion of the circuit component 3 and the circuit board 2 and the periphery thereof when the head 7 and the thermocompression bonding tool 8 are thermocompression bonding the circuit component 3 to the circuit board 2. 21. Using the thermocompression bonding apparatus 1 having a configuration including a hot air supply unit composed of the second hot air nozzle 22, while blowing hot air to the junction between the circuit component 3 and the circuit board 2 and its peripheral portion, The circuit component 3 is pressed against the circuit board 2 with the thermocompression bonding tool 8. [Selection] Figure 1

Description

  The present invention relates to a thermocompression bonding apparatus and a thermocompression bonding method for joining a second member such as a flexible substrate to a first member such as a rigid substrate by thermocompression bonding.

  Generally, a configuration in which individual functional modules are connected to a main electronic circuit provided on a rigid board via a film-like flexible board is used for a small-sized and high mounting density electronic device such as a portable terminal. As a method of connecting the terminals provided on the flexible board to the circuit electrodes of the rigid board, the terminal and the electrode are soldered or anisotropically heated by pressing the flexible board against the rigid board with a thermocompression bonding head. Thermocompression bonding using a conductive material is widely used (see, for example, Patent Document 1). In the prior art shown in Patent Document 1, a thermocompression bonding head is provided with a plurality of heaters and temperature sensors capable of individually controlling the temperature, and by controlling the plurality of heaters based on the detection result of the temperature sensor. An example of flattening the temperature distribution in is described.

JP 2000-277893 A

  However, the above-described prior art has the following drawbacks in effectively reducing the temperature variation of the crimped part in the thermocompression bonding with a simple configuration. That is, in the thermocompression bonding, since the joining portion is heated by contact heat conduction from the crimping tool provided in the thermocompression bonding head, the joining portion is heated and heat conduction to the surroundings in the crimping process. The temperature decreases due to heat dissipation. The degree of the temperature decrease due to the heat radiation varies depending on the heat capacity of the rigid substrate or the flexible substrate. For this reason, when the distribution of heat capacity is non-uniform due to the arrangement of electrodes and components around the joint, it is inevitable that the heating temperature varies at the joint that is heated by the same crimping tool.

  In the above-described prior art, it is possible to flatten the temperature distribution in the thermocompression bonding head. However, when the distribution of the heat capacity around the bonding portion is not uniform, the heating temperature of the bonding portion to be heated is uniform. The difficulty of making it is not solved. Furthermore, since it is necessary to provide a plurality of heaters and temperature sensors in the above-described prior art, it is difficult to make the thermocompression bonding head and the crimping tool compact, and the thermocompression bonding apparatus is intended for small and high-density mounting parts. It is difficult to adapt. As described above, in the prior art including the above-described prior art, it is possible to reduce the thermocompression failure by uniformizing the temperature distribution of the heating temperature of the joining portion while maintaining the equipment such as the thermocompression bonding head in a compact structure. There was a difficult problem.

  Therefore, the present invention has an object to provide a thermocompression bonding apparatus and a thermocompression bonding method that can reduce the thermocompression failure by uniformizing the temperature distribution of the heating temperature at the joining portion while maintaining the equipment in a compact structure. To do.

  The thermocompression bonding apparatus of the present invention is a thermocompression bonding apparatus that joins a second member to a first member by thermocompression bonding, and has a thermocompression bonding tool for thermocompression bonding the second member to the first member. Warm air that blows warm air on the joint between the second member and the first member and its peripheral part when the crimping head and the thermocompression bonding tool are thermocompression bonding the second member to the first member And a supply unit.

  The thermocompression bonding method of the present invention is a thermocompression bonding method in which a second member is joined to a first member by thermocompression bonding, and hot air is applied to a joining portion of the second member and the first member and its peripheral portion. While spraying, the second member is pressed against the first member with a thermocompression bonding tool.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature distribution of the heating temperature of a joining location can be equalize | homogenized and thermocompression-bonding defect can be reduced, maintaining an installation in a compact structure.

The perspective view which shows the structure of the thermocompression bonding apparatus of one embodiment of this invention. The perspective view of the electronic component used as the object of the thermocompression bonding by the thermocompression bonding apparatus of one embodiment of this invention Operation explanatory diagram showing a thermocompression bonding method of an embodiment of the present invention

  Next, embodiments of the present invention will be described with reference to the drawings. First, the structure of the thermocompression bonding apparatus 1 will be described with reference to FIG. The thermocompression bonding apparatus 1 has a function of joining a circuit component 3 as a second member to a circuit board 2 as a first member by thermocompression bonding. The electronic component 4 shown in FIG. 2 is manufactured by this thermocompression bonding. The electronic component 4 has a joint portion 3a in which a connection end portion of the circuit component 3 is overlapped with solder or a bonding material 6 containing solder on an edge portion of the circuit board 2 on which a plurality of components 5 are previously mounted by solder bonding. (See FIG. 3).

  As shown in FIG. 1, the thermocompression bonding apparatus 1 is a thermocompression bonding tool in which a substrate holding part 12 and a component holding part 15 are arranged on the upper surface of a base 11 in a first direction, and the circuit board 2 is thermocompression bonded to the circuit component 3. 8 and a thermocompression bonding head 7 provided with a camera 10 are arranged above the substrate holding part 12. Here, the first direction is a direction in which the operator inserts and removes the circuit board 2 and the circuit component 3 with respect to the board holding unit 12 and the component holding unit 15. Here, the operator side in the first direction (in FIG. 1). The right front side) is defined as the front side.

  The thermocompression bonding head 7 is driven by the head driving unit 7 a, whereby the thermocompression bonding tool 8 moves up and down with respect to the circuit component 3 made of a flexible substrate received by the backup unit 13. Then, the circuit component 3 is pressed against the circuit board 2 by the thermocompression-bonding tool 8 coming into contact with the joining portion 3 a (see FIGS. 2 and 3) set at the end of the circuit component 3. The head driving unit 7a has a built-in heating mechanism for heating the thermocompression bonding tool 8. When the circuit component 3 is thermocompression bonded to the circuit board 2, the heating mechanism is used to connect the circuit via the thermocompression bonding tool 8. The component 3 is heated, and this heat is transmitted to the bonding material 6 to perform bonding by thermocompression bonding. In addition, the structure which raises the board | substrate holding | maintenance part 12 and the component holding | maintenance part 15 instead of lowering | hanging the thermocompression-bonding head 7 may be sufficient.

  Below the thermocompression bonding tool 8, a sheet 9 wound and held by a sheet holding unit (not shown) is arranged so as to be fed in the longitudinal direction (direction perpendicular to the first direction) of the thermocompression bonding tool 8. Yes. The sheet 9 is interposed between the crimping surface of the thermocompression bonding tool 8 and the upper surface of the circuit component 3 when the circuit component 3 is crimped by the thermocompression bonding tool 8 (see FIG. 3). The fouling of the thermocompression bonding tool 8 due to adhesion is prevented.

  The substrate holding part 12 in the thermocompression bonding apparatus 1 is a stage on which the circuit board 2 is placed. The circuit board 2 has a function of receiving a connection portion to be crimped from the lower surface side and holding the position of the circuit board 2. It is what has. In the present embodiment, the substrate holding unit 12 is configured by combining a backup unit 13, a substrate support unit 14a, and a plurality of substrate guide units 14b. The backup unit 13 receives the connection end corresponding to the joint portion 3a (see FIG. 3) to be joined to the circuit component 3 on the circuit board 2 from the lower surface side, and heats the connection end for thermocompression bonding. It has a function. The component holding unit 15 has a configuration in which a component stage 18 on which the circuit component 3 is placed at a predetermined position is held by a moving base 17 that is moved by a component stage moving mechanism 16.

  A first hot air nozzle 21 and a second hot air nozzle 22 are arranged above the component stage 18 and the substrate support portion 14a, respectively. The first hot air nozzle 21 and the second hot air nozzle 22 heat the hot air generated by the hot air generator (not shown) from the air outlets 21a and 22a (see FIG. 3) provided at the tip. It has a function to spray on the target part. In the present embodiment, the first hot air nozzle 21 and the second hot air nozzle 22 are the circuit component 3 placed on the component stage 18 at the connection end of the circuit board 2 supported by the substrate support portion 14a. Are arranged in the thermocompression bonding apparatus 1 in such a disposition posture that hot air can be blown to the joint portion 3a (see FIG. 3) where the connection end portions are overlapped and the periphery thereof.

  That is, the first hot air nozzle 21, the second hot air nozzle 22, and a hot air generator (not shown) constitute a hot air supply unit provided in the thermocompression bonding apparatus 1. In this hot air supply unit, in the thermocompression bonding operation by the thermocompression bonding apparatus 1, the thermocompression bonding tool 8 of the thermocompression bonding head 7 thermocompresses the circuit component 3 as the second member to the circuit board 2 as the first member. At the same time, simultaneously with this thermocompression bonding operation, hot air is blown to the joint portion 3a between the circuit component 3 and the circuit board 2 and its peripheral portion. In the example shown in the present embodiment, the two hot air nozzles of the first hot air nozzle 21 and the second hot air nozzle 22 are arranged so as to sandwich the thermocompression bonding head 7, and the joining location 3 a is 2 It is possible to efficiently heat from the direction.

  In addition, as a warm air supply part, what is necessary is just to have at least 1 warm air nozzle which ejects warm air toward the joining location 3a and its peripheral part. Thus, by providing the warm air supply part, in addition to the heating by the contact heat transfer from the thermocompression bonding tool 8 which contact | joined the joining location 3a and its peripheral part contact | abutted to the joining location 3a, the 1st hot air nozzle 21, It is heated more uniformly by the hot air blown by the second hot air nozzle 22.

  Next, a thermocompression bonding method for joining the circuit component 3 as the second member to the circuit board 2 as the first member by thermocompression bonding with the thermocompression bonding apparatus 1 having the above-described configuration will be described with reference to FIG. . In the thermocompression bonding operation, as shown in FIG. 3 (a), the connection end of the circuit component 3 is soldered to the connection end of the circuit board 2 received by the backup unit 13, solder, cream solder, soldered resin, or the like. It overlaps with the joining material 6 containing solder, and it is set as the joining location 3a. A plurality of components 5 are mounted in advance on the circuit board 2 by solder bonding (see FIG. 2). At this time, the thermocompression bonding tool 8 is located immediately above the joint location 3 a, and the sheet 9 is interposed between the joint location 3 a and the crimping surface of the thermocompression bonding tool 8. And the 1st warm air nozzle 21 and the 2nd warm air nozzle 22 which are arrange | positioned on both sides of the thermocompression-bonding tool 8 are located in the attitude | position which orient | assigned the blower outlets 21a and 22a to the junction location 3a and its peripheral part. .

  When the thermocompression bonding is started, the thermocompression bonding tool 8 is lowered (arrow a) and the sheet 9 is interposed between the joint part 3a of the circuit component 3 as shown in FIG. Then, the joint 3a is heated while being pressed by the pressure contact surface of the thermocompression bonding tool 8. Along with this heating, the first hot air nozzle 21 and the second hot air nozzle 22 are operated, and hot air is blown to the joint portion 3a between the circuit board 2 and the circuit component 3 and its peripheral portion (arrow b). Then, the circuit component 3 is pressed against the circuit board 2 with the thermocompression bonding tool 8. Even when the heat transmitted by the hot air blowing through the heating surface of the thermocompression bonding tool 8 is dissipated through the circuit board 2 or the circuit component 3, a heating loss occurs. It becomes possible to make uniform the temperature distribution in each part of the joint part 3a by heating the whole peripheral part by spraying.

  That is, in the circuit board 2 and the circuit component 3, the distribution of the heat capacity is often uneven depending on the area of the circuit board 2 and the circuit component 3 due to the uneven distribution of the components and circuit patterns. In such a case, the amount of heat dissipated by the heat conduction from the joint portion 3a heated by the heating surface of the thermocompression bonding tool 8 varies depending on the portion of the joint portion 3a, resulting in uneven temperature distribution in the joint portion 3a. . Even in such a case, it is possible to compensate for the heat loss due to heat radiation in the peripheral area including the joint portion 3a by blowing warm air on the joint portion 3a and the peripheral portion thereof. It is possible to prevent the variation in the heating temperature caused. Therefore, it is possible to reduce bonding defects due to uneven temperature distribution in each part of the bonding part 3a.

  At this time, the temperature of the hot air blown from the first hot air nozzle 21 and the second hot air nozzle 22 is preferably set higher than the melting point of the solder used for the bonding material 6. When the temperature of the hot air is set to be higher than the melting point of the solder, it is necessary to set the temperature so as not to melt the solder joining the component 5 and the circuit board 2 located in the vicinity of the joining portion 3a. As a result, it is possible to prevent problems such as the solder of the component 5 already mounted on the circuit board 2 by solder bonding by melting with the hot air being melted and coming off from the circuit board 2.

  As described above, in the thermocompression bonding apparatus and the thermocompression bonding method shown in the present embodiment, in addition to the thermocompression bonding head 7 having the thermocompression bonding tool 8 for thermocompression bonding the circuit component 3 to the circuit board 2, the thermocompression bonding tool. When the circuit component 3 is thermocompression-bonded to the circuit board 2, a hot air supply unit that blows warm air to the joint part 3 a of the circuit component 3 and the circuit board 2 and its peripheral part is provided.

  As a result, the thermocompression bonding head is provided with a plurality of heaters and temperature sensors capable of individually controlling the temperature, and a problem in the prior art of a configuration in which a plurality of heaters are controlled based on the detection result of the temperature sensor, that is, the thermocompression bonding head While solving the problem that it is difficult to make the tool a compact structure and it is difficult to adapt it to a thermocompression bonding device for small and high-density mounting parts, while maintaining the equipment in a compact structure, It is possible to make the temperature distribution of the heating temperature at the joint portion uniform and reduce the thermocompression bonding failure.

  The thermocompression bonding apparatus and the thermocompression bonding method of the present invention have the effect that the temperature distribution of the heating temperature at the joint portion can be made uniform by reducing the thermocompression failure while maintaining the equipment in a compact structure. This is useful in the field of joining a second member such as a flexible substrate to a first member such as a substrate.

DESCRIPTION OF SYMBOLS 1 Thermocompression bonding apparatus 2 Circuit board 3 Circuit component 3a Joining location 6 Joining material 7 Thermocompression-bonding head 8 Thermocompression-bonding tool 21 1st hot air nozzle 22 2nd hot air nozzle

Claims (5)

A thermocompression bonding apparatus for joining a second member to a first member by thermocompression bonding,
A thermocompression bonding head having a thermocompression bonding tool for thermocompression bonding the second member to the first member;
When the thermocompression bonding tool is thermocompression bonding the second member to the first member, a joining portion of the second member and the first member and a hot air supply unit that blows hot air around the peripheral portion are provided. A thermocompression bonding device.   2. The thermocompression bonding apparatus according to claim 1, wherein the hot air supply unit includes at least one hot air nozzle that ejects hot air toward the joining portion and the peripheral part.   The thermocompression bonding apparatus according to claim 2, wherein at least two of the hot air nozzles are arranged so as to sandwich the thermocompression bonding head. A thermocompression bonding method in which a second member is joined to a first member by thermocompression bonding,
A thermocompression bonding method in which the second member is pressed against the first member with a thermocompression bonding tool while blowing warm air to the joining portion of the second member and the first member and its peripheral portion. The first member and the second member are joined with solder or a joining material containing solder,
The thermocompression bonding method according to claim 4, wherein a temperature of the hot air is higher than a melting point of the solder.

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