JP2014229784A - Electronic component mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably fix and mount an electronic component onto a board by forming an adhesion portion with a satisfactory height on the board.SOLUTION: The electronic component mounting method includes the steps of: forming an adhesive layer of a first adhesive containing a thermosetting resin at a position away from a land in an electronic component mounting area on a board by means of screen printing; forming a projecting adhesion portion which is integrated with the adhesive layer by applying a second adhesive containing a thermosetting resin using a dispenser on the upper face of the adhesive layer; mounting an electronic component onto the mounting area and causing a main body of the electronic component to contact with the adhesion portion; and fixing the main body to the board by curing the adhesive layer and the adhesion portion.

Description

  The present invention relates to an electronic component mounting method for soldering a component electrode to a substrate electrode and mounting the electronic component on the substrate.

  Methods for soldering electronic components to a substrate are roughly classified into a flow method and a reflow method. In the flow method, a substrate on which electronic components are mounted is brought into contact with molten solder in a solder bath. Thereby, soldering is performed by making solder adhere to a component electrode and a substrate electrode (land).

  In the flow method, the electronic component is fixed to the substrate in advance with an adhesive so that the electronic component does not fall when the substrate passes through the solder bath (see Patent Document 1). In the reflow method, in order to secure the adhesive strength between the electronic component and the substrate, the peripheral portion (for example, the corner portion) of the electronic component may be adhered to the substrate with an adhesive to reinforce the solder joint between the electrodes. (See Patent Document 2). In any of the above cases, an adhesive is applied onto the substrate through the nozzle of the dispenser to form an adhesive portion. The electronic component is mounted on the substrate so that the central portion and the peripheral portion of the lower surface of the main body portion of the electronic component are brought into contact with the bonded portion. Thereafter, the adhesive portion is cured, and the main body portion of the electronic component is fixed to the substrate by the cured product, or the solder joint portion between the electrodes is reinforced.

Japanese Patent Laid-Open No. 4-127597 JP-A-8-078431

  By the way, some electronic parts, such as leaded electronic parts and bumped electronic parts (for example, BGA type electronic parts), have a relatively large main body, and compare the distance between the upper surface of the substrate and the lower surface of the main body. Some of them are soldered to the board with a large gap. Hereinafter, such an electronic component is referred to as a large electronic component. The bonding portion for fixing the large electronic component to the substrate needs to have a sufficient height to contact the lower surface of the main body portion of the electronic component. In order to form an adhesive portion having a sufficient height on the substrate, it is considered that the discharge speed of the adhesive by the dispenser and the moving speed of the nozzle should be low. However, recently, from the viewpoint of productivity, speeding up of the adhesive application work has been demanded.

  When the adhesive is applied at a high speed, the bonded portion attached to the substrate may be dragged by the nozzle and fall down or be displaced. In such a case, it is difficult to form a sufficiently high adhesion portion. For this reason, in the flow type soldering, there is a problem that the fixing of the component by the bonding portion becomes insufficient, and the electronic component falls off during the soldering. On the other hand, in the reflow soldering, there is a problem that sufficient adhesive strength between the electronic component and the substrate cannot be secured.

  Accordingly, an object of the present invention is to provide an electronic component mounting method capable of securely fixing or mounting an electronic component on a substrate by forming an adhesive portion having a sufficient height on the substrate. Yes.

One aspect of the present invention is an electronic component mounting method in which an electronic component is mounted in an electronic component mounting region of a substrate, and a land formed in the mounting region and a component electrode formed in a main body portion of the electronic component are soldered. Because
Forming an adhesive layer of a first adhesive containing a thermosetting resin at a position not in contact with the land in the mounting region by screen printing;
Applying a second adhesive containing a thermosetting resin using a dispenser on the upper surface of the adhesive layer, thereby forming a protrusion-like adhesive portion integrated with the adhesive layer;
Mounting the electronic component in the mounting region and bringing the main body into contact with the bonding portion;
Curing the adhesive layer and the adhesive portion and fixing the body portion to the substrate;
The present invention relates to an electronic component mounting method.

Another aspect of the present invention provides a substrate including at least a first mounting region and a second mounting region, and a chip including a first main body portion and a pair of first electrodes in the first mounting region. A large-sized electronic component having a second main body portion larger than the first main body portion and a plurality of second electrodes protruding from the second main body portion is mounted in the second mounting area. An electronic component mounting method in which the first electrode and the second electrode are soldered to lands formed in each mounting region,
Forming an adhesive layer of a first adhesive containing a thermosetting resin by screen printing at a position where the first mounting area and the second mounting area do not contact the land;
By using a dispenser on the upper surface of the adhesive layer formed in the second mounting region and applying a second adhesive containing a thermosetting resin, a protrusion shape integrated with the adhesive layer. Forming an adhesive portion of
Mounting the chip-type electronic component on the first mounting region and bringing the first body portion into contact with the adhesive layer;
Mounting the large-sized electronic component on the second mounting region and bringing the second main body portion into contact with the adhesive portion;
By curing the adhesive layer and the adhesive portion, the first body portion is fixed to the substrate by a cured product of the adhesive layer in the first mounting region, and in the second mounting region, the Fixing the second body part to the substrate with a cured product of the adhesive layer and the adhesive part;
The present invention relates to an electronic component mounting method.

  According to the present invention, an electronic component can be reliably fixed or mounted on a substrate by forming an adhesive portion having a sufficient height on the substrate with an adhesive containing a thermosetting resin.

It is sectional drawing which shows the 1st step of the electronic component mounting method which concerns on one Embodiment of this invention. It is sectional drawing which shows the 2nd step of the electronic component mounting method same as the above. It is sectional drawing which shows the 3rd step of the electronic component mounting method same as the above. It is sectional drawing which shows the 4th step of the electronic component mounting method same as the above. It is sectional drawing which shows the 5th step of the electronic component mounting method same as the above. It is sectional drawing which shows the 6th step of the electronic component mounting method same as the above. It is sectional drawing which shows the 1st step of the printing process which forms an adhesive bond layer by screen printing by the electronic component mounting method same as the above. It is sectional drawing which shows the 2nd step of the printing processing same as the above. It is sectional drawing which shows the 3rd step of a printing process same as the above. It is sectional drawing which shows the 4th step of a printing process same as the above.

It is sectional drawing which shows the 1st step of the coating process which apply | coats an adhesive agent on a board | substrate with a dispenser with the electronic component mounting method which concerns on one Embodiment of this invention, and forms an adhesion part. It is sectional drawing which shows the 2nd step of the coating process same as the above. It is sectional drawing which shows the 3rd step of the application | coating process same as the above. It is a conceptual diagram which shows the detail of the process which supplies a molten solder between electrodes with a jet-type solder tank by the electronic component mounting method which concerns on one Embodiment of this invention. It is sectional drawing which shows the 1st step of the electronic component mounting method which concerns on another embodiment of this invention. It is sectional drawing which shows the 2nd step of the electronic component mounting method same as the above. It is sectional drawing which shows the 3rd step of the electronic component mounting method same as the above. It is sectional drawing which shows the 4th step of the electronic component mounting method same as the above. It is sectional drawing which shows the 5th step of the electronic component mounting method same as the above.

  In a first electronic component mounting method of the present invention, an electronic component is mounted on an electronic component mounting region of a substrate, and a land formed in the mounting region and a component electrode formed on a main body portion of the electronic component are soldered. Regarding the method. In this first method, a step of forming an adhesive layer of a first adhesive containing a thermosetting resin at a position that does not contact a land in a mounting region by screen printing, and, for example, the bonding on the upper surface of the adhesive layer A step of forming a protruding adhesive unit integrated with the adhesive layer by applying a second adhesive containing a thermosetting resin using a dispenser to a portion that does not contact the outer edge of the adhesive layer; A step of mounting the electronic component in the mounting region and bringing the main body portion into contact with the bonding portion; and a step of curing the adhesive layer and the bonding portion to fix the main body portion of the electronic component to the substrate.

  As described above, in the first method, the second adhesive is applied to a predetermined area in the electronic component mounting area by using a dispenser to form a protruding adhesive portion. At this time, the region is printed by screen printing using the first adhesive as a primer to form an adhesive layer or an adhesive film. As a result, when the second adhesive is applied onto the substrate, it is dragged by the nozzle of the dispenser, the adhesive part falls down, or the position of the adhesive part deviates from the desired position. Can be prevented. Therefore, it is possible to securely fix or mount the electronic component on the substrate by forming an adhesive portion having a sufficient height.

  Furthermore, due to the anchor effect described above, even if the movement speed of the dispenser nozzle is increased and the application speed of the second adhesive is increased, the bonded portion may fall down or the position of the bonded portion may deviate from the desired position. Can be prevented. As a result, it is possible to form an adhesive portion having a height high enough to fix the electronic component to the substrate at a high adhesive application speed. Therefore, it becomes easy to shorten the tact time of the electronic component mounting line. As a result, it becomes easy to increase the productivity of electronic devices.

  Here, the thickness of the adhesive layer is preferably 30 to 120 μm. On the other hand, the height of the adhesion part when measured from the surface of the substrate, that is, the total thickness of the adhesive layer and the height of the adhesion part is calculated from the surface of the substrate when the electrode of the electronic component is landed on the land. It is set to be larger than the distance to the lower surface of the main body of the component. By printing the first adhesive as a primer on the substrate so as to form a relatively thin adhesive layer having a thickness within the above range, a greater anchor effect can be exhibited, and the collapse or position of the adhesive portion Deviation can be prevented more effectively.

  The present invention can be suitably applied when at least the surface of the substrate on which the adhesive layer is formed is formed of a solder resist. When the surface of the substrate is formed of a solder resist, the second adhesive is easily repelled by the solder resist. As a result, particularly when the application rate of the second adhesive is high, the bonded portion tends to fall or shift from the desired position. According to this invention, even if it is the part covered with the soldering resist on the board | substrate surface, a 2nd adhesive agent can be apply | coated to the part and a protrusion-like adhesion part can be formed rapidly. Thereby, the freedom degree of design can be enlarged. Therefore, it becomes easy to mount the electronic component on the board with a higher mounting density.

  Here, it is preferable that the 1st adhesive agent for forming an adhesive bond layer and the 2nd adhesive agent for forming a protrusion-shaped adhesion part have the same composition. By using an adhesive having the same composition as the first adhesive and the second adhesive, the adhesive portion and the adhesive layer are easily compatible, and a stable anchor effect can be expected. As a result, the anchor effect described above can be obtained more stably. Thereby, the fall and position shift of an adhesion part can be prevented more effectively. Furthermore, by using the same adhesive, it becomes easy to manage manufacturing raw materials and reduce the manufacturing cost of electronic components.

  In the second electronic component mounting method of the present invention, a substrate including at least a first mounting area and a second mounting area is prepared, and a first main body portion and a pair of first electrodes are provided in the first mounting area. A chip-type electronic component provided is mounted, and a large electronic component including a second main body portion larger than the first main body portion and a plurality of second electrodes protruding from the second main body portion is mounted in the second mounting area. The present invention also relates to an electronic component mounting method in which a first electrode and a second electrode are soldered to lands formed in each mounting region. Here, an electronic component having three or more second electrodes can be used as the large electronic component.

  The second method includes a step of forming an adhesive layer of the first adhesive by screen printing at a position that does not contact the lands of the first mounting area and the second mounting area, and the adhesive formed in the second mounting area. The process of forming the protrusion-like adhesion part united with the adhesive layer by applying the second adhesive to the upper surface of the layer, for example, in a region that does not contact the outer edge of the adhesive layer using a dispenser Mounting the chip-type electronic component in the first mounting area and bringing the first main body into contact with the adhesive layer; mounting the large electronic component in the second mounting area; The first body portion is fixed to the substrate with a cured product of the adhesive layer in the first mounting region by curing the adhesive layer and the adhesive portion, and the adhesive in the second mounting region. The second body part is fixed to the substrate by the cured product of the layer and the adhesive part. Including that a step.

  According to the second method, for large electronic components, as described above, the electronic components can be reliably mounted on the substrate by forming an adhesive portion having a sufficient height. Furthermore, for the chip-type electronic component, an adhesive layer for fixing the chip-type electronic component to the substrate can be formed on the substrate without increasing the number of man-hours. This is because when the adhesive layer is formed under the bonding portion for fixing the large electronic component to the substrate, the adhesive layer for fixing the chip-type electronic component to the substrate can be simultaneously formed by screen printing. Therefore, even on a large-scale substrate on which a large number of chip-type electronic components and large electronic components are mounted, the electronic components can be quickly mounted on the substrate without increasing the number of steps.

  Also in the 2nd method, the anchor effect by an adhesive bond layer can be exhibited more favorably by the thickness of an adhesive bond layer being 30-120 micrometers. As a result, a sufficiently high adhesive portion can be formed more stably. At this time, the height from the base material surface of the adhesive portion formed on the upper surface of the adhesive layer is from the surface of the substrate when the electrode of the electronic component is landed on the land of the substrate to the lower surface of the main body portion of the electronic component. Will be larger than the distance to.

  The second method can also be suitably applied when at least the surface of the substrate on which the adhesive layer is formed is formed of a solder resist. As a result, the above-described adverse effects in the case where the protruding adhesive portion is rapidly formed can be prevented by covering the part of the solder resist to which the second adhesive is applied with the adhesive layer. Therefore, the degree of freedom in design increases, and further high-density mounting becomes easy.

  Furthermore, also in the second method, it is preferable that the first adhesive for forming the adhesive layer and the second adhesive for forming the protruding adhesive portion have the same composition. By using the same adhesive for the first adhesive and the second adhesive, it is possible to form a sufficiently high adhesive portion more stably.

Hereinafter, an electronic component mounting method according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
1A to 1F show a procedure for mounting an electronic component on a substrate by an electronic component mounting method according to an embodiment of the present invention. In the electronic component mounting method of the present embodiment, a substrate 10 including at least a first mounting area AR1 and a second mounting area AR2 is prepared (FIG. 1A). A chip-type electronic component 34 including a first main body 34a and a pair of first electrodes 34b is mounted in the first mounting area. In the second mounting area, a large electronic component 36, which is a leaded electronic component, includes a second main body 36a larger than the first main body and a plurality of second electrodes 36b protruding from the second main body. Installed. Then, the first electrode and the second electrode are soldered to the lands 12A and 12B formed in the respective mounting regions.

  The lands 12 </ b> A and 12 </ b> B are formed on the component mounting surface (upper surface in the drawing) of the base material 14 of the substrate 10. The component mounting surface of the base material 14 is covered with the solder resist 16 except for the portion where the land is formed. In addition, as the base material 14, not only a flexible base material such as a resin sheet or a resin film but also a rigid base material such as a resin plate or a glass plate can be used.

  Leaded electronic components are SOP (Small Outline Package or Small Outline L-Leaded Package), QFP (Quad Flat Package or Quad Flat L-Leaded Package), and SSOP (Shrink Small Outline Package or Shrink Small Outline L -Leaded Package). The lead of the electronic component with leads includes a horizontal portion that extends from the side portion of the electronic component main body and extends laterally, and a foot portion that extends in the thickness direction of the package main body so as to be bent from an end portion of the horizontal portion. The tip of each lead functions as a component electrode.

  In this method, the adhesive layer 18 of the first adhesive is formed by screen printing at a position that does not contact the lands 12A and 12B of the first mounting area AR1 and the second mounting area AR2 (FIG. 1B). By applying the second adhesive to the upper surface of the adhesive layer 18 (18B) formed in the second mounting region using a dispenser, a protruding adhesive portion 28 integrated with the adhesive layer 18B is formed. (FIG. 1C). The chip-type electronic component 34 is mounted in the first mounting area, the first main body 34a is brought into contact with the adhesive layer 18A, and the large electronic component 36 is mounted in the second mounting area, so that the second main body 36a. Is brought into contact with the adhesive portion 28 (FIG. 1D). By curing the adhesive layer and the adhesive portion, the first main body portion 34a is fixed to the substrate by the cured product 38A of the adhesive layer 18A in the first mounting region, and the adhesive layer 18B and the adhesive layer 18B in the second mounting region. The 2nd main-body part 36a is fixed to a board | substrate with the hardened | cured material 38B of the adhesion part 28 (FIG. 1E).

  Hereinafter, the electronic component mounting method of the present embodiment will be described more specifically. First, a substrate 10 having at least a first mounting area AR1 and a second mounting area AR2 is prepared (FIG. 1A). Next, the adhesive layer 18 of the first adhesive is formed by screen printing in the first mounting area AR1 and the second mounting area AR2 (FIG. 1B).

  2A to 2D show an example of a printing process procedure for forming the adhesive layer of the first adhesive by screen printing. First, the substrate 10 is placed on a printing apparatus (not shown) with the component mounting surface facing upward. And the mask 20 is arrange | positioned above it (refer FIG. 2A). The mask 20 has an opening 22 corresponding to each of the adhesive layers 18 shown in FIG. 1B.

  Next, alignment is performed so that each of the openings 22 is positioned at a portion where the adhesive layer 18 is to be formed, and the lower surface of the mask 20 is brought into contact with the upper surface of the substrate 10 (see FIG. 2B). Next, the first adhesive 24 on the mask 20 is moved by the squeegee 26 so as to pass over each opening 22. In this way, each adhesive layer 18 is formed (see FIG. 2C).

  Next, the mask 20 is separated from the component mounting surface of the substrate 10 (see FIG. 2D), and the printing process is terminated. As described above, the adhesive layer 18 of the first adhesive is formed by screen printing at a position not in contact with the lands of the first mounting area AR1 and the second mounting area AR2.

  Here, the thickness T1 of the adhesive layer 18 is preferably 30 to 120 μm. By forming a relatively thin adhesive layer having a thickness within the above range by screen printing, when the second adhesive is applied to the upper surface later to form an adhesive portion, the anchor effect can be stabilized. It can be demonstrated. Thereby, the fall and position shift of an adhesion part can be prevented more certainly.

  When the above printing process is completed, as shown in FIG. 1C, the second adhesive is applied to the upper surface of the adhesive layer 18 (18B) formed in the second mounting area AR2 using a dispenser. A protruding adhesive portion 28 integrated with the adhesive layer 18B is formed. Such an adhesive portion is not formed on the upper surface of the adhesive layer 18 (18A) formed in the first mounting area AR1. An adhesive having the same composition as the first adhesive can be used for the second adhesive. Alternatively, an adhesive having a composition different from that of the first adhesive can be used for the second adhesive.

  FIGS. 3A to 3C show an example of a procedure of an application process in which a second adhesive is applied onto a substrate by a dispenser to form an adhesive portion. First, the substrate 10 on which the adhesive layer 18 is formed is placed in a coating apparatus (not shown). Next, for example, a mark on the substrate is recognized from an image captured by the substrate recognition camera. Based on the recognition result, the nozzle 30 of the dispenser is aligned, and as shown in FIG. 3A, the nozzle 30 is moved from the initial position (indicated by a two-dot chain line in the drawing) to the application position. At this time, for example, alignment is performed so that the center of the nozzle 30 coincides with the center 32 of the adhesive layer 18B.

  Next, as shown in FIG. 3B, a predetermined amount of the second adhesive is discharged through the nozzle 30 to form a protruding adhesive portion 28 on the upper surface of the adhesive layer 18B. At this time, the height L1 of the bonding portion 28 from the surface of the substrate is a distance L2 from the surface of the substrate to the lower surface of the second main body portion 36a when the second electrode 36b is landed on the land 12B (see FIG. 1D). (L1> L2). Next, as shown in FIG. 3C, the nozzle 30 is moved from the application position (indicated by a two-dot chain line in the drawing) to the retracted position. Thereby, the coating process ends.

  When the above coating process is completed, as shown in FIG. 1D, the chip-type electronic component 34 is mounted on the first mounting area AR1 on the substrate by the electronic component mounting apparatus, and the large electronic component 36 that is the leaded electronic component is mounted. Mount in the second mounting area. At this time, the position of the lands 12A, 12B or the reference mark (not shown) is recognized from the image captured by the board recognition camera of the electronic component mounting apparatus, and the chip-type electronic component 34 held by the mounting head of the electronic component mounting apparatus. And the attitude | position of the large sized electronic component 36 is each recognized by the captured image of the component recognition camera of an electronic component mounting apparatus.

  The electronic component mounting apparatus mounts the chip-type electronic component 34 on the first mounting area AR1 on the substrate based on the recognition result. At this time, each of the pair of first electrodes 34b provided on the side portion of the first main body 34a of the chip-type electronic component 34 is landed or opposed to the land 12A. Thereby, the first main body 34a of the chip-type electronic component 34 is brought into contact with the adhesive layer 18A.

  Further, based on the recognition result, the large electronic component 36 is mounted on the second mounting area AR2 on the substrate. At this time, each of a plurality (for example, three or more) of the second electrodes 36b protruding from the side of the second main body portion 36a of the large electronic component 36 is landed on the land 12B. As a result, the second main body portion 36 a of the large electronic component 36 is brought into contact with the bonding portion 28.

  Next, the substrate 10 on which the chip-type electronic component 34 and the large electronic component 36 are mounted is heated by, for example, a heating furnace, so that the adhesive layer and the adhesive portion are cured. Thereby, as shown in FIG. 1E, in the first mounting region, the first main body 34a is fixed to the substrate 10 by the cured product 38A of the adhesive layer 18A. In the second mounting region, the second main body portion 36a is fixed to the substrate 10 by the adhesive layer 18B and the cured product 38B of the adhesive portion 28. At this time, in the heating furnace, for example, the substrate 10 is heated to a temperature higher than the glass transition point of the cured product of the thermosetting resin contained in the first adhesive and the second adhesive.

  Next, the chip-type electronic component 34 and the large electronic component 36 are soldered to the substrate 10 by, for example, a flow method. FIG. 4 shows a procedure for soldering a chip-type electronic component and a large electronic component to a substrate by a flow method. In the illustrated example, a rising portion 42A is formed by a molten solder jet 40 from below on a molten solder liquid surface 42 placed in a jet solder bath (not shown).

  The chip-type electronic component 34 and the large electronic component 36 are mounted, and the substrate 10 on which the chip-type electronic component 34 and the large-sized electronic component 36 are fixed with an adhesive is moved so that the surface on which the electronic component is mounted faces downward and touches the raised portion 42A. Thereby, molten solder adheres between the first electrode 34b and the land 12A and between the second electrode 36b and the land 12B. Thereafter, by melting the molten solder, as shown in FIG. 1F, the first electrode 34b is bonded to the land 12A by the solder bonding portion 44A in which the molten solder is solidified, and the solder bonding portion 44B containing a solidified product of the molten solder is used. Thus, the second electrode 36b is joined to the land 12B.

  As described above, in the present embodiment, the adhesive layer 18 is formed first, and then the protruding adhesive portion 28 is formed on the upper surface thereof. Thereby, it becomes easy to form a bonding portion for fixing the large electronic component 36, which is a relatively large electronic component, to the substrate 10 to a sufficient height. Therefore, the electronic component can be securely fixed to the substrate. Moreover, it becomes easy to increase the productivity of the electronic device by increasing the application speed of the adhesive.

  Further, the adhesive layer is simultaneously formed on both the first mounting area and the second mounting area by screen printing. Thereby, an adhesive layer for adhering the chip-type electronic component to the substrate and an adhesive layer as a primer for an adhesive portion for adhering the large electronic component to the substrate can be formed simultaneously. Therefore, when the large electronic component and the chip electronic component are mounted on one substrate, the large electronic component and the chip electronic component can be securely fixed to the substrate without particularly increasing the number of steps.

  The first adhesive and the second adhesive can be prepared by mixing a thermosetting resin with a curing agent, a thixotropic agent, a pigment, a coupling agent, and the like. The thermosetting resin contained in the adhesive is not particularly limited, but various resins such as epoxy resin, urethane resin, acrylic resin, polyimide resin, polyamide resin, bismaleimide, phenol resin, polyester resin, silicone resin, oxetane resin, etc. Can be included. These may be used alone or in combination of two or more. Among these, an epoxy resin and an acrylic resin are particularly preferable from the viewpoint of excellent heat resistance.

  As the epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin and the like are suitable. Used. Epoxy resins obtained by modifying these are also used. These may be used alone or in combination of two or more.

  As the curing agent used in combination with the thermosetting resin as described above, for example, a thiol compound, a modified amine compound, a polyfunctional phenol compound, an imidazole compound, an acid anhydride compound, or the like can be used. These may be used alone or in combination of two or more.

Next, another embodiment of the present invention will be described with reference to the drawings.
(Embodiment 2)
5A to 5E show a procedure for mounting an electronic component on a substrate by an electronic component mounting method according to another embodiment of the present invention. In the electronic component mounting method of the present embodiment, the electronic component 46 is mounted on the electronic component mounting area AR3 of the board 10A, and the land 12C formed in the mounting area AR3 and the lower surface of the third main body portion 46a of the electronic component 46 are projected. The present invention relates to an electronic component mounting method for soldering a plurality of third electrodes 46b. The illustrated electronic component 46 is a BGA type electronic component, and a plurality of third electrodes 46b including solder bumps are formed on the lower surface of the third main body 46a.

  In the figure, only four lands 12C are shown. Actually, it is possible to form five or more lands 12C in the third mounting area AR3 or to form a land 12C having a number smaller than four. The land 12C is formed on the component mounting surface of the base material 14 of the substrate 10A. The component mounting surface of the base material 14 is covered with the solder resist 16 except for the portion where the land is formed. As in the first embodiment, a flexible or rigid material can be used for the base material 14 of the substrate 10A.

  This method includes a step (FIG. 5B) of forming an adhesive layer 18 of a first adhesive by screen printing at a position not in contact with the land 12C of the mounting area AR3 of the substrate 10A (FIG. 5A), By applying a second adhesive on the upper surface using a dispenser, a step (FIG. 5C) of forming a protrusion-like adhesive portion 28 integrated with the adhesive layer 18, and an electronic component 46 in the mounting area A step of mounting and bringing the third main body portion 46a into contact with the bonding portion 28 (FIG. 5D), and a step of curing the adhesive layer 18 and the bonding portion 28 to fix the third main body portion 46a to the substrate 10A (FIG. 5E). And including.

  Hereinafter, the electronic component mounting method of the present embodiment will be described more specifically. First, the substrate 10 having the third mounting area AR3 is prepared (FIG. 5A), and a plurality of adhesive layers 18 of the first adhesive are formed on the third mounting area AR3 by screen printing (FIG. 5B). At this time, the adhesive layer 18 can be formed by screen printing in the same procedure as shown in FIGS.

  When the printing process is finished, as shown in FIG. 5C, the second adhesive is applied to the upper surface of the adhesive layer 18 formed in the third mounting area AR3 using a dispenser. As a result, a protruding adhesive portion 28 integrated with the adhesive layer 18 is formed. An adhesive having the same composition as the first adhesive can be used for the second adhesive. Alternatively, an adhesive having a composition different from that of the first adhesive can be used for the second adhesive. At this time, the adhesive part 28 can be formed by applying the second adhesive by the same procedure as shown in FIGS.

  When the above coating process is completed, as shown in FIG. 5D, the electronic component 46, which is a BGA type electronic component, is mounted on the third mounting region by the electronic component mounting apparatus. At this time, the position of the land 12C or the reference mark (not shown) is recognized from the captured image of the board recognition camera of the electronic component mounting apparatus, and the posture of the electronic component 46 held by the mounting head of the electronic component mounting apparatus is electronically changed. It recognizes with the picked-up image of the component recognition camera of a component mounting apparatus. Based on the recognition result, the electronic component mounting apparatus mounts the electronic component 46 in the third mounting area AR3 on the substrate. At this time, each of the third electrodes 46b including a plurality of solder bumps protruding from the lower surface of the third main body 46a of the electronic component 46 is landed on the land 12C. As a result, the third main body 46 a of the electronic component 46 is brought into contact with the bonding portion 28. Note that a flux (not shown) is preferably applied to the third electrode 46b in advance.

  Next, the adhesive layer and the bonded portion are cured by heating the substrate 10A with, for example, a heating furnace. As a result, as shown in FIG. 5E, in the third mounting region, the third main body portion 46a is fixed to the substrate 10A by the adhesive layer and the cured product 38 of the adhesive portion. Also, the solder bumps included in the third electrode 46b are melted by heating the substrate in a heating furnace. Thereafter, by cooling the melt, the third electrode 46b and the land 12C are joined by the solder joint portion 48 including the solidified product of the melt. The heating temperature in the heating furnace at this time is, for example, a temperature higher than the glass transition point of the cured product of the thermosetting resin and higher than the melting point of the solder bump of the third electrode 46b.

  As described above, in this embodiment, the electronic component 46, which is a BGA type electronic component, is soldered to the substrate 10A by the reflow method. At this time, the adhesive portion 18 for reinforcing the solder joint portion is not formed directly on the surface of the substrate 10A but on the upper surface of the adhesive layer 18. As a result, when the second adhesive is applied onto the substrate using a dispenser to form an adhesive part, the adhesive part falls down or the adhesive part deviates from a desired position by being dragged by the nozzle of the dispenser. Can be prevented. Therefore, the electronic component can be reliably mounted on the substrate by forming the adhesive portion having a sufficient height.

  Furthermore, even if the application rate of the second adhesive is increased, the above-described adverse effects can be easily prevented, so that the tact time of the electronic component mounting line can be easily shortened. As a result, it becomes easy to increase the productivity of electronic devices.

  According to the present invention, the electronic component can be more quickly fixed to the substrate with the adhesive, and the electronic component can be mounted on the substrate by, for example, the flow method. In addition, the solder joint can be reinforced more quickly with an adhesive, and the electronic component can be mounted on the substrate by, for example, a reflow method. Therefore, the present invention is particularly useful for high-density mounting for portable electronic devices and for mounting a large number of electronic components on a large-scale board.

  DESCRIPTION OF SYMBOLS 10,10A ... Board | substrate, 12A, 12B, 12C ... Land, 14 ... Base material, 16 ... Solder resist, 18, 18A, 18B ... Adhesive layer, 20 ... Mask, 22 ... Opening, 24 ... 1st adhesive agent, 26 ... Squeegee, 28 ... Adhesion part, 30 ... Nozzle, 34 ... Chip type electronic component, 34a ... First main body part, 34b ... First electrode, 36 ... Large electronic component, 36a ... Second main body part, 36b ... Second electrode , 38, 38A, 38B ... cured product, 40 ... jet, 42 ... liquid level, 44A, 44B, 48 ... solder joint, 46 ... electronic component (BGA type electronic component), 46a ... third main body, 46b ... first 3 electrodes, AR1 ... first mounting area, AR2 ... second mounting area, AR3 ... third mounting area

Claims (8)

An electronic component mounting method for mounting an electronic component on an electronic component mounting region of a substrate and soldering a land formed in the mounting region and a component electrode formed in a main body of the electronic component,
Forming an adhesive layer of a first adhesive containing a thermosetting resin at a position not in contact with the land in the mounting region by screen printing;
Applying a second adhesive containing a thermosetting resin using a dispenser on the upper surface of the adhesive layer, thereby forming a protrusion-like adhesive portion integrated with the adhesive layer;
Mounting the electronic component in the mounting region and bringing the main body into contact with the bonding portion;
Curing the adhesive layer and the adhesive portion and fixing the body portion to the substrate;
An electronic component mounting method including:   The thickness of the adhesive layer is 30 to 120 μm, and the height of the adhesive portion from the surface of the substrate is from the surface of the substrate when the component electrode is landed on the land of the substrate. The electronic component mounting method according to claim 1, wherein the electronic component mounting method is larger than a distance to a lower surface of the portion.   The electronic component mounting method according to claim 1, wherein at least a surface of the substrate on which the adhesive layer is formed is formed of a solder resist.   The electronic component mounting method according to claim 1, wherein the first adhesive and the second adhesive have the same composition. Preparing a substrate having at least a first mounting area and a second mounting area, mounting a chip-type electronic component including a first main body and a pair of first electrodes on the first mounting area; A large electronic component including a second main body portion larger than the first main body portion and a plurality of second electrodes protruding from the second main body portion is mounted in the second mounting region, and formed in each mounting region. An electronic component mounting method for soldering the first electrode and the second electrode to the land formed,
Forming an adhesive layer of a first adhesive containing a thermosetting resin by screen printing at a position where the first mounting area and the second mounting area do not contact the land;
By using a dispenser on the upper surface of the adhesive layer formed in the second mounting region and applying a second adhesive containing a thermosetting resin, a protrusion shape integrated with the adhesive layer. Forming an adhesive portion of
Mounting the chip-type electronic component on the first mounting region and bringing the first body portion into contact with the adhesive layer;
Mounting the large-sized electronic component on the second mounting region and bringing the second main body portion into contact with the adhesive portion;
By curing the adhesive layer and the adhesive portion, the first body portion is fixed to the substrate by a cured product of the adhesive layer in the first mounting region, and in the second mounting region, the Fixing the second body part to the substrate with a cured product of the adhesive layer and the adhesive part;
An electronic component mounting method including:   The thickness of the adhesive layer is 30 to 120 μm, and the height of the adhesive portion from the surface of the substrate is from the surface of the substrate when the second electrode is landed on the land of the substrate. The electronic component mounting method according to claim 5, wherein the electronic component mounting method is larger than a distance to the lower surface of the second main body portion.   The electronic component mounting method according to claim 5 or 6, wherein at least a surface of the substrate on which the adhesive layer is formed is formed of a solder resist.   The electronic component mounting method according to claim 5, wherein the first adhesive and the second adhesive have the same composition.