JP2668330B2 - Resin substrate bump bonding method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to heat a plurality of resin substrates, each having a bump bonding portion and a circuit pattern provided in a wiring circuit portion of a resin substrate, on top of each other while pressing the bumps at a predetermined temperature. TECHNICAL FIELD The present invention relates to a resin substrate bump bonding method and device for electrically bonding resin substrates to each other by cooling after melting, and particularly, setting and removal operations are easy when mounting the resin substrate to the resin substrate bonding device. Of course, the present invention relates to a resin substrate bump bonding method and device capable of performing heating required for bump bonding and subsequent cooling in a short time.

[0002]

2. Description of the Related Art Conventionally, as a method of electrically bonding a plurality of resin substrates each having a circuit pattern to each other, bumps, that is, constant melting, are applied to portions of a plurality of resin substrates which are to be joined to each other. After sandwiching solder formed in a granular form of tin-silver eutectic solder material or the like having points and applying a pressing force thereto, the entire resin substrate is heated to a predetermined melting temperature of this bump, and the bump is melted. A resin substrate bump bonding method is widely used in which the resin substrate bumps are electrically bonded to each other by cooling the entire structure.

A conventionally used resin substrate bump bonding method and apparatus therefor will be described below with reference to FIGS. 7 to 9.

FIG. 7 is a perspective view of a conventional resin substrate bump bonding jig device, FIG. 8 is a schematic sectional view showing a state where a plurality of bumps are set on a plurality of resin substrates, and FIG. It is a schematic perspective view which shows the state which mounted the whole board | substrate bump bonding jig apparatus.

[0005] As shown in FIG. 7, a conventional resin substrate bump bonding jig apparatus is configured as follows.

Two support rods 35 are planted substantially vertically at both ends of a base 36 having a flat surface on which a resin substrate is placed, and a screw 35a is provided at the tip of the support rod 35.
Are provided respectively. The pressing plate 30 is provided with two through-holes for inserting only the screw 35a portion (small-diameter portion) of the support rod 35, and the pressure adjusting screw 31 is screwed into each penetrating screw 35a.

A plurality of resin substrates 32 sandwiched between a pair of jig plates 33a and 33b are mounted on the flat surface of a base 36. Upper jig plate 33a and holding plate 30
And the three coil springs 34 held by the spring holding portions 37 fixed to the holding plate 30 are arranged at substantially equal intervals, and the resin substrate 32 is substantially evenly distributed by the elastic force of the three coil springs 34. It is configured to be able to be pressed.

[0008] A bonding method using the resin substrate bump bonding jig apparatus described above will be described.

As shown in FIG. 8, in order to bump-bond a plurality of resin substrates 32 in which electronic components such as a chip resistor 39, a chip capacitor 42, a bare chip 43, and a printed resistor 44, respectively, are mounted to each other by bump bonding, If necessary, a plurality of granular bumps 38 are arranged on the surface of each circuit pattern portion to be joined, and the bumps 3 are formed on each resin substrate 32.
8 is sandwiched, and the resin substrate 32 is sandwiched by the pair of jig plates 33a and 33b as described above.

Next, two pressure adjusting screws 31 shown in FIG.
Are uniformly rotated in the pressing direction, thereby lowering the holding plate 30 toward the base 36, whereby the elastic force of the three coil springs 34 reduces the jig plates 33a and 3d.
The resin substrate 32 is pressed and fixed via 3b.

At this time, in order to uniformly bond the entire plurality of resin substrates by melting the bumps, it is important that the plurality of coil springs 34 uniformly and evenly press the resin substrate 32 via the pair of jig plates. Therefore, if the elastic force of each coil spring 34 is uniform, the holding plate 3
It is necessary to perform a delicate adjustment operation of adjusting the pressure adjusting screw 31 so that 0 falls while maintaining a well-balanced horizontal state.

As described above, as shown in FIG. 9, the plurality of resin substrates 32 set in the bonding jig device are heated in a heating furnace 40 filled with nitrogen gas to prevent bump oxidation.
After that, the bump is heated until it reaches a predetermined melting temperature of the bump.

After the melting temperature is maintained for a predetermined time and the bumps are sufficiently melted, heating is stopped, and after a predetermined time has elapsed, the entire resin substrate bump bonding jig is placed in a heating furnace 40.
And is forcibly air-cooled using natural cooling or a fan as it is.

Thereafter, by loosening each pressure adjusting screw 31, the resin substrate can be removed from the jig plates 33a and 33b, and the electrical interconnection of the plurality of resin substrates is achieved.

The time required for the resin substrate bonding work process described above is about 50 minutes for the process from placing the resin substrate bump bonding jig device on the heating furnace 40 to heating and melting the bumps. It took about 25 minutes to remove the resin substrate bump bonding jig from the heating furnace 40, cool it, and join the bumps.

Therefore, it takes a long time of about 75 minutes to bond the bumps on the resin substrate.

[0017]

However, in the above-mentioned conventional resin substrate bump bonding apparatus, in order to apply uniform pressing force to the jig plate by utilizing the elastic force of the plurality of coil springs, Not only does it require skill such as the need to rotate the pressure adjusting screws individually to make subtle fine adjustment operations, but the resin substrate bump bonding jig is heated in the heating furnace. There has been a problem that the heat capacity of the object to be heated is large, so that not only a long time is required for heating but also a long time is required for cooling.

The present invention has been made in view of the above problems of the prior art.
Setting and removing operations of the resin substrate are easy, and by making the heat capacity of the object to be heated including the resin substrate small, not only the heating required for bump bonding but also cooling can be performed in a short time. It is an object of the present invention to provide a resin substrate bump bonding method and apparatus.

[0019]

In order to solve these drawbacks, the present invention is directed to a resin substrate bump bonding apparatus in which upper and lower planes of a plurality of resin substrates are sandwiched to heat and heat the resin substrates. A bonding unit composed of a pair of heating / cooling units for cooling, and a driving unit for moving one of the heating / cooling units up and down, and heating the heating / cooling unit A heating unit for cooling, a cooling unit for circulating cooling water in a cooling pipe for cooling the heating / cooling unit with water, and a nitrogen gas pipe for placing the bonding unit in a nitrogen gas atmosphere. The present invention is characterized by a configuration including a nitrogen gas injection unit for injecting and a control unit for controlling the operation of the entire apparatus.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a schematic configuration diagram of a resin substrate bump bonding apparatus according to the present invention, FIG. 2 is a front view schematically showing a bonding section in the embodiment, and FIG. 3 is a bonding section shown in FIG. FIG. 4 is a plan view of the bonding unit shown in FIG. 2, FIG. 5 is a schematic perspective view showing a heating / cooling unit, and FIG.
It is a flow chart which shows operation of the resin substrate bump bonding device by the present invention.

In the embodiment of FIGS. 1 to 6, FIG.
9 to 9, the same or equivalent members as those shown in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the resin substrate bump bonding apparatus of the present invention uses a pair of heating / cooling units and one of the heating / cooling units to move up and down in order to bond the resin substrates. And a control unit 51 for controlling the operation of the entire apparatus, and a driving unit 52 for moving the heating / cooling unit 15a in the vertical direction. , For cooling the pair of heating / cooling units 15a and 15b with water, the cooling pipes 10a, 10b, 1
Cooling unit 53 for circulating cooling water to 0c and 10d
And a nitrogen gas injecting section 54 for injecting nitrogen gas into the inside of the bonding section 50 via the nitrogen gas pipe 20.

As shown in FIGS. 2 and 3, the detailed structure of the bonding portion 50 moves up and down by the operation of the base 1 for fixing the bonding portion 50 to a predetermined place and the driving portion 52. Fixed to the tip of the movable shaft 19 and fixed to the tip of the column-shaped support rod 12 that is planted at four corners of the base 1 perpendicularly to the plane. It is composed of a support plate 14, a heating / cooling unit 15b mounted / fixed to the support plate 14, and a heating / cooling unit 15a mounted / fixed to the lift 2.

A movable shaft 19 is provided at the center of the plane of the base 1.
Further, through holes 27a, 27b, and 27c for inserting the cooling pipes 10a and 10b are provided. Lifting table 2
Since each insertion hole is provided at a position corresponding to each support rod 12, the lifting platform 2 is supported by each support rod 12 and can move up and down while maintaining a horizontal state.

Further, through holes 27a and 29b for passing the cooling pipes 10a and 10b at positions corresponding to the through holes 27b and 27c for inserting the cooling pipe provided on the base 1 on the elevating table 2. After the movable shaft 19 is inserted into the through hole 27a of the base 1, the tip end of the movable shaft 19 is fixed to the lift table 2 so that the lift table 2 is integrated in response to the vertical movement of the movable shaft 19. To move up and down.

On the upper surface 21 of the lift 2, a heating / cooling unit 15 a is provided with a pressing surface 23 via a flat heat insulating plate 6.
It is mounted and fixed with a facing up. This heat insulating plate 6 is heated and
The purpose is to prevent heat held by the cooling unit 15a from being directly transmitted to the elevating table 2, and to maintain the heating or cooling effect of the heating / cooling unit 15a.

Further, the four through holes 9a, 9b, 9c and 9d provided in the support plate 14 are respectively inserted with the threaded portions 11 provided at the tips of the four support rods 12, respectively. A fixing screw 13 is attached to each of the screw portions 11.

With the above configuration, the lifting platform 2 is provided with the support bars 1
2 is used as a guide to smoothly move up and down in accordance with the vertical movement of the movable shaft 19 while maintaining a horizontal state.

On the lower surface 22 of the support plate 14, the same heat insulating plate 6 as described above is interposed, and the heating / cooling unit 15b is
It is attached and fixed with 3b facing downward.

Next, a detailed configuration of the heating / cooling unit 15a will be described.

As shown in FIG. 5, this heating / cooling unit 15
a is formed of a substantially rectangular block made of a metal having a high thermal conductivity, for example, aluminum and having a constant thickness, and in order to efficiently transfer heat, the entire surface of the jig plate 33b (see FIG. 8) is pressed against the pressing surface 23a. However, the flatness of the pressing surface 23a is formed within about 0.05 mm so as to make close contact.

Further, a plurality of through holes (eight in FIG. 5) having a diameter slightly larger than the outer diameter of the heater 4 are arranged at equal intervals in parallel with the pressing surface 23a at the upper portion of the side surface 25 of the heating / cooling portion 15a. Four heaters 4 are inserted into each of the through holes from the side surface 25 side, and four heaters are inserted into the through hole not inserted yet from the side surface facing the side surface 25. Each is fixed to the side face by a fixing screw 5.

The reason why the heaters 4 are inserted alternately from each side to assemble them is to prevent the lead wires 16 of the heaters 4 from being concentrated on one side and to facilitate the operation of mounting and removing the heaters 4. is there.

As shown in FIG. 2, each of the lead wires 16 of the heater 4 is connected to a lead wire terminal box 17 attached to one side surface of the lifting table 2 and the support plate 14, and further connected to the control section 51. (See FIG. 1).

As shown in FIG. 5, the pressing surface 2 is located on the side surface 24 of the heating / cooling portion 15a and below the heater 4.
A plurality (three in FIG. 5) of cooling water passages 28a parallel to 3a
Is provided so that each end is sealed.

Further, cooling water passages 28b (two in FIG. 5) are also provided at both ends in the longitudinal direction of the side surface 25 so as to be parallel to the pressing surface 23a and orthogonal to the cooling water passage 28a. Seal tightly.

Accordingly, the cooling water passages 28a and 28b are formed on the same plane, and the cooling water passages 28a and 28b are connected at the intersection. Holes for mounting the cooling pipes 10a and 10b are provided substantially perpendicular to the mounting surface 26 so as to be orthogonal to and connected to the respective cooling water channels 28b, and the ends of the cooling pipes 10a and 10b are fixed to the respective holes.

The structure of the heating / cooling unit 15a described above is
The heating / cooling unit 15b has the same configuration.

Therefore, as shown in FIG.
The ends of 0c and 10d are through holes 9c provided in the support plate 14.
And 9d.

With the configuration described above, the cooling water entering from the two cooling pipes 10a and 10c passes through the water passages 28b and 28a, respectively, and passes through the heating / cooling units 15a and 15a.
After cooling b, it is discharged from the two cooling pipes 10b and 10d.

The circulation of the cooling water is caused by the operation of the cooling unit 53.

Inside the center of the support plate 14, as shown in FIG. 4, a temperature sensor 18 composed of a thermocouple is provided with a heating / cooling section 15.
The output is connected to the control unit 51 via the lead terminal box 17.

Similarly, a similar temperature sensor 18 is embedded in the heating / cooling section 15a in the center of the lifting table 2.
The output is connected to the control unit 51 via the lead wire terminal box 17, and the temperature of the heating / cooling unit is monitored by these temperature sensors.

The end of the nitrogen gas pipe 20 is connected to the support plate 1.
After being inserted into a through hole provided at the center of the upper surface of the upper surface 4, it is fixed and the other end is connected to the nitrogen gas injection unit 54. This nitrogen gas fills the inside of the bonding portion 50 to prevent oxidation due to heating of the bumps.

The operation of the apparatus of the present invention described above with reference to FIGS. 1 to 5 will be described below with reference to the flowchart of FIG.

A pair of jig plates 33a and 33b (see FIG. 8) sandwiching the resin substrate 32 which is the workpiece is placed on the pressing surface 23a of the heating / cooling unit 15a (see step 100). When the placement is completed, for example, the information that the workpiece is placed on the pressing surface 23a is detected by using an optical sensor or the like, and the information is notified to the control unit 51, whereby the command of the control unit 51 is issued. The heating / cooling unit 15a heats / heats the jig plate 33a.
It moves upward until it comes into contact with the pressing surface 23b of the cooling unit 15b (Step 102).

At the same time that the jig plate 33a comes into contact with the pressing surface 23b, the completion of the mechanical positioning is detected by a position sensor (not shown) (step 104).

The positioning completion information is notified to the control unit 51, and the drive unit 52 stops moving up (step 10).
6).

As another embodiment of stopping the driving unit 52, for example, a pressure applied to the resin substrate 32 sandwiched above and below the heating / cooling units 15a and 15b by using a strain sensor or the like. It is also possible to detect whether (stress) has reached the set pressing force, and stop the heating / cooling unit 15a from rising when the set pressing force is reached.

Normally, this pressing force can be obtained by multiplying a predetermined pressing force per bump by the number of bumps set in the resin substrate.

This stop information is notified to the control unit 51, and the nitrogen gas injection unit 54 is operated immediately after the stop due to the operation of the control unit 51, and the entire resin substrate bump bonding apparatus is placed in a nitrogen gas atmosphere. Immerse (Step 10
8).

This nitrogen gas is for preventing the bumps from being oxidized when they are heated and melted for bonding.

In this nitrogen gas atmosphere, a plurality of heaters 4 incorporated in the heating / cooling sections 15a and 15b
Is operated to heat the heating / cooling units 15a and 15b to a predetermined temperature (step 110).

Information from the above-mentioned temperature sensor 18 mounted on the heating / cooling units 15a and 15b is notified to the control unit 51, and it is detected whether or not the temperature has reached the predetermined temperature (step 112). If the temperature has reached, the set temperature is maintained for a certain period of time (step 114). For example, the set temperature is set to about 190 ° C for high temperature bumps and about 175 ° C for low temperature bumps, and the cooling temperature is set to about 100 ° C.
Set to C.

Here, if the heating / cooling sections 15a and 15b are not cooled to room temperature and are kept at about 100 ° C. at all times, the time required for heating to a predetermined temperature can be shortened, and similarly, the predetermined temperature can be reduced. Can be shortened.

For example, after it takes several tens of seconds to maintain the set temperature, the cooling unit 53 is operated to flow cooling water and cooling air through the cooling pipe 10a, and the heating / cooling units 15a and 15b
After cooling, the cooling water is collected by the cooling pipes 10b and 10d, and this circulation operation is repeated to cool (step 116).

When the temperature of the heating / cooling units 15a and 15b drops to the set temperature (step 118), the cooling is stopped (step 120).

After the cooling operation is stopped, the nitrogen gas injection is also stopped (step 122).

At this point, the bumps in the resin substrate have been completely joined.

Next, under the control of the control unit 51, the drive unit 5
2 is driven, the heating / cooling unit 15a moves downward to its initial position (see FIG. 2), and stops at that position (step 124). Thereafter, the bonded resin substrate as a workpiece is taken out (step 126).

The operation described above can be repeated for each resin substrate to be joined.

In the embodiment described above, the lower heating / cooling section 15a of the pair of heating / cooling sections constituting the bonding section is moved up and down by the drive section 52. The invention is not limited to the embodiment, and the effect of the present invention is obtained even if the lower heating / cooling unit 15a is stationary and the upper heating / cooling unit 15b is moved up and down. It can be achieved similarly.

[0064]

As described above, in the resin substrate bump bonding apparatus according to the present invention, only a pair of jig plates sandwiching the resin substrate is mounted on the heating / cooling unit.
Setting can be performed without requiring any delicate horizontal adjustment of the holding plate in the conventional example.

The time required for heating is about 7 minutes and the cooling time is about 4 minutes, and the bump bonding step can be completed in a short time of about 11 minutes in total.

About 8 minutes compared with about 75 minutes in the conventional example
The time can be reduced by as much as 5%, and productivity is remarkably improved.

The use of a robot or the like for the handling of the resin substrate as the workpiece, which is set sandwiched between a pair of jig plates, enables automation, and furthermore, the resin substrate bump bonding apparatus of the present invention. If, for example, a plurality of units are used and the resin substrate set by the robot is supplied to each device, the productivity can be further improved.

For example, if six devices are used at the same time,
One tact can be made 110 seconds, and mass production becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a resin substrate bump bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of a bonding portion in the embodiment of the present invention.

FIG. 3 is a right side view of the bonding section shown in FIG. 2;

FIG. 4 is a plan view of the bonding section shown in FIG. 2;

FIG. 5 is an enlarged perspective view of a heating / cooling unit according to the embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the apparatus according to the embodiment of the present invention.

FIG. 7 is a perspective view schematically showing a conventional resin substrate bump bonding apparatus.

FIG. 8 is a cross-sectional view showing a state in which bumps are set on a resin substrate in the conventional example of FIG. 7;

9 is a perspective view showing a state in which a resin substrate bump bonding apparatus is placed in a heating furnace in the conventional example shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 base 2 elevator 4 heater 5 fixing screw 6 heat insulating plate 9a, 9b, through hole 9c, 9d through hole 10a, 10b cooling pipe 10c, 10d cooling pipe 11 screw part 12 support rod 13 fixing screw 14 support plate 15a 15b Heating / cooling unit 16 Lead wire 17 Lead wire terminal box 18 Temperature sensor 19 Movable shaft 20 Nitrogen gas pipe 21 Upper surface 22 Lower surface 23a, 23b Pressing surface 24 Side surface 25 Side surface 26 Mounting surface 27a, 27b Through hole 27c, 27d Through hole 28a , 28b Cooling water passages 29a, 29b Through holes 30 Holding plate 31 Pressure adjusting screw 32 Resin substrate 33a, 33b Jig plate 34 Coil spring 35 Support rod 35a Screw 36 Base 37 Spring holder 38 Bump 39 Chip resistor 40 Heating furnace 42 Chip Capacitor 43 Bare chip 44 Printing resistor 50 Laminating unit 51 Control unit 52 Drive unit 53 Cooling unit 54 Nitrogen gas injection unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasutoshi Ogawa 5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan Radio Co., Ltd. (72) Inventor Takao Oiwa 5-1-1 Shimorenjaku, Mitaka City, Tokyo Sun Examiner in the Radio Co., Ltd. Tomoya Kato (56) References JP-A-63-58892 (JP, A) JP-A-5-55741 (JP, A)

Claims (3)

(57) [Claims] A plurality of resin substrates each having a bump bonding portion and a circuit pattern provided in a wiring circuit portion are overlapped with each other, pressed and heated, and the bumps are melted to electrically connect the plurality of resin substrates to each other. A pair of heating / cooling units for heating and cooling the resin substrate by sandwiching the upper and lower flat surfaces of a plurality of laminated resin substrates,
A bonding unit including a drive unit for moving one of the cooling units in the vertical direction, a heating unit for heating the heating / cooling unit, and water-cooling the heating / cooling unit. A cooling unit for circulating cooling water through a cooling pipe, a nitrogen gas injecting unit for injecting nitrogen gas through the pipe in order to place the bonding unit in a nitrogen gas atmosphere, and A resin substrate bump bonding apparatus, comprising: a control unit for controlling the operation of the entire apparatus. 2. The resin substrate bump bonding apparatus according to claim 1, wherein the heating / cooling unit is formed of a metal block having a certain thickness, and the heating / cooling unit is provided inside the heating / cooling unit as the heating unit. And a plurality of interconnected cooling water passages for circulating the cooling water from the cooling unit. 3. A method of bonding a resin substrate by bumps using the resin substrate bump bonding apparatus according to claim 1, wherein the step of maintaining the heating / cooling unit at about 100 ° C. and a step of pump bonding. At this time, a step of pressing a jig plate for holding a plurality of resin substrates, a step of heating the heating / cooling section in a nitrogen gas atmosphere until a bump joint of the resin substrate is melted, and In order to fix the bump joint, the heating / cooling unit has about 100
A method of bonding the resin substrate bumps, the method comprising: