JPH03254185A - Bonding method and bonding device - Google Patents

Abstract

PURPOSE:To extend the life of a heating tool and also elevate the bonding quality with solder by pressing the sides opposite to contacted sides of a plurality of leads with the top of a heating element through the sheet member made of the material having heat resistance and not having solder wettability so as to fuse a solder layer. CONSTITUTION:A plurality of leads 40 of a part 4 are so arranged as to abut on the topsides of the plurality of foot print patterns 2 formed at a printed board 1, and a sheet member 6 is applied on the sides opposite to contacted sides of the plurality of leads 40, and it is pressed with the top of a heating element 5 through the sheet member 6 so as to fuse a solder layer 3 to join the leads 40 to the foot print patterns 2. Hereby, the solder wettability of the top of the heating element 5 by the use of repeat use is prevented, and also the solder junction quality improves.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a bonding method and a bonding device in which the tip of a heating element is pressed and heated via a sheet member or tape member onto the lead of a component in contact with a solder layer of a footprint pattern. The purpose of the present invention is to provide a bonding method and a bonding device that can extend the life of heat-generating tools used for bonding and improve the quality of solder joints. A solder layer is formed on a predetermined range of the surface of the plurality of footprint patterns formed on the printed circuit board in correspondence with the plurality of leads to be arranged, and the plurality of leads of the component are made to correspond to the solder layer of the plurality of footprint patterns. The tip of the heating element is connected to the tip of the heating element through a sheet member made of a heat-resistant and non-solder wettable material, and the surface opposite to the surface in contact with the plurality of leads is This method melts the solder layer by pressing the solder layer.

2) The multiple leads of the component are formed on the printed circuit board in correspondence with the arrayed multiple leads of the component mounted on the printed circuit board, and the multiple leads of the component are made to correspond to the multiple fund print patterns on which a solder layer is formed on the surface. A heating element is connected to the heating element through a tape member made of a material that is heat resistant, flexible, and does not have solder wettability. This device connects the leads to the footprint pattern by pressing with the tip of the tape to melt the solder layer. and a winding unit that winds up the tape member wound around the tip of the heating element, and the winding unit is driven to wind the tape member every time the operation of connecting the lead to the footprint pattern is completed a predetermined number of times. It is configured to wind up only a predetermined size.

[Industrial application field]

The present invention relates to solder bonding of component leads onto a printed circuit board, and in particular, by pressing the tip of a heat-generating tool through a sheet member or tape member onto the lead of a component that is in contact with a solder layer of a footprint pattern. The present invention relates to a heating bonding method and bonding device.

In recent years, with the miniaturization of electronic devices, printed circuit boards and mounted components have also become smaller and more dense, and surface mount technology (SM
Printed boards based on T) are becoming mainstream. The normally mounted components also have a lead pitch of about 0.5 rm or more (e.g. small outline package: SOP, Fort flat package: QFP), etc.
0.3ma+ (tape automated bonding:
The conventional method of printing solder paste on the footprint pattern, such as for SOP and QFP, cannot cope with the short circuit between the footprint patterns after the solder melts, so there is a way to solve this problem. As such, gigantic bonding is often used in which solder is supplied to the footprint pattern in advance using a solder leveler, plating, etc., and component leads on one side or multiple sides can be bonded at the same time. At this time, the heating element (chip) at the tip of the bonding tool is made of a material that does not have solder wettability, but due to repeated bonding, the tip becomes dirty with flux residue, causing solder sharpness at the joint, and This may cause damage to the parts, making it impossible to achieve a good bond. Therefore, a method is desired to extend the life of the chip and improve bonding quality.

[Conventional technology]

A conventional example will be explained with reference to FIGS. 5 and 6. The same reference numerals indicate the same objects throughout the figures.

As shown in FIG. 5(a), TAB is attached to the printed circuit board 1a.
When mounting the component 4a, a solder layer is formed on the footprint patterns 2a+2b, ``-'' formed on the printed circuit board la, and a plurality of leads 40a, 40b, ``-'' on the outer periphery of the TAB component 4a are connected to the footprint pattern 2a+2b, ``-''. The solder layer is melted and soldered in accordance with the pattern 2a+2b+'-.

To explain this in detail, as shown in FIG. 5(b),
A plurality of rectangular footprint patterns 2a, 2b, - are formed side by side on a printed circuit board 1a, aligned at a small pitch (for example, 0.1 to 0.3 mm).

On this footprint pattern 2a+2bl'-,
As shown by hunting in the figure, a solder layer 3a is formed in advance.

Therefore, as shown in Figure 6, footprint pattern 2
Leads 40a, 40 of TAB component 4a to a, 2b, -
After positioning the parts b, the solder layer 3a is melted and soldered by heating with the bonding tool 5a.

The bonding tool 5a is made of a material 1 having heat resistance and no solder wettability, such as molybdenum, and is heated to the solder melting temperature by a high-frequency current around which a coil (not shown) is wound around the bonding tool 5a.

(Problem to be Solved by the Invention) According to the above conventional method, the bonding tool is made of a material that does not have solder wettability, but due to repeated bonding, the tip surface becomes dirty with flux residue, and the solder wet appearance appears. It's like you've caused a problem. If gigantic bonding is performed in such conditions, solder sharpness may occur at the joint, and the joint may be destroyed as the bonding tool is pulled up after the solder has solidified, making it impossible to perform good solder joints and requiring frequent cleaning of the tool. (polishing), the life of the bonding tool is short. For this reason, they are coated with ceramics or the like, but there is still a problem in that they are still far from long lasting.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bonding method and a bonding tool that can extend the life of a heat-generating tool used for bonding and improve solder joint quality.

[Means to solve the problem]

FIG. 1 is a diagram showing the principle of the present invention, in which (a) is a side view corresponding to claim 1, and (b) is a configuration diagram corresponding to claim 2.

In the figure, 1 is a printed circuit board, 2 is a footprint pattern, 3 is a solder layer, 4 is a component, 5 is a heating element, and 40 is a lead.

1) Means Corresponding to Claim 1 In FIG. 1(a), 6 is a sheet member formed of a material that has heat resistance and does not have solder wettability.

Therefore, a solder layer 3 is formed in a predetermined range on the surface of a plurality of footprint patterns 2 formed on a printed circuit board l, corresponding to a plurality of adhesives 40 arranged on a component 4 mounted on a printed circuit board 1. footprint pattern 2
A plurality of glues 40 of the component 4 are brought into contact with the solder layer 3 of the component 4 in a corresponding manner, and the surface opposite to the surface of the plurality of glues 40 that is in contact is placed on the heating element 5 via the sheet member 6. In this method, the solder layer 3 is melted by pressing with the tip of the solder layer 3.

2) Means Corresponding to Claim 2 In the front and side views of FIGS. The formed roll-shaped tape member 7 holds the roll-shaped tape member 60, and the tape member 6
A tape supply section 8 supplies the tape member 60, and a winding section 8 winds up the tape member 60 supplied from the tape supply section 7 and wound around the tip of the heating element 5.

Therefore, each time the operation of connecting the lead 40 to the footprint pattern 2 is completed a predetermined number of times, the winding section 8 is driven to wind up the tape member 60 by a predetermined length.

[Function] 1) Effect according to claim 1 A plurality of glued leads 40 of the component 4 are brought into contact with each other in a corresponding manner on a plurality of footprint patterns 2 formed on the printed circuit board l. A sheet member 6 is applied to the surface opposite to the surface in contact with the surface, and the tip of the heating element 5 is pressed through the sheet member 6 to melt the solder layer 3 and form the leads 40 on the matte print pattern 2. By joining, it is possible to prevent the tip of the heating element 5 from getting wet with solder due to repeated use, thereby extending the life of the heat generating element 5 and improving the quality of the solder joint.

2) Effect according to claim 2 A plurality of glued leads 40 of the component 4 are brought into contact with the plurality of glued leads 40 in a corresponding manner on the plurality of footprint patterns 2 formed on the printed circuit board 1. A tape member 6 supplied from the tape supply section 7 is placed on the opposite side to the surface.
0 is wound around the tip of the heating element 5, the tape member 60 is brought into contact with the solder layer 3 by the heat generated by the heating element 5, and the lead 40 is joined to the footprint pattern 2, and the bonding operation is completed a predetermined number of times. Each time, by driving the winding unit 8 and winding up the tape member 60 by a predetermined dimension on the winding unit 8, the tape member 60 is heated and bonded.
Moreover, since the thin tape material 60 is automatically fed one after another and a new tape member 60 is supplied to the tip of the heating element 5, it is possible to completely prevent the tip of the heating element 5 from getting wet with solder due to repeated use, and the service life is significantly extended. Moreover, the quality of solder joints can be improved without causing solder sharpness or joint breakage.

〔Example] 1) Example corresponding to claim 1 One embodiment will be explained with reference to FIG.

The bonding tool 5a and tape 6a in FIG.
This corresponds to the heating element 5 and sheet member 6 in the figure.

As shown in FIGS. 2(a) and (b), the printed circuit board 1
When bonding the TAB component 4a to a, the leads 40a, 40b, - of the TAB component 4a are bonded to the footprint patterns 20a, 2 with the solder layer 3a formed on the surface.
0b.

A tape 6a made of a material 1 having heat resistance and no solder wettability, such as polyimide, is placed thereon.

The tape 6a has a thickness of about 50 μm and a width of about 0.9 μm, for example, and the width is set to be equal to or smaller than the width of the bonding chip 5a.

When the bonding tool 5a is pressed from above the tape 6a and heated to the solder melting temperature, the solder layer 3a melts.
Lead 4 to footprint patterns 20a, 20b, -
0a, 40b, - are joined.

If the width of the tape 6a is widened, there will be no place for the molten solder to escape under the tape 6a, making it more likely that solder shorts will occur. If the tape 6a is too thick, the leads 40a and 40b will be removed from the bonding tool 5a.

For example, a thickness of 100 μm or less is appropriate because the heat transfer efficiency to other parts of the body decreases. Moreover, if it is too thin, there is a risk that it will be damaged when the leads 40a, 40b, etc. are pressurized by the pounding tool 5a.

In this way, since the heat-resistant tape 6a is applied to the tip of the bonding tool 5a and heated, the tip of the bonding tool 5a is not contaminated with flux residue, and bonding can be performed without causing solder sharpness or joint breakage. Quality is improved, the life of the bonding tool 5a is extended, and costs are improved. Further, since the tape 6a has some elasticity in the thickness direction, the footprint patterns 20a, 2
0b, - and leads 40a, 40b.

Even if there are variations in the thickness of the bonding tool 5a, the gap between the bonding tool 5a and the joint can be filled, heat transfer can be ensured, and the quality of the joint can be improved.

In the above example, the case where the tape 6a is made of polyimide has been explained, but the same effect can be obtained by using other materials such as fluorine-based resins, silicon-based resins, etc., or by forming the tape 6a from aluminum or the like.

2) Example corresponding to claim 2 One embodiment will be described with reference to FIGS. 3 and 4.

The bonding tool 5a and tape 60a in FIG. 3 correspond to the heating element 5 and tape member 60 in FIG. 1.

The front and side views of FIG. 3 (al and (b)) show the case of bonding (-side bonder) with one bonding tool 5a, and as shown in the figure, the left side of the bonding tool 5a in the longitudinal direction A tape supply section 7a is provided on the right side of the tape supply section 7a, which holds a roll-shaped tape 60a, winds the tape 60a, and supplies the tape 60a to the tip of the bonding tool 5a, and a winding section 8a is provided on the right side.

The tape 60a is made of a material 1, such as polyimide, that has heat resistance and flexibility and does not have solder wettability, and has a thickness of 50 μm and a width of 1 side and covers the arrayed footprint patterns 20a, 20b, -. Width 5
For example, it is set to 10m.

A winding shaft 80 of the winding section 8a is connected to a pulse motor M, and the rotation of the pulse motor M winds up the tape 60a supplied from the tape supply section 7a to the tip of the bonding tool 5a. The pulse motor M is controlled to rotate by a predetermined number of steps S every time the bonding operation is repeated a predetermined number of times n (for example, about n=4 times). The predetermined number of steps S is the amount of winding of the tape 60a at one time, that is,
It is set corresponding to the width 10α of the tip of the bonding tool 5a.

Although not shown, the shaft 70 of the tape supply section 7a is pressed by a spring to apply tension to the tape 60a in the direction opposite to the direction of winding by the winding section 8a.

In addition, in the main control block diagram of FIG. 4, 9 is a counter that counts the number of bonding operations up to a predetermined number n, 10 is a setting section in which the predetermined number n is set, 11 is a motor driver, 12 is for controlling each section, A control unit is shown that causes the counter 9 to count the number of bonding operations, and instructs the motor driver 11 to rotate the pulse motor M by a predetermined number of steps S to rotate the winding shaft 80 based on a signal that has counted a predetermined number of times n.

Since it has such a configuration, the operation will be explained next. First, the leads 40a, 40b, - corresponding to the footprint pattern 2a12El+'- are positioned, and bonding is performed with the bonding tool 5a wound.

The counter 9 counts the number of times for each bonding operation, and when it counts a predetermined number n set in the setting section 10, it notifies the control section 12 and clears the count. Then, in response to a command from the control section 12, the motor driver 11 rotates the pulse motor M by the commanded predetermined number of steps S, rotates the winding shaft 80, and winds up the tape 60a on the winding section 8a. A new tape 6 is attached to the tip of the bonding tool 5a.
The surface 0a is located.

Then, the next bonding operation is performed. That is, although the tape 60a is a material that has heat resistance and does not have solder wettability, repeated bonding operations cause stains due to heating and flux residue, so it must be wound up one after another after each use. then use the new tape side for the bonding operation.

By repeating the above operations, it becomes possible to continuously perform good bonding for a long time.

Furthermore, when the supply of the tape 60a is finished, it goes without saying that the tape is replaced.

In this way, the tape 60a, which is sequentially supplied in the form of a roll, is heated by applying it to the tip of the bonding tool 5a, so that even if the bonding tool 5a is operated continuously, the tip of the bonding tool 5a will not be contaminated with flux residue, and will not have solder sharpness. Bonding quality is improved without causing joint breakage, the life of the bonding tool 5a is extended, and costs are improved.

〔Effect of the invention〕

As explained above, according to the present invention, heat is generated by pressing the tip of the heating element via a sheet member or tape member onto the lead of the component that is in contact with the solder layer of the Fundoprint pattern. The tip of the body is not contaminated with flux residue, etc., and solder sharpness and joint breakage are prevented, joint quality is improved, and the life of the heating element can be extended, leading to cost improvements.

(2) Furthermore, in the case of claim 2, by winding up a predetermined amount of the tape member every time the bonding operation is performed a predetermined number of times, the bonding operation can be continued automatically using a new surface of the tape member. can.

There is an effect.

[Brief explanation of drawings]

Fig. 1 is a principle diagram of the present invention, Fig. 2 is an explanatory diagram showing an embodiment corresponding to claim 1, Fig. 3 is a configuration diagram showing an embodiment corresponding to claim 2, and Fig. 4 is an embodiment. FIG. 5 is a configuration diagram showing an example of mounting a TAB to which the present invention is applied, and FIG. 6 is an explanatory diagram of a conventional example. In the figure, 1.1a is a printed circuit board, 2.2a, 2b are footprint patterns, 3a is a solder layer, 4 is a component, 4a is a TAB component, 5 is a heating element, 5a is a bonding tool, 6 is a sheet member, 6a , 60a is a tape, 7.7a is a tape supply section, 8.8a is a winding section, 40.40a and 40b are leads, and 60 is a tape member. 1α: Brinite board a: Wooden body construction! 4α: Front view of TABTA B parts (1)) However, 1st view @ Explanation of height 1m vs. 1 tip σ11 Child's funeral 2 drawing (W) 1 Self-bundle top 1 Text April YoTuf Shell '1 side section] (a) Front view - (b) ■ 11th view (J)) One foot is constructed on the top 2 of the east. Part 2 [Month JiT Sao Naru 1 Do-1 Configuration Diagram Figure 3 Fuaka Do 1f > Main Parts Control Pro 1, 2 Wa Diagram Page 4 489 Hashitafugi (1) Ali〉to station - Enlarged plan view of the opposite section Explanatory diagram of the conventional example Fig. 6

Claims (1)

[Claims] 1) A plurality of footprint patterns formed on a printed circuit board (1) corresponding to a plurality of arranged leads (40) of a component (4) mounted on the printed circuit board (1). (2
) a solder layer (3) is formed in a predetermined range of the surface of the plurality of footprint patterns (2);
3), a plurality of leads (40) of the component (4) are brought into contact with each other, and the surface opposite to the surface of the plurality of leads (40) that is in contact with the component (4) is made of heat-resistant material. , a heating element (5) is inserted through a sheet member (6) made of a material with no solder wettability
) A bonding method characterized in that the solder layer (3) is melted by pressing with the tip of the solder layer (3). 2) The printed circuit board (1) corresponds to the plurality of leads (40) arranged in the component (4) mounted on the printed circuit board (1).
The component (4) is placed on the plurality of footprint patterns (2) formed in 1) and having a solder layer (3) formed on the surface.
A plurality of leads (40) are brought into contact with each other in a corresponding manner, and the surface of the plurality of leads (40) on the opposite side to the corresponding contact surface is made of a heat-resistant, flexible and solder-wetting surface. The leads (40) are applied to the footprint pattern (2) by pressing with the tip of the heating element (5) to melt the solder layer (3) through the tape member (60) formed of a material that does not have ), the apparatus includes a tape supply section (7) that holds the tape member (60) in a roll shape and supplies the tape member (60); A tape member (60) wound around the tip of the heating element (5).
) for winding the lead (40) in the footprint pattern (2);
) Each time a predetermined number of bonding operations are completed, the winding section (8) is driven to wind the tape member (60) by a predetermined dimension.