JPH0382050A - Bonding device for film carrier semiconductor device - Google Patents

Abstract

PURPOSE:To obtain always optimum bonding conditions by performing the picture processing of a bonding state with a TV camera in a semiconductor device through which bonding is complete and measuring the amount of shift of each lead from each position of bump and the like, thereby correcting the position of a semiconductor chip on a bonding stage as well as the bonding conditions. CONSTITUTION:The position of each lead in a film carrier tape 6 and the position of a bump in a semiconductor chip 2 on a bonding stage 15 is aligned by recognizing and detecting positions of the above lead and bump with a TV camera 16. Then, in an automatic bonding device where the lead of the film carrier tape 6 and the bump in the semiconductor chip 2 are heated and attached under pressure with a bonding tool 18 by making a bonding stage 15 come into contact with the above tape 6 from the lower side, the bonding state of the above bonding device through which bonding is complete is image processing with each TV camera 20 and the amount of shift of the lead from the position of the bump and the rate of deformation are measured. Then, the positional coordinates of the above chip 2 in the bonding stage 15 as well as bonding conditions, such as pressures, temperatures, and hours and the like are corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic bonding apparatus for film carrier semiconductor devices.

[Conventional technology]

A method of manufacturing a semiconductor device using a conventional film carrier method will be explained with reference to FIGS. 3 and 4.

A semiconductor chip 2 is prepared in advance in which bumps 7, which are metal protrusions, are provided on electrode terminals.

Furthermore, there is a sprocket hole 1 for transportation and positioning, and a device hole 3 which is an opening into which a semiconductor chip 2 is inserted.
A film carrier tape 6 is prepared by adhering a metal foil such as copper onto an insulating bulk rem made of polyimide or the like, and then etching the metal foil to form leads 4 and pads 5 for electrical selection.

Next, inner lead bonding (hereinafter referred to as IL, B) is performed between the leads 4 of the film carrier tape 6 and the bumps 7 of the semiconductor chip 2 by a thermocompression bonding method or a eutectic method, and the film carrier tape is bonded to an electrical screening pad. 5
Electrical screening and bias tests can be carried out by contacting a 10-beam on top.

Suspenders 8, which are frames made of insulating film, are provided to prevent the leads 4 from deforming.

Finally, for reliability improvement and mechanical protection, a resin 9 is potted and sealed as shown in FIG. 5, and then the leads 4 are cut to a desired length to complete the film carrier semiconductor device.

When mounting on an external circuit, for example, adhesive 10 is applied onto the printed circuit board 11 to fix the semiconductor chip 2, and the leads 4 are bonded to the bonding pads 12 on the printed circuit board by outer lead bonding (OLB). do.

The range of application of this film carrier semiconductor device is expanding because it can be bonded at once regardless of the number of leads, and because it uses a continuous film carrier tape, it is easy to automate. 4 General automatic ILB bonders are After recognizing and detecting the lead position of the film carrier tape with a TV camera, the semiconductor chip is transported onto the bonding stage, and the bump position of the semiconductor chip is recognized and detected again with the TV camera, and the leads and bumps are aligned. Then, the bonding is completed by heating and pressing with a bonding tool at a preset pressure and temperature for a certain period of time.

Next, the film carrier tape is conveyed by one frame corresponding to one semiconductor chip, and then bonding is repeated.

Furthermore, in order to reduce the working time (index) per semiconductor chip, the lead position of the film carrier tape and the bump position of the semiconductor chip are recognized and detected at the same time. punch holes, etc.) and detects the ILB.
It has a function to skip to the next frame by omitting the .

T check any lead bends that were not discovered before ILB work.
Some have a function that detects them with the V-camera and skips to the next frame.

[Problem to be solved by the invention]

The lead position of the film carrier tape is the recognition mark 12.
It is usually determined from.

The TV camera image is patterned by binarization processing.

However, the recognition mark provided on the film carrier tape may be misaligned between lofts or within a loft due to expansion and warping of the film carrier tape due to heat or humidification, variations in photo-etching during the film carrier tape manufacturing process, and the like.

Even if the contraction/expansion is only ±0.2%, if the distance between the patterns is 10 mm, it will reach ±20 μm, resulting in a fatal misalignment.

Changes over time due to heat and vibration in the bonder and lighting system cannot be ignored.

Furthermore, regarding the ILB conditions of pressure, temperature, and time,
Variations in the physical and chemical properties of leads and bumps are common.

For example, in the case of Au-Au thermocompression bonding in which Au bumps and Au-plated leads are bonded, the lead deformation rate (lead width after bonding divided by lead width before bonding), which is the degree of lead collapse, is controlled. By doing so, bonding conditions can be optimized.

Figure 2 shows the relationship between lead deformation rate and fracture strength.

When the deformation rate of the lead is small, the pressure and temperature are insufficient, and the lead peels off, resulting in a significant decrease in strength.

On the other hand, if the deformation rate of the lead is large, the pressure and temperature are excessive and the lead is crushed too much, resulting in a gradual decrease in strength.

Generally, if the temperature setting is 450-500°C.

For leads with a width of 100 μm, approximately 100
Bonded at a pressure of gf.

As described above, the lead width, which has a significant effect on condition setting, is generally controlled with a tolerance of ±15 μm, and even within the same lot there is a variation of about ±10 μm.

In the case of Au-3n eutectic bonding or brazing metal bonding using solder, it is not appropriate to control the amount of deformation of the lead, so it is common to control the amount of Au-8n eutectic alloy or the amount of melted solder. .

In the production process, the current situation is to stop the line after each lot and frequently repeat measurements, inspections, and condition corrections.

An object of the present invention is to automatically inspect the positional deviation between the leads and bumps of a film carrier semiconductor device after bonding and the bonding shape, and to always obtain the optimal bonding conditions while making corrections to the bonding conditions. [Means for Solving the Problems] The bonding apparatus for film carrier semiconductor devices of the present invention has the following features: When a semiconductor chip is picked up and placed on a bonding stage, the positions of the bumps, which are the electrodes of the semiconductor chip, are recognized and aligned using a TV camera, and the bonding stage is brought into contact with the film carrier tape from below to attach the film carrier. In an automatic bonding machine equipped with a function of heat-pressing the tape lead and the bump of the semiconductor chip using a bonding tool, the bonding state of the buoy carrier semiconductor device after bonding is image-processed using a TV camera, and the lead is bonded. The device is configured to measure the deviation amount of the bump and the lead deformation rate to correct the position coordinates of the semiconductor chip on the bonding stage and the bonding conditions such as pressure, temperature, and time.

〔Example〕

An automatic bonding apparatus according to a first embodiment of the present invention will be described with reference to FIG.

First, the conveying sprocket wheel 13 is rotated to convey one frame of the film carrier tape 6 onto the bonder stage 15.
The lead position is recognized and detected by the bonding TV camera 16.

Defective identification marks such as punch holes provided in advance on the film carrier tape 6 are detected by the photosensor 14, and the defective frames are skipped.

Next, the semiconductor chips 2 lined up on the semiconductor chip stage 19 are recognized by the semiconductor chip TV camera 20, and the semiconductor chips 2 are suctioned and conveyed onto the bonding stage 15 by the semiconductor chip pickup arm 17.

Thereafter, the position of the bumps on the semiconductor chip 2 is recognized and detected by a bonding TV camera 16 and aligned with the leads, and then the leads and bumps are bonded by heating and pressing with a bonding tool 18 at a preset pressure and temperature for a certain period of time.

After this, the bonding work starting from the first rotation of the sprocket wheel 13 is repeated.

In parallel with the bonding, a separate inspection TV camera 20 is used to inspect the semiconductor chip 2 that has completed bonding several frames behind the film carrier tape 6.
The system recognizes the bonding state, calculates the positional deviation between the lead and bump and the amount of deformation of the lead, and automatically makes corrections to the position coordinates and bonding conditions.

When actually performing correction, in order to avoid sudden deviations and variations, it is preferable to use an average value of, for example, 10 to 20 pieces of data, excluding values that are extremely outside the control limit.

Next, a second embodiment of the present invention will be described.

In Figure 1, three TV cameras are used,
One TV camera can serve as the bonding TV camera 16 used for alignment and the inspection TV camera 20.

In this case, after the bonding is completed, a bonding inspection is performed using the bonding TV camera 16 without frame-by-frame advance.

Unlike the first embodiment, this method can be inspected on the spot, so it is particularly suitable for products that require high precision and quality, such as products with a large number of leads.

Since one TV camera is used, bonding work and bonding inspection are performed in series, which increases the bonding index, but for example, bonding inspection is performed by sampling a control width every 50 to 100 pieces. By doing so, quality can be maintained without increasing the bonding index.

These examples are based on outer lead bonding (OL
B) and wire bonding.

〔Effect of the invention〕

The automatic bonding apparatus for film carrier semiconductor devices of the present invention uses a TV camera to inspect the misalignment of the leads and bumps of the film carrier semiconductor device after bonding and the crushing of the leads due to thermocompression bonding without stopping the line. You can proceed with the bonding work while making corrections.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an automatic bonding apparatus showing an embodiment of the present invention, FIG. 2 is a graph showing the relationship between lead deformation rate and bonding strength, FIG. 3 is a plan view of a film carrier semiconductor device, and FIG. 6 to 6 are cross-sectional views illustrating the film carrier semiconductor device in the order of manufacturing steps. l...Sprocket hole, 2...Semiconductor chip,
3... Device hole, 4... Lead, 5... Electrical sorting pad, 6... Film carrier tape, 7
...Bump, 8...Suspenders 9...Resin,
10...Adhesive, 11...Printed circuit board, 12...
・Recognition mark, 13... Sprocket wheel, 14
... Photo sensor 15 ... Bonding tool, 16 ... TV camera for bonding, 17 ... Pickup arm, 18 ... Bonding tool, 1
9... Semiconductor chip stage, 20... Semiconductor chip mm TV camera, 21... TV camera for inspection, 22
... Enlarger ring, 23... Positioning pin.

Claims (1)

[Claims] The position of the lead protruding into the device hole opening from the bottom surface of the film carrier tape that is being conveyed intermittently,
When a semiconductor chip is picked up from the chip stage and placed on the bonding stage, the positions of the bumps, which are the electrodes of the semiconductor chip, are recognized and aligned using a TV camera, and the bonding stage is brought into contact with the film carrier tape from below. In an automatic bonding device having a function of heat-pressing the leads of a film carrier tape and the bumps of a semiconductor chip using a bonding tool, the bonding state of the film carrier semiconductor device after bonding is image-processed using a TV camera, An automatic bonding device that measures the amount of deviation between a lead and a bump and the lead deformation rate to correct the position coordinates of a semiconductor chip on a bonding stage and bonding conditions such as pressure, temperature, and time.