Tolong mas saya dah pasrah ngadapin ( Unknown column 'Array' in 'field list' ) CI

Controllernya :

public function proses_input_vaksin1()
    {
       $this->form_validation->set_rules('nama_anak', 'Nama Anak', 'required');
        // $this->form_validation->set_rules('jumlah', 'Jumlah', 'required');
        if ($this->form_validation->run() == FALSE) {

            $data['judul'] = 'Data Anak';
            $data['nama'] = $this->session->userdata('nama');
            $this->load->view('template/header', $data);
            $this->load->view('admin/tindakan3/tindakan_vaksin', $data);
            $this->load->view('template/footer');
        } else {
            $array = array(
                'nama_anak' => $this->input->post('nama_anak'),
                'nik_anak' => $this->input->post('nik_anak'),
                'lahir' => $this->input->post('lahir'),
                'ttl' => $this->input->post('ttl'),
                'nama_ibu' => $this->input->post('nama_ibu'),
                'nama_ayah' => $this->input->post('nama_ayah'),
                'kabupaten' => $this->input->post('kabupaten'),
                'kecamatan' => $this->input->post('kecamatan'),
                'kelurahan' => $this->input->post('kelurahan'),
                'alamat' => $this->input->post('alamat'),
                'jk' => $this->input->post('jk'),
                'nik_anak' => $this->input->post('nik_anak'),
                'telpon' => $this->input->post('telpon'),
                'vaksin_ke' => $this->input->post('vaksin_ke'),
                'petugas' => $this->input->post('petugas'),
                'vaksin' => $this->input->post('vaksin'),
                'keterangan' => $this->input->post('keterangan'),
                "tgl" => $this->input->post('tgl'),
            );
            $this->db->insert('tahap1', $array);
            return redirect('admin/imunisasi1');
        }
    }

Viewsnya :

                          </div>
                            <div id="checkboxes">
                                <h7><label for="satu">
                                <input type="checkbox" id="satu" name="vaksin[]" value="HBO (Hepatitis.B)" />HBO (Hepatitis.B)</label>
                                <label for="dua">
                                <input type="checkbox" id="dua" name="vaksin[]" value="BCG" />BCG</label>
                                <label for="tiga">
                                <input type="checkbox" id="tiga" name="vaksin[]" value="DPTHB-Hib" />DPTHB-Hib</label>
                                <label for="empat">
                                <input type="checkbox" id="empat" name="vaksin[]" value="Polio" />Polio</label>
                                <label for="lima">
                                <input type="checkbox" id="lima" name="vaksin[]" value="IPV" />IPV</label>
                                <label for="enam">
                                <input type="checkbox" id="enam" name="vaksin[]" value="MR" />MR</label>
</div>